JPH0634930A - Projection type display system - Google Patents

Abstract

PURPOSE:To easily project two kinds of polarized light by one projection type display device so as to improve the diversification of the projection type display device to a stereoscopic image projection type display system. CONSTITUTION:The projection type display system consisting of two projection type display devices each consisting of a light source 7, a liquid crystal panel 10 which performs image modulation, an optical element 11 which performs color separation, an optical element 12 which performs color composition, and a projection lens 2 is provided with a half-wavelength plate 3 atop of the projection lens 2 of one or both the projection type display devices, and even when the same projection type display device 1 is used, two kinds of polarized light which have a 90 deg. difference in polarizing direction can be projected from both the projection lenses 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection display system. In particular, it relates to a projection type stereoscopic display system using polarized light.

[0002]

2. Description of the Related Art A stereoscopic display system is one in which left and right image information is projected by polarized light having different polarization directions, and is perceived as a stereoscopic image by observing the projected image information with two pairs of left and right polarizing plates having different polarization axes. Are known. In order to obtain polarized light for use in such a display system, conventionally, two kinds of liquid crystal panels having different alignment directions are used in order to change the respective polarization directions of projection light having left and right image information, or Light with different polarization directions was obtained by using a polarization beam splitter.

FIG. 8 shows an example of a conventional stereoscopic display system. The projection-type stereoscopic display system includes projection-type display devices 1 and 1a, a screen 4, and stereoscopic glasses 5. The projection-type display devices 1 and 1a include a light source 7, a total reflection mirror 9, liquid crystal panels 10 and 10a, and a dichroic mirror 11. , A dichroic prism 12 and a projection lens 2.
Two projection display devices 1 and 1a having different configurations using liquid crystal panels 10 and 10a having different alignment directions are required, and the projection display device 1 uses the polarization component transmitted through the liquid crystal panel 10, whereas In the mold display device 1a, by using the liquid crystal panel 10a having an alignment direction different from that of the liquid crystal panel 10, polarized lights having polarization directions different from each other by 90 degrees are obtained.

[0004]

Therefore, in order to obtain a stereoscopic image, a liquid crystal projection device for displaying a planar image cannot be used as it is, and a dedicated projection display device for emitting two kinds of polarized light different from each other is required. Therefore, the applicability of the device was low. Therefore, there has been a demand for a projection display device that can easily emit two types of polarized light with one projection display device.

[0005]

In the present invention, a light source 7, an optical element 11 for color separation, and a liquid crystal panel 1 for image modulation are provided.
0, an optical element 12 for performing color combination, and a projection display system including two projection display devices each including a projection lens 2. In a projection display system including one or both projection display devices, a half-wave plate is provided at the tip of the projection lens 2. 3 is provided, so that even if the same projection type display device 1 is used, two types of polarized light whose polarization directions are different from each other by 90 degrees can be emitted from both projection lenses 2. is there.

[0006]

The operation of the present invention will be described with reference to the embodiment of FIG. 1 and the principle explanatory view of FIG. On the a-plane of the projection display apparatus 1 shown in FIG. 1, polarized light of the same polarization direction is emitted from the projection lens as shown in FIG. By installing the half-wave plate 3 at the tip of the projection lens at the position of b in FIG. 1, the polarization direction of the thick line shown in FIG. 2 (b) can be obtained. It is possible to emit polarized lights having polarization directions different from each other by 90 degrees. At this time, the fast axes of the half-wave plates (shown by dotted lines in FIG. 2B) are arranged as shown in FIG. 2B. In this way, the projection display system can be configured using the same projection display device. .

[0007]

Embodiment 1 FIG. 1 shows Embodiment 1 of the present invention. Reference numeral 1 denotes a projection display device 1 that projects a planar image by itself, and includes a light source 7, an optical element 11 that performs color separation, a liquid crystal panel 10 that performs image modulation, an optical element 12 that performs color combination, and a projection lens 2. Composed. Reference numeral 3 is a half-wave plate that changes the polarization direction of outgoing light with respect to incident light, 4 is a screen, and 5 is polarizing glasses for perceiving a stereoscopic image. Two projection display devices 1
A half-wave plate 3 and a polarizing plate 6 are installed at the tip of the projection lens 2.

The polarization state of each transmitted light is shown in FIG. Figure 2
(A) is the polarization direction in the a plane of FIG. 1, and FIG.
Indicates a direction of the fast axis of the half-wave plate 3. It shows that the angle is set to α with respect to the polarization axis of the polarization of one projection lens 2 and α ° + 45 ° with respect to the polarization axis of the polarization of the other projection lens 2. The thick line indicates the polarization direction of the polarized light on the plane b of FIG. 1 obtained at that time. FIG. 2C shows the direction of polarized light on the c-plane of FIG.

Next, the function and effect of the first embodiment will be described. The light emitted from the tip of each projection lens 2 has the same polarization component on the a-plane because it is the same device. If the half-wave plates 3 are attached to the ends of both projection lenses 2 so that their fast axes differ from each other by 45 degrees, the polarization axis can be rotated by 90 degrees with respect to the transmission axis of one light on the b-plane after transmission. . When viewing this through polarizing glasses 5 in which the polarization directions of the right eye and the left eye are different by 90 degrees and the respective polarization axes match the optical axis of the light from the projection display device 1, as shown in FIG. Only light that matches the polarization axis of the glasses appears to be transmitted, and light that does not match is cut off.

Therefore, when a video signal for the right eye is applied to one of the projection display devices 1 and a video signal for the left eye is applied to the other projection display device 1 and the image is projected through the destination eyeglasses, a stereoscopic image is observed. You can For this reason, a flat image can be obtained with one device and a stereoscopic image can be obtained with two devices, and the diversion and expansion of one type of projection display device can be enhanced. In FIG. 2, the half-wave plate 3 is mounted at an angle of 22.5 degrees with respect to the transmitted light of the projection lens 2, but if the conditions in which the polarization directions of the projection light differ by 90 degrees are satisfied, another mounting method is used. Is also the same.

FIG. 3 shows the configuration of the second embodiment of the present invention, and FIG. 4 shows the polarization state of the transmitted light on each surface. 4 (a),
3B and 3C respectively show polarization directions on planes a, b, and c of FIG. In the second embodiment, the half-wave plate 3 is attached to only one of the projection lenses 2, and the half-wave plate 3 is attached so that the fast axis of the half-wave plate 3 is 45 degrees with respect to the polarization direction of the lens-transmitted light. In this way, both projection lenses 2
The polarized light of the projection light from can be different from each other by 90 degrees.

FIG. 5 shows a third embodiment of the present invention. Figure 5
FIG. 5A shows the polarization state at the tip of the projection lens in the configuration of Example 2, and FIG. 5B shows the polarization state emitted from the projection lens when the half-wave plate 3 is attached to the tip of the projection lens 2. Is shown. The linearly polarized light emitted from the liquid crystal panel 10 of the projection display device 1 has its polarization property disturbed by the projection lens 2 to generate polarization components having different polarization directions. When this is large, when viewed through the polarized glasses 5, the image originally to be cut is transmitted and perceived as noise, and the stereoscopic effect is reduced. Therefore, in the fifth embodiment, the polarization axis is aligned and the polarizing plate 6 is attached to the tip of the projection lens 2 so as to remove the excess polarization component, thereby improving the stereoscopic effect.

6 and 7 show Embodiment 4 of the present invention. Example 4 shows a method for electrically adjusting the deviation of a display image that occurs when two projection display devices are projected on a screen. FIG. 6 shows that it is possible to adjust the shift of the display image caused by the two projection display devices by moving the display region 16 in the displayable region 15 of the liquid crystal panel without moving the display device. Indicates.

It is possible to adjust this deviation by moving the projection unit, but fine adjustment is difficult due to problems such as movement accuracy. Therefore, the liquid crystal displayable area 15 is previously formed.
Is set to be larger than the display area 16 and the display image is electrically moved so that the pixel alignment can be easily performed. FIG. 7 shows a method of electrically moving the display image. FIG. 7A shows that the display area 16 is moved in parallel in the X and Y directions within the displayable area 15 to change the display position. 7 (b) (c)
(D) is an example of a block diagram of a circuit for electrically translating the display region 16. (B) is an overall view, (c)
Is a portion related to movement in the X direction, and (d) is a portion related to movement in the Y direction.

In FIGS. 7B, 7C and 7D, the data driver 20, the scan driver 21 and the delay circuit 22 are shown.
a, 22b, coordinate input circuits 23a, 23b, controller 2
7 (c), the display position in the X direction can be changed by the phase difference between the delay circuit b ₁ and the delay circuit b ₂ in FIG. 7 (c). The display position in the Y direction can be changed by shifting the phase of the start pulse.

[0016]

Since a stereoscopic image can be formed by using the same projection type display device, the diversion and expansion of the projection type display device are enhanced.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is an operation explanatory view of the first embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a second embodiment of the present invention.

FIG. 4 is a diagram illustrating the principle of Embodiment 2 of the present invention.

FIG. 5 is a diagram showing a configuration of a third exemplary embodiment of the present invention.

FIG. 6 is a diagram showing a configuration of a fourth exemplary embodiment of the present invention.

FIG. 7 is a circuit block according to a fourth embodiment of the present invention.

FIG. 8 is a diagram showing a configuration example of a conventional projection display device.

[Explanation of sign]

 1, 1a, 1b Projection display device 2 Projection lens 3 Half-wave plate 4 Screen 5 Polarizing glasses 6 Polarizing plate 7 Light source 9 Total reflection mirror 10 Liquid crystal panel 11 Dichroic mirror 12 Dichroic prism 15 Displayable area 16 Display area 20 Data driver 21 Scan driver 22a, b Delay circuit 23a, b Coordinate input circuit 24 Controller

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Tetsuya Hamada 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa within Fujitsu Limited (72) Inventor Takeshi Goto 1015, Kamedota-chu, Nakahara-ku, Kawasaki, Kanagawa within Fujitsu Limited ( 72) Inventor Hisashi Yamaguchi 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited

Claims (3)

[Claims] 1. A light source (7), a liquid crystal panel (10) for image modulation, an optical element (11) for color separation, an optical element (12) for color combination, and a projection lens (2). In a projection display system including two projection display devices (1, 1a), a half-wave plate (3) is provided at the tip of a projection lens (2) of one or both projection display devices (1, 1a). The projection display system is characterized in that polarized light beams having polarization directions different from each other by 90 degrees are emitted from both projection lenses (2) by 2. The projection type display according to claim 1, wherein a polarizing plate having a transmission axis coinciding with the fast axis of the half-wave plate (3) is provided at the tips of the two projection lenses (2). system 3. A display area (15) wider than the display area (16) and having a function of changing the position of the display area (16) within the electrically displayable area (15).
The described projection display system.