[Technical Field]
[0001] The present invention relates to an automotive lamp and, in particular, a structure
of a lamp installed at a rear part of a vehicle.
[Background Art]
[0002] Known in the art is a daylight running lamp (DRL) or clearance lamp that is lit up
in the daytime. DRL and clearance lamp are used for the purpose of having the drivers
of other vehicles and the pedestrians visually recognize the presence of a driver's
own vehicle in an accurate and clear manner. Such a lamp as DRL or clearance lamp
is often installed not only at a front part of the vehicle but also at a rear part
thereof. In order to improve the safety, it is required that the visibility of this
type of lamps be enhanced.
[0003] A vehicular indicator lamp described as follows is disclosed in Patent Document 1.
This vehicular indicator lamp has fan-shaped reflection regions where a group of linearly-arranged
bright parts, in which the size of each bright part is gradually increased radially
outward, are generated and where another group of linearly-arranged small bright parts,
in which these small bright parts having approximately equal size are arranged in
a chain-like form, are generated. This lamp having such the reflection regions causes
a glittering and lively-varied effect when the lamp is lit. As a result, the visibility
of the driver's own vehicle relative to a vehicle behind the driver's own vehicle
(hereinafter referred to as "following vehicle" also) is supposedly improved.
[Related Art Documents]
[Patent Documents]
[0004] [Patent Document 1] Japanese Patent Application Publication No.
2006-216455.
[Disclosure of Invention]
[Problems to be solved by the Invention]
[0005] A white transparent cover is generally mounted to the daytime running lamp or clearance
lamp. Since such a white transparent cover hardly absorbs the sunlight, the sunlight
enters the lamp and is reflected by a reflector p when the morning or evening sunlight
hits the lamp. Thus there is problem that it is not easy for the driver of the following
vehicle to recognize whether the light source of the lamp itself is lit or not. For
this reason, new regulations may possibly be formulated in the near future. Here,
the new regulations may so regulate that a predetermined difference in the brightness
between when the light source is turned off and when it is turned on can be ensured
when the automotive lamp is irradiated with the artificial sunlight.
[0006] The present invention has been made in view of the foregoing circumstances, and a
purpose thereof is to provide a technology that improves the visibility for a driver
of the following vehicle as to a lighting state of the light source of a lamp, when
the sunlight hits the lamp installed at a rear part of the vehicle.
[Means for Solving the Problem]
[0007] In order to resolve the above-described problems, an automotive lamp according to
one embodiment of the present invention includes: a light source; a transparent cover,
placed in front of the light source, through which light emitted from the light source
passes; and a reflection structure that reflects at least part of light in a direction
excluding a predetermined range of angles including an optical axis of the light source,
wherein the at least part of light enters the automotive lamp through the transparent
cover from above at a predetermined angle relative to a horizontal line.
[0008] According to this embodiment, the reflection structure reflects a part of light,
which enters the automotive lamp, in the direction excluding the predetermined range
of angles including the optical axis of the light source. Provision of this reflection
structure reduces an area where the sunlight reflected inside the lamp and the light
emitted from the light source overlap with each other. This allows the lighting state
of the light source to be easily determined. Note that the "predetermined range of
angles" may be a range of light that can directly enter the eyes of the driver of
the following vehicle, for instance.
[Advantageous Effects]
[0009] The present invention improves the visibility for a driver of the following vehicle
as to a lighting state of the light source of a lamp, when the sunlight hits the lamp
installed at a rear part of the vehicle.
[Brief Description of Drawings]
[0010]
FIG. 1 schematically shows a cross-sectional view of an automotive lamp according
to a first exemplary embodiment;
FIG. 2 schematically shows a cross-sectional view of an automotive lamp according
to a second exemplary embodiment;
FIG. 3 schematically shows a cross-sectional view of an automotive lamp according
to a third exemplary embodiment;
FIG. 4 schematically shows a cross-sectional view of an automotive lamp according
to a fourth exemplary embodiment;
FIG. 5 schematically shows a cross-sectional view of an automotive lamp according
to a fifth exemplary embodiment;
FIG. 6 schematically shows a cross-sectional view of an automotive lamp according
to a sixth exemplary embodiment;
FIG. 7 schematically shows a cross-sectional view of an automotive lamp according
to a seventh exemplary embodiment;
FIG. 8 schematically shows a cross-sectional view of an automotive lamp according
to an eighth exemplary embodiment;
FIG. 9 schematically shows a cross-sectional view of an automotive lamp according
to a ninth exemplary embodiment; and
FIG. 10 schematically shows a cross-sectional view of an automotive lamp according
to a tenth exemplary embodiment.
[Modes for Carrying Out the Invention]
First Embodiment
[0011] A first exemplary embodiment of the present invention is characterized by a feature
wherein a light shielding structure is provided in a lamp and whereby the visibility
of the lamp when the lamp is lit is improved. Specifically, the light shielding structure
is a structure that reduces an amount of irradiated light, which has reached a light
source of the lamp, in the sunlight entering the lamp through a transparent cover
from above at a predetermined angle relative to a horizontal line.
[0012] FIG. 1 is a schematically illustrated cross-sectional view of an automotive lamp
10, according to a first exemplary embodiment, cut along a vertical plane including
an optical axis. The automotive lamp 10 is installed at a rear part of a vehicle,
and the leftward direction (part) in FIG. 1 corresponds to a rearward or rear part
of the vehicle. The automotive lamp 10 is a daytime running lamp (DRL) or a clearance
lamp (CLL), for instance.
[0013] In the automotive lamp 10, a lamp chamber 15 is formed by a lamp body 13, having
an opening in a direction toward the rear of the vehicle, and a transparent cover
12, made of white transparent resin, which is so disposed as to cover the opening.
A plurality of light sources 16 mounted on a substrate 14 are provided inside the
lamp chamber 15. The light sources 16 are each constituted by a semiconductor light-emitting
element such as a light emitting diode (LED). An inner lens 18 made of resin having
translucency is placed adjacent to the substrate 14. Lens portions 19 for controlling
the distribution of light emitted from the light sources 16 (e.g., for refracting
or diffusing the light) are formed in partial areas of the inner lens 18; the partial
areas thereof face the light emission surfaces of the light sources 16, respectively.
The light emitted from the light sources 16, which has been subjected to the light
distribution control performed by the lens portions 19, transmits the transparent
cover 12 and is irradiated in a rearward area of the vehicle.
[0014] A plurality of extensions 2, 4 and 6 having non-translucency are disposed between
the transparent cover 12 and the inner lens 18. The extensions 2, 4 and 6 have a role
to block the light entering the lamp from above at a predetermined angle α relative
to the horizontal line so that this light entering the lamp does not directly hit
the light sources 16. Note here that the light entering the lamp from above at the
predetermined angle α relative thereto is indicated by solid arrows in FIG. 1. For
example, the angle α is set according to the angle of the morning or evening sunlight
formed relative to the horizontal line, when it is especially hard to see the emission
of light from the light sources in the automotive lamps, due to the reflected light
of sun, for instance. And the angle α is preferably set at 10 to 15 degrees. For this
purpose, the extensions 2, 4 and 6 have extending sections 2a, 4a and 6a, respectively,
which extend from near the inner lens 18 toward the transparent cover 12 up to the
positions where the extensions 2, 4 and 6 intersect respectively with lines extending
upward from the light sources 16 by the predetermined angle α. Note here that the
lines extending upward therefrom by the predetermined angle α is indicated by dotted
lines in FIG. 1.
[0015] The extensions 2, 4 and 6 that extend between the transparent cover 12 and the inner
lens 18 are provided in the automotive lamp 10 according to the first exemplary embodiment.
Provision of the extensions 2, 4 and 6 therebetween can reduce the amount of irradiated
light, which has reached near the light sources 16, in the sunlight entering the lamp
through the transparent cover from above at the predetermined angle relative to the
horizontal line. Thus, the sunlight reflected by the inner lens and the like does
not overlap with the light emitted from the light sources 16. This allows the driver
of the following vehicle to easily determine the lighting state of the light sources.
[0016] FIG. 2 is a schematically illustrated cross-sectional view of an automotive lamp
20, according to a second exemplary embodiment, cut along a vertical plane including
an optical axis. Some of the components and constituent members shown in FIG. 2 to
FIG. 10 have the reference numbers identical to those of FIG. 1. This indicates that
those in FIG. 2 to FIG. 10 identical to those of FIG. 1 have similar structures and
functions to those of FIG. 1, and the repeated description thereof will be omitted.
[0017] The automotive lamp 20 according to the second exemplary embodiment is configured
such that the substrate 14, on which the light sources 16 are mounted, and the inner
lens 22 are provided inside the lamp chamber 15, similarly to the first exemplary
embodiment, but such that the non-translucent extensions are not provided therein.
Instead, a non-translucent coating material is applied to side surfaces of the inner
lens 22, facing the transparent cover 12, except for the side surfaces thereof corresponding
to lens portions 24 located near the line of intersections intersecting with optical
axes Ax that pass through the respective light sources 16 and extend in an approximately
horizontal direction. Applying the coating material to the side surfaces thereof reduces
the amount of irradiated light, which has reached near the light sources 16, in the
sunlight entering the lamp through the transparent cover from above at a predetermined
angle relative to the horizontal line. This therefore reduces an area where the sunlight
reflected by the inner lens and the like and the light emitted from the light sources
overlap with each other. Hence, the driver of the following vehicle easily determines
the lighting state of the light sources.
[0018] FIG. 3 is a schematically illustrated cross-sectional view of an automotive lamp
30, according to a third exemplary embodiment, cut along a vertical plane including
an optical axis. In the third exemplary embodiment, extensions 32, 34 and 36 are disposed
between the transparent cover 12 and the inner lens 18, similarly to the first exemplary
embodiment. However, the extensions 32, 34 and 36 do not extend toward the transparent
cover 12, and merely form openings near the line of intersections intersecting with
the optical axes Ax that pass through the respective light sources 16 and extend in
an approximately horizontal direction. The extensions 32, 34 and 36 can reduce the
amount of irradiated light, which has reached the light sources 16, in the sunlight
entering the lamp through the transparent cover from above at a predetermined angle
relative to the horizontal line. This therefore reduces an area where the sunlight
reflected by the inner lens and the like and the light emitted from the light sources
overlap with each other. Hence, the driver of the following vehicle easily determines
the lighting state of the light sources.
[0019] Note that the extensions in the first or third exemplary embodiment may be such that
the natural colored resin constituting the extensions is used as it is or such that
a coating for suppressing reflection may be applied thereto.
[0020] FIG. 4 is a schematically illustrated cross-sectional view of an automotive lamp
40, according to a fourth exemplary embodiment, cut along a vertical plane including
an optical axis. In the fourth exemplary embodiment, a bulb 42, such as a halogen
lamp or discharge lamp, which has a certain depth as compared with the LED is used
as the light source.
[0021] A reflector 44 is arranged in the lamp chamber 15. In the reflector 44, a reflecting
surface by which the light, emitted from the bulb 42, is reflected toward a direction
opposite to the bulb 42 (namely, toward a rearward area of the vehicle), is formed
in the inner surface of the reflector 44. The reflecting surface of the reflector
44 is formed as an approximately rotated-parabolic curved surface with the optical
axis Ax as the central axis, and the luminous point of the bulb 42 is located on the
focal point of the rotated-parabolic curved surface.
[0022] An upper wall side of the reflector 44 has an extending section 44a. The extending
section 44a extends toward the transparent cover 12 up to a position where the upper
wall side thereof intersects with a line extending upward from the luminous point
of the bulb 42 by a predetermined angle α. Note here that the line extending upward
therefrom by the predetermined angle α is indicated by dotted lines in FIG. 4. The
extending section 44a can reduce the amount of sunlight entering the reflector 44
through the transparent cover from above at the predetermined angle relative to the
horizontal line.
[0023] A non-translucent member having light shielding parts 46 where a plurality of slits
48 are formed may further be arranged on the opening side of the reflector 44. In
this case, the reflecting surface of the reflector 44 is configured such that the
light emitted from the bulb 42 is reflected toward the slits 48 and such that the
sunlight entering the reflector is reflected toward the light shielding parts 46.
Thus, the sunlight reflected by the reflector is not emitted toward a rearward area
of the vehicle while the light emitted from the bulb 42 passes through the slits and
is irradiated in the rearward area thereof.
[0024] According to the fourth embodiment, as described above, the amount of sunlight entering
the reflector 44 is reduced, and the sunlight reflected by the reflecting surface
of the reflector 44 is not emitted toward the rearward area of the vehicle. Thus,
an area where the sunlight and the light emitted from the bulb overlap with each other
is reduced. Thereby, the driver of the following vehicle easily determines the lighting
state of the light sources.
[0025] FIG. 5 is a schematically illustrated cross-sectional view of an automotive lamp
50, according to a fifth exemplary embodiment, cut along a vertical plane including
an optical axis. In the fifth exemplary embodiment, a bulb 42 and a reflector 54 are
arranged in the lamp chamber 15, similarly to FIG. 4. A diffusion structure 56 (e.g.,
embossment, knurling) is formed in a partial area of the reflecting surface, inside
the reflector 54, where the sunlight entering the reflector 54 is reflected. The diffusion
structure diffuses the reflected light in directions excluding the direction in which
to enter the eyes of the driver of the following vehicle. Thus, an area where the
light, emitted from the bulb, and the reflected light of the sunlight overlap with
each other is reduced. Thereby, the driver of the following vehicle easily determines
the lighting state of the light sources.
Second Embodiment
[0026] A second exemplary embodiment of the present invention is characterized by a feature
wherein a light shielding structure is provided in a lamp and whereby the visibility
of the lamp when the lamp is lit is improved. Specifically, the reflection structure
is a structure that reflects at least part of light in directions excluding a predetermined
range of angles including an optical axis of the light source; the at least part of
light enters the lamp through the transparent cover from above at a predetermined
angle relative to the horizontal line.
[0027] FIG. 6 is a schematically illustrated cross-sectional view of an automotive lamp
60, according to a sixth exemplary embodiment, cut along a vertical plane including
an optical axis.
[0028] In the automotive lamp 60, a lamp chamber 15 is formed by a lamp body 13, having
an opening in a direction toward the rear of the vehicle, and a transparent cover
12, made of white transparent resin, which is so disposed as to cover the opening.
A plurality of light sources 16 mounted on a substrate 62 having a step or steps are
provided inside the lamp chamber 15. The light sources 16 are each constituted by
a semiconductor light-emitting element such as a light emitting diode (LED). An inner
lens 64 made of resin having translucency is placed adjacent to the substrate 62.
Lens portions 66 for controlling the distribution of light emitted from the light
sources (e.g., for refracting or diffusing the light) are formed in partial areas
of the inner lens 64; the partial areas thereof face the light emission surfaces of
the light sources 16, respectively. The light emitted from the light sources 16, which
has been subjected to the light distribution control performed by the lens portions
66, transmits the transparent cover 12 and is irradiated in a rearward area of the
vehicle.
[0029] Adjacent lens portions 66 of the inner lens 64 are connected by a reflective member
68. The reflective member 68 is tilted such that the reflective member 68 is positioned
approximately vertical with respect to a direction of light entering the lamp through
the transparent cover from above at a predetermined angle α relative to the horizontal
line (this direction of light entering the lamp being indicated by solid arrows in
FIG. 6). For example, the angle α is set according to the angle of the morning or
evening sunlight formed relative to the horizontal line, when it is especially hard
to see the emission of light in the automotive lamps, due to the reflected light of
sun, for instance. The angle α is preferably set at 10 to 15 degrees. The reflective
member 68 reflects the sunlight, which enters the lamp, in a direction approximately
identical to the incident direction. Thus, the sunlight reflected by the inner lens
64 does not overlap with the light emitted from the light sources 16. This allows
the driver of the following vehicle to easily determine the lighting state of the
light sources.
[0030] The angle of the reflective member 68 is not limited to the direction approximately
identical to the direction of light entering the lamp and may be an arbitrary angle
as long as it is an angle at which the sunlight is reflected in directions excluding
a predetermined range β of angles that can directly enter the eyes of the driver of
the following vehicle. The predetermined range β of angles is, for example, 15 degrees
above or below the optical axis Ax of the light source.
[0031] FIG. 7 is a schematically illustrated cross-sectional view of an automotive lamp
70, according to a seventh exemplary embodiment, cut along a vertical plane including
an optical axis.
[0032] In the seventh exemplary embodiment, extensions 72 are provided in addition to the
substrate 62, on which the light sources 16 are mounted, and the inner lens 64. More
specifically, the extensions 72 are placed in close proximity to parts of the inner
lens 64 excluding the lens portions 66. Each extension 72 is tilted such that the
extension 72 is positioned approximately vertical with respect to a direction of light
entering the lamp through the transparent cover from above at a predetermined angle
α relative to the horizontal line (this direction being indicated by solid arrows
in FIG. 7). And the reflecting surface of the extension 72 is formed on a transparent
cover 12 side. The reflecting surface thereof is formed by aluminum evaporation or
a like processing, for instance, and the reflecting surface thereof reflects the sunlight,
which enters the lamp, in a direction approximately identical to the incident direction.
Thus, the sunlight reflected by the reflecting surfaces of the extensions 72 does
not overlap with the light emitted from the light sources 16. This allows the driver
of the following vehicle to easily determine the lighting state of the light sources.
[0033] FIG. 8 is a schematically illustrated cross-sectional view of an automotive lamp
80, according to an eighth exemplary embodiment, cut along a vertical plane including
an optical axis. In the eighth exemplary embodiment, a plurality of light sources
16, mounted on a flat substrate 14, and an inner lens 82, made of resin having translucency,
which is placed adjacent to the substrate 14 are arranged inside the lamp chamber
15. Lens portions 84 for controlling the distribution of light emitted from the light
sources 16 (e.g., for refracting or diffusing the light) are formed in partial areas
of the inner lens 82; the partial areas thereof face the light emission surfaces of
the light sources 16, respectively. The light emitted from the light sources 16, which
has been subjected to the light distribution control performed by the lens portions
84, transmits the transparent cover 12 and is irradiated in a rearward area of the
vehicle.
[0034] Many small steps 86 are formed on a surface of the inner lens 82, on the light source
side thereof, excluding the partial areas of the inner lens 82 where the lens portions
84 are formed. The small steps formed thereon are so designed that the light, which
enters the lamp from above at a predetermined angle α relative to the horizontal line
and then enters the inner lens 82, is reflected in directions excluding the aforementioned
predetermined range β of angles. Thereby, the internally reflected light of the sunlight
entering the inner lens 82 does not overlap with the light emitted from the light
sources 16. This allows the driver of the following vehicle to easily determine the
lighting state of the light sources.
[0035] FIG. 9 is a schematically illustrated cross-sectional view of an automotive lamp
90, according to a ninth exemplary embodiment, cut along a vertical plane including
an optical axis. In the ninth exemplary embodiment, the bulb 42, such as a halogen
lamp or discharge lamp, which has a certain depth as compared with the LED is used
as the light source.
[0036] A reflector 92 is arranged in the lamp chamber 15. In the reflector 92, a reflecting
surface by which the light, emitted from the bulb 42, is reflected toward a direction
opposite to the bulb 42 (namely, toward a rearward area of the vehicle), is formed
in the inner surface of the reflector 92. The reflecting surface of the reflector
92 is formed as an approximately rotated-parabolic curved surface with the optical
axis Ax as the central axis, and the luminous point of the bulb 42 is located on the
focal point of the rotated-parabolic curved surface.
[0037] A non-translucent member having reflecting surfaces 94 where a plurality of slits
96 are formed are arranged on the opening side of the reflector 92. Each reflecting
surface 94 is tilted such that the reflecting surface 94 is positioned approximately
vertical with respect to a direction of light entering the lamp through the transparent
cover from above at a predetermined angle α relative to the horizontal line (this
direction of light entering the lamp being indicated by solid arrows in FIG. 9). Each
reflecting surface 94 reflects the sunlight, which enters the lamp, in a direction
approximately identical to the incident direction. Also, the reflecting surface of
the reflector 92 is configured such that the light emitted from the bulb 42 is reflected
toward the slits 96. Thus, the sunlight reflected by the reflecting surfaces 94 does
not overlap with the light emitted from the bulb 42. This allows the driver of the
following vehicle to easily determine the lighting state of the light sources.
[0038] FIG. 10 is a schematically illustrated cross-sectional view of an automotive lamp
100, according to a tenth exemplary embodiment, cut along a vertical plane including
an optical axis.
[0039] In the tenth exemplary embodiment, an extension 104 is placed between a light source
102 and a transparent cover 12. The extension 103 has a recess 108 in a central part
of a curved surface, which is constituted by two convex curved surfaces 106a and 106b
on a transparent cover 12 side. And the light source 102 is arranged in a hole 108a
formed in a center of the recess 108. Reflecting surfaces are formed on the transparent
cover 12 side of the extension 104 by subjecting the surfaces to aluminum evaporation
or a like processing, for instance. The light emitted from the light source 102 is
irradiated frontward from the recess 108 and it is observed that the area, only covering
the light source 102 and the recess 108, emits light. Formation of the recess 108
reduces the amount of irradiated light, which has reached near the light source 102,
in the sunlight entering the lamp through the transparent cover from above at a predetermined
angle α relative to the horizontal line (this direction of sunlight entering the lamp
being indicated by solid arrows in FIG. 10).
[0040] The upper reflecting surface 106a of the extension 104 is formed in such a shape
that the sunlight entering the lamp is reflected upward. The lower reflecting surface
106b thereof is formed in such a shape that the sunlight entering the lamp is reflected
downward. Thus, the sunlight reflected by the reflecting surfaces of the extension
104 does not overlap with the light emitted from the light source 102. This allows
the driver of the following vehicle to easily determine the lighting state of the
light sources. The angle of light reflected by the upper reflecting surface 106a and
the lower reflecting surface 106b may be an arbitrary angle as long as it is an angle
at which the sunlight is reflected in directions excluding a predetermined range β
of angles that can directly enter the eyes of the driver of the following vehicle.
The predetermined range β of angles is, for example, 15 degrees above or below the
optical axis Ax of the light source.
[0041] As described above, the second embodiments provides a blocking structure or a reflection
structure. In other words, in the blocking structure, the sunlight entering the lamp
at a predetermined angle is blocked so that the sunlight does not directly hit the
light sources or nearby regions of the light sources. In the reflection structure,
the sunlight entering the lamp at a predetermined angle is reflected in directions
excluding a predetermined range of angles that can directly enter the eyes of the
driver of the following vehicle. As a result, even though the sunlight hits the automotive
lamps, the driver of the following vehicle easily determines the lighting state of
the light sources and therefore the overall safety is improved.
[0042] The present invention is not limited to the above-described embodiments only, and
it is understood by those skilled in the art that changes in design may be added to
the embodiments based on their knowledge. The structure shown for each Figure is for
illustrative purposes only and may be changed, as appropriate, as long as the similar
functions can be attained and the similar advantageous effects can also be achieved.
[0043] In each of the above exemplary embodiments, components may be arbitrarily combined
and used in between any of the exemplary embodiments as long as they do not contradict
with each other in function as well as in structure.
[0044] In each of the above-described exemplary embodiments, the transparent cover may be
a smoked lens instead of the white transparent one. In such a case, the reflected
amount of sunlight can be reduced.
[Explanation of Reference Numerals]
[0045]
2, 4, 6, 32, 72 Extension
2a, 4a, 6a, 44a Extending section
10, 20, 30, 40, 50, 60, 70, 80, 90 100 Automotive lamp
12 Transparent cover
16 Light source
18, 22 64, 82 Inner lens
42 Bulb
44, 54, 92 Reflector
46 Light shielding part
48, 96 Slit
68, 94, 106a, 106b Reflective member
86 Steps
[Industrial Applicability]
[0046] The present invention improves the visibility for a driver of the following vehicle
as to a lighting state of the light source of a lamp, when the sunlight hits the lamp
installed at a rear part of the vehicle.