JPH11119154A - Virtual screen type three-dimentional display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a virtual screen type three-dimentional display device compact in structure, low in cost, reduced in energy consumption and capable of easily obtaining clear stereoscopic images without using specific spectacles or a lenticular lens. SOLUTION: In this virtual screen type three-dimetional display device consisting of two display means 1-1, 1-2 for displaying character or image information, two projection means 2-1, 2-2 for enlarging and projecting real images of objects to be images displayed on the two display means 1-1, 1-2 to prescribed space and a converging optical system 3 for guiding beams from the two projected space images to two prescribed visual areas 6-1, 6-2, the centers of the two visual areas 6-1, 6-2 are separated about by a human pupil interval (60 to 70 mm) in a horizontal direction and both the areas 6-1, 7-2 are brought into contact with each other or slightly superposed (<7 mm) in the horizontal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a head-up display (HUD) and a head-mounted display (HUD).
MD), virtual screen for displaying stereoscopic images (VS: Virtual Scre
The present invention relates to an en) type stereoscopic display device.

[0002]

2. Description of the Related Art The following is known as a prior art relating to a display device for displaying a three-dimensional image. Journal of the Institute of Television Engineers of Japan Vol.41, No.7, P610-P618 (19
87) "Three-dimensional display-various methods and application to television-" discloses three-dimensional display methods of various methods, and FIG. 2 (i) on page 611 shows a three-dimensional display without concave mirror using a concave mirror. There is a visual style picture. 612
The page states that "There is an object that forms images of two projectors at intervals between both eyes using the large concave mirror or the large convex lens of FIG. 2 (i)".

In the "stereoscopic image display device" disclosed in Japanese Patent Application Laid-Open No. 8-5956, spatial modulation elements (display elements) for the left and right eyes are arranged at substantially right angles with a half-mirror type combiner interposed therebetween. A light-emitting device for backlight is placed on the back side of the modulation element (each light-emitting device has a light-emitting area for one eye and a non-light-emitting area for the other?), Between the spatial modulation element and the light-emitting device. A directional optical element for enlarging the light emitting area is arranged, and the presented images for the left and right eyes are
The stereoscopic image can be viewed without using polarized glasses or the like because the image is directed to the left and right eyes. According to the second aspect, the backlight is lighted in a time-division manner. In the third aspect, a light emitting area for one eye and a non-light emitting area for the other are provided between each light emitting device and the spatial light modulator. 5. The transmission area of the light control device according to claim 4, wherein a control device is provided, and an optical element having directivity for guiding light from each transmission region to each eye is added to the front side of the half mirror. In addition, in claim 5, a polarizing device is provided on the front surface of the display surface of each display element to put orthogonal linearly polarized light into a half mirror, and the front surface of the half mirror is provided with a polarizing device. It describes the placement of a light control device having left and right divided regions that only pass the respective polarizations.

The "monocular viewing distance adjustment type display device" described in Japanese Patent Application Laid-Open No. 8-146348 has at least an original image forming means, a projection lens means, and a pupil mapping optical means. The pupil of the projection lens means is configured to map to the pupil of at least one eye of the observer, and the monocular viewing distance feeling is adjusted for the pupil mapping by adjusting the imaging position of the original image by the projection lens means. It is configured to be adjusted independently of the position of the optical means. In one embodiment of the present invention, it is described that natural stereoscopic vision can be achieved by matching the sense of monocular viewing distance to the binocular viewing distance, and in other embodiments, special glasses and lenticular lenses are used. It describes that a clear stereoscopic image can be obtained without using it.

In the "stereoscopic device" described in Japanese Patent Application Laid-Open No. 8-186649, a polarizing member having a polarization direction orthogonal to the adjacent one is arranged in a stripe shape on the back side of the screen, and the polarizing member is provided on the front side of the screen. A lenticular lens plate having a pitch equal to the width of the set of stripes is arranged, and the left eye for the left eye and the right eye for the right eye having the polarization matched to the polarization direction are projected on the screen by the projector with the projector for the right eye. A transmission type stereoscopic vision device that does not use polarized glasses is characterized by having such a configuration.

[0006]

In the above-mentioned prior art, the spatial modulation elements (display elements) for the left and right eyes are arranged at substantially right angles with a half-mirror type combiner interposed therebetween. A light emitting device for a backlight is placed (each light emitting device is provided with a light emitting region for one eye and a non-light emitting region for the other. Why is this necessary?), A spatial modulation element and a light emitting device. A directional optical element for enlarging the light emitting area is arranged between the devices, and the presented images for the right and left eyes are directed to the right and left eyes, respectively, without using polarized glasses or the like. You can see the image, but because the half mirror is used, the amount of light is reduced by half even if estimated. Also,
Various measures have been described, such as controlling the light emitting area and the non-light emitting area so that the left and right images do not overlap, but all of them have little effect despite their large scale (since the picture is like an aerial image, It also describes methods that may not be necessary in practice.)

[0007] The prior art cites the following documents:
Knowing that it is known that "images of two projectors are formed at the distance between both eyes using a concave mirror or a positive lens" is known, "the image formation position of the original image by the projection lens means is adjusted. The monocular viewing distance is configured to be adjusted independently of the position of the optical means for pupil mapping, thereby making the monocular viewing distance match the binocular viewing distance. It provides a more natural stereoscopic vision, and a clear stereoscopic image can be obtained without using special glasses or lenticular lenses. However, there is no specific description on how to arrange the two viewing zones, although it specifically describes how to match the monocular viewing distance to the binocular viewing distance and how to match it. .

In the prior art, a polarizing member having a polarization direction orthogonal to the adjacent direction is disposed in a stripe shape on the back side of the screen, and a lenticular lens having a pitch equal to the width of the set of stripes is provided on the front side of the screen. A plate is arranged, and the left eye having the polarization matched to the polarization direction is configured to project the projection light for the left eye and the right eye for the right eye onto a screen by a projector, so that the polarization is Although a transmission type stereoscopic vision apparatus without using glasses can be made, the amount of light is estimated to be reduced to 1/4 since polarization is used and the screen is divided into two parts. In addition, there is a disadvantage that the whole system becomes large (long) because of the rear projection type.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned drawbacks of the prior art, and is a method for easily obtaining a compact, low-cost, energy-saving and clear stereoscopic image without using special glasses or lenticular lenses. It is an object of the present invention to provide a virtual screen type stereoscopic display device.

[0010]

In order to achieve the above object, the present invention provides two display means for displaying information of characters and images, and a real image in which the images displayed on the two display means are objects. A virtual screen type solid body comprising two projection means for enlarging and projecting an image in a predetermined air and forming an image, and one focusing optical system for bringing light beams from the two projected aerial images to two predetermined viewing zones, respectively. The display device is characterized in that the centers of the two viewing zones are separated from each other by about a human pupil distance (60 to 70 mm) in the left-right direction, and contact each other or slightly overlap each other (7 mm or less) in the left-right direction. (Claim 1).

[0011] In the virtual screen type stereoscopic display device of the present invention, the two display means are respectively a CRT (cathode ray tube), an LCD (liquid crystal), an LCD (liquid crystal), which can display an output from a computer or a TV (television) screen. It is a small display means such as a DMD (Digital Mirror Device), which can display images independently of each other, and can display the same or different images as required (claim 2).

Further, in the virtual screen type stereoscopic display device of the present invention, the two display means display image information for the right eye on the left side and image information for the left eye on the right side when a human faces the two display means. (Claim 3).

Further, in the virtual screen type stereoscopic display device according to the present invention, the focusing optical system is a reflection type imaging element such as a concave mirror or the transmission optical system is a transmission type such as a positive lens. It is an imaging element (Claim 5), or the focusing optical system is a Fresnel optical element (Claim 6), or the focusing optical system is a diffractive optical element such as a hologram (Claim 7) It is characterized by.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 2 is a view showing the basic concept of a virtual screen (VS) display device, in which a display means (1) for displaying image information and an image having the object as an object are projected and formed in a predetermined air. This is an example of a display device including a projection unit (2) and a focusing optical system (3) for directing a light beam from the projected aerial image toward the eyes of an observer.

The display means (1) is a CRT capable of displaying an output of a computer or a screen of a television (TV).
(Cathode ray tube), LCD (liquid crystal display), DMD (digital mirror device), and other small display means. If the display means (1) is a CRT, no additional illumination means is required, but if the display means (1) is an LCD, an illumination light source, a diffuser, a filter, etc. are required on the back side of the display means as shown in the figure. is there.

The focusing optical system (3) is a real screen (RS (Real Screen): an imaging position without the focusing optical system) (4). A virtual screen (VS (Virtual Sc)
reen): an image of a focusing optical system having the RS as an object) An aerial image is formed at the position of (5), and a divergent light beam diverging therefrom is a viewing area (a range where an observer's eye should be placed) 6). In the example shown in the figure, a transmission type imaging element such as a positive lens is shown as the focusing optical system (3), but a reflection type imaging element such as a concave mirror or a Fresnel optical element is also used as the focusing optical system. Alternatively, a diffractive optical element such as a hologram can be used.

According to the present invention, the virtual screen shown in FIG. 2 is formed for the left eye and the right eye so that a stereoscopic image can be viewed. The stereoscopic display device is provided for the left eye and the right eye. Two display means and two projection means, and a configuration including one focusing optical system for bringing light fluxes from two aerial images projected by the two projection means to predetermined two viewing zones, respectively. It was done. Hereinafter, examples of the present invention will be described.

(Embodiment 1) FIG. 1 is a view showing one embodiment of the present invention, wherein (1-1) is a display means for the left eye,
(1-2) is display means for the right eye, (2-1) is projection means for the left eye, (2-2) is projection means for the right eye, (3) is a focusing optical system, and (5-1) is Virtual screen for left eye (V
S) and (5-2) are virtual screens for the right eye (V
S) and (6-1) represent the left-eye viewing zone, and (6-2) represents the right-eye viewing zone.

In FIG. 1, a display means for left eye (1-1)
Is acted by the left-eye projection means (2-1) so as to form an image at a real screen (RS) position (not shown), and travels to the focusing optical system (3). The focusing optical system (3) has a positive power, and makes an additional contribution to the image formation while directing the incident light beam to the left-eye viewing zone (6-1), and performs the left-eye VS (5-1). ). The luminous flux after image formation passes through the left-eye viewing zone (6-1) while diverging. In this way, the light beam corresponding to each image height forms an image in the vicinity of the left-eye VS (5-1) and travels toward the left-eye viewing zone (6-1). The position of the left-eye display means (1--) is set by placing the pupil of the left eye in the left-eye viewing zone (6-1).
Images corresponding to all image heights of 1) can be seen at once.

Here, the same thing as the left eye also applies to the right eye from the right eye display means (1-2) to the right eye viewing zone (6-2).
When the pupil of the right eye is placed in the visual field (6-2) of the right eye, images corresponding to all image heights of the display means for a right eye (1-2) can be seen at a time. What is characteristic here is that the distance between the centers of the two viewing zones (6-1) and (6-2) is equal to the distance between the human eyes and is approximately 60 to 70 mm. The regions (6-1) and (6-2) are in contact with each other in the left-right direction or overlap with each other by a very small amount (7 mm or less). According to this method, the VS (5-1) for the left eye and the V
Although S (5-2) largely overlaps (in FIG. 1, the two VSs are drawn shifted in the direction of the optical axis of the focusing optical system in FIG. 1 for convenience of display, but they are actually hardly shifted). Instead, the information from the respective display means is provided to the left and right eyes without interference, and the range in which the stereoscopic image can be seen is relatively wide, approximately 60 to 70 mm.

(Embodiment 2) FIG. 3 is a view showing another embodiment of the present invention, wherein (1-1) is a display means for the left eye,
(2-1) is a projection means for the left eye, (3) is a focusing optical system,
(5-1) is a virtual screen (VS) for the left eye,
(6-1) is the left-eye viewing zone, (6-2) is the right-eye viewing zone,
(7-1) indicates a left-eye bending mirror.

In FIG. 3, the display means for left eye (1-1)
Is acted by the left-eye projection means (2-1) so as to form an image at a real screen (RS) position (not shown), and travels to the focusing optical system (3). In this case, the focusing optical system (3) has a positive power with a concave mirror as shown, or a hologram element, a Fresnel element, or the like having a similar function, and converts the incident light beam into the visual field of the left eye (6-1). )
VS for the left eye (5
An image is formed in -1). The luminous flux after image formation passes through the left-eye viewing zone (6-1) while diverging. In this way, it is the role of the focusing optical system that the light beams corresponding to the respective image heights are imaged in the vicinity of the left-eye VS (5-1) and directed toward the left-eye viewing zone (6-1). Thus, if the pupil of the left eye is placed in the viewing zone (6-1) of the left eye, images corresponding to all image heights of the display means (1-1) for the left eye can be seen at a time.

Here, since the folding mirror (7-1) is used for facilitating the arrangement, as shown in the figure, the projection mirror (2-1) is positioned on the optical axis of the focusing optical system (3). It is not always necessary to arrange them so that the optical axes are orthogonal,
It can be almost parallel. In addition, when necessary, this can be a half mirror, and if possible, an arrangement without using a folding mirror can be considered.

FIG. 3 shows only the visual field (6-2) of the right eye for the right eye for the sake of simplicity, and other components are omitted from the drawing, but are symmetrical to those for the left eye. Arrangement
The same operation as that for the left eye is performed for the right eye for the right eye viewing zone (6-2) from the right eye display means, and the right eye pupil is displayed in the right eye viewing zone (6-2). , Images corresponding to all image heights of the display means for the right eye can be seen at once.

Here, the characteristic point is that the distance between the centers of the two viewing zones (6-1) and (6-2) is equal to the distance between both eyes of a human being and is approximately 60 to 200, as in the case of the first embodiment. 70 mm, and the two viewing zones (6-1) and (6-2) are in contact with each other in the left-right direction or overlap by a small amount (7 mm or less). By this method, the VS for the left eye (5-1)
And the VS for the right eye (not shown) largely overlap (in this figure, the VS for the left eye is shifted in the direction of the optical axis of the focusing optical system for the sake of display, but is actually slightly shifted. Despite this, the information from the respective display means is provided to the left and right eyes without interference, and the range in which the stereoscopic image can be seen is relatively wide, approximately 60 to 70 mm.

(Embodiment 3) FIG. 4 shows still another embodiment of the present invention, which is similar to the virtual screen display device (Japanese Patent Application No. 9-57947) previously filed by the present applicant. It is a figure showing the example of the display of form. The display device of the prior application displays a two-dimensional image on a virtual screen. In the present embodiment, a three-dimensional image can be viewed in substantially the same form as that of the prior application. In the case of this embodiment, as shown in the first and second embodiments, optical systems corresponding to the left and right eyes are required except for the combiner (the focusing optical system (3) in FIGS. 1 and 3). However, since the example of FIG. 4 is a view from the side, the components corresponding to the left and right eyes overlap,
Only the configuration on one side is shown.

In FIG. 4, there are a projector (10) having a display element and a projection optical system for a left eye and a right eye, and a light beam from each projector (10) is reflected by a bending mirror (20). After that, the light is reflected and focused by the combiner (30) (41) (or (4)
2)) The image is enlarged and formed on the virtual screen (VS) position. As a result, from the operator's eyes (50), it appears as if there is a display element enlarged at the VS position.
At this time, the optical system of the projector (10) and the combiner (30) are so arranged that the VS (41) (or (42)) and the display element in the projector (10) have a conjugate relationship.
And the synthetic system works. On the other hand, the illumination optical system, the projection optical system, and the projection optical system of the projector (10) are arranged such that the operator's eye (50) has a substantially conjugate positional relationship with the light source in the projector.
And a synthesizing system with the combiner (31) acts.

Since the combiner (30) of this embodiment is composed of a diffractive optical element (31) in which a hologram diffraction grating is formed on a transparent substrate, as shown in the figure, the light flux is directed in a direction that does not follow the law of reflection on a plane. Can be collected. A similar effect can be achieved with a concave mirror or a Fresnel mirror, in which case it is necessary to provide a half mirror or appropriate reflectance and transmittance. In FIG. 4, (32) is PF-L.
The see-through rate of the combiner (30) can be adjusted by electrically adjusting the transmittance with a see-through rate adjusting plate made of a CD (plastic flexible liquid crystal).

The position of the virtual screen (VS) is
(41) in the figure according to the ability of the operator's eyes and the type of work
Alternatively, it can be set freely at a position such as (42). Incidentally, the VS position of (41) is a case where the VS is set to the same diopter as the hand of the presbyopia, and the VS position of (42) is a data based on the projection image at the same time as seeing the face of the other party during a meeting or the like. This is the case when you look at and talk. Of course, it is also possible to set VS to an infinite distance.

[0031]

As described above, in the virtual screen type stereoscopic display device according to the present invention, since the luminous flux from the image display means corresponding to each of the left and right eyes is brought to each eye without interference, a special A stereoscopic image can be easily viewed without wearing spectacles or the like. Further, the virtual screen is not a so-called virtual image but a real image formed in the air, and almost all luminous fluxes involved in the image formation are brought to the eyes, so that a very bright stereoscopic image equivalent to the luminance of the image display means can be obtained. Therefore, it is possible to contribute to power saving and energy saving. If the virtual screen type stereoscopic display device of the present invention is used as a computer terminal, the occupied space on the desk can be greatly reduced as compared with the conventional CRT display. Also, because you do not need to look directly at the CRT screen,
Eye fatigue is reduced and health concerns due to concerned electromagnetic waves are avoided.

Further, by providing the function of adjusting the imaging position (optical axis direction) as shown in the third embodiment, the optimum imaging position (optical axis direction) for the user at the time of use can be easily set. It can reduce eye fatigue (the display can be displayed at the same viewing distance as at hand, so it should be particularly convenient and valuable for people with presbyopia). Also, as shown in the third embodiment, by providing a see-through function to the combiner (focusing optical system), it is possible to talk while viewing the three-dimensionally displayed material with each other's face up. And for students, etc.), and of course, applications to TV conferences are also conceivable. It can also be used as a prompter for a speaker or announcer (a device that can read a manuscript with his face up). If there is no need for stereoscopic display, the same information can be presented on the left and right or different It is also possible to present information and view different information for each viewing zone.

Further, as shown in the third embodiment, by adding a function of changing the see-through rate of the combiner (focusing optical system), a desired see-through state can be set according to the surrounding environment (for example, during work). You can keep the foreground out of sight and increase the see-through rate when talking to people in front or at meetings.) As a result, the worker himself / herself can control a work environment that tends to cause stress.

Since the virtual screen type stereoscopic display device of the present invention is of a type for viewing an aerial image, it has a narrow viewing angle in principle, and the viewable range of the screen is limited. But,
In consideration of the fact that computer terminals are usually used by individuals, a wide viewing angle that makes designing difficult is unnecessary, and a narrow viewing angle with high secrecy is rather welcomed.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of the present invention, and is an explanatory diagram of a configuration and operation of a virtual screen type stereoscopic display device.

FIG. 2 is a diagram illustrating a basic concept of a virtual screen display device.

FIG. 3 is a view showing another embodiment of the present invention, and is an explanatory view of the configuration and operation of a virtual screen type stereoscopic display device.

FIG. 4 is a view showing still another embodiment of the present invention,
It is explanatory drawing of a structure and operation | movement of a virtual screen type | mold stereoscopic display device.

[Explanation of symbols]

(1-1) Display means for left eye (1-2) Display means for right eye (2-1) Projection means for left eye (2-2) Projection means for right eye (3) Focusing optical system (5-1) ) Left eye virtual screen (V
S) (5-2) Virtual screen of right eye (V
S) (6-1) Viewing area of left eye (6-2) Viewing area of right eye (7-1) Bending mirror for left eye (10) Projector (display means and projection means) (20) Bending mirror (30) Combiner (focusing optical system) (31) Diffractive optical element (32) See-through rate adjusting plate (41), (42) Virtual screen (VS) (50) Eye of operator

Claims (7)

[Claims] 1. Two display means for displaying information of characters and images, and two projecting means for enlarging and projecting a real image having an image displayed on the two display means as an object in a predetermined air. In a virtual screen type stereoscopic display device comprising a single focusing optical system for bringing light beams from the two projected aerial images to two predetermined viewing zones, the center of the two viewing zones is in the left-right direction. A virtual screen type stereoscopic display device, which is separated from a human pupil distance (60 to 70 mm) and touches or slightly overlaps (7 mm or less) in the left-right direction. 2. A virtual screen type three-dimensional display device according to claim 1, wherein said two display means are respectively a CRT (cathode ray tube), LC which can display an output from a computer or a TV (television) screen.
D (liquid crystal), DMD (digital mirror device), and other small display means, each of which can independently display an image, and which can display the same or different images as required. Screen type stereoscopic display device. 3. The virtual screen type stereoscopic display device according to claim 1, wherein said two display means are:
A virtual screen type stereoscopic display device, wherein when a human faces the two display means, image information for the right eye is displayed on the left side and image information for the left eye is displayed on the right side. 4. The virtual screen type stereoscopic display device according to claim 1, wherein said focusing optical system is a reflection type imaging device such as a concave mirror. 5. The virtual screen type stereoscopic display device according to claim 1, wherein said focusing optical system is a transmission type imaging element such as a positive lens. 6. A virtual screen type stereoscopic display device according to claim 1, wherein said focusing optical system is a Fresnel optical element. 7. A virtual screen type stereoscopic display device according to claim 1, wherein said focusing optical system is a diffractive optical element such as a hologram.