JP2800191B2 - Automotive display device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a display device for an automobile.

2. Description of the Related Art Conventionally, there is a display device for an automobile disclosed in Japanese Patent Application Laid-Open No. Sho 62-143084 in order to improve the display density. This is to provide a hologram dry plate on which the instrument image is exposed in front of the driver's line of sight with respect to the instrument panel, and irradiate the light of the reproduction lamp to the hologram dry plate to reproduce the instrument image of the hologram dry plate. When the lamp is not turned on, the instrument panel can be viewed through the transparent hologram plate, and when the reproduction lamp is turned on, the instrument image reproduced on the hologram plate can be viewed.

[Problems to be Solved by the Invention] However, when the reproduction lamp is turned on, the instrument panel located on the rear side may be seen together with the instrument image reproduced on the hologram dry plate (the image may be doubled). There is.

An object of the present invention is to provide a display device for a vehicle which is easy to see.

[Means for Solving the Problems] The present invention provides a liquid crystal screen which is disposed in front of a driver's line of sight with respect to an instrument panel, and which can be switched between a transparent state and a cloudy state, and a record on which necessary information is recorded. Medium, driving means for driving a recording medium for selecting necessary information recorded on the recording medium, a recording medium is driven by the driving means, and the recording content of the selected recording medium is An image display apparatus for an automobile, comprising: a re-imaging unit that re-images the liquid crystal screen while the liquid crystal screen is clouded.

[Operation] When the liquid crystal screen is in a transparent state, the driver can see the instrument panel through the liquid crystal screen. Then, the driving unit drives the recording medium to select necessary information recorded on the recording medium. The re-imaging means re-images the selected recording medium on the liquid crystal screen when the recording medium is driven by the driving means and the liquid crystal screen is opaque.

Embodiment An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view of a display device provided on an instrument panel of an automobile, and FIG. 2 is a front view of the display device in a state where a voltage is not applied to a liquid crystal screen described later;
FIG. 3 is a front view of the display device when a voltage is applied to the liquid crystal screen.

An analog tachometer 2 as an instrument panel is provided at the back of the instrument panel 1. That is, the pointer 4 is provided on the dial 3 on which the engine speed is drawn, and the pointer 4 is rotated by the drive mechanism 5 according to the engine speed. The tachometer 2 is a meter of relatively low importance among automobile meters.

In front of the driver's line of sight of the tachometer 2 (arrow G in FIG. 1), a dynamic scattering mode (Dynamic Scattering
Mode) is provided.
The structure of the liquid crystal screen 6 is as shown in FIG.
It has a multilayer structure. That is, a shift-type liquid crystal thin film 7 having a film thickness of about 10 μm is provided at the center, transparent electrodes 8 are provided on both sides thereof, and glass plates 9 are provided on both sides thereof. The size of the whole LCD screen 6 is 10cm x 15
cm.

The transparent electrode 8 is supplied with an AC voltage (AC
V, several tens of Hz), the liquid crystal thin film 7 flows,
Light is scattered. At this time, the liquid crystal thin film 7 has a frosted glass appearance. On the other hand, when no AC voltage is applied to the transparent electrode 8 by the AC power supply, the liquid crystal thin film 7 loses scattering properties and becomes transparent. Therefore, the liquid crystal screen 6 functions as a screen when a voltage is applied, and simply becomes a glassy transparent plate when no voltage is applied.

In FIG. 1, a holographic memory 10 as a recording medium is disposed below the liquid crystal screen 6 at a mounting angle θ with respect to the liquid crystal screen 6. The holographic memory 10 stores information such as road map information and an automobile maintenance manual. This information is recorded as analog information. Further, as the recording medium, information is recorded on a high-resolution holographic photosensitizer such as silver salt or gelatin dichromate, or aluminum, resin, or the like by using an embossing technique.

Here, information recording in the holographic memory 10 will be briefly described with reference to FIG. 5 (this recording method is called Fresnel holography).

The holographic memory recording laser oscillator 11 has He
A highly coherent laser oscillator such as a Ne laser, an Ar laser, and a Kr laser is used. Laser light oscillated from the laser oscillator 11 is reflected by a mirror 12 and split by a beam splitter 13. One of the split laser beams is changed from a beam to a diverging beam by a lens 14, and
It can be changed to parallel light by 15. The parallel laser light is scattered by a transmission diffusion plate (eg, ground glass) 16. Slide 17 is a recording medium for information. A dry plate (negative) on which information such as a road map and a maintenance manual is recorded.
It is. The laser light scattered by the transmission / diffusion plate 16 passes through the slide 17 to become object light on which information is carried.

The other laser beam split by the beam splitter 13 is reflected by mirrors 18, 19, and 20, changed from a beam into a divergent light by a lens 21, and further converted by a lens 22 into a parallel light. This light becomes reference light for forming a hologram by interfering with the object light. The light-shielding plate 23 is for positioning the information recorded on the slide 17 when recording the information on the dry plate 24. Drive device 25
Moves the dry plate 24 to change the position where information is recorded.

Then, the object light and the reference light are incident on the dry plate 24 and interfere with each other, and the interference fringes are recorded (2 to 3 m on the dry plate 24).
portions P ₀ which mφ about information is recorded is formed). Similarly, the information on the slide 17 is changed, the position of the light shielding plate 23 is changed, and a large number of information is recorded on one dry plate 24 while the dry plate 24 is rotated by the driving device 25. The dry plate 24 is developed to complete the holographic memory. Here, the arrangement angle between the slide 17 and the dry plate 24 is set to the same θ as the mounting angle between the liquid crystal screen 6 and the holographic memory 10.

Returning to the description of FIG. 1, the holographic memory 10 is moved by a drive mechanism 26 as drive means to select information. Below the holographic memory 10, there is provided a laser oscillator 27 which constitutes a re-imaging means.
27 is, for example, a He-Ne laser oscillator or a semiconductor laser oscillator. The laser oscillator 27 oscillates a laser beam as a light source for reproducing information in the holographic memory 10. The laser light is guided to the holographic memory 10 by a mirror 28 constituting a re-imaging means.

An image is formed on the liquid crystal screen 6 by the reproduction light from the holographic memory 10. As a result, images such as a road map and a maintenance manual are reproduced.

Next, the operation of the thus configured automobile display device will be described.

When it is desired to visually check the engine speed with the tachometer 2, no voltage is applied to the liquid crystal screen 6. Since no voltage is applied, as shown in FIG. 2, the liquid crystal screen 6 becomes transparent, and the tachometer 2 can be visually recognized.

When information of the holographic memory 10 is required, a predetermined AC voltage is applied to the liquid crystal screen 6. Then, the liquid crystal thin film 7 becomes cloudy and loses transparency, and becomes a display screen on which information can be displayed.

And the holographic memory from the laser oscillator 27
Laser light having the same or substantially the same wavelength as that at the time of recording is incident on the mirror 10 by a mirror 28 in a direction opposite to the reference light at the time of recording. Then, from the holographic memory 10, the amplitude and phase of the object light are exactly the same, and the holographic memory
Reproduction light is generated from 10 toward the liquid crystal screen 6. This reproduction light forms an image on the same plane as that at the time of recording the information on the slide 17, that is, on the liquid crystal screen 6, and reproduces a map as shown in FIG. Therefore, as described above, the information of the slide 17 is completely distorted on the liquid crystal screen 6 by the holographic technique, and reproduced without blur.

As described above, in the present embodiment, the liquid crystal screen 6 disposed in front of the driver's line of sight (arrow G) with respect to the tachometer 2 is turned into a cloudy state or a transparent state by applying or not applying an AC voltage. By switching and irradiating the holographic memory 10 with laser light in the cloudy state, the recorded contents can be re-imaged on the liquid crystal screen 6.
Therefore, the information of the tachometer 2 and the holographic memory 10 can be displayed depending on whether or not the AC voltage is applied,
The display density is improved. This display content can easily display other information by changing the information recording position of the holographic memory 10 or replacing the holographic memory 10. That is, a conventional device (Japanese Patent Laid-Open No. 62-14 / 1987)
No. 3084), other information cannot be obtained because the hologram dry plate is fixed. However, in this embodiment, the fixed liquid crystal screen 6 is merely used as a screen, and the information is not used. Since the information is obtained from the holographic memory 10, various information can be obtained.

Also, when the reproduced image is projected on a screen such as a normal frosted glass, a very unpleasant glare is generated in the reproduced image. This is a phenomenon called specifications. However,
In the present embodiment, since the liquid crystal molecules are flowing by the AC electric field in the liquid crystal screen 6, the scattered light fluctuates with time and the glare is averaged over time. Fewer images are reproduced.

When a microfilm 31 is used instead of the holographic memory as shown in FIG. 6, even if the image is reproduced by the optical system (projector 32), the image on the screen 33 is only partially. Although it is difficult to focus, it can be dealt with by considering the arrangement of the optical system and the state of scattering of light from the optical system onto the screen 33.

The present invention is not limited to the above embodiment, but may be implemented as shown in FIG.

That is, a safety pad 29 serving as a housing for meters and the like is provided on the front upper surface of the liquid crystal screen 6, and a mirror 30 is provided on the lower surface thereof, and the reproduction light is directed to the liquid crystal screen 6 by the mirror 30. Then, the reproduction light from the holographic memory 10 is turned back by the mirror 30,
An image is formed on the liquid crystal screen 6. The liquid crystal screen 6 may scatter the reproduced light imaged thereon in the backward direction, that is, in the direction of the driver, so that the driver can recognize the image by looking at the light.

Further, in the above embodiment, the liquid crystal screen is disposed in front of the driver's line of sight with respect to the tachometer as the instrument panel.
A liquid crystal screen may be provided in front of another instrument panel such as a speedometer.

[Effects of the Invention] As described in detail above, according to the present invention, the instrument panel and the recorded contents imaged on the liquid crystal screen do not appear together, and information that is easy to see for the driver can be given.
In addition, information reimaged on the liquid crystal screen can be selectively displayed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an automobile display device according to an embodiment of the present invention, FIG. 2 is a front view of the automobile display device, FIG. 3 is a front view of the automobile display device, and FIG. 5 is a cross-sectional view, FIG. 5 is a view for explaining a recording method of a holographic memory, FIG. 6 is a view showing a reproducing method using another example of a microfilm, and FIG. It is a cross section of a device. 2 is a tachometer as an instrument panel, 6 is a liquid crystal screen,
Reference numeral 10 denotes a holographic memory, 27 denotes a laser oscillator constituting the re-imaging means, and 28 denotes a mirror constituting the re-imaging means.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-143084 (JP, A) JP-A 49-18544 (JP, U) JP-A 53-12351 (JP, U) (58) Investigation Field (Int.Cl. ⁶ , DB name) G03H 1/22 G02F 1/13 G02B 27/02

Claims (3)

(57) [Claims] 1. A liquid crystal screen disposed in front of a driver's line of sight with respect to an instrument panel and switched between a transparent state and an opaque state, a recording medium on which necessary information is recorded, and a recording medium on the recording medium Driving means for driving the recording medium for selecting the necessary information, and the recording medium is driven by the driving means, and the recorded contents of the selected recording medium are displayed in a state where the liquid crystal screen is clouded. And a re-imaging means for re-imaging on the liquid crystal screen. 2. The display device according to claim 1, wherein said recording medium is a holographic memory. 3. The apparatus according to claim 2, wherein said re-imaging means comprises a laser oscillator for oscillating laser light, and a mirror for irradiating the holographic memory with laser light from the laser oscillator. 3. The display device for a vehicle according to claim 2.