JPH05278498A - Head-up display device - Google Patents

Abstract

PURPOSE:To display image information having a wide angle of visibility and low distortion by means of a simple constitution. CONSTITUTION:When the small gasoline residual quantity in an automobile is detected, a displaying light projection direction control part 7 controls the projection direction of displaying light so that the displaying light from a displaying light projection part 6 may be projected at the part P5 of a hologram combiner 5. Image information on gasolie quantity warning is previously momorized in the part P5 of the hologram combiner 5. Thus, when the displaying light is projected at the part P5, the displaying light of the image information on the gasoline quantity warning is reflected to a driver 4 from the part P5. Terefore, the driver 4 can learn that the situation is in head up and the residual quantity of gasloine is low. Namely, even if the driver 4 watches the foreground during driving, the image information is superimposed on the foreground for display, positively learning that the residual quantity of the gasoline is small.

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 used in vehicles such as automobiles and vehicles and OA equipment.

[0002]

2. Description of the Related Art Head-up display devices are used in aircraft, automobiles, etc., as highly safe display devices with a small amount of viewpoint movement. 7 and 8 are a front view and a side view of a conventional head-up display device used in an automobile. In FIGS. 7 and 8, reference numeral 51 is an automobile windshield, 52 is a steering wheel, 53 is a head-down display, 58 is a dashboard, 54 is a driver, and a head-up display device is a half mirror with an oxide multilayer film coat. It is composed of a combiner 59, an optical system 60 having a lens function, and a liquid crystal display device 71.

In such a structure, image information to be displayed, for example, a gasoline amount warning is displayed on the liquid crystal display device 71, a virtual image 75 of this image information is formed by the optical system 60, and this display light is displayed by the half mirror combiner 59. It can be reflected by and displayed to the driver 54. That is, driver 5
In No. 4, the foreground can be seen by the transmitted light from the half mirror combiner 59, and at the same time, the image information from the liquid crystal display device 71 can be seen by the reflected light from the half mirror combiner 59. Image information such as a gasoline amount warning is also displayed on the head-down display 53, so that the driver 54
The necessary information can also be obtained by looking at 3. However, in this case, the amount of movement of the line of sight from the state of looking at the foreground increases for the driver 54. On the other hand, according to the head-up display device, that is, the half mirror combiner 59, the driver 5
In No. 4, the necessary information can be obtained by the reflected light from the half-mirror combiner 59 while looking at the foreground, so that display with excellent visibility can be performed.

[0004]

However, in the conventional head-up display device as described above, the image information to be displayed is displayed as a virtual image 75 by the optical system 60 so that it can be seen floating in the foreground. The image information is easily distorted by the aberration of the system 60, and is easily distorted by the curvature of the windshield 51, so that the driver 54 cannot easily recognize the image information when the image information is complicated. was there.

In order to reduce this drawback, the optical system 60
It is also possible to reduce the aberration of and increase the viewing angle, but increasing the viewing angle of the display increases the number of lenses to correct various aberrations, or requires an aspherical lens, Further, a glass material is required, which increases the size, weight and cost of the head-up display device. Particularly, in automobiles and the like, the capacity around the dashboard is limited, and therefore the increase in size of the head-up display device is disadvantageous when applied to automobiles and the like. Note that Japanese Patent Laid-Open No. 3-42694 discloses a technique of correcting image distortion caused by the bending of the windshield by bending a part of the Fresnel lens forming the optical system. However, the optical system requires a plurality of lenses, there is a limit to downsizing the head-up display device, and the distortion of the image information due to the aberration of the optical system cannot be solved at all.

An object of the present invention is to provide a head-up display device capable of displaying image information having a wide viewing angle and little distortion with a simple structure.

[0007]

In order to achieve the above object, a head-up display device according to claim 1,
The display light emitting means for emitting the display light and the combiner for reflecting the display light from the display light emitting means and transmitting the foreground light are stored in the combiner at least a part of the image information to be displayed in advance. It is characterized by being.

Further, in the head-up display device according to the second aspect, the display light from the display light emitting means is
The light is controlled by a spatial modulator and projected onto the combiner.

A head-up display device according to a third aspect of the present invention has display light emitting means for emitting display light, and a combiner for reflecting the display light from the display light emitting means and transmitting the foreground light. The combiner is characterized by being composed of a diffraction grating formed so as to obtain a plurality of display directions or viewing distances.

[0010]

According to the present invention, the display light from the display light emitting means is projected on the combiner. Since at least a part of the image information to be displayed is stored in advance in the combiner, the display light is projected onto a predetermined part of the combiner, so that, for example, a driver of an automobile can obtain an image stored in the predetermined part of the combiner. Information can be viewed with little distortion.

According to the second aspect of the invention, the first aspect is
In the head-up display device according to the description, the display light from the display light emitting means is controlled by a spatial modulator and projected onto the combiner, whereby a plurality of images are displayed by a single display light. Information can be displayed simultaneously.

According to the third aspect of the invention, since the combiner including the diffraction grating formed so as to obtain a plurality of display directions or viewing distances is provided, the viewing range for viewing the display light can be expanded. it can.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are a front view and a side view of a first embodiment of a head-up display device according to the present invention, and FIGS. 1 and 2 show a case where the head-up display device is applied to an automobile. ing. 1 and 2,
Reference numeral 1 is a windshield, 2 is a steering wheel, 3 is a head-down display, 4 is a driver, 8 is a dashboard, and the head-up display device is a hologram display using a diffraction grating in which predetermined image information is stored in advance. A combiner 5, a display light projection unit 6 for projecting display light on the hologram combiner 5, a display light projection direction control unit 7 for controlling the projection direction of the display light, and an infrared light emitting infrared light. It has a light emitting section 14, an infrared light sensor 13, and an object position determination section 14.

Here, the display light projection unit 6 is, for example,
It is composed of a light emitting diode (LED) and a lens. The hologram combiner 5 is a hologram formed of a diffraction grating formed on a photopolymer, and each portion P of the hologram of the hologram combiner 5 is formed.
_{1 to} P ₆ , in the example of FIG. 1, six pieces of image information of exhaust temperature warning, engine oil temperature warning, seat belt wearing warning, battery status warning, gasoline amount warning, and cooling water temperature warning are stored in advance. There is. The image information is stored by being prepared so that the reflectance from the direction in which the display light is projected is high in the vicinity of the wavelength of the light of the red LED having a narrow wavelength width used in the display light projection unit 6. Has been done.

Next, the operation of the head-up display device having such a structure will be described. The six parts P _{1 to} P ₆ of the hologram of the hologram combiner 5 are shown in FIG.
As shown in FIG. 6, when six pieces of image information are stored in advance, the projection direction of the display light from the display light projection unit 6 is projected onto any of the portions P _{1 to} P ₆ where the six pieces of image information are stored. By controlling the display light projection direction control unit 7 to
Any of the six types of image information can be displayed. Specifically, for example, when it is detected that the amount of gasoline remaining in the vehicle is low, the display light projection direction control unit 7 displays so that the display light from the display light projection unit 6 is projected on the portion P _5. Controls the projection direction of light. Hologram part P
Since the _fifth image information amount of gasoline warning are stored in advance, when projecting the display light to this portion P _5, as shown in FIG. 3, the display light of the image information of the amount of gasoline warning from this portion P ₅ Is reflected by the driver 4. As a result, the driver 4 can know that the remaining amount of gasoline is low in the head-up state. In this case, the gasoline amount warning is also displayed on the head-down display 3,
The driver 4 is less likely to notice the display on the head-down display 3 while driving and is concentrating on the foreground, and overlooking the image information displayed on the head-down display 3 may lead to an accident. On the other hand, in the head-up display device, when the driver concentrates on the foreground while driving, the image information is superimposed and displayed on the foreground, so that the driver surely knows that the remaining amount of gasoline is low. be able to.

By the way, in the first embodiment, since the image information to be displayed is stored in the hologram combiner 5 in advance, even if the optical system has a simple structure,
It is possible to avoid a situation where the image information is easily distorted due to the aberration of the optical system or the curvature of the windshield. That is, even when the image information to be displayed has a large viewing angle and is complicated, it is possible to suppress the image distortion and display the image as compared with the conventional case where the image information to be displayed is displayed as a virtual image by an optical system. The image display can be clearly recognized by the driver.

In the above example, six pieces of image information are stored in the hologram combiner 5, but the type of image information that can be stored in the hologram combiner 5 is the minimum visibility without deterioration of the resolution of the image information. The number can be increased to 6 or more as long as a good size can be secured. Actually, the resolution of the combiner is very high as compared with the case where a virtual image of the display device is created because the image information is present on the windshield, and the size of the image information or the viewing angle and the size of the combiner can be secured. Affect the number of information.

Further, as a method of displaying image information while changing the viewing distance, there is a holographic technique itself for reproducing a recorded object light. This is a silver salt film,
It is also possible to use a hologram obtained by simultaneously exposing a photosensitizer such as dichromated gelatin and a photopolymer to the object light and the reference light by coherent light, or a spatial modulator such as AOM and LCD, It is also possible to irradiate with coherent light or white light depending on the conditions. In FIG. 3, assuming the combiner using the image hologram method, the position of the combiner and the visual distance of the image information match, but this visual distance is
A hologram combiner can be easily preset.

Further, in the above example, only one display light projecting means, that is, one display light projecting section 6 is provided, but since the hologram combiner has a direction dependency in the reflection characteristics, a plurality of display light projecting means are provided. By using the projection means and projecting the display light from these in the same position of the combiner in different directions with respect to each other, the hologram combiner,
A plurality of different image information can be displayed at this position. In addition, since the hologram combiner has wavelength dependence in its reflection characteristics, a display light projection device that can project display light with a plurality of narrow wavelength widths is used, and a wavelength band with high reflectance corresponding to image information is visible. It is possible to display a plurality of different image information at the same position of the combiner in the same manner by dividing the display light and changing the wavelength of the display light.

Further, in the above example, the hologram combiner 5 preliminarily stores the figurative image information, but the image information preliminarily stored in the combiner 5 may not be the figurative image information. For example, a plurality of matrix-shaped dots or a simple 8-segment pattern character for expressing numbers may be used. By controlling the projection direction of the display light for displaying this with high resolution by raster scanning, it is possible to perform a complicated and diverse display with dots or segment characters as in a normal display device.

Further, in the above example, the hologram combiner 5 is used, but instead of this, a half mirror combiner made of a multilayer film having a high reflectance of the display light near the wavelength of the display light may be used. Good. Further, by using a display light projection device capable of projecting a plurality of display lights having narrow wavelength widths, a wavelength band having a high reflectance corresponding to image information is divided into plural visible regions, and the wavelength of the display light is changed. Due to
It is possible to display a plurality of different image information at the same position as the projected portion.

Further, in the above example, the case where all the image information is stored in the combiner in advance is shown. However, by making a part of the hologram combiner act as a simple half mirror, a liquid crystal display device or It is also possible to perform various displays in combination with a display device using a fluorescent display tube or the like.

Further, in order to achieve both the high transmittance of the foreground of the combiner and the high reflectance of the display light, it is desirable that the reflectance be close to 100% only in a region having a narrow wavelength width at a specific wavelength. Therefore, the laser light is effective as the display light. Further, when the hologram combiner is used, the reflection angle of the combiner can have a large wavelength-dependent characteristic. From this point, the laser light is effective as the display light.

At this time, since laser light has high coherence, it is necessary to pay attention to safety for the human body. The infrared light emitting unit 14, the infrared light sensor 13, and the object position determination unit 15 shown in FIG. 1 are provided for this purpose, whereby the laser light is transmitted to the outside of the windshield 1 and the It can prevent harm to the eyes. That is, since the human eye is located in the center of the face, when the infrared light emitting unit 14, the infrared light sensor 13, and the object position determination unit 15 detect any peripheral portion of the face, the laser light is emitted at the same time. By stopping the projection or reflection of light, it is possible to prevent the laser light from entering the human eye. The determination of the object position can be easily realized by measurement by triangulation or measurement of reflectance. Further, the same effect can be obtained by using ultrasonic reflection or image processing of an image input by a camera.
This is effective when the laser beam is used also for a hologram combiner in which normal image information is not recorded.

4 and 5 are a front view and a side view of the second embodiment of the head-up display device according to the present invention. In the second embodiment, in order to project the display light on a predetermined portion of the hologram combiner 5, the display light, that is, the laser diode 16 for emitting the laser light, and the laser light emitted from the laser diode 16 are made into plane waves. Lenses 17a, 17b, and 18 and a spatial modulator 19 that controls so as to project only a portion of a predetermined range of the plane wave laser light onto a predetermined portion of the hologram combiner 5 are provided. That is, in this second embodiment,
Instead of controlling the projection direction of the display light to control the projection position on the combiner 5 as in the first embodiment, the spatial modulator 19 partially controls the transmission of the display light to thereby selectively combine the display light. It is designed to control the projection position on.

In the second embodiment, since the transmission of the display light is partially controlled by using the spatial modulator 19 as described above, the display light is simultaneously projected onto a plurality of portions of the hologram combiner 5. It is possible to display a plurality of image information at the same time.

In the examples of FIGS. 4 and 5, when the hologram combiner 5 stores six kinds of image information exactly the same as those in FIGS. 1 and 2, a battery state warning and a seat belt wearing warning are given. The case where two pieces of image information are simultaneously displayed by the display light from one laser diode 16 is shown. When this display is performed, the display light from the laser diode 16 is made into a plane wave by the lenses 17a, 17b, 18 and passed through the spatial modulator 19. At this time, the range of 21a and 21b of the spatial modulator is controlled so as to have a high transmittance, and only the display light of these ranges 21a and 21b is transmitted, so that only the portions P ₃ and P ₄ of the combiner 5 can display light. Can be projected. As a result, two image displays, a battery state warning and a seat belt wearing warning, can be displayed at the same time by the display light from one laser diode, and a hologram combiner having a large number of image information and a high resolution spatial modulator. Using, it is possible to display a large number of image information at the same time. Furthermore, by combining a large number of image information displayed at the same time into a set, this can be easily made into one image information. Also, by using a spatial modulator,
It is also possible to display a segmented character with a three-dimensional effect and good visibility.

Since there is a distance of about 5 to 30 cm between the spatial modulator and the hologram, it is conceivable that each image information will be reproduced incorrectly due to diffraction.
Since the portions 1a and 21b are relatively large, and because they are reflection holograms, their influence is relatively small. Further, it is effective to fabricate a hologram combiner in consideration of the disturbance of parallel waves due to this diffraction.

FIG. 6 is a front view of a third embodiment of the head-up display device according to the present invention. In the third embodiment, a hologram combiner 24 is provided in which a diffraction grating is formed so that a plurality of different directions can be obtained as a display direction. The hologram combiner 24 is, for example, one in which two types of diffraction gratings are preliminarily formed in multiple layers. In FIG. 6, the display device 11 is composed of, for example, a liquid crystal display device similar to the display device 71 in FIGS. 7 and 8, and the optical system 10 is similar to that shown in FIG.
Similar to the optical system 60 in FIG. 8, it is provided to create a virtual image of the image information displayed on the display device 11.

In the head-up display device having such a configuration, the display device 11 is caused to display image information of, for example, an exhaust temperature warning, a virtual image of the image information is made by the optical system 10, and the hologram combiner 24 is used to make a driver and the assistant. Seat passenger 2
It can be reflected in two divided directions. As a result, the driver 4 can see the display light 23a, and the passenger 22 with the passenger seat can also see the display light 23b.

In the example of FIG. 6, two types of diffraction gratings are preliminarily formed in the hologram combiner 24 in advance, but
It is also possible to pre-form multiple types of diffraction gratings in multiple layers. At this time, the display light can be reflected in three or more directions including not only the passenger seat but also the rear seat. As described above, according to the third embodiment, the fellow passenger can obtain the same image information as the driver, and can reliably recognize and judge the image information.

In this case, however, the directions of the 0th order light that does not contribute to the reflection by the diffraction grating having the same spacing and direction as the different directions and the direction of the secondary light having a low reflectance are not used, and the diffraction gratings formed in multiple It is effective to display in a plurality of different directions by the primary light according to.

In order to widen the viewing area without dividing into a plurality of directions (for example, two directions) while keeping the reflection with the optical axis in one direction, it is necessary to increase the area of the combiner. Therefore, since the angle of view becomes wide, it is difficult to suppress the aberration of the optical system 10 and practical application is difficult. In contrast,
When the image information is stored as a hologram in the combiner in advance, if the image information is set in a plurality of directions in advance, that is, if multiple types of interference fringes are recorded by the object light and the reference light, the area of the combiner is increased. It is possible to easily expand the field of view without increasing the size. At this time, the viewing distances may be different in the respective viewing directions, which is effective when the normal viewing distances of the passenger and the driver are not always the same.

Further, by changing the viewing distance for the same image information and storing it in the hologram combiner, the driver can select the optimum viewing distance even when the display directions are the same. The visual distance can be changed periodically, which is effective for improving the visibility of the driver.

In each of the above-described embodiments, the case where the head-up display device is applied to an automobile has been described, but the present invention can be applied to other vehicles such as an aircraft. Further, in recent years, a means for surely informing that a trouble has occurred with a buzzer which is voice information has been used, but it is difficult to recognize the type of information only from voice information. In such a case, it is effective to use the expression by the audio information including the change or difference of the wavelength signal and the display of the image information by these head-up displays together.

[0036]

As described above, according to the first aspect of the invention, since the combiner in which at least a part of the image information to be displayed is stored in advance, it is possible to display a complicated resolution with a wide viewing angle. It can be shown to the driver with a simple indicator light.

According to the second aspect of the invention, since the display light controlled by the spatial modulator is projected to the combiner in which at least a part of the image information to be displayed is stored in advance, a single display is performed. It is possible to easily display a plurality of image information by light at the same time.

According to the third aspect of the present invention, since the combiner including the diffraction grating formed so as to obtain a plurality of display directions or viewing distances is provided, the viewing area for viewing the display light can be easily widened. be able to.

[Brief description of drawings]

FIG. 1 is a front view of a first embodiment of a head-up display device according to the present invention.

FIG. 2 is a side view of the first embodiment of the head-up display device according to the present invention.

FIG. 3 is a diagram for explaining how the display light of the image information of the gasoline amount warning is reflected by the driver from the hologram combiner in the configuration of FIGS. 1 and 2.

FIG. 4 is a front view of a second embodiment of the head-up display device according to the present invention.

FIG. 5 is a side view of the second embodiment of the head-up display device according to the present invention.

FIG. 6 is a front view of a third embodiment of the head-up display device according to the present invention.

FIG. 7 is a front view of a conventional head-up display device.

FIG. 8 is a side view of a conventional head-up display device.

[Explanation of symbols]

 1 Windshield 2 Handle 3 Head-down display 4 Driver 5,24 Hologram combiner 6 Display light projection unit 7 Display light projection direction control unit 8 Dashboard 10 Optical element 11 Display device 16 Laser diode 17a, 17b, 18 Lens 19 Space Modulator

Claims (3)

[Claims] 1. A display light emitting means for emitting display light, and a combiner for reflecting the display light from the display light emitting means and transmitting the foreground light, wherein the combiner displays image information to be displayed. A head-up display device, at least a part of which is stored in advance. 2. The head-up display device according to claim 1, wherein the display light from the display light emitting means is
A head-up display device, characterized in that it is controlled by a spatial modulator and projected onto the combiner. 3. A display light emitting means for emitting display light, and a combiner for reflecting the display light from the display light emitting means and transmitting the foreground light, wherein the combiner has a display direction or viewing distance. A head-up display device comprising a diffraction grating formed so as to obtain a plurality of diffraction gratings.