JPH0632174A - Lamp fixture for vehicle - Google Patents

Abstract

PURPOSE:To satisfy the light distribution performance as a high mount stop lamp and provide the degree of freedom for design. CONSTITUTION:A hologram plate 2 comprises a first hologram plate 8 for reflecting the beam 7 radiated from a light source with a first divergent angle in a first direction and a second hologram plate 9 for reflecting the beam radiated by this first hologram plate 8 with a second divergent angle in a second direction different from the first direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle lamp,
In particular, the present invention relates to a vehicle lamp using a hologram.

[0002]

2. Description of the Related Art As a conventional vehicle lamp using a hologram, for example, a plurality of segments (small areas) are arranged in a grid pattern.
There is one in which light from a light source is applied to one hologram divided into two to function as a high mount stop lamp (JP-A-3-224837).

[0003]

The high mount stop lamp is required to provide a light distribution of ± 45 ° in the left / right direction, 10 ° in the upward direction, and 5 ° in the downward direction when mounted on a vehicle according to the standards such as SAE and FMVSS. This light distribution is determined by the shape of the hologram (one segment) and the position of the point light source during hologram exposure. Therefore, in order to generate the above-mentioned light distribution in the left-right direction and the vertical direction by one hologram, The shape of the segment was longer in the horizontal direction than in the vertical direction and could not be changed, reducing the degree of freedom in design.

Therefore, an object of the present invention is to provide a vehicular lamp which satisfies the light distribution performance as a high mount stop lamp and has a degree of freedom in design.

[0005]

In order to solve the above-mentioned problems, the present invention is, firstly, a vehicular lamp including a light source and a hologram plate for irradiating light incident from the light source in a predetermined direction. The hologram plate includes a first hologram plate which irradiates the light incident from the light source in a first direction with a first spread angle, and a light which is irradiated by the first hologram plate. The gist is that it is formed by a second hologram plate that irradiates with a second divergence angle in a second direction different from the first direction.

Secondly, in the first configuration, the hologram plate irradiates the light incident from the light source to the vehicle in the left-right direction at a first spread angle.
And a second hologram plate for irradiating the vehicle with the light radiated by the first hologram plate in a vertical direction at a second divergence angle.

[0007]

In the above structure, first, the light incident on the hologram plate from the light source is diffracted by the first hologram plate so as to have the first spread angle in the first direction, and then the second hologram. The plate is diffracted in a second direction different from the first direction so as to have a second spread angle, and it becomes possible to obtain a required light distribution range. The design of the first hologram plate and that of the second hologram plate can be independently changed. Specifically, since the spread angle is geometrically determined, the focal length at the time of exposure can be changed. This makes it possible to change the size independently without changing the spread angle. This allows the hologram plate to have a degree of freedom in design.

Secondly, the light that has entered the hologram plate from the light source is first reflected by the first hologram plate in the left-right direction relative to the vehicle.
After being diffracted so as to have a spread angle of, the second hologram plate diffracts the light so as to have a second spread angle in the vertical direction with respect to the vehicle. This makes it possible to satisfy the light distribution performance as a high mount stop lamp.

[0009]

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

1 to 10 are views showing an embodiment of the present invention. First, the configuration will be described with reference to FIGS. 1 and 2. 6 is a vehicle body, 1 is a rear window, and 2 is a hologram plate. The hologram plate 2 is composed of first and second transmission holograms 8 and 9, and a surface protection film 10.
3 is a rear bar cell and 4 is a light source for irradiating the hologram plate 2. As shown in FIG. 3, the light source 4 includes a bulb 12, a parabolic reflector 13, and a red filter 11. Reference numeral 7 denotes red light emitted from the light source 4, which is substantially parallel light. The hologram plate 2 will be described with reference to FIG. As described above, the hologram plate 2 is composed of the two transmission holograms 8 and 9. The first transmissive hologram 8 and the second transmissive hologram 9 are superposed so that they are on the inside and the outside of the vehicle, respectively. The light 7 emitted from the light source 4 is first diffracted by the first transmission hologram 8 and then diffracted by the second transmission hologram 9 and emitted rearward of the vehicle. The first transmission hologram 8 is divided in the vertical direction, and each of the divided segments 8a has a uniaxial lens (cylindrical lens) effect that spreads light only in the horizontal direction. At this time, it has a lens effect so that the incident light 7 is spread ± 45 ° in the left-right direction. The second transmission hologram 9 is divided in the horizontal direction, and each divided segment 9a is divided.
Has the effect of a uniaxial lens (cylindrical lens) that spreads light only in the vertical direction. At this time, there is a lens effect so that the incident light 7 is spread upward by 10 ° and downward by 5 °.

The characteristics of the diffraction grating will be described with reference to FIGS. 5a is a hologram and 5b is a diffraction grating in the hologram. The light incident on the diffraction grating 5b has a wavelength of λ, a grating interval of d, an incident angle to the grating of θ (an angle formed by the normal line of the diffraction grating and the incident light), and a refractive index of n, then λ / d = 2ncosθ Diffraction occurs only when λ = 2n · dcos θ is satisfied or close to it. When the incident light is changed in the illustrated direction A, the incident angle θ changes greatly, but when the incident light is changed in the direction B perpendicular to the direction A, the incident angle θ hardly changes. Therefore, when the incident angle changes in the direction A, diffraction does not occur, but when the incident angle changes in the direction B, diffraction occurs as usual. Further, since the incident light is diffracted by the diffraction grating in the same manner as regular reflection, it is diffracted with a spread angle in the direction B.

Therefore, the light diffracted by the first transmission hologram 8 and spread in the lateral direction is further spread in the vertical direction by the second transmission hologram 9, and the light spread in both the vertical and horizontal directions as a whole. Become. Further, each segment 8a in the first transmission hologram 8 serving as a lens in the left-right direction and each segment 9a in the second transmission hologram 9 serving as a lens in the up-down direction can be independently designed. Is. Specifically, the divergence angle is determined geometrically, so the lens size (width) in the left-right direction
In order to shorten the distance, the focal length (corresponding to the point light source position at the time of exposure shown below) can be shortened to change the size without changing the spread angle. At this time, the appearance of the hologram plate 2 looks like a plurality of segments separated by a lattice in which lines that divide the first and second transmission holograms 8 and 9 into segments are overlapped. Since the vertical and horizontal lens sizes can be changed independently, the entire segment, in other words, the aspect ratio of the hologram plate 2 can be changed.

7 to 10 show a hologram exposure system. First, the first transmission hologram 8 will be described with reference to FIGS.
The exposure will be described. The principle of exposure is omitted. 1
Reference numeral 5 is an unexposed hologram photosensitive material. 16 is the wavelength 6
It is coherent light of 32.8 (nm). Reference numeral 16a denotes parallel light, which is formed by using the objective lens 18, the pinhole 19 and the collimating lens 20. 16b is light having a spread only in one axis (see FIGS. 7 and 8 for how to spread), and this is the objective lens 18, the pinhole 19, and the collimating lens 20.
And using the cylindrical lens 21. However, the parallel light 16a is omitted in FIG. Cylindrical lens 21
If the focal length of is f, then it can be expanded to ± 45 ° by using a convex lens having a width of 2f. The incident angle of the parallel light 16a is determined from the layout of the vehicle.
The incident angle of the light 16b having only one axis spread is free, but it is necessary to match the incident angle of the second transmission hologram 9. Masking 17 is used at the time of exposure, and only one segment 8a is exposed at one time. The masking 17 is moved to expose all the segments 8a.

Next, the exposure of the second transmission hologram 9 will be described with reference to FIGS. 9 and 10. The principle of exposure is omitted. Reference numeral 15 is an unexposed hologram photosensitive material.
Reference numeral 16 is a coherent light having a wavelength of 632.8 (nm). The angle of incidence is determined from the vehicle layout. 16a is parallel light. 16c is light having a spread only in one axis (see FIGS. 9 and 10 for how to spread). This is the objective lens 1
8, the pinhole 19, the collimating lens 20, and the cylindrical lens 23. If the focal length of the cylindrical lens 23 is f, it can be expanded to ± 7.5 ° by using a convex lens having a width of 2f × tan30 (the divergence angle in the vertical direction is 15 °). The incident angle of the parallel light 16a is determined from the incident angle of the spread light 16b of the second transmission hologram 9. The angle of incidence of the diverging light 16c is determined by the layout of the vehicle. Masking 22 is used at the time of exposure, and one segment 9 is used for one exposure.
Only a is exposed. The masking 22 is moved to expose all the segments 9a. In FIG. 9, 40 is a slit.

Regarding the number of times of exposure, the number of times of exposure is greatly reduced as compared with the case where the segment is divided into a lattice shape as in the conventional example. In the case of a lattice shape, for example, in the case of 5 columns × 5 rows, 25 times of exposure are required, but in the case of the present embodiment, the first transmission hologram 8 is 5 times and the second transmission hologram 9 is. 5 times, 10 times in total. Therefore,
Since the number of exposures can be greatly reduced, the number of steps can be reduced, the yield can be improved, and the cost as a product can be reduced.

Next, the operation of the vehicular lamp according to this embodiment constructed as described above will be described. The light source 4 is turned on in conjunction with the brake lamp, and the substantially parallel red light 7 is emitted. The lighting circuit and the like are similar to those of the conventional high-mount stop lamp, and therefore will be omitted here. The light 7 emitted from the light source 4 is first diffracted by the first transmissive hologram 8 so as to have a spread only in the horizontal direction, and then by the second transmissive hologram 9, in addition to this, in the vertical direction. It is diffracted to have a spread. As a result, the light is diffracted so as to spread in the vertical and horizontal directions. The diffracted light acts as an indication of the high mount stop lamp and is visually recognized by the driver of the following vehicle.

Next, FIGS. 11 to 16 show another embodiment of the present invention. The hologram plate will be described with reference to FIGS. 11 and 12. The hologram plate is composed of two reflection type holograms 24 and 25. In this embodiment, the second reflection type hologram 25 is superposed so that it is on the inside of the vehicle and the first reflection hologram 24 is on the outside of the vehicle. ing. The light emitted from the light source 4 is first diffracted by the first reflection hologram 24, then by the second reflection hologram 25, and emitted to the rear of the vehicle. First reflection hologram 24
Is divided vertically, and each divided segment 2
4a has a uniaxial lens (cylindrical lens) effect that spreads light only in the left-right direction. At this time, it has a lens effect so that the incident light 7 is spread ± 45 ° in the left-right direction. The second reflection hologram 25 is divided in the horizontal direction, and each divided segment 25a has a uniaxial lens (cylindrical lens) effect that spreads light only in the vertical direction. At this time, the incident light 7 is directed upward 10
It has a lens effect so that it can be expanded 5 ° downwards.

13 to 16 show a hologram exposure system. First, the exposure of the first reflection hologram 24 will be described with reference to FIGS. 13 and 14. The principle of exposure is omitted. Reference numeral 15 is an unexposed hologram photosensitive material. 16
Is coherent light having a wavelength of 632.8 (nm). 16a
Is a parallel light and is formed using the objective lens 18, the pinhole 19 and the collimator lens 20. 16d is light having spread only in one axis (see FIGS. 13 and 14 for how to spread). This is made by using the objective lens 18, the pinhole 19, the collimating lens 20, and the cylindrical lens 27. If the focal length of the cylindrical lens 27 is f, it can be expanded to ± 45 ° by using a convex lens having a width of 2f. The incident angle of the parallel light 16a is determined from the layout of the vehicle. The incident angle of the spread light 16b is free, but it is necessary to match the incident angle of the second reflective hologram 25. Masking 26 is used at the time of exposure, and only one segment 24a is exposed at one exposure. The masking 26 is moved to expose all the segments 24a.

Next, the exposure of the second reflection type hologram 25 will be described with reference to FIGS. The principle of exposure is omitted. Reference numeral 15 is an unexposed hologram photosensitive material. Reference numeral 16 is a coherent light having a wavelength of 632.8 (nm). The angle of incidence is determined from the vehicle layout. 16a
Is parallel light. 16e is light having spread only in one axis (see FIGS. 15 and 16 for how to spread). This is made by using the objective lens 18, the pinhole 19, the collimating lens 20, and the cylindrical lens 29. When the focal length of the cylindrical lens 29 is f, the width is 2f × ta
± 7.5 ° by using a convex lens with n30
Can be extended to (Vertical spread angle is 15
°). The incident angle of the parallel light 16a is determined from the incident angle of the spread light 16d of the first reflection hologram 24. The angle of incidence of the diverging light 16e is determined from the vehicle layout.
Masking 28 is used at the time of exposure, and only one segment 25a is exposed at one exposure. The masking 28 is moved to expose the entire segment 25a.

Next, the operation of the vehicular lamp according to this embodiment constructed as described above will be described. The light source 4 is turned on in conjunction with the brake lamp, and the substantially parallel red light 7 is emitted. The light 7 emitted from the light source 4 is first diffracted by the first reflection type hologram 24 so as to have a spread only in the left and right direction, and then by the second reflection type hologram 25, in addition to this, in the vertical direction. It is diffracted to have a spread. As a result, the light is diffracted so as to spread in the vertical and horizontal directions. The diffracted light acts as an indication of the high mount stop lamp and is visually recognized by the driver of the following vehicle.

[0021]

As described above, according to the present invention, first, the hologram plate irradiates the light incident from the light source in the first direction with the first spread angle.
And a second hologram plate for irradiating the light emitted by the first hologram plate in a second direction different from the first direction with a second spread angle. A required light distribution range can be obtained as a lamp. The first hologram plate and the second hologram plate
The hologram plate can be changed in its design independently, and its size can be changed independently without changing the spread angle, so that the hologram plate can have a degree of freedom in design. . Furthermore, the number of exposures can be significantly reduced, the yield can be improved, and the product cost can be reduced.

Secondly, the hologram plate is irradiated by the first hologram plate which irradiates the vehicle with the light incident from the light source in the left-right direction at the first spread angle, and by the first hologram plate. Since it is formed by the second hologram plate that irradiates the vehicle with the second spread angle in the vertical direction to the vehicle, it is possible to further satisfy the performance as a high mount stop lamp in addition to the above effects. .

[Brief description of drawings]

FIG. 1 is a perspective view showing an overall configuration of an embodiment of a vehicular lamp according to the present invention.

FIG. 2 is an enlarged side view of the hologram plate in the above-described embodiment.

FIG. 3 is a configuration diagram of a light source in the one embodiment.

FIG. 4 is a diagram for explaining the diffracting action of the hologram plate in the above-mentioned embodiment.

FIG. 5 is a side view for explaining the diffraction condition of the hologram plate in the above-mentioned embodiment.

FIG. 6 is a plan view for explaining the diffraction condition of the hologram plate in the above-mentioned embodiment.

FIG. 7 is a diagram showing an exposure system of a first transmission hologram in the above-mentioned embodiment.

8 is a view on arrow X in FIG. 7. FIG.

FIG. 9 is a diagram showing an exposure system of a second transmission hologram in the above-mentioned embodiment.

10 is a view on arrow Y of FIG. 9. FIG.

FIG. 11 is a side view of a hologram plate according to another embodiment of the present invention.

FIG. 12 is a diagram for explaining the diffracting action of the hologram plate in the other embodiment.

FIG. 13 is a diagram showing an exposure system of a first reflection type hologram in the other example.

FIG. 14 is a view on arrow Z in FIG.

FIG. 15 is a diagram showing an exposure system of a second reflective hologram in another example.

16 is a view on arrow U of FIG.

[Explanation of symbols]

 2 hologram plate 4 light source 6 vehicle body 8 first transmissive hologram 9 second transmissive hologram 24 first reflective hologram 25 second reflective hologram

Claims (2)

[Claims] 1. A vehicular lamp including a light source and a hologram plate for irradiating light incident from the light source in a predetermined direction, wherein the hologram plate is configured to emit light incident from the light source as a first light source.
A first hologram plate that irradiates with a first divergence angle in the direction of, and a second divergence angle with the light radiated by the first hologram plate in a second direction different from the first direction. A vehicle lamp characterized by being formed by a second hologram plate for irradiation. 2. The hologram plate is provided with a first hologram plate for irradiating the vehicle with the light incident from the light source in the left-right direction at a first spread angle, and the first hologram plate. 2. The vehicle lamp according to claim 1, wherein the light is formed by a second hologram plate that irradiates the vehicle with a second spread angle in the vertical direction.