Field
[0001] The present invention relates to illumination light sources and lighting apparatuses,
and particularly relates to a light bulb-shaped lamp which includes a light-emitting
module having a light-emitting diode (LED) and others, and a lighting apparatus in
which the light bulb-shaped lamp is used.
Background
[0002] Semiconductor light-emitting elements such as LEDs are highly efficient, long-life
elements having a small size, and thus are expected to be used as light sources for
various products. In particular, there has been progressive development of light bulb-shaped
LED lamps (LED bulbs) serving as illumination light sources substituting for conventional
light bulb-shaped fluorescent lights and incandescent light bulbs (see
JP 2006-313717 A, for example).
[0003] A light bulb-shaped LED lamp includes, for example, an LED module serving as a light
source, a globe which covers the LED module, a support component which holds the LED
module, a drive circuit which supplies power to the LED module, an outer case formed
so as to surround the drive circuit, and a base which receives power. An LED module
includes a board and plural LEDs (light-emitting elements) mounted on the board.
[0004] US 2012/0013237 A1 discloses a heat-dissipating structure of a LED bulb that includes: a base, a heat-absorbing
member, a heat-dissipating member, an assembling portion and a heat-conducting member.
The base has a trough and a first hole in communication with the trough. The heat-absorbing
member is provided in the trough and having a second hole in communication with the
first hole. The heat-dissipating member has a third hole opposite to the first hole
and a first heat-diffusing portion extending outwardly from the third hole. The first
heat-diffusing portion and the base define a first heat-dissipating space there between.
The assembling portion has a fourth hole and a second heat-diffusing portion extending
outwardly from the fourth hole. The assembling portion and the heat-dissipating member
define a second heat-dissipating space there between. A connecting end protrudes from
an outer end of the second heat-diffusing portion away from the base. The heat-conducting
member is disposed through the first, second, third and fourth holes to be combined
with the base, the heat-absorbing member, the heat-dissipating member and the assembling
portion.
[0005] EP 1 503 139 A2 discloses that a compact LED light source providing intensive LED positioning along
with thermal dissipation can be made with a heat conductive plate supporting a plurality
of LEDs mounted on the plate and in thermal contact with the plate. The plate further
supports electrical circuitry providing electrical connection to the LEDs. A heat
conductive stem mechanically supports the plate and may provide a thermal conduction
path from the plate away from the LEDs.
[0006] US 2010/0264799 A1 discloses an LED lamp that includes a hollow lamp housing, a front optical part,
a rear electrical part provided with a circuit board, and a middle heat dissipation
part. The heat dissipation part includes a heat sink, and a mounting seat located
in front of and thermally connected to the heat sink. The lamp housing defines a plurality
of air exchanging holes therein. The mounting seat is in the form of a polyhedron,
and has a polyhedral rear end surface and a plurality of heat absorbing surface. The
optical part includes a plurality of light sources respectively arranged on the heat
absorbing surfaces, a light reflector located between the heat sink and the light
sources, and an optical lens located in front of the light reflector. The heat absorbing
surfaces extend forwardly from a peripheral edge of the rear end surface towards the
optical lens and facing the optical lens.
[0007] US 2010/0207502 A1 discloses a three dimensional LED arrangement and heat management method using a
heat transfer or conduction pipe to enable rapid heat transfer from a three dimensional
cluster of LEDs to a heatsink with or without active cooling, the light emitted from
the three dimensional cluster not being obstructed by a heat sink arrangement such
that the light beam profile generated by the light appears similar to that generated
by traditional incandescent bulbs.
[0008] WO 2012/132736 A1 discloses an LED light bulb equipped with a light source device that is arranged
on a mounting plate and is covered with a spherical-shell-shaped globe, wherein the
light source device comprises a truncated-corn-shaped reflective body and multiple
LED chips arranged on the upper surface of a substrate, at least a side surface of
the reflective body has a light-reflecting function, and the light source device is
arranged on the mounting plate in such a manner that the lower surface of the substrate
faces the mounting plate.
[0009] JP 2012-227172 A discloses a bulb-type lamp that includes: a hollow globe with an opening; a plurality
of LED modules housed in the globe and equipped with semiconductor light-emitting
elements as light sources; and a stem provided to support the plurality of LED modules
and extend toward inside of the globe through its opening. The stem penetrates at
least a sheet of the plurality of LED modules, and at the same time, the plurality
of LED modules are fitted at a given interval on an axis of the stem.
[0010] US 2011/090699 A1 discloses a lamp comprising a first heat sink member, a mounting substrate placed
in surface contact with a surface of the heat sink member, a light-emitting unit placed
on a surface of the mounting substrate, a globe covering the light-emitting unit in
light emission directions thereof, and a second heat sink member that has a first
part in surface contact with a perimeter of the surface of the mounting substrate
where the light-emitting unit is not mounted and a second part in surface contact
with the first heat sink member.
Summary
Technical Problem
[0011] In recent years, a study has been conducted on light bulb-shaped LED lamps having
light distribution characteristics and appearance equivalent to those of incandescent
light bulbs. For example, a light bulb-shaped LED lamp has been proposed which is
formed using a globe (clear bulb) made of clear glass used for an incandescent light
bulb, and holds an LED module at the center position in a space inside the globe.
In this case, for example, a support extending from the opening of the globe toward
the center of the globe is used, and an LED module is fixed at a top end of this support.
[0012] An LED mounted on the LED module generates heat by emitting light, which increases
the temperature of the LED and decreases optical power. In other words, the heat generated
by an LED itself decreases the light-emission efficiency of the LED. Thus, it is important
to take measures to dissipate heat.
[0013] Also, there has been a demand for light bulb-shaped LED lamps to achieve higher luminous
flux, and thus research and development are now conducted on high-output LED lamps
in which many LEDs are used. For example, a light bulb-shaped LED lamp having brightness
of about 60 watts is being under consideration. Thus, taking measures to dissipate
heat is an extremely important issue.
[0014] The present invention has been conceived in light of the above conventional problems,
and an object thereof is to provide an illumination light source and a lighting apparatus
which can increase the efficiency of dissipating heat generated by a light-emitting
module.
Solution to Problem
[0015] The above object is achieved by an illumination light source according to claim 1.
[0016] In the illumination light source according to an aspect of the present invention,
the heat dissipation portion may be a protrusion sticking out from the back surface
of the mounting.
[0017] In the illumination light source according to an aspect of the present invention,
the mounting may have a through-hole for fixing the support in a state where an end
portion of the support is passing through the through-hole, and the protrusion may
be formed by the end portion of the support that is sticking out of the through-hole
from the back surface of the mounting.
[0018] The illumination light source according to an aspect of the present invention may
further include an insulating component between the heat dissipation portion and the
drive circuit, wherein the insulating component may have a heat-receiving portion
having a recessed shape conforming to a shape of the heat dissipation portion.
[0019] In the illumination light source according to an aspect of the present invention,
the heat dissipation portion may be a recess depressed relative to the back surface
of the mounting.
[0020] In the illumination light source according to an aspect of the present invention,
the mounting may have a through-hole for fixing the support in a state where an end
portion of the support is inserted in the through-hole, and the recess may be formed
by an inner surface of the through-hole and an end surface of the end portion.
[0021] The illumination light source according to an aspect of the present invention may
further include an insulating component between the heat dissipation portion and the
drive circuit, wherein the insulating component may have a heat-receiving portion
having a protruding shape conforming to a shape of the heat dissipation portion.
[0022] A lighting apparatus according to an aspect of the present invention includes the
illumination light source according to one of the above aspects.
Advantageous Effects
[0023] According to the present invention, heat generated by a light-emitting module can
be efficiently dissipated.
Brief Description of Drawings
[0024]
[FIG. 1] FIG. 1 is an external perspective view of a light bulb-shaped lamp according
to an embodiment.
[FIG. 2] FIG. 2 is an exploded perspective view of the light bulb-shaped lamp according
to the embodiment.
[FIG. 3] FIG. 3 is a cross-sectional view of the light bulb-shaped lamp according
to the embodiment.
[FIG. 4] FIG. 4 shows a simplified structure of an LED module in the light bulb-shaped
lamp according to the embodiment.
[FIG. 5] FIG. 5 shows an example of a way of connecting a support and a mounting according
to the embodiment.
[FIG. 6] FIG. 6 shows an external perspective view of a cap part according to the
embodiment.
[FIG. 7] FIG. 7 is a cross-sectional view of a simplified structure of the cap part
according to Variation 1 of the embodiment.
[FIG. 8] FIG. 8 is a cross-sectional view of a simplified structure of a protrusion
according to Variation 2 of the embodiment.
[FIG. 9] FIG. 9 is a cross-sectional view of a simplified structure of a pedestal
according to Variation 3 of the embodiment.
[FIG. 10] FIG. 10 shows cross-sectional shapes of protrusions of two types according
to Variation 4 of the embodiment.
[FIG. 11] FIG. 11 is a cross-sectional view of a simplified structure of a heat dissipation
portion according to Variation 5 of the embodiment.
[FIG. 12] FIG. 12 shows cross-sectional shapes of recesses of two types according
to Variation 6 of the embodiment.
[FIG. 13] FIG. 13 shows a way of connecting a support and a mounting according to
Variation 7 of the embodiment.
[FIG. 14] FIG. 14 shows a simplified cross-sectional view of a lighting apparatus
according to the embodiment.
Description of Embodiments
[0025] The following describes an illumination light source and a lighting apparatus according
to an embodiment of the invention, with reference to the drawings. It should be noted
that the drawings are schematic diagrams, and do not necessarily provide strictly
accurate illustration.
[0026] The exemplary embodiments described below each show a preferable, specific example.
The numerical values, shapes, materials, constituent elements, the arrangement and
connection of the constituent elements, and others indicated in the following exemplary
embodiments are mere examples, and therefore do not intend to limit the inventive
concept. Therefore, among the constituent elements in the following exemplary embodiments,
constituent elements not recited in any of the independent claims are described as
optional constituent elements.
[0027] A description is given of a light bulb-shaped LED lamp (LED bulb) as an example of
an illumination light source, in the embodiments below.
[Overall configuration of light bulb-shaped lamp]
[0028] First, a description is given of an overall configuration of a light bulb-shaped
lamp 1 according to an embodiment of the present invention, using FIGS. 1 and 2.
[0029] FIG. 1 is an external perspective view of a light bulb-shaped lamp according to an
embodiment.
[0030] FIG. 2 is an exploded perspective view of the light bulb-shaped lamp according to
the embodiment. It should be noted that lead wires 53a to 53d are not illustrated
in FIG. 2.
[0031] As shown in FIGS. 1 and 2, the light bulb-shaped lamp 1 according to the present
embodiment is a light bulb-shaped lamp that is a substitute for a light bulb-shaped
fluorescent light or an incandescent light bulb.
[0032] The light bulb-shaped lamp 1 includes a globe 10, an LED module 20 which is an example
of a light-emitting module, and a pedestal 45 which includes a support 30 and a mounting
40.
[0033] In the present embodiment, the light bulb-shaped lamp 1 further includes a drive
circuit 50, a circuit case 60, a heat sink 70, an outer case 80, and a base 90.
[0034] It should be noted that the light bulb-shaped lamp 1 has an envelope composed of
the globe 10, the outer case 80, and the base 90.
[0035] The following describes in detail using FIG. 3, constituent elements of the light
bulb-shaped lamp 1 according to the present embodiment, with reference to FIG. 2.
[0036] FIG. 3 is a cross-sectional view of the light bulb-shaped lamp 1 according to the
embodiment.
[0037] It should be noted that the dashed dotted line drawn in the vertical direction of
FIG. 3 indicates a lamp axis J of the light bulb-shaped lamp (central axis), the lamp
axis J is the same as the axis of the globe 10 (globe axis) in the present embodiment.
Further, the lamp axis J indicates the center of rotation when the light bulb-shaped
lamp 1 is attached to the socket of a lighting apparatus (not illustrated in FIG.
3), and is the same as the rotation axis of the base 90. Further, FIG. 3 shows a side
view of the drive circuit 50, not a cross-sectional view.
[Globe]
[0038] As shown in FIG. 3, the globe 10 is a substantially hemispherical, light-transmissive
cover for allowing the light emitted by the LED module 20 to be sent out of the lamp.
The globe 10 according to the present embodiment is a glass bulb (clear bulb) made
of silica glass transparent to visible light. Thus, the LED module 20 housed in the
globe 10 can be visually recognized from the outside of the globe 10.
[0039] The LED module 20 is covered by the globe 10. Consequently, light from the LED module
20 that is incident onto the inner surface of the globe 10 passes through the globe
10 to be sent out of the globe 10. In the present embodiment, the globe 10 is formed
so as to house the LED module 20.
[0040] The globe 10 is shaped so as to have a spherically closed end and an opening 11 at
the other end. Specifically, the globe 10 is shaped such that a portion of a hollow
sphere extends to be narrow in a direction away from the center of the sphere, and
the opening 11 is formed at the position distant from the center of the sphere.
[0041] As the globe 10 having such a shape, a glass bulb having a shape similar to those
of general light bulb-shaped fluorescent lights and general incandescent light bulbs
can be used. For example, a glass bulb such as a type-A, type-G, or type-E bulb can
be used as the globe 10.
[0042] Further, the opening 11 of the globe 10 is placed on the surface of the pedestal
40, for example, and an adhesive such as a silicone resin is applied between the pedestal
40 and the outer case 80 in this state, thereby fixing the globe 10.
[0043] It should be noted that the globe 10 does not necessarily need to be transparent
to visible light, and may have a light diffusion function. For example, a resin or
white pigment that contains light diffusion material such as silica or calcium carbonate,
or the like is applied onto the entire inner or external surface of the globe 10,
thereby forming a milky light diffusion film thereon. In this manner, the light diffusing
function given to the globe 10 allows light incident from the LED module 20 onto the
globe 10 to be diffused, thus increasing a light distribution angle of the light bulb-shaped
lamp 1.
[0044] Further, the shape of the globe 10 is not limited to type-A, and may be a spheroid
or oblate spheroid. The material of the globe 10 is not limited to glass, and a resin
such as acrylic (polymethyl methacrylate (PMMA)) or polycarbonate (PC) may be used
therefor.
[LED module]
[0045] The LED module 20 is a light-emitting module which includes a light-emitting element,
and emits light of a predetermined color (wavelength) such as white.
[0046] As shown in FIG. 3, the LED module 20 is placed inside the globe 10, and is preferably
placed at the center position of the spherical shape formed by the globe 10 (for example,
inside of a large diameter portion of the globe 10 where the inside diameter is large).
[0047] In this way, light distribution characteristics similar to those of a conventional
incandescent light bulb using a filament coil can be achieved by placing the LED module
20 at the center position of the globe 10.
[0048] Further, the LED module 20 is held in the space of the globe 10 by the support 30,
and emits light using power supplied from the drive circuit 50 via the lead wires
53a and 53b. In the present embodiment, a board 21 of the LED module 20 is held by
the support 30.
[0049] Here, a description is given of constituent elements of the LED module 20 according
to the embodiment of the present invention, using FIG. 4.
[0050] FIG. 4 shows a simplified structure of the LED module 20 in the light bulb-shaped
lamp 1 according to the embodiment.
[0051] Specifically, (a) of FIG. 4 is a plan view of the LED module 20 of the light bulb-shaped
lamp 1 according to the embodiment. Part (b) of FIG. 4 is a cross-sectional view of
the LED module 20 taken along the line A-A' in (a). Part (c) of FIG. 4 is a cross-sectional
view of the LED module 20 taken along the line B-B' in (a) of FIG. 4.
[0052] As shown in (a) to (c) of FIG. 4, the LED module 20 includes the board 21, LEDs 22,
sealing components 23, metal lines 24, wires 25, and terminals 26a and 26b.
[0053] The LED module 20 according to the present embodiment has a chip on board (COB) structure
in which a bare chip is directly mounted on the board 21. The following describes
in detailed constituent elements of the LED module 20.
[0054] First is a description of the board 21. The board 21 is a mounting board on which
the LEDs 22 are mounted, and has a first main surface on which the LEDs 22 are mounted
(front surface), and a second main surface opposite the first main surface (back surface).
[0055] As shown in (a) of FIG. 4, the board 21 has, for example, a rectangular plate shape
in plane view (when viewed from the top of the globe 10).
[0056] The board 21 is connected to an end of the support 30. Specifically, the board 21
and the support 30 are connected such that the second main surface of the board 21
and the end surface of the support 30 are in contact.
[0057] A board having a low transmittance of light emitted from the LEDs 22 can be used
as the board 21. Examples of such a board include a white substrate such as a white
alumina board whose total transmittance is 10% or less, a resin-coated metal board
(metal base board), and the like.
[0058] Consequently, the use of a board having a low light transmittance helps in preventing
light from passing through the board 21 and being emitted from the second main surface,
thereby avoiding the occurrence of color unevenness. In addition, an inexpensive white
substrate can be used, which achieves cost reduction.
[0059] A light-transmissive board having a high light transmittance can also be used as
the board 21. The use of a light-transmissive board allows light from the LEDs 22
to pass through the board 21, and to be emitted also from a surface (back surface)
on which the LEDs 22 are not mounted.
[0060] Thus, even if the LEDs 22 are mounted only on the first main surface (front surface)
of the board 21, light is also emitted from the second main surface (back surface),
and thus light distribution characteristics equivalent to those of an incandescent
light bulb can be obtained. In addition, light can be omnidirectionally emitted from
the LED module 20, and thus it is possible to achieve omnidirectional light distribution
characteristics.
[0061] Examples that can be used as a light-transmissive board include a board whose total
transmittance to visible light is 80% or more, and a board transparent to visible
light (in other words, a board whose transmittance is extremely high, which allows
the view on the other side to be seen through the board). As such a light-transmissive
board, a light-transmissive ceramics board made of polycrystalline alumina or aluminum
nitride, a clear glass board made of glass, a crystal substrate made of crystal, a
sapphire substrate made of sapphire, a transparent resin board made of a transparent
resin material, or the like can be used.
[0062] In the present embodiment, a white polycrystalline-ceramics board made of sintered
alumina is used as the board 21. For example, a white alumina board having a thickness
of 1 mm, whose light reflectance is 94% or a white alumina board having a thickness
of 0.635 mm, whose light reflectance is 88% can be used as the board 21.
[0063] It should be noted that a resin board, a flexible board, or a metal base board can
also be used as the board 21. Further, the shape of the board 21 is not limited to
a rectangle, and another shape such as a square or a circle can also be used.
[0064] The board 21 has two insertion holes 27a and 27b for electrical connection with the
two lead wires 53a and 53b. Tip portions of the lead wires 53a and 53b pass through
the insertion holes 27a and 27b and soldered onto the terminals 26a and 26b formed
in the board 21, respectively.
[0065] Next is a description of the LEDs 22. The LED 22 is an example of a light-emitting
element, and is a semiconductor light-emitting element which emits light by using
predetermined power. All the LEDs 22 on the board 21 are of the same type, and selected
so as all to have the same VF characteristics.
[0066] The LEDs 22 are bare chips which emit single-color visible light. In the present
embodiment, blue LED chips which emit blue light by being electrically connected are
used. As a blue LED chip, for example, a gallium nitride-based semiconductor light-emitting
element can be used which is formed using InGaN based material and the center wavelength
of which is at least 440 nm and at most 470 nm.
[0067] The LEDs 22 are mounted only on the first main surface (front surface) of the board
21, in plural lines along a long side of the board 21. In the present embodiment,
48 LEDs 22 are disposed on the board 21 in order to achieve brightness of about 60
watts. Specifically, 48 LEDs 22 are disposed on the first main surface (front surface)
of the board 21 so as to be in four parallel lines each including 12 LEDs 22.
[0068] In the present embodiment, one of adjacent LEDs 22 has a cathode electrode connected
to an anode electrode of the other of the adjacent LEDs 22 via the metal line 24 by
wire-bonding using the wires 25.
[0069] It should be noted that wire-bonded portions of adjacent LEDs 22 may be directly
connected using the wires 25. In other words, adjacent LEDs 22 may be connected by
chip-to-chip wire-bonding. In this case, the metal line 24 disposed between the adjacent
LEDs 22 is unnecessary.
[0070] It should be noted that although the plural LEDs 22 are mounted on the board 21 in
the present embodiment, the number of the mounted LEDs 22 may be changed as appropriate
according to the usage of the light bulb-shaped lamp 1.
[0071] For example, when the light bulb-shaped lamp 1 is achieved as a low-output LED lamp
that is a substitute for a miniature bulb, the LED module 20 may have one LED 22.
[0072] In contrast, if the light bulb-shaped lamp 1 is achieved as a high-output LED lamp,
the number of LEDs 22 to be mounted in one line may further be increased.
[0073] In addition, the number of lines of the LEDs 22 is not limited to four, and may be
one, two, or three, or even five or more.
[0074] Next is a description of the sealing components 23. The sealing components 23 are
made of, for example, resin and formed so as to cover the LEDs 22.
[0075] Specifically, the sealing components 23 are each formed so as to seal all the plural
LEDs 22 in one line. In the present embodiment, four lines of the LEDs 22 are provided,
and thus four sealing components 23 are formed. The four sealing components 23 are
each provided linearly on the first main surface of the board 21, along the aligned
lines of the plural LEDs 22 (in the line direction).
[0076] The sealing components 23 mainly include light-transmissive material, and wavelength
conversion material is mixed into the light-transmissive material when a wavelength
of light from the LEDs 22 needs to be converted into a predetermined wavelength.
[0077] The sealing components 23 according to the present embodiment include a fluorescent
substance as a wavelength conversion material. In other words, the sealing components
23 are wavelength conversion components which convert the wavelength (color) of light
emitted by the LEDs 22.
[0078] Such sealing components 23 can be formed using, for example, insulating resin material
which contains fluorescent particles (fluorescent substance containing resin). Fluorescent
particles are excited by the light emitted by the LEDs 22, and emit light having a
desired color (wavelength).
[0079] An example of a resin material used to form the sealing components 23 is a silicone
resin. Light diffusion material may be dispersed in the sealing components 23. It
should be noted that the sealing components 23 do not necessarily need to be formed
using a resin material, and may be formed using an inorganic material such as low-melting
glass and sol-gel glass, other than an organic material such as fluororesin.
[0080] For example, yttrium aluminum garnet (YAG) based yellow fluorescent particles are
used to obtain white light, as fluorescent particles to be contained in the sealing
components 23, when the LEDs 22 are blue LEDs which emit blue light.
[0081] In this manner, blue light emitted by the LED22 is partially converted into light
having a yellow light wavelength by yellow fluorescent particles contained in the
sealing components 23. Then, blue light not absorbed by the yellow fluorescent particles
and yellow light whose wavelength has been changed by yellow fluorescent particles
are diffused and mixed in the sealing components 23 so as to be emitted as white light
from the sealing components 23. Silica particles, for instance, are used as light
diffusion material.
[0082] The sealing components 23 according to the present embodiment are formed using a
fluorescent substance containing resin obtained by dispersing predetermined fluorescent
particles into a silicone resin. For example, a fluorescent substance containing resin
is applied onto the first main surface of the board 21 by a dispenser and cured, thereby
forming the sealing components 23. In this case, the shape of the sealing components
23 in a cross section perpendicular to the long side thereof is substantially semicircular.
[0083] It should be noted that in order to change the wavelength of light directed to the
back surface of the board 21 (leaked light), a fluorescent film (fluorescent layer)
such as a sintered film which includes fluorescent particles and an inorganic bonding
material (binder) such as glass, or a fluorescent substance containing resin which
is the same as that applied on the surface of the board 21 may further be applied
as the second wavelength conversion component, between the board 21 and the LEDs 22
or on the second main surface (back surface) of the board 21.
[0084] In the above manner, further forming the second wavelength conversion component on
the second main surface of the board 21 allows white light to be emitted from both
sides of the board 21 even if light leaks from the second main surface.
[0085] Next is a description of the metal lines 24. The metal lines 24 are conductive lines
through which a current for causing the LEDs 22 to emit light flows, and formed on
the surface of the board 21 by patterning so as to have a predetermined shape. As
shown in (a) of FIG. 4, the metal lines 24 are formed on the first main surface of
the board 21. The metal lines 24 supply, to the LEDs 22, power supplied from the lead
wires 53a and 53b to the LED module 20.
[0086] The metal lines 24 can be formed by patterning or printing on a metal film made of
a metal material, for example. Examples to be used as the material of the metal lines
24 include silver (Ag), tungsten (W), copper (Cu), gold (Au), and the like.
[0087] In addition, except for the terminals 26a and 26b, the metal lines 24 exposed from
the sealing components 23 are preferably covered with a glass film (glass coated film)
which includes a glass material or a resin film (resin coated film) which includes
a resin material. This achieves improvement in insulating properties of the LED module
20 and a reflectance of the surface of the board 21, for example.
[0088] The wires 25 are electric wires such as gold wires, for example. As shown in (b)
of FIG. 4, the wires 25 connect the LEDs 22 and the metal lines 24.
[0089] Specifically, wire bonding portions on the top surface of each LED 22 and the metal
lines 24 formed on both sides of the LED 22 and adjacent to the LED 22 are wire-bonded
using the wires 25.
[0090] It should be noted that in the present embodiment, the wires 25 are entirely embedded
in the sealing components 23 so as not to be exposed therefrom. This prevents light
from being absorbed and reflected by the exposed wires 25, for instance.
[0091] Next is a description of the terminals 26a and 26b. The terminals 26a and 26b are
external connection terminals which receive, from the outside of the LED module 20,
direct-current power for causing the LEDs 22 to emit light. In the present embodiment,
the terminals 26a and 26b are soldered onto the lead wires 53a and 53b, respectively.
[0092] The terminals 26a and 26b are formed in a predetermined shape on the first main surface
of the board 21 so as to surround the insertion holes 27a and 27b, respectively. The
terminals 26a and 26b are integrally formed with the metal lines 24, and electrically
connected to the metal lines 24. It should be noted that the terminals 26a and 26b
are formed by patterning simultaneously with the metal lines 24, using the same metal
material as the metal lines 24.
[0093] In addition, the terminals 26a and 26b serve as power supply portions for the LED
module 20, and supply, via the metal lines 24 and the wires 25, the LEDs 22 with direct-current
power received from the lead wires 53a and 53b.
[Pedestal]
[0094] The pedestal 45 according to the present embodiment has the support 30 and the mounting
40, as described above.
[0095] The pedestal 45 includes a heat dissipation portion 46 as a distinguishing structure.
The heat dissipation portion 46 is between the drive circuit 50 and an area 44 for
disposing the support 30 on a main surface 40a of the mounting 40 which is on a side
where the LED module 20 is provided.
[0096] In the present embodiment, the pedestal 45 includes a protrusion 47 as the heat dissipation
portion 46, as shown in FIG. 3.
[0097] A description will be given below of the heat dissipation portion 46 and the structure
around the heat dissipation portion 46 in the light bulb-shaped lamp 1, using FIGS.
5 to 13.
[0098] The following describes the support 30 and the mounting 40 of the pedestal 45.
[Support]
[0099] As shown in FIG. 3, the support 30 is a long component extending from a portion near
the opening 11 of the globe 10 toward the inside of the globe 10. In the present embodiment,
the axis of the support 30 extends along the lamp-axis J. In other words, the axis
of the support 30 and the lamp-axis J are parallel.
[0100] The support 30 functions as a support component which holds the LED module 20, and
the LED module 20 is connected to an end of the support 30. In other words, the LED
module 20 is fixed at a predetermined position inside the globe 10 by the support
30.
[0101] In this manner, attaching the LED module 20 to the support 30 extending toward the
inside of the globe 10 achieves wide light distribution characteristics similar to
that of an incandescent light bulb. The mounting 40 is connected to the other end
of the support 30.
[0102] The support 30 also functions as a heat dissipation component (heat sink) for dissipating
heat generated by the LED module 20 (the LEDs 22). Thus, the support 30 is preferably
formed using a metal material mainly containing aluminum (Al), copper (Cu), iron (Fe)
or the like, or a resin material having high thermal conductivity.
[0103] This allows heat generated by the LED module 20 to be efficiently conducted to the
mounting 40 via the support 30. It should be noted that the support 30 preferably
has higher thermal conductivity than the board 21. In the present embodiment, the
material of the support 30 is aluminum.
[0104] An end of the support 30 on the top side of the globe 10 is connected to the central
portion of the board 21 of the LED module 20, whereas the other end of the support
30 on the base 90 side is connected to the central portion of the mounting 40.
[0105] It should be noted that in the present embodiment, the support 30 is fixed to the
mounting 40, passing through a through-hole 43 in the mounting 40.
[0106] The board 21 of the LED module 20 and an end surface of the support 30 are firmly
attached using an adhesive such as a silicone resin, for example. Consequently, an
adhesive may be present between the board 21 and the end surface of the support 30.
In this case, the thickness of the silicone resin is preferably is 20 micrometers
or less, in consideration of the thermal conductivity of the board 21 and the support
30.
[0107] In addition, the board 21 and the support 30 may be fixed using, for example, a screw,
rather than an adhesive. In this case, the surfaces of the board 21 and the support
30 may have minute unevenness, depending on a material or a processing technique,
and thus a minute space may be present between the second main surface of the board
2 and the end surface of the support 30. Even if there is such a minute space, the
board 21 and the support 30 can be considered to be substantially in contact if the
space has a size of about 20 micrometers at most.
[0108] For the support 30, for example, a solid-structured cylindrical shape is used which
has a constant cross-sectional area (an area in a cross section obtained when the
support 30 is cut through along a plane normal to the axis thereof).
[0109] It should be noted that the support 30 does not need to have a shape whose cross-sectional
area is constant, and may have a shape whose cross-sectional area changes at one or
more points, such as a shape obtained by combining a column and a square pillar.
[Mounting]
[0110] The mounting 40 is a support pad for holding the support 30. As shown in FIG. 3,
the mounting 40 is formed so as to close the opening 11 of the globe 10. The mounting
40 is connected to the heat sink 70. In the present embodiment, the mounting 40 is
fitted in an opening 70a of the heat sink 70 such that the outer circumference of
the mounting 40 is in contact with the inner surface of the heat sink 70.
[0111] The mounting 40 also functions as a heat dissipation component (heat sink) for dissipating
heat generated by the LED module 20 (the LEDs 22). Thus, the mounting 40 is preferably
formed using a metal material which mainly contains aluminum (Al), copper (Cu), or
iron (Fe), or a resin material having high thermal conductivity. This allows heat
to be efficiently conducted from the support 30 to the heat sink 70. In the present
embodiment, the material of the mounting 40 is aluminum.
[0112] Here, a detailed description is given of a structure of the mounting 40, with reference
to FIG. 3. As shown in FIG. 3, the mounting 40 is a disc-shaped component having a
step portion, and includes a small diameter portion 41 having a smaller diameter and
a large diameter portion 42 having a larger diameter. The small diameter portion 41
and the large diameter portion 42 form the step portion.
[0113] For example, the small diameter portion 41 has a thickness of about 3 mm and a diameter
of about 18 mm, whereas the large diameter portion 42 has a thickness of about 3 mm
and a diameter of about 42 mm. It should be noted that the step portion has a height
of about 4 mm, for example.
[0114] In the present embodiment, the small diameter portion 41 has the through-hole 43
for fixing the support 30 in a state where the end portion thereof is passing through
the through-hole 43.
[0115] It should be noted that in the present embodiment, a circular area formed by the
edge of the through-hole 43 on the main surface 40a side corresponds to the area 44
for disposing the support 30. A description will be given below of a process of connecting
the support 30 and the mounting 40, using FIG. 5.
[0116] Furthermore, the small diameter portion 41 has two insertion holes for inserting
the lead wires 53a and 53b.
[0117] The large diameter portion 42 forms connection with the heat sink 70, and is fitted
in the heat sink 70. As shown in FIG. 3, the mounting 40 is fitted in the opening
70a of the heat sink 70 such that the outer circumferential surface of the large diameter
portion 42 is in contact with the inner circumference surface of the heat sink 70.
This allows heat to be efficiently conducted from the mounting 40 to the heat sink
70.
[0118] In addition, the top surface of the large diameter portion 42 is in contact with
the opening 11 of the globe 10 so as to close the opening 11 of the globe 10. It should
be noted that the mounting 40 and the heat sink 70 may be fixed using an adhesive
such as a silicone resin, rather than by caulking.
[Drive circuit]
[0119] As shown in FIG. 3, the drive circuit (circuit unit) 50 is a light circuit (power
supply circuit) for causing the LED module 20 (the LEDs 22) to emit light (be turned
on), and supplies predetermined power to the LED module 20. For example, the drive
circuit 50 converts alternating current power supplied from the base 90 via the pair
of lead wires 53c and 53d into direct current power, and supplies the direct current
power to the LED module 20 via the pair of lead wires 53a and 53b.
[0120] The drive circuit 50 includes a circuit board 51 and plural circuit elements (electronic
components) 52 mounted on the circuit board 51.
[0121] The circuit board 51 is a printed circuit board on which metal lines are formed by
patterning, and electrically connects the plural circuit elements 52 mounted on the
circuit board 51. In the present embodiment, the circuit board 51 is disposed in an
orientation in which the main surface thereof crosses the lamp-axis J at right angles.
[0122] Examples of the circuit elements 52 include a capacitative element such as an electrolytic
condenser or a ceramic condenser, a resistance element, a rectifier circuit element,
a coil element, a choke coil (choke transformer), a noise filter, a semiconductor
element such as a diode or an integrated circuit element, and the like. Most of the
circuit elements 52 are mounted on the main surface of the circuit board 51 on the
base 90 side.
[0123] The drive circuit 50 formed in this way is housed in the circuit case 60. In the
present embodiment, the circuit board 51 is placed on projections (board holding portions)
on the inner surface of a case body portion 61, and the main surface of the circuit
board 51 is in contact with projections on a cap part 62. In this manner, the circuit
board 51 is held in the circuit case 60. It should be noted that a light control circuit,
a booster circuit, and the like may be suitably selected and combined as the drive
circuit 50.
[0124] The drive circuit 50 and the LED module 20 are electrically connected by the pair
of lead wires 53a and 53b. Furthermore, the drive circuit 50 and the base 90 are electrically
connected by the pair of lead wires 53c and 53d. The four lead wires 53a to 53d are,
for example, alloy copper lead wires, and each include a core wire made of alloy copper
and an insulating resin coating which covers the core wire.
[0125] In the present embodiment, the lead wire 53a is a conducting wire (plus output terminal
wire) for supplying a positive voltage from the drive circuit 50 to the LED module
20, whereas the lead wire 53b (minus output terminal wire) is a conducting wire for
supplying a negative voltage from the drive circuit 50 to the LED module 20. The lead
wires 53a and 53b pass through the insertion holes in the mounting 40, and are pulled
out on the LED module 20 side (inside the globe 10).
[0126] It should be noted that the ends (core wires) of the lead wires 53a and 53b pass
through the insertion holes 27a and 27b in the board 21 of the LED module 20, respectively
and soldered onto the terminals 26a and 26b, respectively. The other ends (core wires)
of the lead wires 53a and 53b are soldered onto the metal lines of the circuit board
51.
[0127] Furthermore, the lead wires 53c and 53d are electric wires for supplying power for
turning on the LED module 20, from the base 90 to the drive circuit 50. The lead wires
53c and 53d each have an end (core wire) electrically connected to the base 90 (a
shell part 91 or an eyelet part 93), and another end (core wire) electrically connected
to a power-input portion (metal line) of the circuit board 51 by soldering, for instance.
[Circuit case]
[0128] As shown in FIG. 3, the circuit case 60 is an insulating case for housing the drive
circuit 50, and formed so as to surround the drive circuit 50. The circuit case 60
is housed in the heat sink 70 and the base 90. In the present embodiment, the circuit
case 60 includes the case body portion 61 and the cap part 62.
[0129] The case body portion 61 is an insulating case (housing) having openings on both
sides. Projections (board holding portions) are provided for placing the circuit board
51, at two or more positions (for example, three positions) on the inner surface of
the case body portion 61. An example of the material of the case body portion 61 is
insulating resin material such as poly butylene terephthalate (PBT), or the like.
[0130] In the present embodiment, the case body portion 61 includes a first case portion
61a having a large-diameter cylindrical shape that is substantially the same as the
shape of the heat sink 70, and a second case portion 61b connected to the first case
portion 61a, and having a small-diameter cylindrical shape that is substantially the
same as the shape of the base 90.
[0131] The first case portion 61a positioned on the globe 10 side is housed in the heat
sink 70. Most of the drive circuit 50 is covered with the first case portion 61a.
[0132] In contrast, the second case portion 61b positioned on the base 90 side is housed
in the base 90, and the base 90 is fitted onto the second case portion 61b. This closes
the opening of the circuit case 60 (the case body portion 61) on the base 90 side.
[0133] In the present embodiment, a screwing portion for screwing into the base 90 is formed
on the outer circumferential surface of the second case portion 61b, and the base
90 is fixed onto the circuit case 60 (the case body portion 61) by screwing onto the
second case portion 61b.
[0134] The cap part 62 is an example of an insulating component between the heat dissipation
portion 46 and the drive circuit 50. In the present embodiment, the cap part 62 is
a cap-shaped substantially cylindrical component having a closed end and insulating
properties.
[0135] An example of the material of the cap part 62 is also an insulating resin material
such as PBT, as with the case body portion 61.
[0136] Furthermore, the cap part 62 has a heat receiving portion 64a having a shape conforming
to the shape of the heat dissipation portion 46 included in the pedestal 45. The heat
receiving portion 64a is in contact with the heat dissipation portion 46, which allows
the heat from the heat dissipation portion 46 to be efficiently led to the circuit
case 60. A detailed description of the heat receiving portion 64a is given below using
FIG. 6, for instance.
[0137] It should be noted that in the present embodiment, although the circuit case 60 includes
the cap part 62, the circuit case 60 may include only the case body portion 61, without
including the cap part 62.
[Heat sink]
[0138] The heat sink 70 is a heat dissipation component, and is connected to the mounting
40. This allows heat generated by the LED module 20 to be conducted to the heat sink
70 via the support 30 and the mounting 40. Consequently, heat generated by the LED
module 20 can be dissipated.
[0139] In the present embodiment, the heat sink 70 is formed so as to surround the drive
circuit 50. Thus, the drive circuit 50 is disposed inside the heat sink 70. The drive
circuit 50 is surrounded by the circuit case 60, and thus the heat sink 70 is formed
so as to surround the circuit case 60. This allows the heat sink 70 to also dissipate
heat generated by the drive circuit 50.
[0140] Furthermore, in the present embodiment, the heat sink 70 extends even up to the boundary
portion between the first case portion 61a and the second case portion 61b of the
circuit case 60.
[0141] The heat sink 70 is preferably formed using a material having high thermal conductivity,
and can be formed using a metal component, for example. The heat sink 70 according
to the present embodiment is molded using aluminum. It should be noted that the heat
sink 70 may be formed using non-metal material such as resin, rather than metal. In
this case, it is preferable to use a nonmetal material having high thermal conductivity
for the heat sink 70.
[0142] In the present embodiment, the heat sink 70 is formed so as to be fitted onto the
mounting 40, and the inner circumferential surface of the heat sink 70 and the outer
circumferential surface of the mounting 40 are in contact with each other in the entire
circumferential direction.
[Outer case]
[0143] As shown in FIG. 3, the outer case 80 is formed so as to circumferentially surround
the heat sink 70. The external surface of the outer case 80 is exposed outside the
lamp (in the air). The outer case 80 is an insulating cover having insulating properties,
formed using insulating material. The insulating properties of the light bulb-shaped
lamp 1 can be improved by covering the metal heat sink 70 with the insulating outer
case 80. An example of the material of the outer case 80 is an insulating resin material
such as PBT.
[0144] The outer case 80 is a substantially cylindrical component having a constant thickness
and gradually changing inside and outside diameters, and can be formed in a flared
shape such that the inner and external surfaces are truncated cone shaped, for example.
In the present embodiment, the outer case 80 is formed such that the inside diameter
and the outside diameter gradually decrease toward the base 90.
[Base]
[0145] The base 90 is a receiving part which receives power for causing the LED module 20
(the LEDs 22) to emit light, from outside the lamp. The base 90 is attached to a socket
of an illuminator, for example. In this manner, the base 90 can receive power from
a socket of the illuminator when the light bulb-shaped lamp 1 turns on.
[0146] Alternating current power is supplied to the base 90 from the AC 100 V commercial
power source, for example. The base 90 according to the present embodiment receives
alternating current power at two contacts, and the power received by the base 90 is
input to the power-input portion of the drive circuit 50 via the pair of lead wires
53c and 53b.
[0147] The base 90 is a metal cylinder having a closed end, and includes the shell part
91 having an outer circumferential surface forming a male screw and the eyelet part
93 attached to the shell part 91 via an insulating part 92. The external circumferential
surface of the base 90 has a screwing portion for screwing into the socket of the
illuminator. The inner circumferential surface of the base 90 has a screwing portion
for screwing onto the screwing portion of the case body portion 61 of the circuit
case 60 (the second case portion 61b).
[0148] Although the type of the base 90 is not particularly limited, an Edison (E) screw
base is used in the present embodiment. Examples of the base 90 include E26, E17,
and E16 bases, for instance.
[Distinguishing structure of light bulb-shaped lamp]
[0149] The following describes a distinguishing structure of the light bulb-shaped lamp
1 according to the present embodiment, and different variations, using FIGS. 5 to
13.
[0150] FIG. 5 shows an example of a way of connecting the support 30 and the mounting 40
according to the embodiment.
[0151] As shown in (a) of FIG. 5, in a state where a caulking die 120 is disposed under
the through-hole 43 of the mounting 40, the end portion of the support 30 is inserted
into the through-hole 43, and the support 30 is pressed downward.
[0152] As a result, as shown in (b) of FIG. 5, the end portion of the support 3 expands
in a diameter direction so as to be fixed onto the inner circumferential surface of
the through-hole 43 of the mounting 40 by being applied pressure. This connects the
support 30 and the mounting 40 as shown in (c) of FIG. 5.
[0153] In other words, the end portion of the support 30 is caulked so that the support
30 and the mounting 40 are connected.
[0154] Furthermore, the end portion of the support 30 that is sticking out of the through-hole
43 on the back surface 40b side of the mounting 40 forms the protrusion 47 serving
as the heat dissipation portion 46. Specifically, the protrusion 47 is between the
drive circuit 50 and the area 44 for disposing the support 30 (see FIG. 3).
[0155] As described above, the pedestal 45 according to the present embodiment includes
the heat dissipation portion 46. The heat dissipation portion 46 is between the drive
circuit 50 and the area 44 for disposing the support 30, and has a surface which forms
an angle with the back surface 40b of the mounting 40 on the drive circuit 50 side.
[0156] In other words, the pedestal 45 includes the heat dissipation portion 46, whereby
the surface area of the pedestal 45 can be increased compared to the case where the
heat dissipation portion 46 is not included in the pedestal 45. An increase in the
surface area does not lead to an increase in the size of the pedestal 45. An increase
in the surface area of the pedestal 45 in the above manner achieves improvement in
heat dissipation efficiency of the pedestal 45 that is in contact with the LED module
20.
[0157] Furthermore, in the present embodiment, the cap part 62 of the circuit case 60 disposed
between the heat dissipation portion 46 and the drive circuit 50 includes the heat
receiving portion 64a having a shape according to the shape of the heat dissipation
portion 46 (the protrusion 47), as described above.
[0158] FIG. 6 is an external perspective view of the cap part 62 according to the embodiment.
[0159] As shown in FIG. 6, the cap part 62 has insertion holes 65a and 65b into which the
lead wires 53a and 53b extending from the circuit board 51 are inserted, respectively.
The cap part 62 further includes the heat receiving portion 64a having a recessed
shape for forming enough space where the protrusion 47 can be inserted.
[0160] This allows the heat receiving portion 64a to be in contact with the end surface
and the circumferential surface of the protrusion 47 having a two-stepped cylindrical
shape, as shown in FIG. 3, for example.
[0161] As a result, the efficiency of thermal conduction from the pedestal 45 to the cap
part 62 improves. Thus, the efficiency of heat dissipation by the pedestal 45 further
improves.
[0162] It should be noted that the end surface and the circumferential surface of the heat
dissipation portion 46 do not need to be in contact with the heat receiving portion
64a. At least part of the heat dissipation portion 46 is in contact with the heat
receiving portion 64a, thereby allowing heat to be efficiently conducted from the
pedestal 45 to the cap part 62.
[0163] In the above manner, the light bulb-shaped lamp 1 according to the present embodiment
includes the LED module 20 as a light source, and has light distribution characteristics
similar to a conventional incandescent light bulb in which a filament coil is used.
[0164] Furthermore, the pedestal 45 which supports the LED module 20 includes the heat dissipation
portion 46 (the protrusion 47) which has a surface that forms an angle with the back
surface 40b of the mounting 40. This improves the efficiency of dissipating heat generated
by the LED module 20.
[0165] Furthermore, the cap part 62 which is an insulating component disposed near the pedestal
45 includes the heat receiving portion 64a having a shape conforming to the shape
of the heat dissipation portion 46 (the protrusion 47). This further improves the
efficiency of dissipating heat generated by the LED module 20.
[0166] It should be noted that the structure of the light bulb-shaped lamp 1 according to
the embodiment may be different from those shown in FIGS. 1 to 6. Now, a description
is given of different variations of the structure of the light bulb-shaped lamp 1,
using FIGS. 7 to 13.
(Variation 1)
[0167] FIG. 7 is a cross-sectional view of a simplified structure of the cap part 62 according
to Variation 1 of the embodiment.
[0168] As described above, the shape of the protrusion 47 according to the embodiment has
a two-stepped cylindrical shape. Thus, the cap part 62 may include a heat receiving
portion 64b having a two-stepped recessed shape conforming to the two-stepped cylindrical
shape of the protrusion 47.
[0169] This can increase an area where the pedestal 45 and the cap part 62 are in contact,
and further improves the efficiency of thermal conduction from the pedestal 45 to
the cap part 62.
(Variation 2)
[0170] FIG. 8 is a cross-sectional view of a simplified structure of a protrusion 47a according
to Variation 2 of the embodiment.
[0171] As shown in FIG. 8, the shape of the protrusion 47a has a flat cylindrical shape
having no level difference, rather than a two-stepped cylindrical shape like the protrusion
47 according to the embodiment.
[0172] For example, the end portion of the cylindrical support 30 having the outside diameter
substantially the same as the inside diameter of the through-hole 43 is inserted into
the through-hole 43 of the mounting 40, and the through-hole 43 and the support 30
are connected using an adhesive or by welding, thereby forming the protrusion 47a
shown in FIG. 8.
[0173] In other words, if the heat dissipation portion 46 is achieved by a protrusion sticking
out from the back surface 40b of the mounting 40, the heat dissipation portion 46
may be formed in various shapes. In any of the cases, the surface area of the pedestal
45 can be increased.
[0174] Furthermore, the pedestal 45 includes the protrusion 47a, whereby an area where the
pedestal 45 and the cap part 62 which includes the heat receiving portion 64a having
a recessed shape with no level difference can be increased.
(Variation 3)
[0175] FIG. 9 is a cross-sectional view of a simplified structure of a pedestal 45a according
to Variation 3 of the embodiment.
[0176] The pedestal 45a shown in FIG. 9 has a structure in which the support 30 and the
mounting 40 are integrally molded, unlike the pedestal 45 having a structure in which
the support 30 and the mounting 40 are connected.
[0177] Furthermore, the pedestal 45a has a flat cylindrical protrusion 47b having no level
difference and sticking out from the back surface 40b of the mounting 40, like the
protrusion 47a according to Variation 2 described above. It should be noted that in
the pedestal 45a, a circular area of the mounting 40 at the bottom of the support
30 corresponds to the area 44 for disposing the support 30.
[0178] The pedestal 45a having such a shape can be fabricated by cutting and bending a metal
block such as an aluminum block, casting, or resin injection molding, for example.
[0179] The support 30 and the mounting 40 integrally molded more efficiently allow heat
conduction to the mounting 40 from the support 30 in direct contact with the LED module
20. As a result, the efficiency of dissipating heat generated by the LED module 20
further improves.
(Variation 4)
[0180] As described above, if the heat dissipation portion 46 is achieved by a protrusion
sticking out from the back surface 40b of the mounting 40, various shapes can be employed
as the shape thereof. Now, an example of a shape of the heat dissipation portion 46
achieved as a protrusion is described as Variation 4.
[0181] FIG. 10 shows cross-sectional shapes of protrusions 47c and 47d according to Variation
4 of the embodiment.
[0182] For example, as shown in (a) of FIG. 10, the heat dissipation portion 46 may be achieved
as the protrusion 47c having a convex shape sticking out from the back surface 40b
of the mounting 40.
[0183] Furthermore, for example, as shown in (b) of FIG. 10, the heat dissipation portion
46 may be achieved as the protrusion 47d having plural fins on the back surface 40b
of the mounting 40.
[0184] Furthermore, the cap part 62 includes a heat receiving portion having a shape conforming
to the shape of the protrusion 47c or 47d, which achieves an increase in an area where
the pedestal 45a and the cap part 62 are in contact.
[0185] It should be noted that in FIG. 10, the protrusions 47c and 47d are each included
in the pedestal 45a having a structure in which the support 30 and the mounting 40
are integrally formed. However, the protrusions 47c and 47d may be each included in
the pedestal 45 having a structure in which the support 30 and the mounting 40 that
are separate components are connected.
[0186] In either case, the surface area of the pedestal 45 (45a) can be increased, without
increasing the overall size of the pedestal 45 (45a). As a result, the efficiency
of dissipating heat by the pedestal 45 (45a) can be improved.
(Variation 5)
[0187] FIG. 11 is a cross-sectional view of a simplified structure of the heat dissipation
portion 46 according to Variation 5 of the embodiment.
[0188] The heat dissipation portion 46 shown in FIG. 11 is achieved as a recess 48 depressed
relative to the back surface 40b of the mounting 40.
[0189] The recess 48 is an example of the heat dissipation portion 46 between the drive
circuit 50 and the area 44 for disposing the support 30, and having a surface which
forms an angle with the back surface 40b of the mounting 40.
[0190] Even in this case, the surface area of the pedestal 45 can be increased, without
increasing the overall size of the pedestal 45.
[0191] Furthermore, in this case, the cap part 62 includes a heat receiving portion 64c
having a protruding shape, which achieves an increase in an area where the pedestal
45 and the cap part 62 are in contact, as shown in FIG. 11.
[0192] In the pedestal 45 shown in FIG. 11, the support 30 is fixed in a state where an
end portion thereof is inserted in the through-hole 43, and the recess 48 is formed
by the inner surface of the through-hole 43 and the end surface of the end portion
of the support 30.
[0193] It should be noted that the recess 48 may be in the pedestal 45a having a structure
in which the support 30 and the mounting 40 are integrally formed.
(Variation 6)
[0194] As described in Variation 5 above, if the heat dissipation portion 46 is achieved
by a recess depressed relative to the back surface 40b of the mounting 40, various
shapes can be employed as the shape thereof. Now, an example of a shape of the heat
dissipation portion 46 achieved as a recess is described as Variation 6.
[0195] FIG. 12 shows cross-sectional shapes of recesses 48a and 48b according to Variation
6 of the embodiment.
[0196] A shown in (a) of FIG. 12, the heat dissipation portion 46 may be achieved as the
recess 48a having a concave shape depressed relative to the back surface 40b, for
example.
[0197] In addition, the heat dissipation portion 46 may be achieved as, for example, the
recess 48b having plural slots in the back surface 40b of the mounting 40, as shown
in (b) of FIG. 12.
[0198] In addition, the cap part 62 includes a heat receiving portion having a shape conforming
to the shape of the recess 48a or 48b, which achieves an increase in an area where
the pedestal 45a and the cap part 62 are in contact.
[0199] It should be noted that even in the case where the heat dissipation portion 46 is
achieved as a recess, at least a portion of the heat dissipation portion 46 is in
contact with the heat receiving portion, whereby heat is efficiently conducted from
the pedestal 45 to the cap part 62.
[0200] It should be noted that in FIG. 12, the recesses 48a and 48b are each included in
the pedestal 45a having a structure in which the support 30 and the mounting 40 are
integrally formed. However, the recesses 48a and 48b may be each included in the pedestal
45 having a structure in which the support 30 and the mounting 40 that are separate
components are connected.
[0201] In either case, the surface area of the pedestal 45 (45a) can be increased, without
increasing the overall size of the pedestal 45 (45a). As a result, the efficiency
of dissipating heat by the pedestal 45 (45a) can be improved.
(Variation 7)
[0202] In the above embodiment, the end portion of the support 30 is caulked, thereby connecting
the support 30 and the mounting 40 (see FIG. 5).
[0203] However, techniques other than caulking processing may be employed as the technique
of connecting the support 30 and the mounting 40.
[0204] FIG. 13 shows a state in which the support 30 and the mounting 40 are connected according
to Variation 7 of the embodiment.
[0205] The support 30 shown in FIG. 13 has a male screw portion 30a at an end, and the through-hole
43 of the mounting 40 has a female screw portion 43a according to the male screw portion
30a formed on the inner surface thereof.
[0206] The support 30 having such a structure screws into the through-hole 43 of the mounting
40, thereby being connected to the mounting 40, as shown in (a) and (b) of FIG. 13.
[0207] It should be noted that in this case, the connection between the support 30 and the
mounting 40 can be strengthened by using an adhesive or by welding, for example.
[0208] In this manner, as a technique of connecting the support 30 and the mounting 40,
a technique other than caulking processing may be employed if the technique at least
allows the support 30 and the mounting 40 to be fixed in contact with each other.
(Lighting apparatus)
[0209] The present invention can be achieved not only as the light bulb-shaped lamp 1 described
above, but also as a lighting apparatus which includes the light bulb-shaped lamp
1. The following describes a lighting apparatus according to an embodiment of the
present invention, using FIG. 14.
[0210] FIG. 14 is a simplified cross-sectional view of a lighting apparatus 2 according
to an embodiment.
[0211] As shown in FIG. 14, the lighting apparatus 2 according to the embodiment of the
present invention is, for example, a device to be attached to an indoor ceiling and
used. The lighting apparatus 2 includes a light-up device 3 and the light bulb-shaped
lamp 1 according to the embodiment described above.
[0212] It should be noted that at least one of various modifications described in Variations
1 to 6 above may be employed for the light bulb-shaped lamp 1.
[0213] The light-up device 3 is for turning on and off the light bulb-shaped lamp 1, and
includes a device body 4 to be attached to a ceiling and a light-transmissive lamp
cover 5 which covers the light bulb-shaped lamp 1.
[0214] The device body 4 has a socket 4a. The base 90 of the light bulb-shaped lamp 1 screws
into the socket 4a. Power is supplied to the light bulb-shaped lamp 1 via the socket
4a.
(Supplementary description of embodiment)
[0215] In the above embodiment, the cap part 62 is used as an example of an insulating component
between the heat dissipation portion 46 and the drive circuit 50. However, the insulating
component may be achieved using a component other than the cap part 62.
[0216] For example, an insulating component between the heat dissipation portion 46 and
the drive circuit 50 may be achieved by using a resin layer obtained by applying a
resin onto the back surface 40b of the mounting 40.
[0217] In addition, although the COB structure in which an LED chip is directly mounted
on the board 21 as a light-emitting element is employed for the LED module 20 in the
above embodiment, the present invention is not limit to this.
[0218] For example, as a light-emitting element, a packaged LED element (surface mount (SMD)
LED element) may be employed which includes a resin container having a recess (cavity),
an LED chip mounted in the recess, and a sealing component (fluorescent substance
containing resin) enclosed in the recess. In other words, the light bulb-shaped lamp
1 may include the SMD LED module 20 which includes plural such LED elements on the
board 21 where the metal lines are formed.
[0219] In addition, although a single white substrate is used as the board 21 of the LED
module 20 in the above embodiment, the back surfaces of two white substrates each
having a surface on which the LEDs 22 and the sealing components 23 are formed may
be attached to each other, thereby forming one LED module 20.
[0220] In addition, the LED module 20 emits white light by using a blue LED chip and a yellow
fluorescent substance in the above embodiment, the present invention is not limited
to this. For example, in order to increase color rendering properties, a red fluorescent
material and a green fluorescent material may be further mixed, in addition to a yellow
fluorescent material. Furthermore, rather than using a yellow fluorescent material,
a fluorescent material containing resin which contains a red fluorescent material
and a green fluorescent material may be used and combined with a blue LED chip, thereby
achieving a structure for emitting white light.
[0221] In the above embodiment, an LED chip which emits light having a color other than
blue may be used as the above-descried LED chip. For example, if an LED chip which
emits ultraviolet light is used, a combination of color fluorescent particles which
emit light of three primary colors (red, green, and blue) may be used as fluorescent
particles. Furthermore, a wavelength conversion material other than fluorescent particles
may be used, and for example, as a wavelength conversion material, a material including
a substance which absorbs light having a certain wavelength and emits light having
a wavelength different from the absorbed light may be used, such as a semiconductor,
a metal complex, an organic dye, or a pigment.
[0222] In addition, although an LED is used in the above embodiment as an example of a light-emitting
element, a semiconductor light-emitting element such as a semiconductor laser, a solid
light-emitting element such as an organic or inorganic electroluminescence (EL) element
may be used.
[0223] Although only some exemplary embodiments of the present invention have been described
in detail above, those skilled in the art will readily appreciate that many modifications
are possible in the exemplary embodiments without materially departing from the novel
teachings and advantages of the present invention. Accordingly, all such modifications
are intended to be included within the scope of the present invention.
[Reference Signs List]
[0224]
1 Light bulb-shaped lamp
2 Lighting apparatus
3 Light-up device
4 Device body
4a Socket
5 Lamp cover
10 Globe
11 Opening
20 LED module
21 Board
22 LED
23 Sealing component
24 Metal line
25 Wire
26a and 26b Terminal
27a, 27b, 65a, and 65b Insertion hole
30 Support
30a Male screw portion
40 Mounting
40a Main surface
40b Back surface
41 Small diameter portion
42 Large diameter portion
43 Through-hole
43a Female screw portion
44 Area
45 45a Pedestal
46 Heat Dissipation portion
47, 47a, 47b, 47c, and 47d Protrusion
48, 48a, and 48b Recess
50 Drive circuit
51 Circuit board
52 Circuit element
53a, 53b, 53c, and 53d Lead wire
60 Circuit case
61 Case body portion
61a First case portion
61b Second case portion
62 Cap part
64a Heat receiving portion
64b Heat receiving portion
64c Heat receiving portion
70 Heat sink
70a Opening
80 Outer case
90 Base
91 Shell part
92 Insulating part
93 Eyelet part
120 Caulking die