JP2001201713A - Video display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable switching observation of a virtual image displaying system and an extended projection system according to the user's observation conditions by incorporating the virtual image displaying system into the video display device of the extended projection system. SOLUTION: Switching of observation of the virtual image displaying system and the extended projection system is enabled by incorporating a video display function of the extended projection system and the virtual image displaying system, and controlling the projector lens 14 to the optical axis direction by a projector lens control part 17 based on instruction given from a remote control device 20. Thereby, when there is a single observer or an observation position is narrow, the virtual image displaying system can be used, and when there are a plurality of observers or the observation position is wide, the extended projection system can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device, and more particularly to an image display device which presents an image as a virtual image to an observer to improve the sense of reality of the observer.

[0002]

2. Description of the Related Art A virtual image display system for displaying an image as a virtual image and presenting it to an observer is used in many head mount displays. Hereinafter, the principle of the conventional virtual image display method will be described with reference to FIG.

In FIG. 11, reference numeral 111 denotes a condenser lens,
Reference numeral 12 denotes a viewer, and 113 denotes a liquid crystal panel for displaying an image. Therefore, if the focal length of the condenser lens 111 is f, the distance between the condenser lens 111 and the liquid crystal panel 113 is a, and the distance at which the image of the liquid crystal panel 113 is formed by the condenser lens 111 is a ′, then −1 / f = 1 / a-1 / a '(1) Therefore, as shown in FIG. 11, when the liquid crystal panel 113 is closer to the condenser lens 111 than the focal length f, a virtual image 114 of the liquid crystal panel is formed, and the observer 11
2 observes the virtual image 114. The magnification β from the liquid crystal panel 113 to the virtual image 114 is given by the following equation.

Β = a ′ / a (2) Advantages of such a virtual image display method are as follows: 1) Even if the angle of view is the same, the image is displayed far away, so that the screen is largely perceived and the sense of reality is improved. 2) Since the image is displayed farther than the actual display position, the eye is focused on the far side, so that fatigue can be reduced.

However, in the virtual image display system, a virtual image can be observed at the observation position 115 in FIG.
In No. 6, there is a problem that the virtual image cannot be observed because the virtual image is located outside the condenser lens 111 as viewed from the observer.

As another image display device, there is an enlarged projection system. This principle is shown in FIG. 13, reference numeral 131 denotes a light source, 132 denotes a lens, 133 denotes a liquid crystal panel, 134 denotes a projection lens, 135 denotes a video input terminal, 1
36 is a liquid crystal driving means, 137 is a screen, and 138 is an observer. The video signal is input from a video input terminal 135, and the liquid crystal driving means 136 drives the liquid crystal panel 133 according to the video signal. On the other hand, light is emitted from the light source 131, enters the liquid crystal panel 133 via the lens 132, and is spatially modulated according to the video signal. The spatially modulated light is enlarged and formed on a screen 137 via a projection lens 134. The observer 138 observes an image on the screen 137.

[0007] The virtual image display system is a head-mounted display and the like, and the display device of the enlarged projection system is often used as a large-screen television for home use. However, the virtual image display system is incorporated in the video display device of the enlarged projection system. There is no example.

[0008]

According to the above-mentioned conventional video display apparatus, a large-screen television for home use can use not only an enlargement method but also a virtual image method that can realize a pseudo-larger screen than the enlargement method. There is a long-awaited demand for realizing a video display device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a video display device in which a virtual image display system is incorporated in a video display device of an enlarged projection system, and which can be observed by switching between the virtual image display system and the enlarged projection system according to observation conditions.

[0010]

In order to achieve the above object, according to the present invention, light emitted from a light source is spatially modulated by using a spatial modulation element, and then imaged by using optical projection means. In an image display device that displays an image formed through a light condensing unit, a position of an image plane displayed through the light condensing unit is changed by changing an image forming position by the optical projection unit. It is characterized by the following.

By adopting such means, it is possible to incorporate a virtual image display system into an image display device of the enlarged projection system and switch between the virtual image display system and the enlarged projection system according to the selection of observation conditions for observation. Will be possible.

An image display for spatially modulating light emitted from a light source using a spatial modulation element, forming an image using optical projection means, and displaying the formed image via a light condensing means. In the device, it is disposed in close contact with the light collecting means,
A first light transmission / diffusion unit capable of switching transmission and diffusion of light from the optical projection unit, and disposed between the optical projection unit and the light collection unit, and within a focal length of the light collection unit. When the light passing through the second light transmission / diffusion means and the optical projection means forms an image at the position of the first light transmission / diffusion means, the light is diffused through the first light transmission / diffusion means. In the case where an image is formed at the position of the second light transmitting and diffusing means, the light is transmitted through the first light transmitting and diffusing means. , And a control means for controlling the second light transmission / diffusion means to diffuse the light.

Further, light transmission / diffusion means capable of switching between transmission and diffusion of light are arranged at an image forming position when observing by the enlarged projection method and an image forming position when observing by the virtual image display method. In addition, it is possible to widen the observation range when observing with a virtual image by the enlarged projection method.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 and 2
FIG. 1 is for describing a first embodiment of the present invention. FIG. 1 is a configuration diagram when an enlarged projection system is selected, and FIG. 2 is a configuration diagram when a virtual image projection system is selected. Show.

Reference numeral 11 denotes a light source, 12 denotes a lens, 13 denotes a liquid crystal panel, 14 denotes a projection lens, 15 denotes a video input terminal, 16 denotes a liquid crystal driving unit, 17 denotes a projection lens control unit, 18 denotes a remote control receiving unit, and 19 denotes a light condensing unit. A lens, 20 indicates a remote controller, and 21 indicates an observer.

First, the operation of FIG. 1 will be described. The video signal is input from the video input terminal 15 to the liquid crystal drive unit 16. The liquid crystal driving section 16 drives the liquid crystal panel 13 based on the video signal.

The light generated by the light source 11 is incident on a liquid crystal panel 13 via a lens 12, is subjected to spatial modulation based on a video signal, and then is incident on a projection lens 14. When the observer 21 wants to observe the image by the enlarged projection method, the user is notified using the remote controller 20 to that effect. The notification from the remote controller 20 is sent to the projection lens controller 17 via the remote controller receiver 18.
It is transmitted to.

In the projection lens control section 17, the liquid crystal panel 1
The lens of the projection lens 14 is moved in the optical axis direction so that 3 and the condenser lens 19 have a conjugate relationship. As a result, the image on the liquid crystal panel 13 forms an image at the position of the condenser lens 19, and the observer 21 observes the position of the condenser lens 19 as an image plane.

Next, the operation of FIG. 2 when the observer 21 selects the virtual image display method will be described. The configuration of FIG. 2 is exactly the same as that of FIG. When the observer 21 selects the virtual image display method, the projection lens control unit 17 determines that the image of the liquid crystal panel 13 is on the image forming surface 22 in front of the condenser lens 19 and within the focal length of the condenser lens 19. As an image,
The lens of the projection lens 14 is moved in the optical axis direction. Image plane 2
The image formed on the virtual image plane 2 is condensed by the condenser lens 19 into the virtual image plane 2.
3, a virtual image is formed, and the observer 21 observes the virtual image plane 23 as an image plane. Note that the virtual image plane 23 and its magnification are
According to the equations (1) and (2), respectively.

In this embodiment, the observation can be performed by switching between the virtual image display method and the enlarged projection method.
The virtual image display method and the enlarged projection method can be switched and used according to the selection of the observer.

Next, a description will be given of a second embodiment of the present invention. Before that, in the embodiment of FIG. 1, light spatially modulated by the liquid crystal panel 13 is projected by a projection lens as shown in FIG. Since the direction of the light beam is restricted by the pupil diameter 31 of 14, the range 32 in which an image can be observed is limited. The second embodiment extends the observation range.

FIGS. 4 and 5 are diagrams for explaining a second embodiment of the present invention. FIG. 4 is a block diagram showing a case where an enlarged projection system is selected, and FIG. 5 is a diagram showing a virtual image projection system. The configuration diagrams when selected are shown. The same components as those in the first embodiment will be described with the same reference numerals.

The difference from FIG. 1 in the case of observation by the enlarged projection shown in FIG. 4 is that a light transmission / diffusion section 41 for controlling transmission and diffusion of light is provided at a position facing the condenser lens 19 on the observer 21 side.
A light transmission / diffusion unit 42 for controlling transmission and diffusion of light is disposed between the projection lens 14 and the condenser lens 19, and these light transmission / diffusion units 41 and 42 are controlled by a light transmission / diffusion control unit 43. Is to do.

As a specific example of the light transmission / diffusion portions 41 and 42, there can be mentioned, for example, a polymer-dispersed liquid crystal introduced by Corona (1994), "Basics of Liquid Crystal and Display Application".

An example when the enlarged projection system shown in FIG. 4 is selected will be described. When the observer 21 selects the enlarged projection method, the fact is first notified using the remote controller 20. The notification from the remote controller 20 is transmitted to the projection lens controller 17 and also to the light transmission / diffusion controller 43 via the remote controller receiver 1. The projection lens control unit 17 moves the lens of the projection lens 14 in the optical axis direction so that the liquid crystal panel 13 and the light transmission / diffusion unit 41 have a conjugate relationship. The light transmission / diffusion controller 43 controls the light transmission / diffusion unit 41 to diffuse and the light transmission / diffusion unit 42 to transmit.

As a result, the image of the liquid crystal panel 13 is formed on the light transmission / diffusion section 41, and the observer 21 observes the position of the light transmission / diffusion section 41 as an image plane. In addition, since light is diffused from the light transmission / diffusion unit 41, observation can be performed in a wide observation range without being affected by the pupil diameter.

An example when the virtual image display method shown in FIG. 5 is selected will be described. When the observer 21 selects the virtual image display method, the projection lens control unit 17 controls the projection lens 14 so that the image of the liquid crystal panel 13 is formed on the light transmission / diffusion unit 42.
Move the lens in the optical axis direction. Light transmission / diffusion controller 4
Reference numeral 3 controls the transmission through the light transmission and diffusion unit 41 and the diffusion of the light transmission and diffusion unit 42.

The image formed on the light transmission / diffusion section 42 becomes a virtual image on the surface 23 by the condenser lens 19, so that the observer 21 observes the virtual image surface 23 as an image surface. In addition, since light is diffused from the light transmission / diffusion unit 42, observation can be performed in a wide observation range without being affected by the pupil diameter.

In this embodiment, when the number of observers is plural or the observation position is wide, it is possible to switch to the enlarged projection system and observe in a wide observation range. Can also be observed as a virtual image display method.

FIG. 6 is a schematic diagram for explaining a third embodiment of the present invention. In this embodiment,
It shows a change in the angle of view of the virtual image due to the difference in the observation distance, and the image of the liquid crystal panel 61 becomes a virtual image 63 by the condenser lens 62.

Here, when the observation distance changes from 64 to 65, the angle of view of the virtual image 63 changes. At the observation distance 65, the virtual image portion 66 located outside the condenser lens 62 when viewed from the observation distance 65 cannot be observed. In this embodiment, the observer can control the angle of view of the virtual image according to the observation distance.

FIG. 7 is a configuration diagram for explaining FIG. 6 more specifically. The difference from the configuration shown in FIG.
3 is transmitted through the light transmission / diffusion unit 42 using the projection lens 141.
The point is that the magnification can be changed when the image is formed.

The magnification can be varied, for example, by forming the projection lens 141 into a plurality of lenses and moving each lens independently in the optical axis direction. For example, when the observer is at the position 21a, the light transmitting / diffusing section 42
The magnification is controlled so that the image becomes b above. At this time, the size of the virtual image is B. When the observer is at the position 21b, the magnification is controlled so that the image becomes c on the light transmission / diffusion section 42. At this time, the size of the virtual image is C.

Thus, even if the observation distance is different, the angle of view of the virtual image can match the angle of view of the condenser lens 19. The angle of view (magnification ratio) may be set by the observer using the remote controller 20, or an appropriate angle of view may be set by separately providing means for detecting the position of the observer.

FIG. 8 is a schematic diagram for explaining a fourth embodiment of the present invention. In this embodiment,
It shows the observation range of the virtual image due to the difference in the observation direction. That is, the image on the liquid crystal panel 81 is
Thus, a virtual image 83 is formed. Here, when the observation position is 84, the entire area of the virtual image can be observed. However, when the observation position is 85, the virtual image portion located outside the condenser lens 82 as viewed from the observation position 85 cannot be observed. In this embodiment, a virtual image portion that cannot be observed can be observed.

A fourth embodiment of the present invention will be described with reference to the configuration diagram of FIG. The difference between this embodiment and FIG. 5 lies in that a means for moving the optical axis in parallel is provided between the light transmitting and diffusing unit 42 and the condenser lens 19.

As means for moving the optical axis in parallel, for example, a flat plate prism 91 is used. Observer is 21d to 21d
Is moved to the position, the angle of the plate prism 91 is changed using the plate prism control unit 92.

Thus, the position of the light transmission / diffusion portion 42 is equivalent to the position where the position has been moved from d to e. The position of the virtual image plane 23 also moves from D to E with the movement to the light transmission / diffusion unit 42.
As a result, the entire region of the image formed on the light transmission / diffusion section 42 can be observed from the position of the observer 21c. The setting of the moving amount of the position of the virtual image may be performed by the observer using the remote controller 20, or an appropriate moving amount may be set by separately providing a means for detecting the position of the observer. Further, the fourth embodiment can be combined with the third embodiment.

Next, a fifth embodiment of the present invention will be described with reference to FIG. In the third and fourth embodiments, the optical means is provided so that the virtual image can be properly observed even when the position of the observer moves. In the fifth embodiment, the same effects as those of the third and fourth embodiments can be obtained by controlling the size and the position of the image displayed on the liquid crystal panel instead of the optical means.

In FIG. 10, when the observer is 21e, the liquid crystal driving section 161 is controlled so that the image is displayed on the liquid crystal panel 131 at the size and position of f. The image of f on the liquid crystal panel 131 is formed as f ′ in the light transmission / diffusion section 42, and the virtual image F is observed by the observer 21e. 2 observers
In the case of 1f, the liquid crystal driving section 161 is controlled so that the image is displayed on the liquid crystal panel 131 at the size and the position of g. The image of g on the liquid crystal panel is formed as g ′ in the light transmission / diffusion section 42, and the virtual image G is observed by the observer 21f.

The size and the position of the image displayed on the liquid crystal panel 131 are set by the observer using the remote controller 20.
Alternatively, a means for detecting the position of the observer may be separately provided to make appropriate settings. Further, the fifth embodiment is described as a third,
It is also possible to configure in combination with the fourth embodiment.

[0042]

As described above, according to the present invention, a virtual image display system is incorporated in an image display device of the enlarged projection system, and observation is performed by switching between the virtual image display system and the enlarged projection system according to observation conditions. Thus, when the number of observers is one or the observation position is narrow, the virtual image display method can be used, and when the number of observers is plural or the observation position is wide, the enlargement projection method can be used.

[Brief description of the drawings]

FIG. 1 is a configuration diagram for explaining a case of observing by an enlarged projection system according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram for explaining a case of observation by a virtual image projection method according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram for describing limitation of an observation range by a pupil diameter of a projection lens.

FIG. 4 is a configuration diagram for explaining a case of observing with an enlarged projection system according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram for explaining a case of observation by a virtual image projection method according to a second embodiment of the present invention.

FIG. 6 is a schematic diagram for explaining a third embodiment of the present invention.

FIG. 7 is a configuration diagram for explaining FIG. 6 more specifically;

FIG. 8 is a schematic diagram for explaining a fourth embodiment of the present invention.

FIG. 9 is a configuration diagram for explaining FIG. 8 more specifically;

FIG. 10 is a configuration diagram for explaining a fifth embodiment of the present invention.

FIG. 11 is a schematic diagram for explaining the principle of a conventional virtual image display method.

FIG. 12 is a schematic diagram for explaining a problem of a conventional virtual image display method.

FIG. 13 is a schematic diagram for explaining the principle of a conventional enlarged projection system.

[Explanation of symbols]

11 light source, 12 lens, 13 liquid crystal panel, 14,
141: Projection lens, 15: Video input terminal, 16, 16
DESCRIPTION OF SYMBOLS 1 ... Liquid crystal drive part, 17 ... Projection lens control part, 18 ... Remote control receiving part, 19 ... Condensing lens, 20 ... Remote control, 21
... observer, 22 ... image plane, 23 ... virtual image plane, 41, 42 ...
Light transmission / diffusion unit 43: light transmission / diffusion control unit 91: flat plate prism 92: flat plate prism control unit 92

Continued on the front page F term (reference) 2H088 EA10 EA13 EA19 GA10 HA23 HA24 HA28 KA30 MA20 5C058 AB06 BA11 BA17 BA31 DA11 EA11 EA12 EA26 EA51

Claims (5)

[Claims] 1. An image display for spatially modulating light emitted from a light source using a spatial modulation element, forming an image using an optical projection unit, and displaying the formed image via a condensing unit. In the apparatus, an image display position is changed by changing an image forming position by the optical projection unit, thereby changing a position of an image plane displayed through the light condensing unit. 2. An image display for spatially modulating light emitted from a light source using a spatial modulation element, forming an image using an optical projection unit, and displaying the formed image via a condensing unit. In the apparatus, a first light transmission / diffusion unit which is disposed in close contact with the light condensing unit and is capable of switching transmission and diffusion of light from the optical projection unit, and between the optical projection unit and the light condensing unit And a second light transmission / diffusion means arranged within the focal length of the light condensing means, and light passing through the optical projection means forms an image at the position of the first light transmission / diffusion means. Are respectively controlled so as to diffuse through the first light transmission / diffusion means and through the second light transmission / diffusion means, and when an image is formed at the position of the second light transmission / diffusion means, The second light transmission and diffusion means are transmitted through the first light transmission and diffusion control means. An image display device comprising: a control unit for controlling each of the over-diffusion units so as to diffuse the over-diffusion unit. 3. When the light is imaged on the second light transmission / diffusion control means, an optical projection means capable of changing the magnification of the spatially modulated light is used to display the light through the light condensing means. 3. The size of an image surface to be changed is changed.
3. The video display device according to 1. 4. An optical axis translating means capable of translating an optical axis of light between said first and second light transmission / diffusion controlling means, and displaying through said light condensing means. The image display device according to claim 2, wherein the position of the image surface is changed. 5. The size and position of an image displayed on the spatial light modulator by changing the size and position of the image displayed on the spatial light modulator. 3. The video display device according to 1.