JPH0885383A - Vehicle warning light - Google Patents

Abstract

(57) [Summary] [Structure] A protective film 9 having a refractive index substantially equal to that of the hologram 2 is laminated on the inner surface of the hologram 2 disposed on the inner side of the rear glass of the vehicle. Warning light for vehicles in which warning information light from is diffracted backward by the hologram 2. [Effect] It is possible to reduce the light reflected by the film that protects the hologram and prevent the hologram diffracted light that causes the warning information to be erroneously recognized by the vehicle behind.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle warning light.

[0002]

2. Description of the Related Art Conventionally, in a vehicle such as an automobile, as a method of urging a vehicle behind to be warned when operating a brake, moving backward, or changing a traveling direction, a brake lamp or a backward lamp located above a bumper is turned on. Is normal. However, in the case of a brake lamp located above a normal bumper, when it snows, the brake lamp will be hidden by the snow and will not be visible to the vehicles behind it. There is a safety problem because it is difficult to determine the lighting display of the above-mentioned brake lamp of the passenger car in front of the vehicle.

In order to solve such a problem, it has been proposed and put into practical use that the light emitting portion of the brake lamp is placed at a relatively high position near the rear glass (hereinafter referred to as a high mount stop lamp).

This is because the light emitting portion as a warning light is at a relatively high position, so that it has an advantage that it can be easily seen from a vehicle behind, and the light emitting portion is not hidden by the snow even when it is snowing, and the safety is high. It is very useful because of its advantage.

As a conventional high mount stop lamp, there are one in which a light source is placed on the back of a rear seat inside a passenger car, and one in which a point light source is linearly arranged in a rear spoiler portion.

[0006] In these high mount stop lamps, there are strong demands for various designs of displays and for a large light emitting portion area. However, if the area of the light emitting portion is made too large, the driver's view of the rear of the vehicle is obstructed, and there is a problem that the light emitting portion cannot be made so large in practice.

In order to solve such a problem, the special table 1-
Japanese Patent No. 502465 discloses a vehicle warning lamp having a hologram on a rear glass, irradiating light from a light emitting means for generating warning information to be displayed on the hologram, and diffracting the light toward the vehicle rear side by the hologram. It is disclosed.

[0008] According to this, it is possible to obtain a warning lamp having high visibility and high position without obstructing the rear view of the driver. Further, as a warning light, when it does not operate, the driver and the driver of the vehicle behind can obtain a clear field of view close to that of a normal rear window.

In such a high mount stop lamp, a tungsten or halogen lamp is used as a light source for the light emitting means.

[0010]

FIG. 2 shows a sectional view of a conventional high mount stop lamp using a hologram. Hologram 2 on the inside of the rear glass 21 of the automobile
2, the light emitted from the white light source 24 on the rear parcel shelf 23 passes through the hologram 22 and is diffracted to the driver 26 of the rear vehicle (11).

However, in the high mount stop lamp using the hologram, when the daytime sunlight or the nighttime spotlight 25 of the streetlight passes through the rear glass 21 and is applied to the hologram 22, the air of the hologram 22 is emitted. It will be reflected at the vehicle side surface which is the interface with the layer. The reflected light passes through the hologram 22 and travels backward. At that time, orange or green light that is easily visible to the driver behind is observed by the driver behind due to the diffraction conditions of the hologram. Will end up. Therefore, the light 25 causes holograms to form extra reflected light that hinders the driving operation of a driver or the like in the rear.

The reflected noise light 12 on the hologram surface due to such external light is erroneously recognized as a warning display of the high mount stop lamp, and is also a problem from the viewpoint of safety.

On the other hand, as disclosed in JP-A-1-502465 and JP-A-2-256535, the hologram protective film is used to protect the hologram from abrasion and moisture. It is proposed to be prepared on the side.

In this case, the hologram has no interface with the air layer. However, since the reflected light as described above still occurs at the interface between the hologram and the protective film, even when it is necessary to provide a protective film for the hologram, the daytime sunlight is the same as when the protective film is not provided. There was an inconvenience caused by the spotlight of street lights at night.

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to provide a warning light for vehicles which has not been known in the past.

[0016]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is provided with a light emitting means for generating warning information to be displayed as light and a rear glass of a vehicle which is arranged inside the vehicle. In a vehicle warning light including a hologram that diffracts light toward the rear of the vehicle and a protective film laminated on the interior surface of the hologram, the protective film has a refractive index substantially equal to that of the hologram. A warning light for a vehicle is provided which is characterized by being equal.

[0017]

According to the present invention, the refractive index of the protective film laminated on the vehicle inner surface side of the hologram arranged on the rear glass is
Since it is almost equal to the refractive index of the hologram, the reflected light at the interface between the two is reduced. At this time, by selecting the material of the protective film for the hologram so that the reflectance of the light at the interface between the two becomes 0.3% or less, the reflected light is diffracted by the hologram and is transmitted to the rear vehicle. Even when irradiated, the intensity of the diffracted light is high enough that it does not hinder the driver or the like.

Although the reflection at the interface between the hologram and the protective film is not as described above, the refractive index of the protective film is the refractive index of the hologram at the car interior side surface of the protective film, that is, at the interface with the air layer of the protective film. The reflected light may be generated from this interface toward the hologram by setting the values substantially equal to. Therefore, by using a red filter as the protective film, light other than red light is absorbed by the protective film, and the light reflected at the interface with the air layer becomes red. Compared to green and orange, red light like this
It does not give the impression of being mistaken for a driver behind.

Further, by providing a groove on the inner surface of the protective film on the vehicle inner surface to form an uneven surface, the light from the light emitting means can be diffused in a specific direction, and warning information such as stop information can be sufficiently rearward. Can be transmitted toward.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic sectional view showing the basic structure of a vehicle warning light according to the present invention. Reference numeral 1 is a rear glass of a vehicle, and 2 is a hologram for transmitting and diffracting light from a light source to a vehicle behind. The hologram 2 is bonded to the inside surface of the rear glass 1 by an adhesive material 7. Further, on the surface of the hologram 2 inside the vehicle, a red filter 9
Are laminated by the optical adhesive 8.

A light emitting means 4 including a light source is provided on the rear parcel shelf 3 below the rear glass 1. Light including the braking information and the like is emitted toward the hologram 2 from the light emitting means 4 in synchronization with the braking operation light of the driver. In this way, the light emitted toward the hologram 2 is
The warning information is transmitted toward the rear vehicle by being diffracted toward the rear vehicle.

The hologram used in this embodiment is a transmission hologram made of a photopolymer material having a diffraction characteristic of a central wavelength of 620 nm, a half width of 50 nm and a diffraction efficiency of 70%. This photopolymer material has a hologram whose refractive index is approximately equal to that of the rear glass after exposure to about 1.5.
Selected to be.

The red filter 9 used in this embodiment is a high-pass filter (characteristic of absorbing blue and green and transmitting red) having a transmittance of 50% at a wavelength of 600 nm. Since a hologram having a refractive index (n) of about 1.5 is used as described above, this red filter has n = 1.5.
An acrylic material close to the above was used. Also, the adhesive 8 is
= 1.5, an acrylic material was used.

The surface of the red filter has the effect of diffusing the reflected light of the outside light in addition to improving the visibility of the driver of the vehicle behind, which is preferable, so that the light from the light source is diffused to the rear of the vehicle. A groove (about 1 mm pitch) was provided for this purpose.

The present invention is not limited to the above embodiment, and for example, the hologram is not limited to the transmission hologram, but a reflection hologram may be used depending on the arrangement of the light emitting means. With this arrangement, the diffraction characteristics such as the diffraction angle of the hologram can be appropriately selected and determined.

Other diffraction characteristics of the hologram can be appropriately determined, and the center wavelength can be determined according to the red filter used in the present invention. In the case of the above-mentioned embodiment, since the red filter is a high-pass filter having a wavelength of 600 nm and a transmittance of 50%, it is preferable that the center wavelength of the hologram is slightly larger than 600 nm. Conversely, the center wavelength of the hologram may be determined in advance, and the wavelength characteristic of the red filter may be determined according to this center wavelength.

The full width at half maximum is also preferably 30 nm or more in view of the wavelength characteristics of the red filter (600 nm in the above embodiment) and the center wavelength of the hologram (620 nm in the above embodiment), and is 50 nm in the above embodiment. At this time, a method that is usually used is adopted as a method for producing a hologram. The hologram material is not limited to photopolymer,
A material having a refractive index close to that of the rear glass is sufficient.

As for the light emitting means, a white light source or L
A light source including an ordinary light source such as a light source including an ED is appropriately selected and used.

[0030]

According to the present invention, since the refractive index of the protective film laminated on the vehicle inner surface side of the hologram arranged on the rear glass is substantially equal to the refractive index of the hologram, the reflected light at the interface between the two is reduced. Therefore, the unnecessary reflected light does not go to the rear, and it is possible to prevent erroneous recognition of the information of the vehicle behind.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a basic configuration of a vehicle warning light according to the present invention.

FIG. 2 is a sectional view of a conventional high mount stop lamp.

[Explanation of symbols]

 1: Rear glass 2: Hologram 9: Red filter 12: External light reflection noise light

Claims (4)

[Claims] 1. A light emitting means for generating warning information to be displayed as light, a hologram arranged inside a rear glass of a vehicle to diffract the light toward the rear of the vehicle, and a hologram laminated on the inside surface of the vehicle. In the vehicle warning light provided with the protective film described above, the refractive index of the protective film is substantially equal to the refractive index of the hologram. 2. The vehicle warning light according to claim 1, wherein the protective film is a red filter. 3. The vehicle warning light according to claim 1, wherein a groove for diffusing light from the light emitting means in a specific direction is provided on the vehicle inner surface of the protective film. 4. The protective film is made of a material having a refractive index that makes the reflectance of light at the interface with the hologram 0.3% or less. Vehicle warning light.