JP2827939B2 - Projection type liquid crystal display device and projection type stereoscopic display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device for displaying an image by using a liquid crystal display element, and more particularly to a projection type liquid crystal display device for enlarging and projecting an image on a screen surface and a viewer wearing special glasses or the like. The present invention relates to a projection type stereoscopic display device capable of recognizing a stereoscopic image without any problem.

[0002]

2. Description of the Related Art A projection type liquid crystal display device will be described with reference to the drawings. FIG. 10 is a perspective view showing an example of a conventional projection type liquid crystal display device. In FIG. 10, a conventional projection-type liquid crystal display device 31 collects light emitted from a light source 32 with a parabolic mirror 33, illuminates a liquid crystal display element 34 with the light flux, and projects a light from the light source 32 through a projection lens 35. The display image 34 is enlarged and projected on the screen 38. FIG.
Is an example in which one liquid crystal display element 34 is used, and each pixel of the liquid crystal display element 34 is formed by arranging red, green, and blue color filters to enable color display. . In addition, a color image is separated into red, green, and blue components, and each image is displayed on three liquid crystal display elements , and light from a light source is separated into three primary colors. There are projection type liquid crystal display devices that perform color display by using an optical system that illuminates a liquid crystal display element and a combining optical system that matches images of each color on a screen. Such a projection type liquid crystal display device has an advantage that a large screen image of an arbitrary size can be easily obtained with a lightweight and small device.

FIG. 11 is a side view showing an example of a rear projection type using a transmission type screen in a conventional projection type liquid crystal display device. 11, a conventional projection type liquid crystal display device 51 has a transmission type screen 46 on which a lenticular lens or a Fresnel lens is formed, attached to the front of a cabinet 45, and a light source 32 and a light source 32 inside the cabinet 45 as in FIG. The object mirror 33, the liquid crystal display element 34, and the projection lens 35 are arranged, and the display image of the liquid crystal display element 34 is enlarged and projected on the transmission screen 46. In particular, by bending the projection optical path using the mirror 47, a rear projection type liquid crystal display device having a small depth can be obtained. Lenticular lenses and Fresnel lenses formed on the transmissive screen 46 make the projection screen uniform in brightness .
Also , it is very effective in expanding the horizontal viewing angle.

[0004] In addition, as a liquid crystal display device using a liquid crystal display element, there is a projection type stereoscopic display device. In recent years, demands for stereoscopic display have been increasing, and various stereoscopic display devices have been studied. In recent years, a projection type stereoscopic display device that realizes stereoscopic vision by presenting an image having binocular parallax separately to the left and right eyes using a lenticular screen has recently attracted attention. This device has the advantage that no special glasses need to be worn.

FIG. 12 is a plan view showing a conventional projection type stereoscopic display device using the lenticular screen. The lenticular screen 66 is configured by arranging a number of vertically long cylindrical lenses. 12, a focal plane of each cylindrical lens is set as an image plane, and an image in which a right-eye image 71 and a left-eye image 72 viewed from different directions are divided into stripes and periodically arranged is defined as an image projection optical system 111.
To project. In FIG. 12, a large number of stripes elongated in the vertical direction with respect to the paper surface are arranged in the left-right direction 83. Since the eyes of the observer from the right eye 73 and the left eye 74 enter the lenticular screen 66 from different angles, the observer sees separate images with parallax,
A stereoscopic image is sensed. Note that, for simplicity, in FIG. 12, the parallax images are two, which are the minimum required, a right-eye image 71 and a left-eye image 72.

In the projection type stereoscopic display device using this lenticular screen, there are discrete regions where stereoscopic vision is possible, and particularly the region where good stereoscopic vision is possible in the left-right direction 83 is limited to about the distance between both eyes. Would.

[0007] In order to enlarge the viewing area in the left-right direction,
A stereoscopic display device that detects the viewpoint of the observer, moves the projected image according to the detected amount, and controls the presenter to always present images corresponding to the left and right eyes of the observer (hereinafter referred to as a viewpoint-following projection stereoscopic display). (Referred to as JP-A-1-107247). FIG. 13 is a perspective view showing this conventional example. Here, a liquid crystal projector 122 is used as an image projection optical system. Observer's viewpoint 12
The liquid crystal projector 122 is moved by the movement stage 123 as a viewpoint follow-up mechanism in accordance with the movement of the projection image 7, and the projected image 7
0 is moved left and right.

[0008]

In a conventional projection type liquid crystal display device, an opaque black matrix is formed in a grid pattern on a liquid crystal display element. However, there is a problem that the image quality is deteriorated as if the user were looking at the image.

FIG. 14 is a diagram for explaining a problem of the conventional projection type liquid crystal display device. FIG. 14A is a partially enlarged view of a projection screen by the conventional projection type liquid crystal display device, and FIG. 14B is a diagram showing an illuminance distribution on a line AB in FIG. 14A. In FIG. 14A, the periodically arranged pixels 40 are the minimum unit for forming an image.
The brightness of each pixel 40 changes according to the input image signal. The black matrix 41 is formed in order to improve the contrast of a projected image by shielding a portion where brightness does not change regardless of an input signal between pixels. Further, when an active matrix type liquid crystal display element having a thin film transistor (TFT) as a switching element is used, a black matrix 41 is used as a light shielding film for preventing illumination light from a light source from entering the TFT. Are formed.

FIG. 14B shows an illuminance distribution when the entire screen is displayed in white. As is clear from the figure, the portion of the black matrix 41 is black, and when the projected image is viewed, the user feels as if he / she is looking over the screen, and the image quality is significantly deteriorated.

Further, a reflection type screen whose surface is periodically fine-processed to enlarge the viewing angle of view of such an image, a lenticular lens or a Fresnel lens used for a rear projection type liquid crystal display device are known. When the light is projected on the formed transmission type screen, moire fringes are generated due to a mismatch between the periodicity of the black matrix and the periodicity of the lenticular lens or the like of the screen, resulting in a problem that the projected image becomes very difficult to see.

Next, problems of the conventional projection type stereoscopic display device will be described with reference to the drawings.

FIG. 15 is a diagram for explaining a problem of the conventional projection type stereoscopic display device. FIG. 15A is a plan view showing a configuration of a projection type stereoscopic display device and a positional relationship between the device and an observer. FIG. 15B shows a state in which the observer is in FIG.
It is a brightness distribution when the lenticular screen 66 is observed from above the middle line segment AB. Thin film transistor (TFT)
Is used, an active matrix type liquid crystal display device 64 in which a black matrix 6 is provided between the right-eye image 71 and the left-eye image 72 displayed on the liquid crystal display device 64.
There are nine.

In this case, since the light from the light source 62 is blocked at the black matrix portion, there is an area 131 where the light does not reach the right eye 73 and the left eye 74 of the observer. Here, the luminance distribution when the observer observes the lenticular screen from above the middle line AB in FIG. 15A is shown in FIG.
The observation viewing zone 132 is as narrow as about ± 10 mm from the center 75 of the observation viewing zone, and even if the observer's head moves even a little, the brightness of the right-eye image 71 and the left-eye image 72 decreases, and stereoscopic vision is reduced. There was a problem that it became impossible.

In a projection type stereoscopic display apparatus of a viewpoint tracking type, it is necessary to control the tracking error while keeping the tracking error within ± 10 mm, which is an observation range in which stereoscopic vision is possible. However, when the observer moves at a high speed, there is a problem that the follow-up cannot catch up and stereoscopic viewing cannot be performed.

FIG. 16 is a diagram for explaining a problem of the conventional viewpoint-following projection type stereoscopic display device. FIG.
(A) is a partial plan view showing a positional relationship between a lenticular screen of this device and an observer. FIG. 16B is a luminance distribution when the observer observes the lenticular screen from above the middle line AB in FIG. 16A.

When the observer follows the movement direction 141 of the observer, if the observer is delayed in following the viewpoint,
A tracking error 144 occurs between the position 142 of the viewpoint of the left eye of the observer and the center 143 of the observation viewing zone of the left eye image. If the tracking error 144 exceeds 10 mm, the observer's right eye 7
3. The left eye 74 is located in the area 131 where light does not arrive.
At this time, as shown in FIG. 16B, at the position 76 of the observer's viewpoint, the luminance of the image observed by the observer becomes significantly dark, and stereoscopic vision becomes impossible.

An object of the present invention is to provide a projection type liquid crystal display device in which a black matrix is made inconspicuous and image quality is improved without significantly impairing the resolution of a projected image. It is still another object of the present invention to provide a projection type liquid crystal display device which can reduce the occurrence of moiré fringes even when using a screen whose surface is finely processed periodically in order to increase the viewing angle of view.

Also, in the projection type stereoscopic display device, the range in which stereoscopic viewing is possible is expanded by enlarging the presentation area of each of the left eye image and the right eye image, and in the viewpoint tracking type projection type stereoscopic display device. Another object of the present invention is to provide an image corresponding to each of the right eye and the left eye of the observer with sufficient luminance to enable stereoscopic vision even when the follow-up of the observer's viewpoint is delayed and the follow-up error increases.

[0020]

A projection type liquid crystal display device according to the present invention comprises a liquid crystal display element having a black matrix formed thereon, and a light source and a projection lens for projecting a display image of the liquid crystal display element on a screen surface. In a projection type liquid crystal display device comprising: in the optical path between the liquid crystal display element and the projection lens, the optical axis is translated at high speed within the pixel pitch of the liquid crystal display element, and the projected image is vibrated.
The brightness of the pixel area and the black matrix area
An optical axis parallel moving means for averaging the rudder over time is arranged.

Further, a transmission screen having a lenticular lens or a Fresnel lens formed thereon, a liquid crystal display element having a black matrix formed thereon, and a light source for projecting a display image of the liquid crystal display element onto the transmission screen surface and in the projection type liquid crystal display device comprising a projection lens, the light path between the liquid crystal display element and the projection lens is moved parallel to the optical axis at high speed within the pixel pitch of the liquid crystal display device, projection Vibrating the image
The brightness between the pixel and the black matrix
An optical axis parallel moving means for averaging over time is arranged.

In a projection type stereoscopic display apparatus comprising a lenticular screen, a liquid crystal display device having a black matrix formed thereon, a light source for projecting a display image of the liquid crystal display device onto the lenticular screen surface, and a projection lens. By moving the optical axis at high speed within the pixel pitch of the liquid crystal display element between the liquid crystal display element and the projection lens, and vibrating the projected image,
The brightness of the black matrix and the black matrix
An optical axis parallel moving means for leveling is arranged.

A lenticular screen, a liquid crystal display element, a light source and a projection lens for projecting a display image of the liquid crystal display element onto the lenticular screen surface, a device for detecting a viewpoint of an observer, and In the projection type stereoscopic display device comprising a viewpoint tracking mechanism that always allows the observer to perform a correct stereoscopic view, the optical axis is rapidly moved within the pixel pitch of the liquid crystal display element between the liquid crystal display element and the projection lens. And translate the projected image to vibrate.
The brightness of the pixel area and the black matrix area
An optical axis parallel moving means for averaging the rudder over time is arranged.

Further, the optical axis parallel moving means is a parallel flat glass that rotates and vibrates.

Further, the optical axis parallel moving means is two parallel flat glass members which vibrate in a direction perpendicular to each other.

[0026]

According to the configuration of the present invention, by using an optical axis translation means for translating the optical axis at high speed within fractions containing peak <br/> pitch of the liquid crystal display device, which is projected on the screen surface Since the image is vibrated at high speed, the brightness of the pixel portion and the brightness of the black matrix portion are averaged over time, and the black matrix becomes inconspicuous. Since the moving amount of the image is within the pixel pitch, the resolution of the projected image is not significantly impaired.

In the projection type liquid crystal display device, since the black matrix becomes inconspicuous, moire fringes do not occur even if a screen having a lenticular lens or the like is used. Therefore, the image quality can be improved by making the black matrix inconspicuous without significantly deteriorating the resolution of the projected image, and moire fringes can be reduced even when a screen that has been subjected to fine processing periodically is used.

In the projection type stereoscopic display device, the image projected on the lenticular screen surface is vibrated at high speed by using the optical axis parallel moving means, so that the brightness of the pixel portion and the black matrix portion is averaged. , The black matrix becomes inconspicuous. Since the black matrix of the image projected on the lenticular screen surface becomes inconspicuous, the presentation area of each of the left-eye image and the right-eye image is enlarged, and the stereoscopic range can be enlarged.

Further, by using the optical axis parallel moving means in the projection type stereoscopic display device of the viewpoint following type, even if the observer's viewpoint following is delayed and the following error increases, the observer's right eye and left eye can be observed. Are presented with sufficient luminance to enable stereoscopic viewing.

[0030]

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

FIG. 1 is a perspective view of a projection type liquid crystal display device according to a first embodiment of the present invention. 1, the projection type liquid crystal display device 1 includes a light source 2, a parabolic mirror 3, a liquid crystal display element 4, a projection lens 5, a parallel plate glass 6, and a rotating mechanism 7. After the light emitted from the light source 2 is condensed by the parabolic mirror 3, the light beam illuminates the liquid crystal display element 4, and the display image of the liquid crystal display element 4 is enlarged and projected on the screen by the projection lens 5. The optical axis translation unit disposed in the optical path between the liquid crystal display element 4 and the projection lens 5 includes:
The optical axis is translated at high speed by rotating and vibrating the parallel flat glass 6 at high speed by the rotation mechanism 7.

Next, the principle of the projection type liquid crystal display device 1 of this embodiment having the configuration shown in FIG. 1 will be described with reference to FIGS. FIG. 2 is a diagram for explaining the principle of the projection type liquid crystal display device of the present invention, and FIG. 3 illustrates the operation of the projection type liquid crystal display device of the present invention in comparison with the conventional example of FIG. FIG.

FIGS. 2A to 2C are partial plan views showing the configuration from the liquid crystal display element 4 to the projection lens 5 in the projection type liquid crystal display device 1 of FIG. In FIG. 2A, the projection lens 5 has an optical axis 8 at the center 9 of the liquid crystal display element.
Are arranged to pass through. The parallel plate glass 6 is disposed in the optical path between the liquid crystal display element 4 and the projection lens 5 so that the light incident and exit surface of the parallel plate glass 6 is perpendicular to the optical axis 8. Here, the focus of the projection lens is adjusted so that the image displayed on the liquid crystal display element 4 is projected on the screen, and this arrangement is set as a reference position.

FIG. 2B shows a case where the parallel flat glass 6 is rotated as compared with the reference position of FIG. 2A. As is clear from the figure, when the parallel flat glass 6 is rotated, the optical axis 8 of the projection lens 5 is refracted at the entrance / exit surface of the parallel flat glass 6. However, since the entrance and exit surfaces are parallel to each other , the optical axes 8 before and after the parallel plate glass 6 are parallel. Here, the distance by which the optical axis 8 is translated by the parallel flat glass 6 is determined by the thickness, the refractive index, and the rotation angle of the parallel flat glass 6. When the optical axis 8 moves in parallel, the optical axis 8 does not pass through the center 9 of the liquid crystal display element. That is, the image projected on the screen moves in parallel compared to the case of FIG.

FIG. 2 (c) shows a case where the parallel flat glass 6 is rotated by the same angle in the opposite direction as compared with FIG. 2 (b). As is clear from the figure, when the parallel flat glass rotates in the opposite direction, the optical axis 8 also moves in the opposite direction. Therefore, the image projected on the screen is translated in the opposite direction as compared with the case of FIG.

As is clear from the above description, when the parallel flat glass 6 is rotated and vibrated at a high speed so as to repeat the states shown in FIGS. 2B and 2C, the image projected on the screen also has a high speed. Vibrates.

FIG. 3 shows a case where the image projected on the screen vibrates at a high speed. FIG. 3 (a)
FIG. 3B is a partially enlarged view of a projection screen by the projection type liquid crystal display device of the present invention, and FIG. 3B shows an illuminance distribution on a line segment AB in FIG. Here, a case where the screen is vibrated in the horizontal direction as indicated by the arrow is shown. FIG.
14B shows the illuminance distribution when the entire screen is displayed in white, as in FIG. 14B. In the figure, the illuminance distribution indicated by the dotted line indicates each state of FIGS. 2A to 2C, and in each state, the portion of the black matrix 11 is black. However, the projected image has a frequency at which flicker does not occur, for example, 60
When vibrated at Hz, as shown by the solid line, the brightness between the pixel 10 and the dark area in the vertical direction of the black matrix 11 is averaged over time. Therefore, the vertical stripes of the black matrix are not noticeable. Here, by setting the moving amount of the image within the pixel pitch, the resolution of the projected image is not significantly impaired.

The configuration shown in FIG.
It shows an example of the mode when using the number of sheets, below,
This will be described more specifically.

The light source 2, the parabolic mirror 3, the liquid crystal display element 4, the projection lens 5, the parallel plate glass 6, and the rotating mechanism 7 used in the configuration of FIG. 1 are specifically as follows. .

The light source 2 uses a 250 W metal halide lamp. A frost process is applied to the surface of the bulb to improve the uniformity of the illuminance distribution on the projection screen.

The parabolic mirror 3 is formed by molding glass.
A cold mirror made of a dielectric multilayer film is formed on the surface on the light source 2 side by vapor deposition, and an infrared light component from the light source 2 is removed so as not to reach the liquid crystal display element 4.

The liquid crystal display element 4 has a structure in which liquid crystal is sealed between two glass substrates provided with a transparent electrode film for forming pixels, and a polarizer and an analyzer are attached. The voltage applied to each pixel is controlled by the video signal from the video signal processing circuit and the liquid crystal drive circuit.
The liquid crystal uses a twisted nematic (TN) liquid crystal. The change in the state of the liquid crystal due to the voltage applied to each pixel is
The polarization state of the illumination light is changed, and intensity modulation according to an image is given to the illumination light by the polarizer and the analyzer. As a driving method of the liquid crystal, an active matrix method in which a TFT is formed for each pixel of one of two glass substrates and the liquid crystal is driven is used. On the other glass substrate, a black matrix made of a chrome film is formed to improve the contrast of the projected image and shield the TFT from light. Red, green, and blue color filters are periodically formed in each pixel so that color display can be performed. The diagonal length of the display area is 76 mm, and the pixel pitch is 95 μm.

The projection lens 5 enlarges and projects the display image of the liquid crystal display element 4 onto a screen. The projection lens 5 changes the size of the screen without changing the projection distance, and a focus adjustment mechanism so that the focus of the projection image can be adjusted. A zoom mechanism with a zoom mechanism is used.

The parallel plate glass 6 is made of BK7, has a refractive index of 1.52 and a thickness of 10 mm. An anti-reflection film made of a dielectric multilayer film is applied to the light entrance / exit surface of the parallel plate glass 6.

The rotation mechanism 7 uses a servomotor. Although not explicitly shown in the figure, the rotation angle and the frequency are controlled by the drive circuit.

The rotation angle of the parallel flat glass 6 corresponds to the amount of vibration of the projected image. If the vibration amount is larger than the pixel pitch, the resolution of the projected image is reduced. Therefore, the vibration amount is smaller than the pixel pitch, preferably the width of the black matrix is good, and here, the vibration amount of the optical axis is set to 50 μm. I have. At this time, the rotation angle of the parallel flat glass 6 is ± 0.4.
2 °. Since the flicker occurs when the frequency of the rotational vibration is low, the frequency is set to 60 Hz here.

Although not explicitly shown in FIG. 1, in addition to the above, a power source such as a light source or a signal processing circuit, a means for cooling the liquid crystal display element 4, and a light beam transmitted through the liquid crystal display element 4 are efficiently incident on the projection lens. The projection type liquid crystal display device 1 is configured using a condenser lens for performing the operation, an outer case, and the like.

The projection type liquid crystal display device 1 of the present embodiment comprising the above components uses a parallel flat glass that rotates and oscillates as the optical axis parallel moving means, so that the optical axis can be adjusted within the pixel pitch of the liquid crystal display element. By parallel moving at high speed and vibrating the image projected on the screen surface at high speed, the brightness of the pixel portion and the brightness of the black matrix portion were averaged over time, and the black matrix became inconspicuous.
The modulation factor (MTF) of the vertical stripes in the lattice image of the black matrix was 0.1 or less. At this time, since the moving amount of the image was within the pixel pitch, the resolution of the projected image was not significantly impaired. In addition, since the black matrix becomes inconspicuous, moire fringes when using a screen that has been subjected to fine processing periodically can be reduced.

FIG. 4 is a perspective view of a projection type liquid crystal display device according to a second embodiment of the present invention. In FIG. 4, the projection type liquid crystal display device 1 has a light source 2 similar to the first embodiment.
, Parabolic mirror 3, liquid crystal display element 4, and projection lens 5
, A parallel plate glass 6 and a rotation mechanism 7. However, two sets of the parallel plate glass 6 and the rotation mechanism 7 are used. The two parallel flat glass plates 6 are arranged in the optical path between the liquid crystal display element 4 and the projection lens 5 so that the incident and exit surfaces are perpendicular to the optical axis. The two parallel flat glass plates 6 are vibrated at high speed by the rotation mechanism 7, respectively, but the rotation axes are orthogonal to each other, one of which is in the horizontal direction of the projection screen, and the other is in the vertical direction of the projection screen. The rotation axis is set in the vibration direction.

The light source 2, parabolic mirror 3, liquid crystal display element 4, projection lens 5, parallel flat glass 6, and rotating mechanism 7 used in the configuration of FIG. 4 are the same as those of the first embodiment shown in FIG. Was used.

If the phases of the rotational vibration motions of the two parallel flat glass plates 6 are equal, the moving direction of the projected image becomes linear, so that the phase must be shifted or the frequency must be changed. Here, one parallel flat glass 6 is set to 60 Hz.
Thus, the projected image is two-dimensionally vibrated by rotating and vibrating the other parallel flat glass at 120 Hz.

The projection type liquid crystal display device 1 of the present embodiment comprising the above-described components uses a parallel flat glass that rotates and vibrates in two directions, so that the image projected on the screen surface vibrates two-dimensionally. By doing so, the brightness of the pixel portion and the black matrix portion is temporally averaged not only for the vertical stripes but also for the horizontal stripes of the grid image of the black matrix as compared with the first embodiment. And the black matrix became inconspicuous. Since the amount of movement of the image is within the pixel pitch, the resolution of the projected image is not significantly impaired, and furthermore, since the black matrix becomes inconspicuous, it is possible to reduce moire fringes when using a screen that has been finely processed periodically. did it.

FIG. 5 is a perspective view of a projection type liquid crystal display device according to a third embodiment of the present invention. In FIG. 5, the projection type liquid crystal display device 21 includes a light source 2, a parabolic mirror 3, a liquid crystal display element 4, a projection lens 5, a parallel flat glass 6,
Rotating mechanism 7, cabinet 15, and transmission screen
16 and a mirror 17.

The light source 2, parabolic mirror 3, liquid crystal display element 4, projection lens 5, parallel flat glass 6, and rotating mechanism 7 used in the configuration of FIG. 5 are the same as those of the first embodiment shown in FIG. And their arrangement is the same.

The display image of the liquid crystal display element 4 is enlarged and projected by the projection lens 5 on a transmission screen 16 arranged on the front of the cabinet 15. However, the projection type liquid crystal display device 21
Is thinner.

The interior of the cabinet 15 is painted black, and a light shielding plate is arranged so that stray light other than the projection light is not reflected on the screen.

The transmission screen 16 is formed by molding a lenticular lens on the surface (observer surface) of an acrylic plate to which a diffusing agent is added, and a Fresnel lens on the back surface (inner surface of the cabinet 15). The aim is to improve the uniformity of the screen brightness and enlarge the horizontal viewing angle of the observer.

The mirror 17 is a surface mirror obtained by evaporating aluminum on the surface of a glass plate. In particular, the mirror 17 has a high reflection coating to increase the reflectance and prevent oxidation.

The projection type liquid crystal display device 21 of the present embodiment, which comprises the above-described components, uses a parallel plate glass that rotates and vibrates, thereby moving the optical axis in parallel at high speed within the pixel pitch of the liquid crystal display element. By vibrating the image projected on the screen surface at high speed, the brightness of the pixel portion and the brightness of the black matrix portion were averaged over time, and the black matrix became inconspicuous. Since the black matrix became inconspicuous, moire fringes did not occur even when a screen having a lenticular lens or a Fresnel lens was used.

FIG. 6 is a perspective view of a projection type stereoscopic display apparatus according to a fourth embodiment of the present invention. In FIG. 6, the projection type stereoscopic display device 61 includes a light source 62, a parabolic mirror 63,
A liquid crystal display device 64, a projection lens 65, a lenticular screen 66, a parallel plate glass 67, a rotating mechanism 6
And 8. After the light emitted from the light source 62 is condensed by the parabolic mirror 63, the light flux illuminates the liquid crystal display device 64, and the display image of the liquid crystal display device 64 is enlarged and projected on the lenticular screen 66 by the projection lens 65. The parallel flat glass 67 includes a liquid crystal display 64 and a projection lens 65.
And is rotationally vibrated at a high speed by the rotation mechanism 68.

Next, the principle of the projection type stereoscopic display device 61 of this embodiment having the configuration shown in FIG. 6 will be described with reference to FIG. FIG. 7 is a diagram for explaining the principle of the projection type stereoscopic display device according to the fourth embodiment of the present invention, in comparison with the conventional example of FIG.

In FIG. 7, when the parallel flat glass 67 rotates, the projected image 70 of the liquid crystal display device 64 moves in the left-right direction 83. Here, when the parallel flat glass 67 is rotationally vibrated at a high speed, the projected image 70 vibrates in the left-right direction 83 at a high speed. When the parallel flat glass 67 is vibrated at a frequency of 60 Hz or more at which humans do not feel flicker, the liquid crystal display 64
Is displayed on the projected image 70 as a time average with the bright portion of the liquid crystal display device 64. The image vibration width 81 is the same as the black matrix 69.
Is about the width of the enlarged projection. As a result, the observation viewing area 82 is enlarged.

A servo motor is used for the rotary vibration mechanism. Although not explicitly shown in the figure, the rotation angle,
The frequency is controlled.

The rotation angle of the parallel plate glass 67 corresponds to the amount of vibration of the projected image. If the amount of vibration is larger than the pixel pitch, the crosstalk between the left and right images of the stereoscopic image increases. Therefore, the width is set to 50 μm, which is about the width of the black matrix. The rotation angle of the parallel flat glass at this time is ± 0.42 °.

FIG. 7 (b) shows the case where the observer
This is the luminance distribution when observing the lenticular screen from above B. By vibrating the image as shown by the dotted line, the distribution of the high luminance part is enlarged, and a good stereoscopic image is observed in a region up to ± 20 mm. It became possible. Also,
Crosstalk between the left and right images was not a problem, and a good stereoscopic image could be obtained.

FIG. 8 is a perspective view of a projection type stereoscopic display apparatus of a viewpoint following type showing a fifth embodiment of the present invention. In FIG. 8, this projection-type projection stereoscopic display device 91 includes a light source 62, a parabolic mirror 63, a liquid crystal display device 64, a projection lens 65, a lenticular screen 66, a parallel plate glass 67, A rotation mechanism 68, a viewpoint detection device 92,
It is composed of a viewpoint tracking mechanism control device 93 and a viewpoint tracking mechanism 94. After the light emitted from the light source 62 is condensed by the parabolic mirror 63, the light flux illuminates the liquid crystal display device 64, and the display image of the liquid crystal display device 64 is enlarged and projected on the lenticular screen 66 by the projection lens 65. The parallel flat glass 67 is arranged in the optical path between the liquid crystal display device 64 and the projection lens 65, and is vibrated at high speed by the rotation mechanism 68. Further, the viewpoint position of the observer is detected by the viewpoint detecting device 92, and the viewpoint following mechanism 94 is controlled by the viewpoint following mechanism control device 93 based on the detected information.

FIG. 9 is a diagram for explaining the principle of the projection type stereoscopic display apparatus according to the fifth embodiment of the present invention, in comparison with the conventional example of FIG.

In the fifth embodiment, the projection type image display 1
01 is moved in the moving direction 103 of the projection-type image display device 101 with respect to the moving direction 102 of the observer to perform the tracking of the viewpoint.

The light source 62, parabolic mirror 63, liquid crystal display device 64, projection lens 65, lenticular screen 66, parallel flat glass 67, and rotating mechanism 8
In this embodiment, the parallel view glass is rotated and vibrated at a high speed to enlarge the observation visual field.

FIG. 9 (b) shows a luminance distribution when the observer observes the lenticular screen from above the middle line AB in FIG. 9 (a) in the viewpoint-following projection type stereoscopic display device. By vibrating the image as indicated by the dotted line as in the fourth embodiment, the distribution of the high-luminance portion is enlarged, the observer's viewpoint 76 deviates from the center 75 of the observation viewing zone, and the tracking error is reduced. Even if it occurs, the observer is presented with an image of sufficient luminance, and a tracking error of up to ± 20 mm is allowed. Also, crosstalk between the left and right images does not pose a problem, and a good stereoscopic image can be obtained even in a moving observer in a viewpoint-following type stereoscopic display device in which a large following error occurs.

Regarding the method of following the viewpoint, in addition to moving the projector, a method of moving the projection lens in a direction perpendicular to the optical axis, a method of moving the optical axis by a rotating parallel plate glass, a prism, etc., and a method of moving a projected image by a rotating mirror It may be a method to make it.

As described above, in the first to fifth embodiments of the present invention, the light source is a metal halide lamp,
High brightness white light sources such as xenon lamps and halogen lamps can be used.

The liquid crystal is not limited to the TN liquid crystal but may be any type of liquid crystal capable of forming an image as a liquid crystal display element, such as a super twisted nematic liquid crystal, a ferroelectric liquid crystal, a birefringence control liquid crystal, and a polymer dispersed liquid crystal. . The driving method of the liquid crystal is not limited to the active matrix method, but may be a simple matrix method of time division driving.

The liquid crystal display element has a monochrome display,
The present invention can be applied to any case where color display is performed by displaying red, green, and blue images in a time-division manner.

Further, the projection light from the light source is separated into three primary colors of red, green and blue by a dichroic mirror or a dichroic prism, and a liquid crystal display element is arranged on each optical path.
A similar projection type liquid crystal display device can be obtained even when color display is performed by combining them.

The rotating mechanism is not limited to the motor, but may be a mechanism for rotating the parallel plate glass using a piezoelectric element or an electromagnetic coil.

The material of the parallel flat glass is not limited to BK7. However, if the fluctuation of the refractive index such as striae or the surface polishing accuracy is poor, the transmitted wavefront is changed, and the resolution of the projected image is degraded. Therefore, it is desirable to use polished optical glass. Also, if the wavelength dispersion of glass is large, chromatic aberration occurs,
It is preferable to use one having a small chromatic dispersion.

Further, in the embodiment of the present invention, the parallel plate glass is rotated and vibrated at a high speed by the rotating mechanism as the optical axis parallel moving means, but the invention is not limited to this.

[0079]

As described above, according to the present invention, the pixel portion and the black portion are moved by moving the optical axis parallel at high speed within the pixel pitch of the liquid crystal display element and vibrating the image projected on the screen surface at high speed. The brightness with respect to the matrix portion is averaged over time, and the black matrix can be made inconspicuous. Since the moving amount of the image is within the pixel pitch, the resolution of the projected image is not significantly impaired. Also,
Since the black matrix becomes inconspicuous, moire fringes do not occur even when a screen having a lenticular lens or the like is used. Therefore, without significantly reducing the resolution of the projected image, it is possible to make the black matrix inconspicuous, improve the image quality, and reduce the moire fringes when using a screen that has been subjected to periodic fine processing. A liquid crystal display device was obtained. Also,
By vibrating the image projected on the screen surface at high speed, alignment defects of liquid crystal in the pixels of the liquid crystal display element,
Light leakage due to the spacer for maintaining the gap between the two glass substrates is also temporally averaged, so that the image quality is improved.

Further, since the optical axis is translated at high speed within the pixel pitch of the liquid crystal display element and the image projected on the lenticular screen surface is vibrated at high speed, the brightness of the pixel portion and the black matrix portion is averaged. And the black matrix becomes inconspicuous. Since the black matrix of the image projected on the lenticular screen surface becomes inconspicuous, the presentation area of each of the left-eye image and the right-eye image is enlarged, and the stereoscopically visible range can be enlarged. In addition, in the viewpoint-following projection type stereoscopic display device, even if the observer's viewpoint tracking is delayed and the tracking error increases, images corresponding to the right and left eyes of the observer are presented with sufficient luminance. Yes, stereoscopic vision is possible.

[Brief description of the drawings]

FIG. 1 is a perspective view of a projection type liquid crystal display device showing a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the principle of the projection type liquid crystal display device of the present invention.

FIG. 3 is a diagram for explaining the operation of the projection type liquid crystal display device of the present invention.

FIG. 4 is a perspective view of a projection type liquid crystal display device according to a second embodiment of the present invention.

FIG. 5 is a side view of a projection type liquid crystal display device according to a third embodiment of the present invention.

FIG. 6 is a perspective view of a projection type stereoscopic display apparatus according to a fourth embodiment of the present invention.

FIG. 7 is a diagram for explaining the principle of a projection type stereoscopic display device according to a fourth embodiment of the present invention.

FIG. 8 is a perspective view of a projection type stereoscopic display apparatus according to a fifth embodiment of the present invention.

FIG. 9 is a diagram for explaining the principle of a projection type stereoscopic display device according to a fifth embodiment of the present invention.

FIG. 10 is a perspective view showing a conventional example of a projection type liquid crystal display device.

FIG. 11 is a side view showing a conventional example of a projection type liquid crystal display device.

FIG. 12 is a plan view showing a conventional projection type stereoscopic display device.

FIG. 13 is a perspective view of a conventional viewpoint-following projection type stereoscopic display device.

FIG. 14 is a view for explaining a problem of a conventional projection type liquid crystal display device.

FIG. 15 is a view for explaining a problem of a conventional projection type stereoscopic display device.

FIG. 16 is a diagram for explaining a problem of a conventional viewpoint-following projection type stereoscopic display device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Projection type liquid crystal display device 2 Light source 3 Parabolic mirror 4 Liquid crystal display element 5 Projection lens 6 Parallel plate glass 7 Rotation mechanism 8 Optical axis 9 Center of liquid crystal display element 10 Pixel 11 Black matrix 15 Cabinet 16 Transmissive screen 17 Mirror 21 Projection type liquid crystal display device 31 Projection type liquid crystal display device 32 Light source 33 Parabolic mirror 34 Liquid crystal display element 35 Projection lens 38 screen 40 Pixel 41 Black matrix 45 Cabinet 46 Transmission type screen 47 Mirror 51 Projection type liquid crystal display device 61 Projection type solid state Display device 62 Light source 63 Parabolic mirror 64 Liquid crystal display device 65 Projection lens 66 Lenticular screen 67 Parallel flat glass 68 Rotating mechanism 69 Black matrix 70 Projection image 71 Right eye image 72 Left eye image 73 Right eye 74 Left eye 75 Observation viewing zone of Heart 76 Position of viewpoint of observer 81 Vibration width of image 82 Observation viewing zone 83 Left and right direction 91 Viewpoint-following projection type stereoscopic display device 92 Viewpoint detection device 93 Viewpoint following mechanism control device 94 Viewpoint following mechanism 101 Projection image display device 102 Moving direction 103 Moving direction 111 Image projection optical system 121 Observer's viewpoint 122 Liquid crystal projector 123 Moving stage 131 Area where light does not reach 132 Observation viewing area 141 Observer's moving direction 142 Position of left eye viewpoint of observation difference 143 Left Center of observation viewing zone of eye image 144 Tracking error

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G02F 1/13-1/141 G02B 27/22

Claims (6)

(57) [Claims] 1. A projection type liquid crystal display device comprising: a liquid crystal display element on which a black matrix is formed; a light source for projecting a display image of the liquid crystal display element on a screen surface; and a projection lens. In the optical path between the element and the projection lens, the optical axis is translated at high speed within the pixel pitch of the liquid crystal display element to oscillate the projected image.
The pixel part and the black matrix part
3. A projection type liquid crystal display device comprising: an optical axis parallel moving means for averaging the brightness of the liquid crystal over time. 2. A transmission screen having a lenticular lens or a Fresnel lens formed thereon, a liquid crystal display element having a black matrix formed thereon, and a light source for projecting a display image of the liquid crystal display element onto the transmission screen surface. and in the projection type liquid crystal display device comprising a projection lens, the light path between the liquid crystal display element and the projection lens is moved parallel to the optical axis at high speed within the pixel pitch of the liquid crystal display device, projection By vibrating the image
Temporal brightness between pixel and black matrix
A projection type liquid crystal display device , wherein an optical axis parallel moving means for averaging is arranged. 3. A projection type stereoscopic display comprising a lenticular screen, a liquid crystal display device having a black matrix formed thereon, a light source for projecting a display image of the liquid crystal display device onto the lenticular screen surface, and a projection lens. In the device, between the liquid crystal display element and the projection lens, the optical axis is parallel-translated at high speed within the pixel pitch of the liquid crystal display element, and the projected image is vibrated.
The brightness of the black matrix and the black matrix
A projection type stereoscopic display device, wherein an optical axis parallel moving means for leveling is arranged. 4. A lenticular screen, a liquid crystal display device, a light source and a projection lens for projecting a display image of the liquid crystal display device onto the lenticular screen surface, a device for detecting a viewpoint of an observer, and a detection amount thereof In the projection type stereoscopic display device comprising a viewpoint tracking mechanism that always allows the observer to make a correct stereoscopic vision according to the optical axis, between the liquid crystal display element and the projection lens, within the pixel pitch of the liquid crystal display element. Translates at high speed and vibrates the projected image.
Akira of the portion of the pixel section and the black Matrix by Rukoto
A projection type three-dimensional display device , wherein an optical axis parallel moving means for averaging the time is arranged. 5. The projection type display device according to claim 1, wherein said optical axis parallel moving means is a parallel plate glass which rotates and vibrates. 6. The projection type display apparatus according to claim 1, wherein said optical axis parallel moving means is two parallel flat glass plates which vibrate in a direction perpendicular to each other.