JPH04134738U - head up display device - Google Patents

Abstract

(57) [Summary] [Objective] To provide a head-up display device that enables color display without impairing the long-distance display effect. [Structure] In a head-up display device in which display information from the display device 1 and other visual recognition information are spatially superimposed through the front window 4 and observed within the same field of view, Light of multiple types of wavelengths is emitted, a portion of the light of these wavelengths is diffracted by the hologram diffraction element 2 and projected onto the front window 4, and light of other wavelengths is passed through the hologram diffraction element 2. Diffraction element 2
The above object is achieved by reflecting the light onto the front window 4 by reflecting it by a reflecting mirror 3 formed integrally with the mirror 3 .

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention allows display information from display elements and other visibility information to be observed within the same field of view. Regarding a head-up display device (hereinafter referred to as HUD), In particular, the present invention relates to a vehicle HUD that enables color display.

0002

[Conventional technology]

It has external image information that is visibility information for the vehicle driver and a display element. The HUD serves as a display device that superimposes driving information from the display device within the same field of view. be. In conventional HUDs, a light flux combining element that superimposes the two information lights is used. A diffractive optical element that diffracts only a single wavelength of light is used in combiners such as windshields. A hologram diffraction element is provided. This hologram diffraction element By using the directional display effect, the imaging position of the driving information display image can be adjusted without using lenses etc. Can be done far away. Therefore, driving information can be improved without adjusting the focus of the driver's eyes. It is possible to superimpose the information and image information of the outside scene in the same field of view and recognize them.

0003

[Problem that the idea aims to solve]

However, with the conventional HUD configured as above, the display colors are limited. Therefore, it was difficult to display color information. For this reason, for example, HUD for automobiles In this case, the speed display and warning display are the same color, which reduces the recognition effect for the driver. There was a problem.

0004 A proposal to solve this problem was described in Japanese Patent Application Laid-Open No. 64-44913. As such, the beam coupling element has an observable diffraction effect for light of at least two wavelengths. A device equipped with a diffractive optical element is known. However, with this diffractive optical element, The diffraction efficiency for each wavelength decreases, the fabrication method becomes complicated, and the diffraction wavelength width widens. Therefore, there were problems such as a decrease in the overall amount of transmitted light.

[0005] This invention was made in view of the above points, and does not impair the long-distance display effect. An object of the present invention is to provide a HUD that can display color without any color display.

[0006]

[Means to solve the problem]

The HUD of the present invention transmits display information from the display element and other visibility information through a light-transmitting system. The beams are spatially superimposed via a beam coupling element, so that they can be observed within the same field of view. In a top-up display device, a display element that emits light of at least two wavelengths. and a diffractive optical element that diffracts at least one wavelength of light emitted from the display element. and a reflecting mirror formed integrally with the diffractive optical element.

[0007]

[Effect]

In the HUD having the above configuration, one of the plurality of wavelengths of light emitted from the display element is is diffracted by the diffractive optical element and projected onto the beam coupling element. Another wave The long beam passes through the diffractive optical element, is reflected by the reflecting mirror, and is projected onto the beam combining element. It will be done. The position and display color of the virtual image of display information due to these projected lights are different. This allows you to clearly see multiple types of displayed information.

[0008]

【Example】

Hereinafter, one embodiment of the HUD of the present invention will be described with reference to the drawings.

[0009] 1, 3 and 3 respectively show first, second and third embodiments of the present invention. In these figures, corresponding parts are designated by the same reference numerals.

0010 The HUD according to the first embodiment shown in FIG. 1 includes a display 1 having a display element and a diffracted light It is formed integrally with the hologram diffraction element 2, which is a chemical element, and the hologram diffraction element 2. It consists of a reflecting mirror 3 and a front window 4 as a light beam coupling element. . The display 1 displays a green body (G light) with a wavelength of 530 nm and a red light (R light) with a wavelength of 650 nm. ) consists of a fluorescent display tube that can display images. Also, the hologram diffraction element 3 has a diameter of 530 It has a diffraction efficiency of 90% or more for light with a wavelength of nm, and 85% for light of other wavelengths. This is a volume phase type hologram diffraction element having the above transmission efficiency. and display 1 The light emitted from the hologram diffraction element 2 or the reflecting mirror 3 is reflected by the is arranged so that it is projected onto the window 4.

[0011]Next, the operation of this embodiment will be explained in the case where it is installed in the driver's seat of a car. The G light emitted from the display 1 enters the hologram diffraction element 2, is diffracted by Bragg diffraction of the hologram, and is projected onto the front window 4. At this time, the hologram performs wavefront transformation such that the image position is at position F at _L3 from the hologram diffraction element 2, and is diffracted. As a result, when the optical path length from the display 1 to the hologram diffraction element 2 is L ₂ and the optical path length from the hologram diffraction element 2 to the front window 4 is L ₁ , the driver's eyes 5 have V ₁ (=L ₁ +L ₃ ), the displayed image appears as a virtual image.

At the same time, the R light emitted from the display device 1 does not meet the black diffraction conditions of the hologram, so it passes through the hologram diffraction element 2 and is reflected by the reflection mirror 3 integrally formed on the back surface of the hologram diffraction element 2, and is reflected by the reflection mirror 3 integrally formed on the back surface of the hologram diffraction element 2. Projected onto window 4. At this time, the driver's eyes see the display image at the position V ₂ (=L ₁ +L ₂ ) as a virtual image.

[0013] According to this embodiment, for example, the G light is used to display the speed, and the R light is used to display the warning. As a result, the speed is displayed in green in the distance and can be displayed without adjusting the focus of the eye 5. be able to read the indications. Also, the warning display is displayed in red in a different position. , can alert the driver.

The second embodiment shown in FIG. 2 is a configuration for a case where the diffraction efficiency of the hologram is low. For example, when using a hologram with low diffraction efficiency, such as an inexpensive surface relief type hologram, in the configuration of the first embodiment shown in FIG. is projected onto the front window 4. Therefore, an image of the G light is generated not only at the position of _V1 but also at the position of _V2 , that is, a ghost image is generated. This embodiment is intended to prevent the occurrence of this ghost image.

[0015] In FIG. 2, a first display device 6 that emits G light and a first display device 6 that emits R light serve as indicators. A second indicator 7 is provided, and the first indicator 6 that emits the diffracted light is oriented toward the optical axis of specular reflection. They are arranged with their optical axes shifted. In addition, the hologram diffraction element 8 has a wavelength of 530 nm. It is a surface relief type hologram that has a diffraction efficiency of 30% for light of the same wavelength.

[0016] Next, the operation of this embodiment will be explained. The G light emitted from the first display 6 is a holo It is diffracted by 30% by the Gram diffraction element 8, and as in the first embodiment shown in FIG. projected onto window 4. Also, the light that was not diffracted by the hologram diffraction element 8 is reflected by the reflected light 3 on the back surface of the hologram diffraction element 8, and is coated with an anti-reflection coating. is projected onto the inner wall of the HUD cover 9. As a result, the G light appears as a ghost image in the freon. It is possible to prevent the image from being projected onto the toe window 4.

[0017] On the other hand, the R light emitted from the second display 7 is transmitted to the hologram diffraction element as in FIG. The light passes through the mirror 8, is reflected by the reflecting mirror 3, and is projected onto the front window 4. Konoto Since the angles of the optical axes of the displays 6 and 7 with respect to the reflector 3 are different, the R light is affected by the G light. There will be no hindrance.

[0018] According to this example, compared to a volume phase type hologram as a hologram diffraction element, Even if a surface relief hologram with low diffraction efficiency but low cost is used, it is difficult to achieve the first practical result. The same effects as in the example can be obtained.

[0019] The third embodiment shown in FIG. 3 is similar to the hologram diffraction element 2 of the first embodiment shown in FIG. The hologram is arranged so that the diffracted light overlaps with the reflected light and is projected onto the front window 4. This is a RAM element fabricated. An example of the display at this time is shown in FIG. Figure 3 shows navigation This is a case where the application system is applied, road information 11 is green, vehicle position 12 is displayed in red. At this time, the green color is imaged far away by the hologram, and the red color is imaged far away. The colors are focused closer together, making the display more three-dimensional and allowing the driver to see where his or her car is. can be clearly recognized. In addition, the code 13 is through the front window 4. It's the car in front that you can see.

[0020] In each of the above embodiments, there are two types of light emitted from the display, G light and R light. Although we have explained the case where only the G light is diffracted by the programmatic diffraction element, The light and diffracted light are not limited to these.

[0021]

[Effect of the idea]

As explained above, according to the HUD of the present invention, the hologram diffraction element and the reflecting mirror The display information from the display element can be transferred to the hologram element from a distance. Color display can be performed without deteriorating the display effect.

[Brief explanation of drawings]

[Fig. 1] First head-up display device of the present invention
An explanatory diagram showing the configuration of an example of

FIG. 2 is an explanatory diagram showing the configuration of a second embodiment of the present invention.

FIG. 3 is an explanatory diagram showing the configuration of the third embodiment of the present invention.

[Explanation of symbols]

1, 6, 7 Display device (display element) 2,8 Hologram diffraction element (diffraction optical element) 3 Reflector 4 Front window (luminous flux coupling element)

──────────────────────────────────────────────── ─── Continuation of front page (72) Creator Takayuki Haruyama 10 Hanazono Tsuchido-cho, Ukyo-ku, Kyoto-shi, Kyoto Inside Muron Co., Ltd. (72) Creator Mamoru Yabe 10 Hanazono Tsuchido-cho, Ukyo-ku, Kyoto-shi, Kyoto Inside Muron Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A head-up display device in which display information from a display element and other visibility information are spatially superimposed via a light-transmissive beam coupling element so that they can be observed within the same field of view. , the display element that emits light of at least two wavelengths, a diffractive optical element that diffracts at least one wavelength of light emitted from the display element, and a reflective element that is integrally formed with the diffractive optical element. A head-up display device characterized by comprising a mirror.