JP2923688B2 - Display and display element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a display and a display element suitable for a security display such as a railway signal and a traffic signal, a road traffic information display, and the like.

<Prior Art> An example of a conventional display, for example, a traffic signal light, will be described with reference to FIG.

In a conventional traffic signal light, an incandescent lamp 3 serving as a light source is disposed at the center of a parabolic reflector 2 provided in a case 1 so that the light of the incandescent lamp 3 is projected to the front without any leakage. . In addition, a color filter 4 such as red, yellow, or blue, which also functions as a lens, is attached to the front opening of the case 1 so as to impart a color to the light emitted from the incandescent lamp 3.

<Problems to be Solved by the Invention> By the way, such a traffic signal light is generally installed such that the front surface of the light is directed perpendicular to the ground and the optical axis of the light source is substantially parallel to the ground. For this reason, the sunlight (western sun) S which directly radiates on the front surface of the lamp substantially in parallel with the optical axis passes through the color filter 4 as shown in FIG. Since the collected sunlight is the surface glass of the incandescent lamp 3, it is reflected here and radiated from the front of the lamp to the outside via the reverse path. Thus, the incandescent lamp 3 itself shines. Further, the color filter 4 on the front of the lamp has a considerably large amount of pigment mixed therein and has low transparency. For this reason, a part of the sunlight S incident on the color filter 4 is scattered in the color filter and is projected on the front surface of the lamp. Therefore, the reflected light inside the lamp and the scattered light of the color filter 4 are combined, and the light of the incandescent lamp 3 itself is projected.
There is a problem that the reflected light of the sunlight S may not be identified.

Also, since we use a single incandescent light source,
It will not light up due to the ball breaking. If this is a red light part, a dangerous situation is assumed, so at present, the incandescent light is replaced regularly (for example, every six months) before the end of its life. However, the number of installed signal indicators is extremely large, the time and effort for replacement are enormous, and there is a problem in maintainability.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a display device and a display element that do not have a risk of erroneous display even when sunlight is directly irradiated.

<Means for Solving the Problems> For this reason, the first invention blackens the surface of a case for housing a light source, mounts a transparent lens on a front opening of the case, and a large number of the light sources are arranged in parallel with each other. The light-emitting diodes are collectively integrated, and the display is configured such that the light-emitting diodes are arranged at positions deviated from the focal point of the lens at least above the middle in the height direction of the case.

Further, in the invention of FIG. 2, a display element having a configuration in which a light source is provided on a concave reflector and the reflected light from the light source is radiated directly to the outside and via a reflector is provided. The optical axis direction is inclined obliquely with respect to the front of the display element, so that the light emission direction has an angle with respect to the front of the display element.

<Operation> In the display having such a configuration, the light incident from the front of the display is applied to the inner surface of the case by the lens, and is absorbed without being reflected on the inner surface of the case. Further, since no color filter is used, there is no scattered light at the filter. Furthermore, sunlight is generally considered as light incident from the front of the display, but it is unlikely that sunlight is incident from below the display. For this reason, it does not directly hit the light emitting diode provided above the middle of the case.

As described above, since there is no direct light to the light emitting diode and the reflected light from the inside of the case or the like is reduced, the distinction between the reflection by the external light and the light emission of the light source itself can be sufficiently distinguished, and the visibility of the display can be improved. .

Further, since the light source is constituted by a large number of light emitting diodes, the function as a display can be maintained even if a part of the light emitting diodes is cut off.

Further, in the display element of the second invention, the optical axis of the concave reflector is inclined obliquely with respect to the front of the display element, and light from the light source is illuminated obliquely with respect to the front of the display element. Then, the light incident from the front side of the display element does not reflect to the irradiation area side of the display element but exits as reflected light in another direction because the reflection plate is inclined. Therefore, since the reflected light of the external light is not irradiated to the irradiation area, the visibility of the display element from the irradiation area is good, and the reflection of sunlight and the light of the display element can be reliably distinguished.

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the display device of the first invention. In the figure, an inner surface 11A of a case 11 for housing a light source is painted black, and a transparent lens 12 is provided in an opening on the front surface of the case 11. In the upper part of the case 11, for example, an integrated light emitting diode 13 in which a number of bare chips are integrated is mounted on the lens 12 in a light emitting direction.
The integrated light-emitting diode 13 has a configuration in which a number of bare chips are arranged on one reflector, and the bare chips are electrically connected in parallel.

According to such a configuration, as shown in FIG.
The light is always displaced from the integrated light emitting diode 13 in the case 11, and is absorbed without being reflected on the inner surface of the case 12. In addition, there is no scattering in the lens 12 and the reflected light of the external light projected from the display is greatly reduced. Light hardly goes. Therefore, the reflected light can be reliably distinguished from the light of the light source itself of the display, and the visibility of the display is improved.

In addition, by using the integrated light emitting diode 13 as a light source as compared with an incandescent lamp, the life of the light source is extended, and even if a part of the bare chip fails to emit light, the display function is performed by emitting light from another bare chip. As a result, the reliability can be improved, and the number of maintenance and inspection operations can be reduced, thereby improving the maintainability.

When the visibility is improved as described above, it becomes possible to use a yellow or green light emitting diode, which has a low luminous efficiency compared to the conventional red light and is difficult to use, and the light source of the traffic signal light can be constituted by the light emitting diode. This makes it possible to improve the reliability of the traffic light.

In addition, as shown in FIG. 3, in addition to a light emitting diode in which a bare chip is integrated as a light source, a normal light emitting diode element 20 having a single bare chip 22 disposed on a reflector 21 as shown in FIG. It is also possible to use a mold type light emitting diode 23 in which a large number are assembled and integrated by a mold.
However, in this mold type light emitting diode 23, since the reflection plate 21 is provided for each bare chip 22, if the same number of bare chips is used, the size is larger than that of the bare chip integrated type and the display is larger.

In addition, as the incident light that may coincide with the optical axis of the irradiation area of the light emitting diode light source, sunlight and headlights are considered, but there is almost no possibility that sunlight enters the display from below, A headlight may be considered, and the amount of light per unit area of the headlight is smaller than that of the light emitting diode light source, so that the visibility does not decrease.
Accordingly, the light emitting diode light source may be positioned at least above the middle in the height direction of the case.

Next, FIG. 2 shows an embodiment of the display element of the second invention. In the figure, a light emitting diode element of the present embodiment is provided with a concave reflecting plate as shown in a transparent resin case 31.
32 and a bare chip 33 mounted on the reflection plate 32, and terminals 34 and 35 connected to the respective electrodes of the bare chip 33 are provided in the same manner as the normal one shown in FIG. In the light emitting diode element of the embodiment, the optical axis direction of the reflection plate 32 is formed so as to be inclined downward with respect to the front of the case 31 as shown by a broken line in the figure.

According to such a configuration, the reflected light of sunlight entering from the front of the element is not reflected on the optical axis of the reflector 32, in other words, on the irradiation area of the light emitting diode element (the area indicated by the broken line in the drawing), but in another direction. It is emitted as reflected light. Meanwhile, bare chip 33
Is reflected directly and on the reflection plate 32 and emitted to a target irradiation area.

Therefore, it is possible to reliably distinguish the sunlight from the light emission of the display element itself, and the visibility from the irradiation area is improved.

Since the orientation of the display element itself may be the same as the conventional orientation, for example, when applied as a light source for a conventional traffic light or traffic information display, the shape and mounting structure of the case are changed. There is no necessity, and the visibility can be improved only by replacing the internal light source.

<Effects of the Invention> As described above, according to the display of the present invention, incident light is condensed at a position shifted from the light source position by the lens, and is not scattered by the lens. Therefore, reflected light due to external light is reduced, it is possible to distinguish between reflected light of external light and light emission of the display itself, and the visibility of the display can be improved. Further, since the light source is composed of a large number of light emitting diodes, the life is long and the replacement interval can be lengthened, so that the maintainability is improved. Further, even if some of the light emitting diodes are cut off, the display function can be maintained by the other light emitting diodes, so that the reliability can be improved.

According to the display element of the present invention, the direction of the display element can be kept as it is, and only the irradiation area can be changed.When the display element is applied to a display device or the like, a conventional element can be used without having to change the case shape. Further, the visibility can be improved without changing the mounting structure.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of a display according to the first invention, FIG. 2 is a schematic configuration diagram showing one embodiment of a display element according to the second invention, and FIG. FIG. 4 is a schematic side view of a mold type light emitting diode in which a large number of light emitting diodes are assembled, FIG.
FIG. 1 is a schematic configuration diagram of a conventional display. 11… Case, 11 …… Case inner surface, 12 …… Lens, 13…
... Light-emitting diode, 31 ... Case, 32 ... Reflector, 33 ...
... Bear chips

Claims (2)

(57) [Claims] 1. An inner surface of a case for housing a light source is blackened,
A transparent lens is mounted on the front opening of the case, and a large number of light-emitting diodes connected in parallel to each other are used as the light source, and the focus of the lens is at least above the middle in the height direction of the case. A display device characterized in that the light emitting diode is arranged at a position shifted from the light emitting diode. 2. A display element having a configuration in which a light source is provided on a concave reflecting plate and light emitted from the light source is emitted directly and to the outside via the reflecting plate. A display element characterized by being obliquely inclined with respect to the front of the display element and having an angle in the light emission direction with respect to the front of the display element.