JPH10288958A - Projection display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make lines of sight of a great many people in conversation coincide with each other in a device used for a TV conference, etc., by making planes of polarization of projection light of a projection device orthogonally intersect with each other and viewing a screen through glasses with a polarizing element according to a video to be viewed for users. SOLUTION: Two projection devices 1A, 1B project videos from a rear surface to a display screen 2. At this time, the polarizing elements 3A, 3B linear polarizing transmission light are set up in front of the projection holes of the projection devices 1A, 1B. Planes of linear polarization are selected so as to orthogonally intersect with each other in the polarizing elements 3A and 3B. Persons (a), (b) being the users put on polarizing glasses 3A', 3B' arranged with linear polarization plates having the same planes of linear polarization as the polarizing elements 3A, 3B. However, in the polarizing glasses 3A', 3B', mutual planes of linear polarization orthogonally intersect with each other, and further, in respective planes of polarization, the polarizing element 3A is made parallel to the polarizing glasses 3A', and the polarizing element 3B is made parallel to the polarizing glasses 3B'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device used in a TV conference system and the like, and more particularly, to a case where multiple images taken from different places or from different directions are displayed, as if in a real space, depending on the position at which the displayed image is viewed. The present invention relates to a projection display device which allows a user to view an image of a place or a direction in which the image was taken as if he / she is, through one display surface.

[0002]

2. Description of the Related Art In recent years, with the development of communication technology such as image coding technology, two-way video communication such as a TV telephone and a TV conference system connecting remote locations by a video / voice communication network has been rapidly spreading. . In the future, it is expected that a more realistic video service can be provided by the enhancement of the ISDN network and the increase in the bandwidth of the transmission network.

FIG. 7 shows a display / imaging device currently used for two-way video communication. An imaging device 22 is provided on the upper surface or side surface of the display device 21 such as a CRT display, and images the user M. However, since a user using such a device usually looks at the display device 21, the imaging device 2
Even when imaging is performed in 2, the user does not look at the imaging device 22. For this reason, there has been a problem that even if it is possible to transmit a video full of a high sense of reality, an unnatural conversation in which the eyes of the interlocutors do not match.

[0004] The eyes of the interlocutors are matched and the TV
As a method capable of coping with a large-screen display used in a conference system or the like, there is a method using a screen for switching between a light transmitting state and a scattering state (see Japanese Patent Application No. 1-44892). In this method, as shown in FIG.
3, a projection type display device 26 including a projection device 24 and a control circuit 25, and the imaging device 22; and when the display screen 23 is in a scattering state, a screen projected by the projection type display device 26 is displayed. In the transmissive state, the user M, who is the subject, is passed through the display screen 23 to the imaging device 22.
By performing the image pickup by using, the eye-gaze coincidence is realized.

[0005] In the above example, one-to-one interlocutors are used. However, in the case of a TV conference, since it is usually performed not by one-on-one but by many people, the eyes of a plurality of interlocutors are matched. It becomes important.

However, this cannot be realized with the configuration shown in FIG. For example, A, B, C and a, b, c shown in FIG.
In a case where a conference is held among the three persons, the imaging devices 22 and 22 ′ that capture the images of these conferences capture images around B and b. When A and b discuss, A will face in the direction of b on the displayed screen, and b will similarly face in the direction of A. Therefore, on the screen viewed by A, b is in a horizontal state, and the eyes do not match. Here, only one case is shown, but the lines of sight do not coincide except when B and b discuss. Further, even if the direction of the imaging device is changed to the direction of the interlocutor or the display screen is switched using a plurality of imaging devices, it is not possible to match the eyes of the interlocutors, that is, A and b in this example. Even if it can be done, the other B, C and a, c will not be able to see the display screen where A or b turns their gaze toward themselves, and it will be an unnatural situation and a natural face-to-face situation The meeting could not be held.

As a method of matching the lines of sight of a plurality of interlocutors, a method of using a directional screen having a narrow divergence angle with respect to incident light has been proposed (Japanese Patent Application No. 6-2).
57234). This method first captures the same video in different directions from different locations by a plurality of imaging devices, and then displays the video from each imaging device by a corresponding projection device when displaying it on a remote display device. Project on a directional screen. Since this directional screen has a very narrow dispersion angle with respect to the incident light as described above,
When viewing the directional screen at an appropriate position, only the image projected from one projection device can be seen.

In such a method, when the same screen is viewed from different directions, different screens can be viewed.
For example, as shown in FIG. 9, three people A, B, and C and a,
If the three people b and c are each having a conference using the TV conference system using this method, when A and b are discussing, A shows the 1-2A screen, and b shows the 1'-screen. Looking at the screen of 1B, the screen of 1-2A is the imaging device 22'-2A, 1'-
Since the screen 1B is a screen captured by the imaging device 22-1B, the eyes can be matched. Of course, when A and a discuss, A, a
Means that the screens of 1-1A and 1'-1A can be seen respectively.

However, this method is a display device dedicated to a TV conference, and when used as a normal projection display device, for example, when giving a presentation to a large audience, the display viewing angle is extremely narrow. There is. Further, since the projection image is distorted due to the oblique projection, it is necessary to newly add an optical system or a video signal processing system for correcting the distortion.

[0010]

An object of the present invention is to provide a TV set.
It is an object of the present invention to provide a technology capable of matching the lines of sight of a large number of interlocutors in a display / imaging device used for a telephone or a TV conference system.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0012]

The outline of a typical invention among the inventions disclosed in the present application will be briefly described as follows.

In a projection display device having a plurality of projection devices and a display screen, the projection light of some of the projection devices is polarized, and the projection light of the other projection devices is polarized so as to be orthogonal to the polarization plane. And means for projecting an image on the display screen, and means for viewing the projected image through a polarizing element. Further, there is provided means for externally controlling the direction of the polarization plane of the polarizing element.

According to the above-mentioned means, the polarization planes of the projection light of the projection device are made orthogonal to each other, and the user sees the display screen through the glasses provided with the polarization element in accordance with the image to be viewed, thereby obtaining one display. Multiple images can be selectively viewed on the screen.

An embodiment (example) of the present invention will be described below in detail with reference to the drawings.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 is a schematic diagram showing a schematic configuration of a projection display apparatus according to Embodiment 1 (Example) of the present invention. The two projectors 1A and 1B display an image from the back side on a screen 2
To project. At this time, a polarizing element 3A that linearly polarizes the transmitted light is provided in front of each of the projection ports of the projection devices 1A and 1B.
And 3B are installed. However, the polarizing elements 3A and 3B
Are selected so that the planes of linear polarization are orthogonal to each other.

A person a and a person b who are users (users)
Wears polarizing glasses 3′A and 3′B on which a linear polarizing plate having the same linear polarization plane as the polarizing elements 3A and 3B is installed. However, it is assumed that the polarizing glasses 3′A and 3′B have their linear polarization planes orthogonal to each other. Here, the respective polarizing planes are parallel to the polarizing element 3A and the polarizing glasses 3′A.
It is assumed that the polarizing element 3B and the polarizing glasses 3′B are parallel.

Now, an image as shown in (1) of FIG. 2 is projected on the projection devices 1A and 1B. If the person c who does not wear the polarizing glasses 3'A and 3'B looks at the display screen 2, as shown in (2) of FIG.
The image of A and the image of 1B will be seen overlapping.

On the other hand, as shown in FIG. 2C, the person a wearing the spectacles 3'A having a polarization plane parallel to the polarizing element 3A and orthogonal to the polarizing element 3B, as shown in FIG. You will only see the video from Conversely, person b wearing polarizing glasses 3′B having a polarization plane parallel to polarizing element 3B and orthogonal to polarizing element 3A, as shown in (3) of FIG. You will only see the video. As a result, in the projection display apparatus according to the first embodiment, by putting on the polarizing glasses 3 ′, even when viewing the same display screen 2, it is possible to change an image that is viewed according to the polarizing plane of the polarizing glasses 3 ′. .

If the same image is input to the projection devices 1A and 1B, the user (user) looks at the display screen without putting on the polarizing glasses 3'A or 3'B, and as a normal projection display device. You can use it exactly the same. However, in this case, it goes without saying that the brightness of the display device is doubled.

(Embodiment 2) FIG. 3 is a schematic diagram showing a schematic configuration of a projection display apparatus according to Embodiment 2 (Example) of the present invention. As shown in FIG. 3, a liquid crystal projection device 1 'is added to the projection device.
When A and 1'B are used, the liquid crystal projectors 1'A and 1'B have their polarization planes orthogonal to each other between the liquid crystal projectors 1'A and 1'B because the projection light is polarized. By doing so, it is not necessary to dispose a polarizing element in front of the projection device as compared with the case of the first embodiment.

(Embodiment 3) FIG. 4 is a schematic diagram showing a schematic configuration of a projection display apparatus according to Embodiment 3 (Example) of the present invention. As shown in FIG. 4, a transmitting unit 4A or 4B is provided outside the display screen 2, and a receiving unit 5A or 5B is provided in the polarizing glasses 3 "A or 3" B. When the polarizing planes of the polarizing glasses 3 ″ A and 3 ″ B can be changed depending on the positions where the persons a and b are present, as shown in FIG.
A signal transmitted from the transmitting unit 4A or 4B provided outside, for example, a signal based on infrared rays or a high frequency is polarized glasses 3 ″.
When the signal is received by the receiving unit 5A or 5B of A or 3 ″ B, the control unit 6 controls the polarizing element driving unit 7 to set the polarization plane according to the received signal.

For example, when a signal from the transmitting unit 4A is received, a polarization plane parallel to the polarizing element 3A is set, and the transmitting unit 4B
Is received, the polarization plane is determined to be parallel to the polarization element 3B. In this case, in FIG. 4, since the person a receives the signal from the transmitting unit 4A, the polarization plane of the polarizing glasses 3 ″ A is parallel to the polarization plane of the polarizing element 3A,
Only the image from the projection device 1A will be seen. Conversely, person B has received the signal from transmitting section 4B,
Only the image from the projection device 1B will be seen. Further, when the position of the person a is moved and the signal from the transmitting unit 4B is received, the image viewed by the person a changes from the image of the projection device 1A to the image of the projection device 1B. Here, which signal is received is determined by the transmitting unit 4A.
Alternatively, it is determined by the distance between 4B and the receiving unit 5A or 5B.

FIG. 6 is a sectional view showing a configuration example of the polarizing element used in the present invention. 11 is a TN liquid crystal, 12 is a transparent electrode,
13 is a linear polarizing plate, 14 is a power supply, and 15 is a switch. As shown in FIG. 6, a TN liquid crystal 11 is sandwiched between transparent electrodes 12, and a linear polarizing plate 13 is provided on the light emitting surface side of the TN liquid crystal. Here, the direction of the polarization plane of the linear polarizing plate 13 is selected such that, when natural light enters the present polarizing element, only the incident light having a polarization plane orthogonal to the linear polarizing plate 13 is emitted. However, since the outgoing light passes through the linear polarizing plate 13, the light has the same polarization plane as the linear polarizing plate 13.

When light having the same polarization plane as that of the linear polarizing plate 13 is incident on such a polarizing element, the light is blocked by the TN liquid crystal 11. However, when a voltage is applied to the TN liquid crystal 11 through the transparent electrode 12, the molecular arrangement of the liquid crystal aligns in the direction of the electric field.
3 will be transmitted.

On the other hand, when light of a polarization plane orthogonal to the linear polarization plate 13 is incident, the polarization plane is rotated by 90 degrees by the TN liquid crystal 11, so that the light can pass through the linear polarization plate 13. However, when a voltage is applied to the TN liquid crystal 11 through the transparent electrode 12, the polarization plane does not rotate by 90 degrees for the above-described reason, and is blocked by the linear polarizer 13.

As described above, when the polarizing element as shown in FIG. 6 is used, the polarization plane of the polarizing glasses 3 ″ can be electrically controlled depending on whether or not a voltage is applied to the TN liquid crystal 11. Although an example using 11 has been shown, it is needless to say that the same effect can be obtained by using a guest-host liquid crystal or ECB. Obviously, a similar effect can be obtained.

Here, the case of a general projection apparatus has been described. However, if a liquid crystal projection apparatus as described in the second embodiment is used, the same effect as described above can be obtained without using the polarizing elements 3A and 3B. Obviously,

As described above, the invention made by the present inventor is:
Although the present invention has been described in detail with reference to the embodiment, the present invention is not limited to the embodiment, and it is needless to say that various changes can be made without departing from the scope of the invention.

[0030]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows.

A projection display device that can easily match the line of sight can be realized simply by having the user wear polarized glasses.

Further, as compared with a system in which the screen state is time-divided into a scattering / transmission state, an expensive circuit or screen for controlling the time division is not required, so that it can be realized at low cost.

Further, if the same image is projected without using polarizing glasses, it can be used as an ordinary large-screen display device.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of a projection display device according to an embodiment (Example) 1 of the present invention.

FIG. 2 is a diagram for explaining a display principle of the projection display device according to the first embodiment.

FIG. 3 is a schematic diagram showing a schematic configuration of a projection display device according to Embodiment (Example 2) of the present invention.

FIG. 4 is a schematic diagram showing a schematic configuration of a projection display device according to Embodiment (Example 3) of the present invention.

FIG. 5 is a block diagram showing a schematic configuration of polarized glasses used in the present invention.

FIG. 6 is a cross-sectional view illustrating a configuration example of a polarizing element used in the present invention.

FIG. 7 is a schematic diagram showing a schematic configuration of a conventional display / imaging apparatus.

FIG. 8 is a schematic diagram showing a schematic configuration of a conventional display / imaging device.

FIG. 9 is a schematic diagram showing a schematic configuration of a conventional display / imaging device for large screen display.

[Explanation of symbols]

1A, 1B, 24: Projection device, 1'A, 1'B: Liquid crystal projection device, 2, 23: Display screen, 3A, 3B: Polarizing element, 3'A, 3'B, 3 "A, 3" B … Polarized glasses,
a, b, c: person, 4A, 4B ... transmitting unit, 5A, 5B ...
Receiving unit, 6: control unit, 7: polarizing element driving unit, 11: TN
Liquid crystal, 12: Transparent electrode, 13: Linear polarizing plate, 14: Power supply, 15: Switch, 21: Display device, 22, 22 '...
Imaging device, 25: control circuit, 26: projection type display device.

Claims (2)

[Claims] 1. In a projection display device including a plurality of projection devices and a display screen, a projection light of a part of the projection devices is polarized, and a projection light of the remaining projection devices is orthogonal to the polarization plane. A projection display device, comprising: means for projecting an image onto the display screen by polarizing the image to light; and means for viewing the projected image through a polarizing element. 2. The projection display device according to claim 1, further comprising means for externally controlling the direction of the plane of polarization of the polarizing element.