JPH08113059A - Head-up display device for vehicle - Google Patents

Abstract

PURPOSE: To make a combiner inconspicuous from the interior and exterior by projecting a combiner part above a dash board when a driver wants to obtain necessary information and storing the combiner part into the dash board when information is not needed. CONSTITUTION: When a switch is turned on by a driver, a light emission display means 2 stored in a dash board 9 and a transparent light transmission body 3 to which a hologram 4 is stuck as a combiner in the upper part thereof go up through a rack with the rotation of a pinion by a motor. Also, a light emission display means 2 is simultaneously electrified, information containing light 7 is reflected by the boundary face between the transparent light transmission body 3 and air, diffracted by the hologram 4 and recognized by a driver 1. When display information is not needed, the transparent light transmission body 3 and the light emission display means 2 are stored into the dash board 9 by turning off the switch.

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 device for a vehicle, in which a driver of a vehicle can see the information on the instrument panel of the vehicle by superimposing the information on the instrument panel on the outside with the line of sight fixed to the front. is there.

[0002]

2. Description of the Related Art In a vehicle such as an automobile, as a display device used to display vehicle speed and other vehicle information, a combiner such as a half mirror or a hologram provided on a windshield displays a CRT or a backlit LCD. There is known a head-up display device that projects a display image by image projection means.

FIG. 6 shows a conceptual diagram of a conventional head-up display device. Here, 11 is the observation position of the driver,
Reference numeral 12 is a light emitting display unit, 15 is a combiner, 16 is a windshield, 17 is light containing information, and 18 is a display image (virtual image). The light emitted from the light emitting display unit 12 is applied to the combiner 15 provided on the windshield 16 and is reflected to be visually recognized by the driver at the observation position 11. At this time, the display information is recognized by the driver as a virtual image at position 18.

[0004]

However, in a vehicle head-up display device having a combiner provided on the windshield as described above, a half mirror is formed on the windshield as a combiner, or a hologram is attached or enclosed. , There is a problem that the combiner part stands out even when the display is not made.

[0005]

The present invention has been made to solve the above-mentioned problems, and a transparent light guide, a combiner provided in the transparent light guide, and a light containing information are displayed on the display image. A head up display device for a vehicle, wherein the light from the light emitting display means can be guided to the combiner by the transparent light guide, and the transparent light guide is movable. The combiner appears on the dashboard of the vehicle when the displayed image is displayed, and when the combiner is hidden, the combiner can be stored in the dashboard. is there.

The present invention will be described below with reference to examples. FIG. 1 is a conceptual diagram of an example of a vehicle head-up display device of the present invention. 1 is a driver's observation position, 2 is a light emitting display means, 3 is a transparent light guide, 4 is a hologram as a combiner attached to the transparent light guide, 6 is a windshield, 7 is light containing information, 8 Is a display image (virtual image) formed at a distance, and 9 is a dashboard.

When a driver or a passenger operates a switch (not shown), the light emitting display means 2 stored in the dashboard 9 and the transparent light guide 3 provided with the hologram 4 are raised, and at the same time, the light emitting display is performed. The means 2 is switched on and a light 7 containing information is emitted. The light 7 including the information emitted by the light emitting display unit 2 is reflected by the interface between the transparent light guide 3 and the air, diffracted by the hologram 4, and visually recognized by the viewer as a driver at the observation position 1. At this time, the display information is recognized by the viewer as a virtual image at position 8. Further, when the viewer does not need the display information, the switch (not shown) is operated to operate the transparent light guide 3 including the hologram 4.
The light emitting display means 2 can be stored in the dashboard, and at the same time, the light emitting display means 2 is turned off.

Here, the information to be displayed is appropriately selected according to its display application, and examples thereof include a vehicle speedometer, tachometer, warning display, navigation and the like.

FIG. 2 is a side view of the main part of the embodiment of the present invention shown in FIG. The light 7 containing the information emitted from the light emitting display means 2 is reflected at the interface between the transparent light guide 3 and the air, and is diffracted by the hologram 4 at a predetermined angle. Visible at position 1.

The light emitting display means 2 in this embodiment is a normal VHC (Very High C) which is a halogen lamp 21 as a backlight and a transmissive LCD (liquid crystal display element).
The LCD 25 includes an LCD 25, an heat absorbing glass 22, a diffusion plate 23, and a bandpass filter 24. The VHC LCD 25 is controlled by an external signal from the vehicle speed detection means and displays the speed according to the segment pattern. The display size in this embodiment is 15 mm (length) × 30 mm.
(Horizontal)

In addition, a dot matrix type or a transmissive LCD of a thin film transistor (TFT) active matrix driving system may be used as a display element in place of the VHC LCD 25, and is not limited to a single color display like the display image in this embodiment. By providing color filters divided in the plane, or in the case of the dot matrix type, by providing color filters of three colors for each dot,
Color display is also possible. In this case, it is necessary to use a light source that emits corresponding light and a hologram that has been subjected to multicolor exposure. Further, the light emitting display means may be a self-luminous type such as a fluorescent display tube without using a light receiving type display element such as an LCD.

Here, as the light source for the LCD backlight, a 12V20W halogen lamp 21 having a rotating parabolic reflector is used and a light source which emits light into a substantially parallel light flux is used. A tube or a semiconductor laser may be used, but a light source close to a parallel light flux is desirable in order to improve the quality of a displayed image. Further, the light emitting display means 2 is provided with a VHC LCD2 by the heat rays of the halogen lamp 21.
A heat ray absorbing glass 22 is provided on the front surface of the halogen lamp 21 in order to prevent damage such as 5. Then, a diffusion plate 23 made of frosted glass is provided to prevent uneven illumination of the light source, and a bandpass filter 24 having a central wavelength of 545 nm, a half value width of 8 nm and a transmittance of 40% is provided between the halogen lamp 21 and the VHC LCD 25 to select the wavelength of the light source. Installed in between.

A combination of a rack 52 and a pinion 51 was used as a drive system for raising and lowering the transparent light guide 3 provided with the hologram 4 serving as a display section and the light emitting display means 2. The rack 52 is located below the side surface of the transparent light guide 3 at a position where it does not affect the light guide of the display image.
I installed it in a position where I could not see it on the dashboard.
The central axis of the pinion 51 is connected to the motor 53. When the driver or passenger operates a switch (not shown) of the motor, the transparent light guide 3 and the light emitting display means 2 are raised or lowered by the forward and reverse driving of the motor. A limit switch (not shown) is provided for raising and lowering to prevent excessive raising and lowering.

In this embodiment, as the transparent light guide 3, a transparent synthetic resin made of methacrylic acid methyl ester having a refractive index of 1.49 and a transmittance of 93% is used, but it is made of other transparent resin or glass. It may be a light guiding means and is not specified as long as it has a similar function, but it is determined in consideration of the refractive index, the transmittance, the refractive index of the hologram material, the durability, and the designability.

In the embodiment, 13 mm (thickness) × 30 mm (horizontal) × 100 in consideration of the size and display area of the LCD.
A transparent light guide 3 having a size of mm (length) is produced, and the end face is polished so as to be almost a mirror surface. Similarly, since the light from the light emitting display means 2 is incident, a wedge-shaped transparent light guide is provided so that the incident light becomes 60 degrees with respect to the vertical line of the wall surface of the transparent light guide which is the basis as shown in the figure. After being manufactured and cured, the transparent light guide was adhered using an optical adhesive having a refractive index substantially equal to that of the transparent light guide to integrate the light emitting display means. In addition to this, the transparent light guide 3 may be manufactured by an injection molding method, and the shape can be appropriately changed depending on the light emitting display means 2, the shape of the vehicle, the mounting position, and the design. Further, the light emitting display means does not necessarily have to be integrated with the transparent light guide, and information can be guided from the light emitting display means to the transparent light guide using a light guide means such as an optical fiber. In terms of accuracy, it is preferable to integrate them.

As the hologram 4 in this embodiment,
It is an acrylic photopolymer and used a Lippmann type volume / phase type hologram. In addition to the above, various photosensitive materials such as polyvinylcarbazole-based photopolymers, dichromated gelatin, photoresists, and silver salts can be used as the hologram material, and as the hologram, volume / phase type such as Lippmann type can be used. Is desirable in that it can obtain high diffraction efficiency,
The so-called holograms such as emboss type and rainbow type can also be widely used.

The hologram 4 of this embodiment has a wavelength of 545 nm so as to match the center wavelength of the bandpass filter 24 of the light emitting display means 2, and has an incident angle of 60 degrees in a medium having the same refractive index as the transparent light guide 3. It is a reflection-type hologram that is produced by exposure using parallel light object light, hologram dry material, and reference light that is a diverging spherical wave having a distance of 30 cm between point light sources so as to have a diffraction angle of 3.5 degrees. The size of the hologram 4 was 35 mm (length) × 30 mm (width).

In this embodiment, the light 7 emitted from the halogen lamp 21, which is a light source, passes through the heat ray absorbing glass 22, the illuminance unevenness is reduced by the diffusion plate 23, and passes through the band pass filter 24 and the VHC LCD 25 for transparent light guiding. It is incident on the body 3. Since the incident light is incident on the wall surface which is the interface between the transparent light guide 3 and the air at an angle equal to or greater than the critical angle, it is almost totally reflected and guided to the hologram 4. The hologram 4 diffracts the guided light and is visually recognized by a driver as a driver.

In this embodiment, the incident angle is 60 degrees and the diffraction angle is 3.5 in the medium having the same refractive index as the transparent light guide 3.
However, it is set appropriately according to the mounting position of the apparatus and the position of the viewer, and is not particularly limited and is comprehensively determined.

In this embodiment, the reflection at the interface due to the difference in the refractive index between the transparent light guide 3 and air is utilized. However, a layer having a lower refractive index than the transparent light guide 3 is used as the transparent light guide. The same effect may be obtained by forming it on the wall surface of.

FIGS. 3 and 4 are side views of the essential parts of another embodiment of the present invention. As shown in FIG. 3, in addition to the hologram 41 serving as a combiner, a second light source is provided below the transparent light guide 31.
The hologram 42 is provided, and the light 71 from the light emitting display means 2 is provided.
Can be guided to the transparent light guide 31 by the second hologram 42, and aberration correction may be performed by the hologram 41 and the second hologram 42 which are combiners.

Further, as shown in FIG. 4, a transparent hologram 43 is provided on the viewer side of the transparent light guide 32, and light 72 from the light emitting display means 2 passes through the transparent hologram 43 and is visually recognized by the viewer. It can also be done.

FIG. 5 is a conceptual diagram of another embodiment of the apparatus of the present invention. The storage direction of the transparent light guide according to the present invention is shown in FIG.
In addition to the ones that drop into the dashboard like
It is also possible to fall down like. In FIG. 5, 7
Reference numeral 3 is a light containing information, and reference numeral 81 is a display image (virtual image).

[0024]

As described above, according to the vehicle head-up display device of the present invention, the combiner section appears on the dashboard only when it is desired to obtain information necessary for driving, and when the information is not required. Enables the combiner unit to be stored in the dashboard. Therefore, unlike the conventional case, the combiner is not directly provided on the windshield, so that the combiner does not stand out from the inside and outside of the vehicle when the information is not displayed, which is not an obstacle. Also, the durability of the combiner portion is improved.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an example of an apparatus of the present invention.

FIG. 2 is a side view of the main part of the embodiment of FIG.

FIG. 3 is a side view of a main part of another embodiment of the present invention.

FIG. 4 is a side view of the main part of another embodiment of the present invention.

FIG. 5 is a conceptual diagram of another embodiment of the present invention.

FIG. 6 is a conceptual diagram of a conventional head-up display device.

[Explanation of symbols]

 1, 11: Driver's observation position 2, 12: Light emitting display means 3, 31, 32: Transparent light guide 4, 41, 42, 43: Hologram 15: Combiner 6, 16: Windshield 7, 17, 71, 72, 73: Light containing information 8, 18, 81: Display image (virtual image) 9: Dashboard 21: Halogen lamp 22: Heat ray absorbing glass 23: Diffuser 24: Bandpass filter 25: VHC LCD 51: Pinion 52: Rack 53: Motor

Claims (3)

[Claims] 1. A transparent light guide, a combiner provided on the transparent light guide, and a light emitting display means for emitting light containing information as a display image. Light from the light emitting display means is transparently conducted. A vehicle head-up display device capable of guiding light to a combiner by an optical body, wherein the transparent light guide is movable, and when the display image is displayed, the combiner appears on the dashboard of the vehicle, A vehicle head-up display device characterized in that the combiner can be stored in the dashboard when it is not displayed. 2. The vehicle head-up display device according to claim 1, wherein the light emitting display means is provided integrally with the transparent light guide. 3. The vehicle head-up display device according to claim 1, wherein the combiner is a combiner using a hologram.