JPH06191325A - Head-up display - Google Patents

Abstract

PURPOSE:To provide a head-up display in which display distance comprising multiple colors is varied to enable stereoscopic display of the multiple colors for various information. CONSTITUTION:An information light comprising multiple colors emitted from an information display source located on the underside of a windshield glass 7 is applied on a combiner 2 composed of a reflection type hologram, diffracted, and recognized visually by an observer at an observation position 1 from a display distance different according to colors.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head-up display (hereinafter referred to as HUD) which displays multicolor information.

[0002]

2. Description of the Related Art HUD has recently been used as a method of displaying information to a driver in a vehicle. This is a system in which optical information projected from an information display source such as a liquid crystal display is displayed on a combiner composed of a half mirror, a hologram, etc., so that the driver can read the information from the driving state without moving the line of sight. Is.

In particular, a hologram using a hologram as a combiner can have a lens function and the like as well as a function of diffracting optical information toward the driver.
It is possible to diffract optical information in the driver's field of view, or to form an image at any position without using an optical system such as a lens, and without impairing the foreground brightness. It is effective as a combiner for HUD because it has a feature that a high-intensity display image can be obtained.

FIG. 3 is a conceptual diagram showing an example of a conventional HUD. A light ray 23 including information to be displayed, which is emitted from a light source 26 and has passed through a transmissive liquid crystal display element 25 through a lens system 24, is applied to a hologram 22 provided on a windshield 27 of a vehicle body and is diffracted. It is visually recognized at observation position 21.

The lens system 24 has a function as a collimator, and the function is the hologram 2.
It can be attached to 2, and speed display 29 and warning display 30
It is also possible to form the display image of (1) in the distance.

Further, since the hologram 22 has a wavelength selection function, an image of a desired color can be displayed. Usually, the color is often single, but if the hologram 22 is exposed in multiple colors, multicolor display is possible, and the amount and quality of display information can be improved. For example, by setting the speed display 29 to green and the warning display 30 to red, it becomes possible to transmit information to the observer more accurately.

The hologram capable of multicolor display as described above can be exposed by the method shown in FIG. 4. For example, a reflection type hologram is exposed as follows.

A laser beam 42 of a first wavelength and a laser beam 4 of a second wavelength are provided on one side of the photosensitive material 41 of the hologram.
3 and at the same time, the other side of the photosensitive material 41 of the hologram is irradiated with the laser light 42 ′ having the first wavelength and the laser light 43 ′ having the second wavelength.

At this time, the laser beams of the first and second wavelengths are
The laser light 42, 42 'of the first wavelength is diffused by the objective lenses 44, 44', 45, 45 ', respectively, and becomes diffused light 46, 46', and the laser light 4 of the second wavelength 4
3, 43 'become diffused light 47, 47' and are applied to the hologram photosensitive material 41. In such a conventional exposure method, the optical distances from the photosensitive material 41 to the objective lenses 44, 44 ', 45, 45' for the respective wavelengths are the same (hereinafter, referred to as the photosensitive material at the time of exposure). The distance to the objective lens is called the exposure distance.).

[0010]

HUDs using conventional holograms are often monochromatic, and as shown in FIG. 3, multicolor display images 29, 30 are formed by the above-described multicolor exposure.
Even in the HUD in which the image is obtained, the distances from the display images 29 and 30 to the combiner 22 are the same. Therefore, since the display images 29 and 30 are observed as a planar image by the observer 21, the information transmission to the observer of the HUD is merely transmission of the situation, and the hologram performance cannot be fully utilized. It was not (hereinafter, the distance between the combiner and the display image is called the display distance).

Further, Japanese Patent Laid-Open No. 2-186319 discloses a HUD in which information is transmitted by light of a plurality of colors in order to utilize the performance of the hologram.
The UD can display information by changing the display distance according to the light rays of each color. However, a light ray containing information emitted toward a hologram has a different position of a light source depending on its color. Therefore, if the positional relationship between these light sources is not proper unless precise adjustment is made, it depends on each color. The viewing direction of the reproduced display image will be shifted.

Further, in the above HUD, since a dedicated information display source is required for each color of light used, the light source becomes extremely large as a whole, and the number of reproducible wavelengths is limited, and the operation is limited. It had the drawback of taking up valuable space in front of the seat.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and to newly provide a head-up display which has not been known.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and includes at least a light source and a display for displaying information to be displayed, and generates information to be displayed as a light beam. In a head-up display having at least an information display source and a combiner provided on a windshield of a vehicle and diffracting the light rays toward an observer, the information display source generates light rays of a plurality of colors. The combiner is a hologram that is exposed so that the display distance from the display image to the combiner varies depending on the color of the light beam.

[0015]

In the hologram used as the combiner of the HUD of the present invention, when the hologram photosensitive material is irradiated with light of a plurality of colors and exposed, the exposure distances of the respective lights to be irradiated are different, so that the respective display distances are colored. It is different depending on.

Therefore, the observer, especially the driver can observe the information to be displayed without moving the line of sight, and since the display distance is different depending on the color, three-dimensional display of a plurality of colors is possible, It is possible to obtain a HUD that enables more advanced information transmission.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram showing an example of a HUD in the present invention. An information display source is provided below the windshield 7, and this information display source allows the light emitted from the light source 6 to pass through the lens system 4, which is a collimator, and to display the display body 5 composed of a transmissive liquid crystal display element. Information that should pass through and be displayed is emitted as a light beam. This light beam is applied to the combiner 2 made of a reflection hologram provided on the windshield 7 of the vehicle body 8 and diffracted, and the observer observes the position 1
Is visible at.

Combiner 2 composed of a reflection hologram
Indicates that the display distance differs depending on the light rays of a plurality of colors, and the distance is independently determined for each of those colors.

For example, when the speed information and the warning information are simultaneously emitted from the information display source, the speed display 9 of the first light ray having a green color has a display image at a position farther than the warning display 10 of the second light ray having a red color. As a result, the red warning display is observed by the observer in a three-dimensional manner as if it were floating, compared to the green speed display. As described above, by giving meaning to the display color and independently defining the display distance, it is possible to express information in a higher degree.

Next, a method of exposing a hologram used as a combiner in the present invention will be described. FIG. 2 is a schematic cross-sectional view illustrating a method of exposing a hologram used as a combiner in the present invention. A laser beam 12 of a first wavelength made of a red Kr laser having a wavelength of 647 nm and a laser beam 13 of a second wavelength made of a green Ar laser having a wavelength of 515 nm are directed toward one side of the photosensitive material 11 of the hologram. Irradiate, and at the same time, the laser light 12 'of the first wavelength is directed toward the opposite surface.
And a laser beam 13 'having a second wavelength.

At this time, the laser light 1 of the first and second wavelengths
2, 12'13, 13 'are objective lenses 14, respectively
14 ', 15, 15' are diffused, and the laser light 12, 12 'of the first wavelength becomes diffused light 16, 16',
The laser light 13, 13 'of the second wavelength is the diffused light 17, 1,
7'is irradiated onto the photosensitive material 11 of the hologram.

The distance between the objective lenses 14 and 15 and the photosensitive material 11 is 350 mm, the distance between the objective lens 14 'and the photosensitive material 11 is 950 mm, and the distance between the objective lens 15' and the photosensitive material 11 is 950 mm. The distance is 1000 mm, and the exposure distance differs depending on the light having different wavelengths.

By providing the hologram thus obtained on the windshield 7 separated from the information display source by 350 mm as shown in FIG. 1, the velocity display 9 of the first light beam having a green color is 1000 mm from the combiner 2. A warning display 10 of a second light ray having a red color with a display image formed at the position 10
A display image is formed at a position of 950 mm from the combiner 2, and the observer observes it three-dimensionally as if the red warning display was raised compared to the green speed display. In this way, it is possible to give more advanced information expression by giving meaning to the display color and independently defining the display distance.

Even if the speed display is the same, if the speed is below the speed limit and the color is above the speed limit and above the speed limit is displayed in red, the display color changes and the display image changes when the speed exceeds the speed limit. Since it looks more floating than before, visibility can be improved and safety can be expected.

Here, the information to be displayed in the present invention is appropriately selected according to its display application, and examples thereof include a vehicle speedometer, a tachometer, and various warning lamps. The display distance can be set according to the urgency and necessity of information transmission.

The observer is mainly a driver of the vehicle, but can also include passengers such as the passenger seat and all the passengers.

The hologram is usually several 10 mm square to several 1
It has an area of about 00 mm square and a thickness of about several tens of μm, and has a light diffraction function. As the hologram, a volume / phase type hologram such as a Lippmann type is preferable, but a so-called hologram such as an emboss type or a rainbow type can be widely used. As the hologram material, various photosensitive materials such as polyvinyl carbazole, acrylic-based photopolymers, dichromated gelatin, photoresists, and silver salts can be used.

Such a hologram is provided in the windshield, and for example, the surface of the windshield (the outer surface of the vehicle).
Although it may be provided on the inner surface of the vehicle or the inside of the vehicle, it is preferably used by being enclosed inside the windshield which is a laminated glass in view of the protection of the hologram.

The information display source in the present invention has a function of emitting light to display, and a cold cathode tube, a hot cathode tube, a fluorescent display tube ( It emits light emitted from a light source such as a VF), a halogen lamp, and an LED, and may have these functions together.

Examples of the liquid crystal display device include a color filter and a transmission type twisted nematic liquid crystal display device,
A liquid crystal display device including a super twist nematic liquid crystal display device or the like can be preferably used, and light emitted from one light source can be irradiated as light of a desired color.

In this way, the light beams of a plurality of colors in the present invention can be emitted from the same information display source, and when the light beams of a plurality of colors are simultaneously displayed, the display images are displayed in an overlapping manner. On the contrary, in order to prevent the overlapping of the displayed images, a combination of a color filter and a light source or a color liquid crystal display element is controlled as necessary so that light of plural colors is not simultaneously irradiated. Good.

In the case where the light source is also used for the light receiving type display element, an appropriate light beam collimating means such as a lens system or a curved reflecting mirror and a suitable light guiding plate are provided between the light receiving type display element and the light source. Light means may be arranged. Further, if necessary, a light deflector or a non-linear optical element such as KNbO ₃ may be arranged in the optical path until the light is projected on the hologram.

In addition to the above, a light-receiving display element is not used, the light sources themselves are patterned and arranged, and a color filter of a color according to the content of information is provided to generate specific information as light. It may be. For example, in the above example, the speed display pattern has a green filter,
It is desirable to provide a red filter for the warning display.

Further, the hologram in the present invention is not limited to the reflection hologram as described above, but a transmission hologram obtained by irradiating laser light from two directions on one side of the hologram photosensitive material to perform exposure is used. It may be the same head-up display.

Further, the HUD of the present invention is not limited to the display of two colors as shown in the above-mentioned embodiment, and it is also possible to display three or more colors by using the hologram exposed by light of three kinds of wavelengths. If, for example, green indicates speed, yellow indicates caution, and red indicates warning, and the distance from these displayed images from the hologram is shortened in the order of green, yellow, and red, the urgency and seriousness of the information will be reduced. As the sex increases from the caution display to the warning display, it is observed by the observer that the displayed images gradually rise, and more accurate and sophisticated information expression is possible.

As a hologram used as such a combiner of HUD, one hologram obtained by so-called multiple exposure, in which one photosensitive material is irradiated with laser light of a plurality of wavelengths as described above, is used. Alternatively, it is also possible to prepare a plurality of photosensitive materials, expose each of them with light of a different wavelength, and superimpose these holograms to form a combiner.

Furthermore, the colors of the display image are not limited to the above three colors, and a desired number of colors can be appropriately selected and used. Further, the distances of the display images of the respective colors may all be different, and, of course, two or more kinds may have the same distance.

Further, when the hologram photosensitive material is exposed, the distance between the objective lens on one side and the hologram photosensitive material is the same, but the same effect can be obtained even if the distances are different. Furthermore, by appropriately determining the exposure distance when exposing the photosensitive material,
Not limited to the above embodiment, display information of various display distances can be transmitted to the observer at various positions.

[0039]

According to the present invention, the light containing the information emitted from the information display source is diffracted toward the observer by the combiner, and the hologram used as the combiner has the light having a plurality of wavelengths as the hologram photosensitive material. When irradiating and exposing, since the exposure distance of each irradiation light is different, the display distance formed by each display image is different.

Therefore, the observer, especially the driver, can observe the information to be displayed without moving the line of sight, and the display distance can be made different depending on the colors, so that the three-dimensional display of a plurality of colors is possible. It is possible to display, and it is possible to obtain a HUD that enables more accurate and high-level information transmission including the perspective of the displayed image.

Further, according to the present invention, display lights of a plurality of colors including information emitted from the same position are emitted as a plurality of colors of information light for the observer to visually recognize as display images of different display distances. The light sources can be concentrated in one place, and a HUD having a compact information display source can be obtained.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing an example of a HUD in the present invention.

FIG. 2 is a schematic cross-sectional view for explaining a hologram exposure method used in the combiner of the present invention.

FIG. 3 is a conceptual diagram showing an example of a conventional HUD.

FIG. 4 is a schematic sectional view showing a method of exposing a conventional reflection hologram.

[Explanation of symbols]

 1, 21: Observing position of observer 2, 22: Combiner 3, 23: Ray containing information 4, 24: Lens system 5, 25: Display 6, 26: Light source 7, 27: Windshield 9, 29: Velocity Display 10, 30: Warning display 11, 41: Photosensitive material 12, 42: Laser light of first wavelength 13, 43: Laser light of second wavelength 14, 15, 44, 45: Objective lens 16, 46: Second Diffused light of laser light of the first wavelength 17, 47: Diffused light of laser light of the second wavelength

Claims (1)

[Claims] 1. An information display source, which comprises at least a light source and a display for displaying information to be displayed, and which generates information to be displayed as a light beam, and a windshield of a vehicle, wherein the light beam is provided to an observer. In a head-up display having at least a combiner diffracting toward,
The head-up display, wherein the information display source generates light rays of a plurality of colors, and the combiner is a hologram that is exposed so that a display distance from a display image to the combiner varies depending on the colors of the light rays.