JP2002132192A - Back light type display device for traffic sign - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a back light type display device for a traffic sign, whose power consumption is seduced, structure is simplified and weight is reduced. SOLUTION: In a back light type display device A for a traffic sign, light beams emitted by many LEDs 11 arranged on a bottom surface section 10b of a casing 10 pass a sign portion 10aa, a center portion 10ab and a peripheral portion 10ac which constitute a semitransparent top surface section 10 and clearly indicate a traffic sign. Many LEDs 11 consist of a white color LED group 11A which clearly shows the portion 10aa, a blue color LED group 11B which clearly shows the portion 10ab and a white color LED group 11C which clearly shows the portion 10ac. Light emitting colors of the LED groups 11A to 11C are same colors or a same group colors with those of the portions 10aa, 10ab and 10ac.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight-type display device for a road sign which is easily recognized even in a low illuminance environment such as at night.

[0002]

2. Description of the Related Art FIG. 5 is a front view and a side sectional view of a fluorescent lamp type road sign, and FIG. 6 is a side sectional view of an edge light type display device.

[0003] Backlights are used in various industrial fields to facilitate display in low-illuminance environments such as indoors with dark lighting and outdoors after sunset. Also, there are various methods. For example, there is a notebook computer backlight that has been rapidly spreading in recent years. In this method, a thin surface light source is arranged on the back side of a liquid crystal display device so that the liquid crystal screen of a personal computer can be easily viewed when the surroundings are dark.

[0004] The backlight technology currently used is called an edge light system, in which fine irregularities are provided on a transparent material substrate (light guide plate) of acrylic or the like, and light from a cold cathode tube or the like is projected from the side of the transparent material substrate. This is a technique of obtaining a uniform light emitting surface by scattering of minute irregularities introduced.

[0005] Backlights are also used in large display devices such as advertisement displays, warning displays, and guidance displays. The most typical ones are advertisements installed outdoors or inside railway stations. Most of these have a fluorescent tube inside and a translucent sheet attached on the surface.

Further, with the maturation of the automobile society and the aging society in recent years, road signs (regulatory signs, warning signs, guide signs, etc.) have come to use light-emitting road signs. Most of them are also of a fluorescent lamp type. Fig. 5
As shown in (A) and (B), the fluorescent lamp 2 is disposed inside the housing 1, and is radiated from the fluorescent lamp 2, but passes through the semi-translucent substrate 3 to form the semi-transparent substrate 3. This is a display device in which the marker portion 4a of the front surface 4 is clearly indicated in white, and the rear portion 4b is clearly indicated in blue. However, this fluorescent lamp type display device has disadvantages such as large power consumption, large depth, and short life of the fluorescent lamp, and has prevented its spread.

On the other hand, a display device using a light source other than a fluorescent lamp is gradually being used. For example, road regulation signs or the like in which an electroluminescence (hereinafter, referred to as EL) panel is incorporated on the back surface are actually used. For example, there is a solar stop sign. However, this display device has disadvantages such as insufficient brightness, short EL life, and relatively large power consumption. For this reason, this display device is devised to reduce power consumption by emitting light only in part of the display (stop characters), blinking the display, and shortening the light time. As a result, the display is easy to see (visibility). Has difficulties.

[0008]

In order to reduce the power consumption of the display device, an edge light type display device using a light emitting diode (hereinafter, referred to as an LED) as a light source has been proposed. That is, the edge light type display device is
As shown in FIG. 6, the LEDs 6 are arranged in an array along the edge 5a of a transparent material substrate (light guide plate) 5 such as acrylic, and fine irregularities 5b are provided on the light guide plate 5, and the light 6a of the LED 6 from the edge 5a side. Is introduced, and the light is transmitted through the diffusion plate 8 by scattering of the minute unevenness 5b and reflection of the reflection plate 7 to obtain a uniform light emitting surface on the surface.

However, in the edge light type display device, since the light 6a of the LED 6 is repeatedly scattered and reflected in the light guide plate 5, a large loss of luminous energy is transmitted to the display surface side 8a of the diffusion plate 8. Therefore, the power consumption is not sufficiently low. Further, since the light guide plate 5 is used, there is a disadvantage that the apparatus becomes heavy.

Accordingly, the present invention provides a display device, wherein light emitted from a large number of LEDs disposed on the bottom surface of a display device housing is provided with a sign portion and a central portion constituting a semi-transparent display plate provided above the bottom surface. A road sign backlight type display device that specifies a predetermined road sign by passing through a peripheral portion, wherein the plurality of LEDs include a first LED group for specifying the sign portion, The first LED group, the second LED group, and the third LED group include a second LED group for specifying a central portion and a third LED group for specifying the peripheral portion. Each light emission color of the group is the same color or similar color as each color of the marker part, the center part, and the peripheral part, so that it is low power consumption, the structure is simple, and the weight can be further reduced. Road sign bag And to provide a write-type display device.

[0011]

In order to solve the above-mentioned problems, the present invention provides a backlight type display device for a road sign having the following constitutions (1) to (4). (1) As shown in FIG. 1, light emitted from a large number of LEDs 11 disposed on the bottom surface (bottom portion 10b) of the display device housing 10 emits a semi-transparent display provided above the bottom surface 10b. A backlight type display device A for a road sign that specifies a predetermined road sign by transmitting a sign portion 10aa, a center portion 10ab, and a peripheral portion 10ac, respectively, which constitute a plate (upper surface portion 10a). LED
Reference numeral 11 denotes a first LED group (white LED group 11A) for specifying the marker portion 10aa, and the central portion 10aa.
The second LED group (blue LED group 1
1B) and a third for clearly indicating the peripheral portion 10ac.
LED group (white LED group 11C), and each emission color (white, blue, white) of the first LED group 11A, the second LED group 11B, and the third LED group 11C.
Are the marker portion 10aa and the central portion 10a, respectively.
ab, a backlight type display device for a road sign, which is the same color or a similar color to each color (white, blue, white) of the peripheral portion 10ac. (2) As shown in FIG. 2, the white LED group 11A,
The blue LED group 11B and the white LED group 11C
Each of the LEs is configured by using a large number of LED sets (units) each including a predetermined number (three) of LEDs a to c, and the light emission luminances of all the LED sets are uniform.
The backlight type display device for a road sign according to claim 1, further comprising adjusting means (adjusting resistor r) for adjusting a drive current supplied to each of the sets D. (3) As shown in FIG. 3, the first LED group (white LED group 11A), the second LED group (blue LED group 11B), and the third LED group (white LED group 11A).
C) to control blinking or lighting (timing generation circuits 12A to 12C, LED drive circuits 13A to 13C, respectively)
The backlight type display device for a road sign according to claim 1 or 2, further comprising control means (comprising C). (4) As shown in FIG. 4, a highly reflective or scattering light-shielding plate 14 is provided at the boundary between the first LED group (white LED group 11A) and the second LED group (blue LED group 11B).
The backlight type display device for a road sign according to any one of claims 1 to 3, wherein the display device is arranged.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is a front view of a backlight type display device for a road sign according to a first embodiment of the present invention, and a diagram for explaining the arrangement of rear LEDs, and FIG. 2 is a diagram showing a driving circuit of the LEDs shown in FIG. FIG. 3 is a block diagram of a light emission control circuit of the LED shown in FIG. 1, and FIG. 4 is a diagram showing a rear LED arrangement and a light shielding plate mounting state of a road sign backlight type display device according to a second embodiment of the present invention. It is a figure for explaining.

[0013] The backlight type display device for a road sign according to the first embodiment of the present invention will be specifically described by taking a case where a road regulation sign is used as a prohibition sign outside a designated direction. The backlight type display device A for road sign is shown in FIG.
As shown in the figure, the top part 10a, the bottom part 10b, and the side part 1
0c, blue LED 11a, white LE
D11b and a large number of LEDs 11
It includes an LED drive device (resistor r (FIG. 3), timing generation circuits 12A to 12C, and LED drive circuits 13A to 13C (FIG. 4)) that drives D11 to emit light. The large number of LEDs 11 and the LED driving device are arranged at a position that does not hinder the display operation (for example, a predetermined position on the side surface portion 10c of the housing 10).

The upper surface portion 10a of the casing 10 is a semi-transparent display panel, and a white sign portion 10aa indicating a prohibition sign outside the designated direction and a blue central portion 10ab adjacent to the sign portion 10aa. And a white peripheral portion 10ac which is a peripheral portion of the central portion 10ab.

The bottom surface portion 10b of the casing 10 has a bottom surface portion 10da corresponding to the marker portion 10aa and a bottom surface portion 10db corresponding to the central portion 10ab.
And a bottom portion 10 corresponding to the peripheral portion 10ac described above.
dc.

The above-mentioned many LEDs 11 are arranged on the bottom surface 10da corresponding to the above-mentioned sign portions 10aa, and are arranged in a white LED group 11 consisting of only a large number of white LEDs 11b.
A, a blue LED group 11B arranged on the bottom portion 10db corresponding to the central portion 10ab described above and including only a large number of blue LEDs 11a, and a plurality of blue LEDs arranged on the bottom portion 10dc corresponding to the peripheral portion 10ac described above. White LED
And a white LED group 11C consisting of only 11b. The emission colors (white, blue, and white) of the white LED group 11A, the blue LED group 11B, and the white LED group 11C are respectively the above-described marker portion 10aa and the above-described central portion 1.
0ab, the same color or similar color as each color (white, blue, white) of the peripheral portion 10ac described above.

The light emission drive of the large number of LEDs 11 is as follows.
White LED group 11A, blue LED group 11B, white LED
For each group 11C, as shown in FIG.
A large number of units (LED sets) each having a series of c and a resistor r in series are prepared, and each unit is driven by a DC battery (for example, 12 V DC). Each of the resistors r is an adjusting resistor for equalizing the brightness of each unit (equalizing the emission luminance), and includes three LEDs.
The resistance value was determined so that there would be no difference in brightness for each of the LEDs a to c due to the difference in the luminance characteristics of a to c. The optimum resistance value of each resistor r was 10 ohms to several hundred ohms.

The above-mentioned white LED group 11A, blue LED
In the light emission driving for each of the group 11B and the white LED group 11C, the LEDs of each group are driven using the LED drive circuit of each group in the unit described above. In this example, an arrow at the center (white LED group 11A), a donut shape at the outer periphery (white LED group 11C), and other (blue LED group 11B) and three Ls
Connected using ED drive circuit, blue LED
The part of the group 11B is always lit, and the white LED groups 11A and 11
C performed a blinking operation (FIG. 5).

Specifically, the above-mentioned white LED group 11A which clearly shows the center arrow is constituted by using a large number of the above-mentioned units, and all the units are formed by the LED drive circuit 13A.
Driven by A. The LED drive circuit 13A is supplied with a timing signal for a blinking operation from the timing generation circuit 12A, and varies the blinking cycle (bright time) of the white LED group 11A. Similarly, the above-mentioned white LED group 11C indicating a donut shape on the outer periphery is configured using a large number of the above-described units, and all the units are driven by the LED drive circuit 13C. The LED drive circuit 13C outputs a timing signal for a blinking operation to the timing generation circuit 1
The cycle (bright time) of the blinking of the white LED group 11C supplied from 2C is varied.

The blue LED group 11B, which indicates the center arrow and the outer peripheral portion other than the donut shape, is constituted by using a large number of the units described above, and all the units are driven by the LED drive circuit 13B. A timing signal for a blinking operation is supplied from the timing generation circuit 12B to the preceding stage of the LED drive circuit 13B to vary the light time (blinking cycle) of the blue LED group 11B. White L as described above
The ED groups 11A and 11C and the blue LED group 11B have individual drive circuits and can independently change the brightness, the blinking cycle, and the light time. By doing so, the light emission luminance as a road sign was increased and the visibility was improved, so that an effect of alerting could be obtained.

Further, in the backlight type display device B for a road sign according to the second embodiment of the present invention, as shown in FIG. 4, the light of the blue LED 11a and the light of the white LED 11b are close to each other and emit light from the same position. More specifically, in order to minimize the occurrence of color blur visually, the white LED group 11A indicating the center arrow and the blue LED group 11B indicating the center arrow and the outer portion other than the donut shape are indicated.
A high-reflection material threshold (light-shielding plate 14) was attached to the boundary between the two. The other configuration is the same as that of the above-described backlight type display device for road sign A (FIG. 1).

In the above description, the case where the present invention is applied to an out-of-specified direction prohibition sign has been described as an embodiment of the present invention. However, the present invention is not limited to this and can be applied to all road signs. Needless to say. In this case, the colors of the respective portions (the sign portion 10aa, the central portion 10ab, and the peripheral portion 10ac) of the upper surface portion 10a of the housing 10 are, of course, colors that match the display colors of the road signs.

In the above description, the blue L
ED group 11B is always on, white LED groups 11A and 11C
Has described the case of performing the blinking operation, respectively. However, the present invention is not limited to this, and the white LED as the first LED group may be used as necessary according to the display form of the road sign to be applied. While the group 11A blinks or is always lit,
Of course, the blue LED group 11B, which is the second LED group, and the white LED group 11C, which is the third LED group, may be turned on or off at all times.

Further, in the above description, the case where the light shielding plate 14 is attached to the boundary between the white LED group 11A and the blue LED group 11B has been described. However, the present invention is not limited to this. If necessary, another light shielding plate 14 may be attached to the boundary between the blue LED group 11B and the white LED group 11C.

[0025]

As described in detail above, according to the present invention, there is provided a backlight type display device for a road sign which can reduce power consumption, has a simple structure, and can reduce the weight of the entire device. can do. In addition, each LED group of each color can blink and change the lighting state independently, so that various display expressions can be made as required, and it can correspond to various types of road signs, and the visibility as a road sign is also improved. Can be enhanced. Further, by providing a light-shielding plate as necessary at the boundary of the LED group of each color, it is possible to prevent mixing of luminescent colors around the sign portion, and to perform luminescent display of a road sign which is easy to see without color bleeding. it can.

[Brief description of the drawings]

FIG. 1 is a front view of a backlight type display device for a road sign according to a first embodiment of the present invention, and a diagram for explaining the arrangement of rear LEDs.

FIG. 2 is a diagram showing a driving circuit of an LED.

FIG. 3 is a block diagram of a light emission control circuit of the LED, and FIG. 4 is a diagram showing a light shielding plate.

FIG. 4 is a view for explaining an arrangement of rear LEDs and an attached state of a light shielding plate of a backlight type display device for a road sign according to a second embodiment of the present invention.

FIG. 5 is a front view and a side sectional view of a fluorescent light type road sign.

FIG. 6 is a side sectional view of an edge light type display device.

[Brief description of reference numerals]

 DESCRIPTION OF SYMBOLS 10 Case 10a Upper surface part (display board) 10aa Mark part 10ab Central part 10ac Peripheral part 10b Bottom part (bottom surface) 11 LED 11A White LED group (first LED group) 11B Blue LED group (second LED group) 11C White LED group (third LED group) 12A to 12C Timing generation circuit 13A to 13C LED drive circuit 14 Shield plate A Backlight type display device for road sign a to c LED r Resistance (adjustment means)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09G 3/32 F21Y 101: 02 // F21Y 101: 02 F21Q 3/00 C (72) Inventor Hiroyuki Uchiyama Kanagawa 3-12-12 Moriya-cho, Kanagawa-ku, Yokohama-shi, Japan F-term (reference) in JVC Co., Ltd. CC06 DC03 FA03

Claims (4)

[Claims] 1. A light emitted from a plurality of LEDs disposed on a bottom surface of a display device housing is provided on a sign portion, a center portion, and a peripheral portion constituting a semi-transparent display plate provided above the bottom surface. A road sign backlight type display device that specifies a predetermined road sign by transmitting light, respectively, wherein the plurality of LEDs include a first LED group for specifying the sign portion and the central portion. A second group of LEDs for indicating, and a third LE for indicating the peripheral portion.
Each of the first LED group, the second LED group, and the third LED group has the same color or the same color as each color of the marker portion, the central portion, and the peripheral portion. A backlight type display device for a road sign, which is a color. 2. The first LED group and the second LED
Group, the third LED group is an LED comprising a predetermined number of LEDs.
Each of the LED sets is configured using a large number of ED sets, and the emission brightness of all the LED sets is uniform.
The backlight type display device for a road sign according to claim 1, further comprising adjusting means for adjusting a driving current supplied to each of the LED sets. 3. The first LED group and the second LED
The backlight type display device for a road sign according to claim 1 or 2, further comprising a control unit that controls blinking or lighting of the group and the third LED group, respectively. 4. The first LED group and the second LED
The backlight type display device for a road sign according to any one of claims 1 to 3, wherein a high-reflection or scattering light-shielding plate is disposed at a boundary with the group.