JPH04361221A - Optical device - Google Patents

Abstract

PURPOSE:To provide a high-safety optical device which prevents a displayed image from disturbing an external field scene in an optical device which can superimpose incident light from a front scene and incident light from the image displayed on a display unit on one over the other nearby a window shield by a hologram. CONSTITUTION:This optical device consists of a display means 1, an image forming means 2, and the reflection type hologram 4; and the image forming means 2 images the light from the image displayed on the display means 1 at the position of the reflection type hologram 4, which is an off-axis type and has a wave front converting function and reflects the light imaged by the image forming means 2. A 1st light 7 which is made incident on the image forming means 2 from the reflection side of the reflection type hologram 4 and transmitted through the reflection type hologram 4 and a 2nd light 8 which is reflected by the reflection type hologram 4 are superposed.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an optical device for displaying an image in front of a vehicle, etc., and in particular, the present invention relates to an optical device for displaying an image in front of an automobile, etc., and in particular, it is displayed by superimposing incident light from the front scenery and incident light from an image displayed on a display using a hologram. The present invention relates to an optical device that can perform

[0002] Recently, heads-up displays (hereinafter referred to as H
(UD) is used in various directions, but when it is installed as a device to display the speed of a car, the image is displayed far ahead of the windshield, so the image is not visible on the driving route or traffic. Since it obstructs people's view of the outside world and takes time to recognize the situation, resulting in a lack of safety, a display that can improve safety is desired.

0003

[Prior Art] Fig. 5 shows a conventional example, in which (a) is a side view showing a general configuration of a HUD device used for displaying the speed of a car, and (b) a truck, respectively, for a passenger car and a truck. . As shown in the figure, a display (hereinafter referred to as CRT) 1a, a lens 2a, a plane mirror 3, and a reflective hologram 4a are arranged inside a windshield 5.

[0004] Having such a configuration, the CRT1a
Green light indicating the speed of the car displayed on the screen is focused by a lens 2a, reflected by a plane mirror 3, reflected by a hologram 4a, and diffracted in a predetermined direction. An image showing the speed can be seen in front of the shield 5. Therefore, in front of the windshield 5, the scenery such as the driving route can naturally be seen through the hologram 4a,
The speed display appears superimposed on this.

[0005]

[Problem to be Solved by the Invention] According to the above conventional method, since the displayed image is enlarged and distanced by the lens,
The image the driver sees is displayed in front of the windshield. This displayed image obstructs the view of the road, passersby, etc., so it takes a lot of time for drivers to carefully look at various locations from far to near in the outside world to ensure safety. This is especially noticeable in vehicles with a driver's seat in the front, such as trucks.
There is a problem that it lacks safety.

[0006] An object of the present invention is to provide an optical device that can improve safety.

[0007]

[Means for Solving the Problems] FIG. 1 is a diagram showing the principle of the present invention. In the figure, 1 is a display means for displaying a predetermined image, 2 is an imaging means for focusing light from the image displayed on the display means 1 on the position of a reflection hologram 4, 4 is an off-axis type, and It is a reflection hologram that has a wavefront conversion function and reflects the light imaged by the imaging means 2.

Reference numeral 7 denotes the first light that enters the imaging means 2 from the opposite side of the reflection hologram 4 and passes through the reflection hologram 4; 8, the first light that is imaged by the imaging means 2 and forms the reflection hologram 4; This is the second light reflected by the

[0009] Therefore, the structure is such that the first light 7 and the second light 8 are superimposed.

0010

[Operation] The first light 7 transmitted through the reflection hologram 4,
The image of the display means 1 is imaged by the imaging means 2 at the position of the reflection hologram 4, and the second light 8 reflected by the reflection hologram 4 appears to be superimposed, and at this time, the second light 8 is reflected. Since it appears at the position of the type hologram 4, the first light 7 and the second light
For example, if the first light 7 is a view of a car path or a passerby, the second light 8 can be distinguished from the view.
It can be clearly distinguished from the displayed image, does not interfere with the recognition of the scenery, and can improve safety.

[0011]

[Embodiment] An embodiment of the present invention will be explained with reference to FIGS. 2 to 4. The same reference numerals indicate the same objects throughout the figures. The CRT 1a, lens 2b, hologram 4b, front view light 7a, and display light 8a in FIG. The second light 7 corresponds to the second light 8, respectively.

FIG. 2 is a side view showing an embodiment in which the present invention is applied to the HUD device described in the conventional example, and as shown in the figure,
A CRT 1a, a plane mirror 3a, a lens 2b, and a filter 6 (corresponding to claim 3) are arranged in a dashboard 9 of an automobile, and a hologram 4b is glued between the joints of a windshield 5 made of laminated glass. ing.

The hologram 4b is an off-axis reflection type multiple hologram (corresponding to claim 4) having a wavefront conversion function (in this case, a concave lens function). Therefore, the image formed by the lens 2b is reflected and diffracted, and the display light 8a is formed at the position of the windshield 5. Further, as for disturbance light from the windshield 5, for example, incident light from the sun, only light in the wavelength band λ0 is transmitted, as shown in FIG. 4(a).

[0014] Here, the method for creating the hologram 4b will be explained. As shown in FIG. It is created by irradiating an object wave (convergent spherical wave) a and a reference wave (divergent spherical wave) b from the opposite side.

At this time, the convergence virtual point of the object wave a (the convergence position indicated by the broken line in the figure) is a point corresponding to the position of the driver's eye 10, and the light source position of the reference wave (the divergence position indicated by the solid line in the figure) is the point corresponding to the position of the driver's eye 10. be the principal point position of

Furthermore, by performing multiple exposures while varying the above-mentioned exposure angle and other production conditions, it is possible to match the emission wavelength band of the CRT 1a, that is, to match different emission colors (so-called colorization).

The lens 2b is set relative to the CRT 1a, the plane mirror 3a and the hologram 4b, and
It is arranged so that the light of the image of RT1a is reflected by the plane mirror 3a, and an image is formed at a position where it intersects with the hologram 4b (at an angle that is easy for the driver to see). (Claim 2
As shown in FIG. 4(b), the filter 6 has the function of passing only the wavelength band λO of light transmitted and reflected by the hologram 4b, and is disposed in front of the lens 2b.

With this configuration, for example, when a driver drives a car, the windshield 5
The front view light 7a from the road ahead of the driver and the scenery passes through the hologram 4b and enters the driver's eyes 10.
The display light 8a of the image displayed on T1a is transmitted through the plane mirror 3.
It is reflected by the lens 2b and formed into an image at the position of the windshield 5 by the hologram 4b, and is reflected and diffracted by the hologram 4b to reach the driver's eye 10, and can be seen at a position intersecting the windshield 5 by the lens function of the hologram 4b. can.

At this time, the scenery outside the vehicle and the display image appear to overlap, but since the display image is located at a position intersecting the windshield 5, it is easy to distinguish from the scenery outside the vehicle due to distance separation, and the front scenery It does not obstruct viewing and improves safety.

Furthermore, sunlight incident from outside the vehicle is light that has passed through the hologram 4b, so by blocking this light with the filter 6, the light that travels in the opposite direction of the optical path and enters the CRT 1a is prevented, thereby reducing the temperature of the CRT 1a. It is possible to suppress the rise and protect the equipment.

[0021]

As explained above, according to the present invention, claim 1 provides a reflection type hologram which is an off-axis type, has a wavefront conversion function, and reflects the light imaged by the imaging means. The first light transmitted through the reflection hologram and the second light reflected by the reflection hologram after the image of the display means is focused on the position of the reflection hologram by the imaging means are superimposed and viewed. Therefore, the image produced by the second light can be viewed closely, and the displayed image can be easily distinguished from scenery such as the road ahead of the vehicle or passersby, and safety can be improved.

In claim 2, the display means, the imaging means, and the reflection hologram are arranged so that the display position of the image of the light reflected by the reflection hologram intersects with the reflection hologram. By crossing the displayed image against the slanted windshield, it becomes easier for the driver to see.

In claim 3, by providing a filter that allows only light in a predetermined wavelength band to pass through the optical path from the display means to the reflection hologram, for example, sunlight incident from outside the automobile can pass through the reflection hologram. The filter can block the transmitted light, and the temperature of the display means can be prevented from rising, thereby protecting the device.

In claim 4, by making the reflection hologram a multiplex hologram, it is possible to correspond to emission wavelength bands of different emission colors of images displayed on the display means. There is an effect.

[Brief explanation of drawings]

[Figure 1] Principle diagram of the present invention

[Figure 2] Side view showing an embodiment of the present invention

[Figure 3]
Diagram of hologram

[Figure 4] Explanatory diagram of the example

[Figure 5] Side view showing a conventional HUD device

[Explanation of symbols]

Claims (4)

[Claims] Claim 1: Consisting of a display means (1), an imaging means (2), and a reflection hologram (4), the display means (1)
) displays a predetermined image, and the image forming means (2) forms an image of light from the image displayed on the display means (1) on the position of the reflective hologram (4). The reflection hologram (4) is an off-axis type and has a wavefront conversion function, and the imaging means (2)
A first beam that is incident on the imaging means (2) from the opposite side of the reflection hologram (4) and transmitted through the reflection hologram (4). An optical device characterized in that the light (7) and the second light (8) imaged by the imaging means (2) and reflected by the reflection hologram (4) are superimposed. 2. The display means (1), so that the display position of the image of the second light (8) reflected by the reflection hologram (4) intersects the reflection hologram (4). The imaging means (2) and the reflection hologram (
4) The optical device according to claim 1, wherein: 3. The display device according to claim 1 or 2, further comprising a filter that allows only light in a predetermined wavelength band to pass through the optical path from the display means (1) to the reflection hologram (4). optical equipment. 4. Claims 1 and 2, wherein the reflection hologram (4) is a multiplex hologram.
and an optical device according to claim 3.