Background of the Invention
[0001] The present invention relates to a luminescent signboard such as a traffic signboard
which is operable to emit light from a character portion or a frame portion surrounding
the character portion so as to permit recognition of the character portion in the
nighttime.
[0002] There has been proposed a luminescent traffic signboard which permits a bicycle rider,
a motorcycle rider, an automobile driver, or a pedestrian to recognize the sign even
after sunset.
[0003] A conventional luminescent traffic signboard includes a planar light emitter such
as an electroluminescence emitter which is mounted on substantially the whole surface
of the signboard and which is operable to emit light after sunset. Acharacter portion
including characters such as "STOP" and a frame portion surrounding the character
portion are drawn on a transparent plate such as an acrylic plate superposed on the
planar light emitter, so that they can be contrasted when the light emitter emits
light.
[0004] With the conventional luminescent traffic signboard, although the planar light emitter
emits light during sunset, its light emitting condition is unchanged, so that it is
difficult for an automobile driver, a motorcycle rider, a bicycle rider, or a pedestrian
to distinctly visually recognize the characters or sign.
[0005] It is, accordingly, an object of the present invention to provide a luminescent signboard
having a luminescent display which can be distinctly visually recognized by a person
such as an automobile driver, a motorcycle rider, a bicycle rider or a pedestrian.
[0006] According to the present invention, there is provided a luminescent signboard comprising;
a base plate;
a first light emitter disposed on the base plate and having a configuration corresponding
to a predetermined sign;
a second light emitter disposed on the base plate at a different position from the
first light emitter;
a sunset sensor operable to detect sunset;
a proximity sensor operable to detect an object ora person which or who has come to
a position within a predetermined distance from the signboard;
a power source for supplying power to the first and second light emitters, the sunset
sensor and the proximity sensor; and
a control unit operable to connect the power source to the second light emitter so
as to permit emission of light therefrom when the sunset sensor detects sunset, the
control unit being operable to connect the power source to the first light emitter
so as to permit emission of light therefrom when the proximity sensor detects an object
or a person during detection of sunset by the sunset sensor.
[0007] The invention will become more fully apparent from the claims and the description
as it proceeds in connection with the drawings. The embodiments shown in the drawings
and described in detail are given by way of example only.
FIG. 1 (A) is a front view of the whole signboard according to an embodiment of the
present invention;
FIG. 1 (B) is a side view of FIG. 1 (A);
FIG. 2 is an exploded perspective view of a signboard panel of the signboard;
FIG. 3 is a block diagram of a control circuit of the signboard;
FIGS. 4(A) and 4(B) are view similar to FIGS. 1 (A) and 1 (B), respectively, but showing
a modification of the embodiment;
FIGS. 5(A) and 5(B) are view similar to FIGS. 1 (A) and 1 (B), respectively, but showing
another modification of the embodiment; and
FIGS. 6(A) and 6(B) are view similar to FIGS. 1 (A) and 1 (B), respectively, but showing
a further modification of the embodiment.
[0008] Referring to the drawings and to FIGS. 1 (A) and 1 (B) in particular, there is shown
a front view of a luminescent signboard 1 which is a traffic signboard for temporary
stop. As shown therein, the signboard 1 includes a pole 2 fixed to the ground (not
shown) and extending upwardly therefrom. A signboard panel 3 having an inverted triangular
configuration is mounted on the upper end of the pole 2. A solar battery 4 chargeable
by sunlight, a proximity sensor 5 and a sunset sensor 6 are mounted on the upper portion
of the signboard panel 3. The proximity sensor 5 is sensitive to thermal changes and
is operable to output an approach detection signal through detection of an automobile,
a motorcycle, a bicycle or a pedestrian when it or he or she has come to a position
within a predetermined distance from the signboard 1. The sunset sensor 6 is operable
to output a sunset detection signal upon detection of sunset. A control unit 15 is
mounted on the rear surface of the signboard panel 3.
[0009] As shown in FIG. 2, the signboard panel 3 includes a base plate 7 made of aluminum
and fixed to the pole 2, a cushion sheet 8 made of resilient material and adhered
to the front surface of the base plate 7, a first and a second planar light emitter
9A and 9B each comprising a long-life electroluminescence emitter and adhered to the
surface of the cushion sheet 8. The first light emitter 9A has a configuration corresponding
to characters "STOP", while the second light emitter 9B has a configuration corresponding
to an inverted triangular frame line. A plurality of light emitting diodes 10 are
disposed along the inner peripheral edge of the second planar light emitter 9B and
are equally spaced from each other. The first and second light emitters 9Aand 9B and
the light emitting diodes 10 are covered by a transparent cover plate 11 made of acrylic
resin. The signboard panel 3 further includes an opaline backing plate 12 made of
polycarbonate and having an extra weather-resistance, a high-intensity reflection
sheet 13 adhered to the backing plate 12 so as to cover the same by the whole area
thereof excluding an area corresponding to the characters "STOP" and the inverted
triangular frame line or the first and the second light emitters 9A and 9B. An outer
peripheral trim 14 made of synthetic resin is fitted on the peripheral portion of
an assembly including the base plate 7, the cushion sheet 8, the transparent cover
plate 11 and the backing plate 12 on which the reflection sheet 13 is attached, so
that these parts of the assembly are fixed together by the trim 14.
[0010] As shown in FIG. 3, the control unit 15 is connected to the solar battery 4 as a
power source of the circuit, the proximity sensor 5, the sunset sensor 6 and the planer
light emitters 9Aand 9B (the long-life elec- troluminescences) corresponding to the
characters "STOP" and the inverted triangular frame line, respectively, and the light
emitting diodes 10.
[0011] The operation of the control unit 15 will now be explained. When the sunset sensor
6 outputs a sunset detecting signal upon detection of sunset, the control units 10
energizes the light emitting diodes 10, so that flashing light is emitted from the
light emitting diodes 10, permitting recognition in the nighttime of the presence
of the signboard 1 by an automobile driver, a bicycle rider, a motorcycle rider, or
a pedestrian who is located away from the signboard 1. When an automobile, a bicycle,
a motorcycle or a pedestrian approaches the signboard 1 to reach the position for
detection by the proximity sensor 5, the proximity sensor 5 outputs the detection
signal which is Inputted to the control unit 15. Then, the control unit 15 energizes
the planar light emitters 9Aand 9B (the long-life elec- troluminescences) corresponding
to the characters "STOP" and the inverted triangular frame line, respectively, so
that the planar light emitters 9Aand 9B emit light. Thus, the automobile driver, the
bicycle rider, the motorcycle rider or the pedestrian may find, while exhibiting a
surprise to some extent, the display of the characters "STOP" which have suddenly
appeared. Therefore, the sign represented by the characters can be effectively recognized,
resulting in contribution to the safety of traffic.
[0012] When the sun rises, the sunset sensor 6 terminates to output the sunset detecting
signal, so that the light emitting diodes 10 are put out by the control unit 15 and
that no more light is emitted from the planar light emitters 9A and 9B even if the
detecting signal is outputted from the proximity sensor 5. Thus, the planar light
emitters 9A and 9B emit light during detection of sunset by the sunset sensor 6.
[0013] Referring to FIGS. 4(A) and 4(B), FIGS. 5(A) and 5(B) and FIGS. 6(A) and 6(B) corresponding
to FIG. 1 (A) and 1 (B), respectively, there are shown various modifications of the
signboard 1 of the above embodiment.
[0014] In the modification shown in FIGS. 4(A) and 4(B), the signboard panel 3 has a box-like
configuration and is formed integrally with the control unit 15. The solar battery
4 is mounted on the rear side of the signboard panel 3 or the control unit 15.
[0015] In the modification shown in FIGS. 5(A) and 5(B), the signboard panel 3 has an enlarged
thin box-like configuration.
[0016] In the modification shown in FIGS. 6(A) and 6(B), the signboard panel 3 has an enlarged
box-like configuration and is formed integrally with the control unit 15. The solar
battery 4 is mounted on the rear side of the signboard panel 3 or the control unit
15.
1. A luminescent signboard comprising;
a base plate;
a first light emitting means disposed on said base plate and having a configuration
corresponding to a predetermined sign;
a second light emitting means disposed on said base plate at a different position
from said first light emitting means;
sunset sensor means operable to detect sunset;
proximity sensor means operable to detect an object or a person which or who has come
to a position within a predetermined distance from the signboard;
a power source for supplying power to said first and second light emitting means,
said sunset sensor means and said proximity sensor means; and
control means operable to connect said power source to said second light emitting
means so as to permit emission of the light therefrom when said sunset sensor means
detects sunset, said control means being operable to connect said power source to
said first light emitting means so as to permit emission of light therefrom when said
proximity sensor means detects an object or a person during detection of sunset by
said sunset sensor means.
2. The luminescent signboard as defined in claim 1 wherein said first light emitting
means includes a planer light emitter and wherein said second light emitting means
includes a flickering light emitter.
3. The luminescent signboard as defined in claim 2 wherein a plurality of said flickering
light emitters are disposed along the peripheral portion of said base plate and are
substantially equally spaced from each other.
4. The luminescent signboard as defined in claim 1 wherein said power source is a
battery chargeable by sunlight.
5. The luminescent signboard as defined in claim 1 and further including a plate made
of weather-resistant polycarbonate so as to cover said base plate and said first and
second light emitting means, and including a high-intensity reflection sheet attached
to said backing plate and having said predetermined sign drawn thereon.
6. The luminescent signboard as defined in claim 1 wherein said proximity sensor means
is sensitive to thermal changes.
7. The luminescent signboard as defined in claim 1 wherein said predetermined sign
includes a character portion and a frame portion surrounding said character portion.