JPH0772551A - Display screen - Google Patents

Abstract

PURPOSE:To provide a display screen capable of improving the image quality of a display picture on the screen in a large-screen display and image pickup device used for a video telephone or a video conference system. CONSTITUTION:By respectively using one or plural minute screens 6 minutely divided and minute mirrors 5, a screen area and a reflection area are formed. Then, the screen area and the reflection area are alternately arranged to constitute the display screen 3. In the case of using the display screen 3 in the display and image pickup device, the lines of sight are aligned by picking up a reflected image from the reflection area. By integrating the screen 6' with the mirror 5', moire is prevented from occurring because both of them can not be brought into contact with each other, and the image quality of a display picture on the screen is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display screen used in a display / image pickup device in which a projection type display device and an image pickup device used in a TV telephone or a TV conference system are combined.

[0002]

2. Description of the Related Art In recent years, two-way video communication such as a TV telephone and a TV conference system in which remote locations are connected by a video / audio communication network has rapidly spread due to the development of communication technology such as image coding technology. . In the future, it is expected that a more realistic video service can be provided by enhancing the ISDN network and increasing the bandwidth of the transmission network.

FIG. 5 shows a display / imaging device currently used for two-way video communication. The image pickup device 2 is on the upper surface or the side surface of the display device 1 such as a CRT display, and picks up an image of the user M. However, a person M who uses such a device usually looks at the display device 1, and therefore the user M does not look toward the image pickup device 2 even if the image pickup device 2 takes a picture. . Therefore, there is a drawback in that even if it is possible to transmit a highly realistic image, it becomes an unnatural conversation in which the line of sight of the interlocutors do not match.

A method using a finely divided half mirror has been devised as a method capable of matching the lines of sight of the interlocutors and supporting a large screen display used in a TV conference system (M. Kuriki et al. , "An
Eye-Contact Technique for
Large-Screen DisplaysUsi
ng a Blazed Half-Transpar
ent Mirror (BHM) ”, SID '93
Digest, pp 919, 1993).

This half mirror is a half mirror (hereinafter referred to as a micro semi-transparent mirror array 4) constructed by arranging a large number of micro half mirrors 4a inclined by θ as shown in FIG. FIG. 7 shows the configuration of a display / imaging device according to this method. In the display device 1, a projection type display device 1 ′ is installed in a frame 9 having a display screen 8, and an image is projected and displayed from the inside of the frame 9 on the display screen 8. The microscopic semi-transparent mirror array 4 shown in FIG. 6 is installed in front of the display surface of the display screen 8, and the image reflected by the micro semi-transparent mirror array 4 is imaged by the imaging device 2 installed in the reflective direction 2θ from the normal direction. By doing so, it is possible to optically image from the display surface, that is, from the direction of the line of sight of the user M.

[0006]

However, as shown in FIG. 7, the micro-semitransparent mirror array 4 is installed in front of the display screen of the display device 1 (in the case of this drawing, in front of the display screen 8). If the display screen 8 and the micro semi-transparent mirror array 4 are not installed in close contact with each other, there is a drawback that moire occurs. In particular, when the micro-semitransparent mirror array 4 has a large area, the mirror itself is warped or swelled, so that the mirrors cannot be in close contact with each other, and the occurrence of moire is remarkable, and the image quality of the display screen is significantly deteriorated.

The present invention has been made to solve the above problems, and an object thereof is to improve the image quality of a display screen in a large-screen display / imaging device used in a TV phone, a TV conference system, or the like. It is to provide a display screen that enables

[0008]

To achieve the above object, the display screen of the present invention comprises a screen area comprising at least one microscreen and a reflective area comprising at least one tilted micromirror, The screen area and the reflection area are alternately arranged.

In the above structure, when the screen area is formed by one micro screen and the reflection area is formed by one micro mirror, the micro mirror pitch and inclination of the reflection area are d and θ, respectively. Then, between the pitch D of the minute screen in the screen area,
It is preferable to have a configuration that satisfies the relationship of D = d · tan θtan 2θ from the viewpoint of preventing the display image from being reflected on the imaging device.

[0010]

In the display screen of the present invention, a plurality of minutely divided minute screens and minute mirrors are used to form a screen area and a reflective area, and the screen area and the reflective area are alternately arranged to provide a display.・ When used in an image pickup device, it enables line-of-sight matching by picking up a reflected image from a reflection area, and prevents the occurrence of moire, which is caused by the inability of the screen and the mirror to be in close contact with each other. To improve the image quality of the display screen.

[0011]

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

[Embodiment 1] FIG. 1 shows a side view of a first embodiment of a display screen used in a display / imaging device according to the present invention. The basic concept of the display screen 3 according to this embodiment is that the mirror 5'and the screen 6'inclined in opposite directions to the plane by angles .theta. And .phi. Respectively are minutely divided, and the divided minute screen 6 and the minute mirror 5 are the same. It is a screen that is rearranged in a plane and integrated. In (a) of FIG. 1, the case where the screen area is constituted by one minute screen 6 and the reflection area is constituted by one minute mirror is shown in (b) of FIG.
Shows the case where each is composed of a plurality of (two in the illustrated example) microscreens or micromirrors. An ordinary display screen is generally composed of a Fresnel lens, a lenticular lens, and a medium (scattering layer) for forming a projection image, and this embodiment also uses the minute screen 6 having such a structure. . Therefore, the decrease in brightness at the peripheral portion of the display screen that occurs when the Fresnel lens is not installed is small.

FIG. 2 shows a structural example of a display / imaging device using the display screen according to this embodiment. The projection type display device 1'installed in the frame 9 is used as the display device 1, and the display screen 3 according to the present embodiment shown in FIG. It is installed in.

An image projected from the projection type display device 1'is displayed on each of the minute screens 6, and the minute mirror 5 tilted by θ shows the image of the subject (user M) in front of the screen in the 2θ direction. Reflect to. Therefore, if the image pickup device 2 is installed in the reflection direction (2θ direction) as shown in FIG. 2, the image projected by the projection type display device 1 ′ is displayed on the display screen 3 and the use in front of the display screen 3 is possible. The image of the person M can be taken from the in-plane direction of the display surface by the image pickup device 2, and the image in which the line of sight matches can be easily obtained.

The fine screen 6 may be composed of the scattering layer alone. In that case, as shown in FIG. 2, if the Fresnel lens 7 is provided by forming a Fresnel lens structure on the back surface of the display screen 3 of this embodiment or installing a Fresnel lens sheet, the display screen can be displayed. It is possible to prevent a decrease in brightness in the peripheral region of the.

Further, in the embodiment shown in FIG. 1A, the pitch D of the fine screen 6 and the pitch d of the fine mirror 5 are set.
And the inclination θ, the relationship of D = d · tan θtan2θ is satisfied. The larger D is, the higher the brightness of the projected display screen is, but there is a drawback that the display image on the minute screen 6 is also captured at the same time when the reflection image is captured by the imaging device 2. However, in the case of the present embodiment, the maximum value of D (= d · tan θtan 2θ) is used so that the minute screen 6 cannot be seen due to the inclined minute mirror 5 when the display screen 3 is seen from the imaging device 2. Therefore, there is no reflection on the reflection image of the display screen,
There is no significant reduction in display brightness.

[Embodiment 2] FIG. 3 shows a sectional view of a second embodiment of the display screen according to the present invention. The configuration shown in FIG. 3 is different from the display screen shown in FIG. 1 in that the inclination φ of each minute screen 6 is 0 °. At this time, the tip of the tilted microscopic mirror 5 projects from the microscopic screen 6. When the display screen 3 having the configuration shown in FIG. 1 is used, when the display screen is projected from the normal line direction of the display screen 3, the display light does not go toward the subject (front) due to the refraction effect. Therefore, the display screen may be dark. On the other hand, in the present embodiment, since the display light incident surface and the display light emitting surface are parallel to each other, the display light is not deflected by the refraction effect as described above, and the display brightness can be prevented from lowering.

[Embodiment 3] FIG. 4 is a block diagram showing a third embodiment of the display screen according to the present invention. In the configuration shown in FIG. 4, unlike the display screen 3 shown in FIG. 1, the microscopic mirrors 5 and the microscopic screens 6 are alternately arranged so as to sandwich the transparent body, and when viewed from the light incident side, The screen 6 is tilted in the opposite direction. Therefore, when the display screen is projected obliquely from below, the display light is directed toward the subject due to the refraction effect. On the other hand, in the configuration shown in FIG. 4, since imaging is performed obliquely from above, the captured image is distorted due to the difference in optical path difference. For example, when the subject is a square, the image is captured as a trapezoid with a long upper side. However, in the present embodiment, the projection direction is diagonally downward, which is the opposite of the projection direction. Therefore, the influence of the optical path difference is canceled out, and the distortion generated in the captured image can be corrected when projected and displayed.

In each of the above-mentioned embodiments, the case of the rear projection type display in which the projection type display device 1'is installed on the back side of the display screen 3 is shown, but in the case of the front projection type installed in front of the display screen 3. However, it goes without saying that the same effect can be obtained. However, in this case, the positions of the projection type display device 1 ′ and the image pickup device 2 are switched in FIG. 2. In addition, the micro mirror 5 configured to reflect the reflected image of the subject upward.
Although the case of using the micro mirror 5 has been described, it is needless to say that the same effect can be obtained even if the micro mirror 5 configured to reflect the light downward or left or right is used. At that time, the direction in which the display screen is projected naturally changes accordingly. further,
Except for (b) in FIG. 1, the case in which the screen area and the reflection area are configured by one micro screen or micro mirror is illustrated, but the same effect can be obtained by configuring by a plurality of micro screens or micro mirrors. It goes without saying that it will be done.

[0020]

As described above, in the present invention, a display capable of easily matching the line of sight is provided by installing a display screen composed of a plurality of minute screens and micromirrors in front of the projection type display device and the image pickup device. An image pickup device can be realized, and moire that occurs when a half mirror is installed on a display screen and image distortion that occurs during image pickup can be prevented or corrected, so that the image quality of the display screen can be improved. further,
Since the number of optical elements through which the display light passes is reduced, there is also an effect of alleviating the loss due to the optical elements, that is, the reduction in the brightness of the display screen.

[Brief description of drawings]

FIG. 1 is a diagram showing the concept and configuration of a display screen used in a display / imaging device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration example of a display / imaging device using the display screen according to the first embodiment.

FIG. 3 is a configuration diagram of a display screen according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a display screen according to a third embodiment of the present invention.

FIG. 5 is a diagram showing a configuration example of a conventional display / imaging device.

FIG. 6 is a sectional view of a conventional micro semi-transparent mirror array.

FIG. 7 is a block diagram of a display / imaging device that achieves line-of-sight matching using the conventional micro-semitransparent mirror array.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Display device 1 '... Projection type display device 2 ... Imaging device 3 ... Display screen 4 ... Micro semi-transparent mirror array 5 ... Micro mirror 6 ... Micro screen 7 ... Fresnel lens

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takahiro Muraki 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (2)

[Claims] 1. A screen region comprising at least one microscreen and a reflective region comprising at least one tilted micromirror, wherein the screen regions and the reflective regions are arranged alternately. Display screen. 2. The display screen according to claim 1, wherein when the screen area is formed by one minute screen and the reflection area is formed by one minute mirror, the pitch and the inclination of the minute mirror of the reflection area are set. A display screen characterized by satisfying a relationship of D = d · tan θ tan2θ between the pitch D of the minute screen in the screen region and d = θ.