JPH08272328A - Light emitting display for outdoor use - Google Patents

Abstract

PURPOSE: To avoid the occurrence of traffic chaos and accidents by providing the front surface of a light source with a hologram having a diffusion effect to diffuse incident light. CONSTITUTION: The light source 14 is housed in a box body 15 subject to an antireflection treatment by applying a black coating material, etc., on its inside surface. The front surface of this box body 1 is provided with a light transmissive part 11. This light transmissive part 11 is provided with the hologram 1 of a transmission type. The light 16 emitted from the light source 14 in such a manner is transmitted and diffracted (arrow 17) toward an observer by the hologram 1. The hologram 1 diffuses the transmitted light (has the diffusion effect) when the light being made incident toward the hologram 1 is transmitted and diffracted. The light emitted from the light source 1 in such a manner progresses while spreading to a prescribed region and the observer requiring signal information is able to observe the traffic signal in the arbitrary position on a road. Not only the transmission type but reflection type holograms as well are usable as the hologram.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal light for emitting traffic signal information such as roads and railroads, and a light emitting display provided outdoors such as a large screen display installed outdoors.

[0002]

2. Description of the Related Art Signal lights are provided outdoors. As a conventional signal light, as shown in FIG. 6, a light reflector having a concave reflecting mirror 23 behind the light bulb 22 and a red, yellow, and green diffused lens-equipped colored glass filter 24 on the front are used.

[0003]

However, when the signal light is directly exposed to the sunlight, the sunlight passing through the colored glass filter is reflected by the concave reflecting mirror, so that the light bulb is not turned on. Sometimes it looked like it was lit. As a result, red, yellow,
All of the green traffic lights seemed to be lit, which could lead to traffic confusion and accidents.

A large screen display provided in a stadium or the like has a plurality of pixels arranged therein, and each pixel emits light to emit display information. Also in the case of such a pixel, erroneous lighting of the light bulb due to sunlight is observed due to the concave reflecting mirror provided behind the light bulb as in the above signal light.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and to provide a novel outdoor light-emitting display which has not been known in the past.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and includes a light source and a hologram arranged in front of the light source for diffracting light from the light source toward an observer. And a hologram for diffusing light that is incident on the hologram.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic sectional view showing an example in which the outdoor light emitting display device according to the present invention is used as a traffic signal light. The light source 14 is housed in a box body 15 whose inner surface is subjected to antireflection treatment by applying black paint or the like. A light transmitting portion 11 is provided on the front surface of the box body 15,
The light transmitting portion 11 is provided with the transmission hologram 1. Thus, the light 16 emitted from the light source 14 is transmitted and diffracted (17) toward the observer 25 by the hologram 1.
To be done.

The hologram 1 is for diffusing the transmitted light (having a diffusing action) when the light incident on the hologram 1 is transmitted and diffracted. Thus, the light source 1
The light emitted from spreads and spreads over a predetermined area, and an observer who needs signal information can observe the traffic signal at any position on the road.

On the other hand, of the external light such as sunlight incident on the hologram 1, the light transmitted through the hologram is the box 1
Although it enters the inside of the box body 5, since the concave reflecting mirror is not arranged in the box body 15, the reflection on the inner surface of the box body 15 is extremely small, and there is no erroneous recognition that the light source is turned on.
The light diffracted by the hologram out of the light that is incident on the hologram 1 is only incident on the inside of the box 15 as in the case of the directly transmitted light because the hologram is a transmission hologram.

Of the external light incident on the hologram, the light reflected by the back surface of the hologram box side is
When the light becomes annoying to the observer, it is preferable to apply an antireflection treatment to this surface.

The hologram having a diffusing action in the present invention is produced, for example, by the following method. FIG. 2 is a schematic cross-sectional view showing an example of the method for producing a hologram in the present invention. The laser light sources 4 and 6 are arranged on one side of the hologram photosensitive material 10. The light from the laser light source 4 is expanded by a lens or the like and then converted into parallel light by a collimator lens 5, while the light from the laser light source 6 passes through one having a diffusing surface 7 such as frosted glass to one side of the hologram photosensitive material 10. From the above, the light flux 2 and the diffused light 3 collimated by the lens 5 and the like are irradiated and exposed to produce a hologram having a diffusing effect.

The hologram thus produced is exposed by diffused light, but the diffused light is also directed to the hologram photosensitive material from a predetermined direction. Therefore, the hologram produced also has a certain directivity, although the diffracted light is diffused. This directivity is
The size of the light emitting surface on the diffusion surface 7 and the hologram photosensitive material 1
It can be adjusted by the distance between 0 and the diffusing surface 7, the divergence and convergence of the light beam 2, and the like. In particular, the directivity becomes stronger as the distance between the diffusing surface 7 and the hologram photosensitive material 10 is increased and the size of the light emitting surface on the diffusing surface 7 is reduced.

Although frosted glass is used as the diffusion surface in the above example, the hologram photosensitive material 10 may be exposed by using the lens array 8 in which a large number of small lenses, prisms, etc. are arranged. Even if a large number of point light sources are used, the same exposure can be performed (see FIG. 3). In these cases, the hologram produced has a lens array image recorded thereon.

Since the hologram has wavelength dependence as a diffraction characteristic, a desired color can be displayed even if white light such as an incandescent lamp is used as a light source. Therefore, it is not necessary to dispose a color filter in front of signals or the like. Further, the exposure light may be exposed in the same color as the reproduction light, or it is possible to shift the exposure wavelength and the reproduction wavelength by using an angle tune.

Since the signal lamp constructed as described above has directivity, it is possible to make the display of the lateral signal lamp facing the direction of the road to be crossed invisible. As a result, there is also the advantage of preventing collision accidents at the encounters that occur when the side traffic lights turn red immediately. In addition, at the time of merging with a narrow angle such as a Y-shaped road, a signal light for another road may be seen, and it may be difficult to understand which signal light is for itself. However, in the signal light using the present invention, due to the directivity, Only certain signal lights can be visible.

As the hologram, not only the transmission type hologram as in the above example but also the reflection type hologram can be used (FIG. 4). In this case, the light source 14 and the reflection hologram 3
Even if 1 and 1 are not assembled in one box, it is sufficient to dispose and support both at a predetermined distance and angle and to provide an antireflection layer 19 such as black paint on the back surface of the hologram. In this case, as a method for producing the reflection hologram,
In the above-mentioned method for producing a transmission hologram, it can be easily performed by disposing one exposure light source on the opposite side to the hologram photosensitive material.

A concave reflecting mirror may be used behind the light source in order to efficiently irradiate the hologram with light, but since there is external light that directly transmits the hologram, the concave reflecting mirror is used. It is desirable to place it in a place where it is not exposed to light. Therefore, the shade plate 18 may be mounted at a suitable position (FIG. 1). It is also possible to reduce the amount of reflection by using a concave reflecting mirror that is as small as possible. In any case,
Since the hologram is used in the present invention, the positions of the light source and the concave reflecting mirror can be arbitrarily set (exposure is performed as such)
Therefore, the concave reflecting mirror can be arranged.

When considering sunlight as the outside light,
Normally, sunlight comes from above the display. Therefore, the expected direction of the external light 20 or the back-surface reflected light 21 of the hologram 1 (31) of this external light and the light source 14 (1
4 ') when the light source 14 (14') is arranged at a position where the incident directions of the light from 4 ') are the same or almost the same (see FIG. 5,
In this figure, the light source is arranged above the hologram), and external light may be diffracted toward the observer by the hologram. In the present invention, by considering the exposure conditions of the hologram, etc., in order not to arrange such a light source,
It is possible to eliminate the above-mentioned problem of external light.

The signal lamp according to the present invention is the same as the signal lamp of FIG.
The three colors may be arranged side by side to correspond to red, yellow, and green, or the display colors may be changed by multiple-exposing each color on one hologram and switching the light source. Instead of multiple exposure, separately exposed ones may be bonded together. Further, since the diffraction wavelength of the hologram changes depending on the incident angle, it is possible to change the display color by arranging a plurality of light sources at different positions and irradiating the hologram at different angles.

INDUSTRIAL APPLICABILITY The present invention is used not only for traffic signal lights, but also for outdoor use, such as advertisements that have been provided with a concave reflecting mirror behind the light source to emit information light, and electronic display boards for outdoor stadiums. It can be widely used for light emitting displays. Further, by arranging a large number of light emitting sources of three primary colors and using a large outdoor display, a color image with good contrast can be obtained.

As the hologram photosensitive material, a silver salt dry plate,
Usual dichromated gelatin, photopolymer, etc. that can be used for hologram recording can be used.

[0023]

Embodiments of the present invention will be described below.

According to the method for producing a hologram shown in FIG. 2, the hologram photosensitive material 10 was spread with the laser beam 2 (wavelength 515 nm) spread by the microscope objective lens and collimated by the collimator lens 5 and the microscope objective lens. Diffuse light 3 with laser light on frosted glass,
Irradiation was performed from one side of the hologram photosensitive material. The distance between the frosted glass diffusion surface 7 and the hologram photosensitive material 10 is 300.
mm, and the diameter of the laser beam on the frosted glass was 50 mm.

The transmissive hologram 1 produced as described above was assembled as shown in FIG. 1 and used as a signal lamp for displaying green. A halogen lamp was used as the light source 14, and the display light 16 was irradiated toward the hologram 1. As a result, the observer 25 observed the green diffracted scattered light 17. Further, when the light source 14 was not lit, even when the direct sunlight was incident on the hologram 1, the signal lamp did not appear to be lit, but appeared black.

[0026]

According to the outdoor light emitting display of the present invention, the diffused light can be emitted toward the observer without disposing the concave reflecting mirror behind the light source, and the outside light such as sunlight can be emitted. Even if the light source does not emit light when the light directly enters the display, it is possible to eliminate the phenomenon that the light source seems to emit light.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of an outdoor light emitting display device according to the present invention.

FIG. 2 is a schematic sectional view showing an example of a method for producing a hologram in the present invention.

FIG. 3 is a schematic sectional view showing an example of a method for producing a hologram in the present invention.

FIG. 4 is a schematic cross-sectional view showing an example of an outdoor light emitting display device according to the present invention.

FIG. 5 is a schematic sectional view showing an example of an undesired light source arrangement.

FIG. 6 is a schematic sectional view showing an example of a conventional signal lamp.

[Explanation of symbols]

 1: Hologram 2: Light flux 3: Diffused light 4: Laser light source 5: Lens 6: Laser light source 7: Diffusing surface 8: Lens array 9: Lens 12: Incident light 13: Diffused light 14: Light source 15: Box 16: Display Light 17: Diffracted and scattered light 18: Sunshade 19: Antireflection layer 20: Sunlight 21: Reflected light of sunlight 22: Light bulb 23: Concave reflector 24: Colored glass filter with diffuser lens

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location // G03H 1/22 G03H 1/22

Claims (3)

[Claims] 1. A hologram comprising a light source and a hologram arranged in front of the light source and diffracting light from the light source toward an observer, the hologram diffusing light incident on the hologram. An outdoor light emitting display characterized by. 2. The outdoor light emitting display according to claim 1, wherein the hologram is a hologram exposed by using diffused light. 3. The hologram is a hologram in which a lens array image has been recorded in advance.
Outdoor light emitting display.