JPH04293632A - Brake lamp for vehicle - Google Patents

Abstract

PURPOSE:To reduce the luminescent area of a hologram element by directly radiating part of the red light with uniform intensity radiated from the luminescent face of a light source to the rear of a vehicle, and radiating the remainder toward the hologram element at the intensity higher than the intensity of the directly radiated red light. CONSTITUTION:When a foot brake pedal is depressed, a white electric bulb 11 is lighted. The light beam radiated from the white electric bulb 11 passes a red filter 12, then it is radiated as the red light 14 with uniform intensity and the red light 15. The red light 14 is directly radiated to the rear of a vehicle. The red light 15 is fed to a hologram element 13 installed on a rear window 21, and it is diffracted by the hologram element 13 and radiated to the rear of the vehicle. The luminescence of the red filter 12 can be directly observed by the occupant of the succeeding vehicle via the red light 14, and the diffraction image of the red filter 12 with nearly the same luminescent area can be concurrently observed on the hologram element 13. The specified area is obtained by the sum of two luminescent areas observed as connected.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake light for a vehicle, and more particularly to a high mount stop lamp using a hologram element.

0002

2. Description of the Related Art A high-mount stop lamp using a hologram element is known. An example of such a device is shown in FIG. In FIG. 11, 21, 22
, 23 are a rear window, a rear parcel, and a roof, respectively.

[0003] Reference numeral 90 denotes a light source, which is composed of a white light bulb or red LED equipped with a red filter, a reflector, and a lens. The light source 90 emits red light when a foot brake pedal (not shown) is depressed. A hologram element 93 is manufactured to diffract red light emitted from the light source 90 toward the rear of the vehicle. Next, the effect will be explained. When the foot brake pedal is depressed by the driver, the light source 90 emits red light with substantially uniform brightness. The red light enters the hologram element 93 and is diffracted by the hologram element 93 toward the rear of the vehicle. As a result, it appears to the passenger 99 of the following vehicle that the hologram element 93 is emitting red light.

0004

[Problems to be Solved by the Invention] According to regulations, high-mounted stop lamps have a red light emitting area displayed at the rear of the vehicle (hereinafter referred to as the light emitting area) that is a predetermined area and emit light with a predetermined brightness. It is defined as follows. Therefore, in the above device, the red light incident on the hologram element 93 must also be distributed over a predetermined area. When the light source 90 is made small, the red light becomes a light beam that travels while spreading at a predetermined aperture angle. Such a luminous flux is generally brighter at the center and darker at the periphery. Therefore, the red light diffracted by the hologram 93 also becomes bright at the center and dark at the periphery.

In order to solve this problem, the red light emitted from the light source 90 must be made into a uniform luminous flux close to uniform parallel light. Therefore, the light emitting surface 92 of the light source 90
The area becomes almost equal to the area of the hologram element 93, and the light source 90 itself becomes large.

As a result, the area occupied by the light source 90 on the rear parcel 22 becomes large. Further, there are problems in that the light source 93 protrudes largely into the trunk space below the rear parcel 22, and furthermore, when the light source is installed on the roof 93 side, the interior of the vehicle becomes narrow.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a more compact brake light for a vehicle.

[0008]

[Means for Solving the Problems] The present invention is a vehicle brake light having a hologram element and a light source, wherein the light source is installed at a position where a light emitting surface emits red light directly to the rear of the vehicle, A part of the red light with uniform brightness is directly emitted from the light emitting surface to the rear of the vehicle, and the remaining red light is emitted toward the hologram element at a brightness higher than the brightness of the red light that is directly emitted to the rear of the vehicle. The hologram element is installed in a rear window, and emits red light emitted from a light emitting surface of the light source with a luminance that is approximately equal to the luminance of the red light that is directly emitted from the light source to the rear of the vehicle, and It diffracts to the rear of the vehicle with uniform brightness.

[0009]

[Operation] According to the above structure, a part of the red light emitted from the light source is emitted directly to the rear of the vehicle. Further, the remaining red light is incident on a hologram element installed in the rear window, and is diffracted by the hologram element toward the rear of the vehicle.

The light emitting area of the red light emitted directly to the rear of the vehicle is determined by the area of the light emitting surface of the light source. Further, the light emitting area of the red light that is diffracted and radiated to the rear of the vehicle is determined by the light emitting area of the hologram element. Then, by combining the light emitting areas of both, a specified light emitting area can be obtained.

That is, since the difference between the defined light emitting area and the light emitting area of the light emitting surface of the light source is the light emitting area of the hologram element, the light emitting area of the hologram element becomes small. As a result, the area of the light emitting surface of the light source can be reduced in accordance with the light emitting area of the hologram element, and the size of the light source itself can also be reduced.

0012

Embodiment A first embodiment of the present invention will be described based on FIGS. 1 to 5. In Figure 1, 21, 22, 2
3 are a rear window, a rear parcel, and a roof, respectively. 10 is a light source, which is installed on the rear parcel 22. Reference numeral 13 denotes a transmission type hologram element, which is installed on the interior side of the rear window 21.

FIG. 2 shows an enlarged sectional view of the vicinity of the light source 10. 11 is a white light bulb. The white light bulb 11 lights up when a foot brake pedal (not shown) is depressed. 12
is a red filter constituting the light emitting surface. The red filter 12 has a plurality of circular lens cuts, and the light distribution is set so that the red light 14 is directly emitted toward the rear of the vehicle, and the red light 15 is emitted toward the hologram element 13. There is. Further, the above light distribution is set so that the amount of red light 15 is larger than the amount of red light 14, and the brightness of red lights 14 and 15 transmitted through the lens cut is uniform.

Next, the operation will be explained. The foot brake pedal is depressed and the white light bulb 11 lights up. white light bulb 11
After passing through a red filter 12, the luminous flux (white light) emitted from the
radiated as. The red light 14 is emitted directly to the rear of the vehicle. Further, the red light 15 is incident on the hologram element 13 installed in the rear window 21, diffracted by the hologram element 13, and radiated toward the rear of the vehicle.

As a result, as shown in FIG. 3, the passenger of the following vehicle can directly see the light emitted from the red filter 12 by the red light 14, and at the same time, the diffraction of the red filter 12, which has approximately the same light emitting area, also appears on the hologram element 13. You can see the statue. Then, the prescribed light emitting area is obtained by the sum of the two light emitting areas that appear to be connected.

Furthermore, due to the wavelength selectivity and diffraction efficiency of the hologram element 13, the red light 15 is transmitted through the hologram element 1.
A loss occurs when it is diffracted by 3. By taking this loss into account and adjusting the ratio of the amounts of red light 14 and red light 15 emitted from the light source 10, it is possible to eliminate the difference in brightness when viewed from the rear of the vehicle. for example,
When the proportion of the red light 15 incident on the hologram element 13 being diffracted toward the rear of the vehicle is 40%, the red light 14 and the red light 1
If the ratio of the amount of light is approximately 3:7, the amount of light directly emitted from the red filter 12 to the rear of the vehicle and the amount of light diffracted to the rear of the vehicle by the hologram element 13 will be approximately equal. Further, the amount of light from the white light bulb 11 is adjusted so that the brightness of both becomes a prescribed value.

Next, a method for manufacturing the hologram element 13 will be explained based on FIGS. 4 and 5. In FIG. 4, 16 is a hologram dry plate. 28 and 29 are red laser beams having the same wavelength. 26 and 27 are lenses for spreading the laser beams 28 and 29;
4 and 25 are pinholes.

As shown in FIG. 4, a laser beam 28 is incident on the surface 16a of the hologram dry plate 16 through a lens 26 and a pinhole 24, and at the same time, a laser beam 28 is incident on the surface 16a through a lens 27 and a pinhole 25.
9 is made incident. As a result, interference fringes between the laser beams 28 and 29 are recorded on the hologram dry plate 16, and the hologram element 13 is manufactured from the hologram dry plate 16. Then, as shown in FIG. 5, the hologram element 13
When red light is made incident on the surface 13a, the red light is diffracted by the hologram element 13.

As described above, according to this embodiment, the light source 1
A red light 14 with uniform brightness is emitted directly to the rear of the vehicle from a red filter 12 of zero, and red light 15 with uniform brightness is incident on a hologram element 13 installed in the rear window 21. is now diffracted to the rear of the vehicle. Therefore, from the rear of the vehicle, the image formed by the red light 14 and the image formed by the red light 15 are joined together, and the prescribed area appears to emit red light with uniform brightness. Therefore, the light emitting area of the hologram element 13 can be approximately halved in accordance with the light emitting area of the red filter 12 that is viewed directly, and as a result, the light source 10 can also be halved in size. . Furthermore, the amount of red light 15 is made larger than the amount of red light 14 by the lens cut made on the red filter 12. Therefore, it is possible to prevent a brightness difference between the directly viewed red light 14 and the diffracted red light 15 due to loss when the red light 15 is diffracted by the hologram element 13, and to obtain uniform light emission. . Furthermore, since approximately half of the light emitting area is radiated directly to the rear of the vehicle, loss during diffraction can be reduced. As a result, the specified brightness can be obtained with a smaller amount of light, and the power consumption of the light source 10 can be reduced. Furthermore, since the hologram element 13 can be made approximately half the size of the conventional one, an effect can be obtained in that the cost of the hologram element can be reduced.

In this embodiment, the luminous flux emitted from the white light bulb 11 is passed through the red filter 12 to emit red light and obtain a predetermined light distribution, but the present invention is not limited to this. For example, a predetermined light distribution may be obtained from the red light emitted from the red LED using a transparent lens.

Next, a second embodiment will be explained based on FIG. 6. Although one hologram element was used in the first embodiment, two hologram elements are used in this embodiment. Note that members equivalent to those in the first embodiment are given the same numbers, and detailed explanations are omitted.

In FIG. 6, 30 is a light source, which is installed on the rear parcel 22. As shown in FIG. A radiation surface of the light source 30 faces toward the rear of the vehicle, and red light with uniform brightness is emitted from the radiation surface. Reference numerals 33 and 34 indicate transmission type hologram elements, which are installed vertically on the inside of the rear window 21 at a predetermined distance from each other. Hologram element 33
, 34 are manufactured to receive a portion of the red light emitted from the light source 30 and to diffract this red light toward the rear of the vehicle with the same brightness as the directly emitted red light. Next, the effect will be explained. When a foot brake pedal (not shown) is stepped on, red light is emitted from the radiation surface of the light source 30. A portion of the red light is directly emitted to the rear of the vehicle through the gap between the hologram elements 33 and 34. Of the remaining red light, the red light emitted upward is incident on the hologram element 33 and diffracted by the hologram element 33 toward the rear of the vehicle. Of the remaining red light, the red light emitted toward the rear parcel 22 is transmitted to the hologram element 34.
and is diffracted toward the rear of the vehicle by the hologram element 34.

As a result, from the rear of the vehicle, the red light diffracted by the hologram element 33, the red light directly emitted from the light source 30, and the red light diffracted by the hologram element 34 are combined to form a light beam of a predetermined area. The rectangle appears to be emitting red light.

[0024] By adjusting the ratio of the amount of red light emitted directly to the rear of the vehicle and the amount of red light incident on the hologram elements 33 and 34, it is possible to make the brightness of the direct light and the diffracted light approximately equal. This allows red light to be emitted with uniform brightness.

As described above, according to the second embodiment, a part of the red light emitted from the light source 30 is directly emitted to the rear of the vehicle, and the rest of the red light is sent to the hologram elements 33 arranged above and below. 34 so that it is diffracted to the rear of the vehicle. Therefore, the same effects as the first embodiment can be obtained, and
Since the red light traveling in the direction of the rear parcel 22 from the light source 30 can also be used, the utilization rate of the luminous flux is further improved. Furthermore, by making the area of the holograms 33 and 34 almost the same as the area of the light emitting part of the light source 30, the area of the light emitting part of the light source can be reduced to approximately one-third of the specified light emitting area. 30 can be further miniaturized.

Next, a third embodiment will be explained based on FIG. 7. In the above two embodiments, a rectangular hologram element was used, but in this embodiment, a ring-shaped hologram element is used. Note that the same numbers are given to the same members as those in the above embodiment, and detailed explanations are omitted.

In FIG. 7, reference numeral 40 denotes a light source, which is installed on the rear parcel 22. As shown in FIG. A radiation surface of the light source 40 faces toward the rear of the vehicle, and uniform red light is emitted from the radiation surface. Reference numeral 43 denotes a transmission type annular hologram element, which is installed on the interior side of the rear window 21. The hologram element 43 is manufactured so that a portion of the red light emitted from the light source 40 is incident thereon, and the red light is diffracted toward the rear of the vehicle with the same brightness as the directly emitted red light.

Next, the operation will be explained. When a foot brake pedal (not shown) is stepped on, red light is emitted from the radiation surface of the light source 40. A portion of the red light passes through the center of the annular hologram element 43 and is emitted directly to the rear of the vehicle. Further, the remaining red light enters the hologram element 43 and is diffracted by the hologram element 43 toward the rear of the vehicle.

As a result, from the rear of the vehicle, the annular light emitted by the red light diffracted by the hologram element 43 and the central light emitted by the red light directly emitted from the light source 40 are connected to form a circle with a predetermined area. It appears to emit red light with uniform predetermined brightness.

As described above, according to the third embodiment, a part of the red light emitted from the light source 40 is directly emitted to the rear of the vehicle, and the rest of the red light is emitted to the rear of the vehicle by the annular hologram element 43. Made it diffract. Therefore, the first and second
In addition to obtaining the same effect as in the embodiment described above, since the red light traveling from the light source 40 in a dispersed manner can also be used, it is possible to obtain the effect that the utilization rate of the luminous flux is further improved.

Next, a fourth embodiment will be explained based on FIG. 8. In the three embodiments described above, the light source was installed in the rear parcel, but in this embodiment, the light source is installed on the roof inside the vehicle. Note that the same numbers are given to the same members as those in the first, second, and third embodiments, and detailed explanations are omitted.

In FIG. 8, reference numeral 50 denotes a light source, which is installed on the interior side of the roof 23. A radiation surface of the light source 50 faces toward the rear of the vehicle, and red light is emitted from the radiation surface. Reference numeral 53 denotes a transmission type hologram element, which is installed on the interior side of the rear window 21. Hologram element 5
3, a part of the red light emitted from the light source 50 is incident;
It is manufactured to diffract this red light towards the rear of the vehicle.

Next, the operation will be explained. When a foot brake pedal (not shown) is stepped on, red light is emitted from the radiation surface of the light source 50. Some of the red light is emitted directly to the rear of the vehicle. Further, the remaining red light enters the hologram element 53 and is diffracted by the hologram element 53 toward the rear of the vehicle.

As a result, from the rear of the vehicle, the red light diffracted by the hologram element 53 and the red light directly emitted from the light source 50 are combined, and a rectangle with a predetermined area appears to emit red light. .

As described above, according to the fourth embodiment, a part of the red light emitted from the light source 50 installed on the interior side of the roof 23 is directly radiated to the rear of the vehicle, and the remaining red light is is diffracted toward the rear of the vehicle by the hologram element 53. Therefore, even when the light source is installed on the roof inside the vehicle, the same effect as in the first embodiment can be obtained, and since the light source 50 is miniaturized, the interior of the vehicle can be used effectively. can get.

Next, a fifth embodiment will be explained based on FIG. 9. This embodiment uses a half mirror to prevent a difference in brightness from occurring between the red light directly radiated to the rear of the vehicle and the diffracted light. Note that members equivalent to those in the first embodiment are given the same numbers, and detailed explanations are omitted.

In FIG. 9, 60 is a light source, which is installed in the rear parcel 22. As shown in FIG. The light source 60 includes a white light bulb 61 inside, and the white light bulb 61 lights up when a foot brake pedal (not shown) is depressed. A red filter 62 changes the light emitted from the white light bulb 61 into red light.

A half mirror 66 constitutes the light emitting surface of the light source 60, and is installed on the inside of the rear parcel 22 so that it can be viewed directly from the rear of the vehicle. The half mirror 66 reflects a portion of the red light 64 emitted from the red filter 62 toward the rear of the vehicle, and transmits the remaining red light 65 as is. In addition, the ratio at which the half mirror separates red light is that the amount of red light 65 is
The amount of light is set to be greater than the amount of light in step 4.

63 is a hologram element. The hologram element 63 is installed on the interior side of the rear window 21 above the light source 60. Further, the hologram element 63 is manufactured so as to diffract the red light 65 transmitted through the half mirror 66 toward the rear of the vehicle.

Next, the operation will be explained. The foot brake pedal is depressed and the white light bulb 61 lights up. white light bulb 61
The luminous flux (white light) emitted from the filter passes through the red filter 62 and then enters the half mirror 66 . and,
The red light that has passed through the red filter 62 is partially transmitted through the half mirror 66 and partially reflected by the half mirror 66, thereby being separated into red light 64 and red light 65. After the red light 64 is reflected by the half mirror 66, it is emitted directly to the rear of the vehicle. Further, the red light 65 passes through the half mirror 66, enters the hologram element 63, and is diffracted by the hologram element 63 toward the rear of the vehicle.

As a result, a passenger in the following vehicle can directly view the red light emitted from the half mirror 66 by the red light 64, and at the same time see the diffraction image of the red filter 62 having approximately the same light emitting area on the hologram element 63. Can be done. Then, the prescribed light emitting area is obtained by the sum of the two light emitting areas that appear to be connected.

Furthermore, due to the wavelength selectivity and diffraction efficiency of the hologram element 63, the red light 65 passes through the hologram element 6.
A loss occurs when it is diffracted by 3. By taking this loss into consideration and adjusting the ratio of the amounts of red light 64 and red light 65 separated by the half mirror 66, the difference in brightness when viewed from the rear of the vehicle can be made substantially equal. For example, when the ratio of red light 65 incident on the hologram element 63 being diffracted toward the rear of the vehicle is 40%, the ratio of the amounts of red light 64 and red light 65 emitted from the red filter 62 should be approximately 3:7. For example, the amount of light diffracted toward the rear of the vehicle becomes equal, and uniform red light can be obtained.

As described above, according to the fifth embodiment, the red light transmitted through the red filter 62 is separated into the red light 64 and the red light 65 by the half mirror 66, and the red light 64 is separated into the red light 64 and the red light 65.
is emitted directly to the rear of the vehicle, and the red light 65 is diffracted to the rear of the vehicle by the hologram element 63. Therefore,
The same effects as in the first embodiment can be obtained, and more uniform red light can be efficiently incident on the hologram element 63. Therefore, it is possible to obtain the effect that the utilization rate of the luminous flux is further improved and power consumption can be further reduced. Furthermore, by controlling the ratio at which the half mirror 66 separates the red light, the brightness of the diffracted red light and the red light that is viewed directly can be made equal to each other more easily than when the light distribution is set by lens cutting. This effect can be obtained.

As shown in FIG. 10, a light source 70 is installed on the rear parcel 22, and the red light transmitted through the half mirror 76 is emitted directly to the rear of the vehicle, and the red light reflected by the half mirror 76 is used as a hologram. A similar effect can be obtained even if the light is diffracted toward the rear of the vehicle by the element 73.

[0045]

As described above, according to the present invention, a part of the uniformly bright red light emitted from the light emitting surface of the light source is directly radiated to the rear of the vehicle, and the remaining red light is emitted directly. The red light is emitted in the direction of the hologram element with a brightness higher than the brightness, and is diffracted toward the rear of the vehicle with the same brightness as the red light directly emitted by the hologram element.

Therefore, since the light emitting area of the hologram element is determined from the difference between the light emitting area and the light emitting area of the light emitting surface of the light source, the light emitting area of the hologram element can be made smaller, and the light source itself can also be made smaller accordingly. can do. As a result, it is possible to effectively utilize the interior of the vehicle and the trunk room. Additionally, since a portion of the red light is emitted directly to the rear of the vehicle, loss during diffraction can be reduced compared to conventional methods in which all the red light emitted from the light source is diffracted by a hologram element. . As a result, the utilization rate of the luminous flux emitted from the light source is increased, resulting in the effect that power consumption can be reduced.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a first embodiment.

FIG. 2 is a sectional view showing the first embodiment.

FIG. 3 is an explanatory diagram of the operating state of the first embodiment.

FIG. 4 is an explanatory diagram of a method of manufacturing the hologram element 13 of the first example.

FIG. 5 is an explanatory diagram of a method of manufacturing the hologram element 13 of the first example.

FIG. 6 is a perspective view showing a second embodiment.

FIG. 7 is a perspective view showing a third embodiment.

FIG. 8 is a perspective view showing a fourth embodiment.

FIG. 9 is a sectional view showing a fifth embodiment.

FIG. 10 is a sectional view showing a fifth embodiment.

FIG. 11 is a sectional view showing a conventional example.

[Explanation of symbols] 10 Light source 13 Hologram element 21 Rear window

Claims (1)

[Claims] 1. A hologram element and a light source, wherein the light source is installed at a position where a light emitting surface emits red light directly to the rear of the vehicle, and the light source emits a portion of the red light with uniform brightness from the light emitting surface. is emitted directly to the rear of the vehicle, and the remaining red light is emitted in the direction of the hologram element at a brightness higher than the brightness of the red light directly emitted to the rear of the vehicle, and the hologram element is installed in a rear window. and diffracts the red light emitted from the light emitting surface of the light source to the rear of the vehicle with a brightness that is approximately equal to the brightness of the red light directly emitted from the light source to the rear of the vehicle, and with uniform brightness; Brake lights for vehicles.