JPH04204591A - Projection type liquid crystal display device - Google Patents

Abstract

PURPOSE:To realize a large screen with a small thin structure and high picture quality by devising the optical layout to correct color irregularities, providing an intensity correcting panel, and using an active matrix type liquid crystal panel with a cooling function. CONSTITUTION:The white light of a white lamp 4101 is separated into three primary colors by dichroic mirrors 4008, 4009, 4010 and guided to liquid crystal panels 4002, 4003, 4004 via mirrors 4011, 4012. Lengths of optical axis paths (optical path lengths) from the lamp 4101 to the liquid crystal panels 4002, 4003, 4004 are made equal. A position adjusting function is applied to the dichroic mirrors 4010, 4008 or a mirror 4100, and the optical axis is displaced from the screen center of panels 4002, 4004. The aspect ratio of the liquid crystal panels is set to 16:9, and the active matrix type is used. Cooling layers 4102, 4103, 4104 are provided on the incidence light side of the liquid crystal panels 4002, 4003, 4004, and the second black matrixes are provided on glass face sections faced to the cooling layers 4102, 4103, 4104. Intensity correcting panels 4112, 4113, 4114 are provided on the incidence light side of the cooling layers 4102, 4103, 4104 to correct intensity irregularities.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention relates to a projection type display device for displaying images such as television signals, and particularly relates to a projection type display device that displays an image such as a television signal, and in particular to a liquid crystal light valve as an image forming means. The present invention relates to a projection type liquid crystal display device used.

(Conventional technology) In recent years, the image quality of broadcast media and package media has improved (
With the spread of satellite broadcasting, VD, and LD, high-quality, large-screen television receivers have become popular in the market. Furthermore, projection type displays (projection TVs), which can have larger screens than CRT direct view types, are also becoming popular for home use.

Among projection-type displays, a projection-type liquid crystal display device that uses a liquid crystal panel as a light valve has recently been attracting attention as a method for easily realizing a large screen. Its characteristics include that it is smaller and lighter than conventional CRT type projection devices, and can produce a large screen.Moreover, it does not require convergence adjustment, is not affected by magnetism, and does not require a deflection circuit. Therefore, you can easily enjoy large-screen images even at home. To explain the principle simply, white light from a light source is separated into three primary colors, R, G, and B, and the intensity of these lights is measured by three liquid crystal panels driven by video signals corresponding to each color. After modulating, they are combined again and enlarged and projected using a projection lens, which is -15=.

Incidentally, although such a projection type liquid crystal display device has the above-mentioned characteristics and has recently been put into practical use, the current situation is that there are still many problems to be improved. In particular, the screen size is wider than that of conventional television receivers (
When applied to future television receivers such as next-generation EDTV receivers (wide aspect) and high-definition receivers,
Furthermore, various problems are expected to arise.

For example, a major issue with large screen projection devices is brightness.

It is desirable for the screen to be large but able to display bright images.

Current liquid crystal panels have low light transmittance, so it is necessary to increase the brightness of the light source to efficiently irradiate the liquid crystal panel with light. L, we need to increase the utilization rate of light. To this end, the challenge is not simply to increase the light emitting power of the lamp, but how to increase the light collection rate. Moreover, it is also necessary to take into account that the aspect ratio of the liquid crystal panel, which is the target of the condensed light, is 16.9, which is wide.

Unused light turns into heat, and the heat generated by the liquid crystal panel in particular affects the operation of the liquid crystal, so it is necessary to suppress the temperature rise, and an effective cooling method is desired.

Furthermore, when displaying high-quality EDTV signals,
The image quality of the display also needs to be further improved. In particular, since a liquid crystal panel has contrast viewing angle characteristics, when used as a light valve, it is desired to use it effectively to obtain the best contrast. Also, wide E
In DTV, because the screen is horizontally long, uneven brightness and color tend to occur in the periphery, so countermeasures are necessary. In addition, in the case of a rear projection type, the viewing angle of the screen becomes a problem, and a wide viewing angle is desired.

Furthermore, even for a wide-aspect large-screen display, it is desirable that the set shape be compact. especially,
For home use, it is preferable that the depth is thin, and the ultimate is a wall-mounted type. Furthermore, there are two types of projection methods: front projection type and rear projection type, and if both types can be realized relatively easily with one set, it will be possible to use it for multiple purposes. Furthermore, if a function is provided to easily configure a multi-screen by combining multiple units, it can be widely used for large-screen displays for business use.

(Problems to be Solved by the Invention) As described above, the projection type liquid crystal display device using a liquid crystal panel and a liquid crystal light valve has many problems, and a technology to solve these problems is desired.

Therefore, the present invention was made based on such a situation, and it is an object of the present invention to create a display that has a large screen, is compact, and has an easy-to-use display format that facilitates development of projection formats and achieves high efficiency and high image quality. The purpose is to provide.

[Configuration of the Invention (Means and Effects for Solving the Problems) A projection type liquid crystal display device according to the present invention includes a light source and a light source that outputs R, G,
A color separation means that separates the B light into the three primary colors, three liquid crystal panels arranged corresponding to the three primary colors and controlling transmission by three primary color video signals, and three primary colors transmitted through the liquid crystal panel. A rear projection type liquid crystal display device equipped with three projection lenses for projecting enlarged light and a screen for forming and combining the enlarged projected light, the device comprising: (A1) a first part of the optical arrangement including the color separation means; The method includes first, second, and third dichroic mirrors, and the first mirror is configured to move the three liquid crystals in the traveling direction of the light reflected by the first dichroic mirror. The liquid crystal panel is arranged so that light enters a first liquid crystal panel in the panel. The second mirror is arranged so that light is incident on the second liquid crystal panel in the traveling direction of the light reflected by the second dichroic mirror. The third dichroic mirror is arranged so that light enters the third liquid crystal panel in the traveling direction of the light transmitted through the second dichroic mirror. The distance between the optical axis centers from the first dichroic mirror to the first mirror is equal to the distance between the optical axis centers from the first dichroic mirror to the second mirror via the second dichroic mirror,
- from the second dichroic mirror to the second mirror
19 = Distance between the optical axis center and the distance from the second dichroic mirror to the third dichroic mirror
The optical arrangement is such that the distances between the optical axis centers and the dichroic mirrors are equal. With this configuration, the optical path length of the three primary colors (distance from the light source to the liquid crystal panel)
Since L is the same and the brightness unevenness characteristics are the same on the three axes,
The occurrence of color unevenness around the screen is reduced. Moreover, the optimization design of the light collection rate of the light source becomes easy.

(A2) Alternatively, as a second method of the optical arrangement, the three liquid crystal panels and the projection lens are arranged in a delta shape, and the light source light is converted into three primary color lights using one dichroic prism or dichroic cross mirror. Along with separation,
The three liquid crystal panels are arranged so that the three primary color lights are incident on the three liquid crystal panels through three mirrors, and the center distances of the optical axes from the light source to each liquid crystal panel are made equal. As a result, the optical path lengths of the three axes are the same L and the brightness unevenness characteristics are the same for the three axes, which reduces the occurrence of color unevenness around the screen. In addition, the optimization design of the light condensing efficiency of the light source becomes easy, and since the optical path length can be shortened, the light condensing efficiency increases and high brightness=20- can be achieved. Furthermore, the shape of the optical system can be made compact, and the projection device can be made smaller.

(A3) Alternatively, as a third method of the optical arrangement, the three liquid crystal panels and the three projection lenses are arranged at equal intervals, and the light source light is transmitted to the first, second, and third polarizing beam splitters.
A combination of a dichroic mirror, a 1/4 wavelength compensator, and a 45-degree polarization conversion liquid crystal panel, or a λ/4 wavelength plate, and a mirror performs color separation, and from the polarizing beam splitter to the first dichroic mirror. ,
1/4 wavelength compensation plate from the first dichroic mirror, 4
The optical axis center distance from the 5 degree polarization conversion liquid crystal panel or λ/4 wavelength plate to the mirror is 1/2 of the projection lens interval.
By arranging them equally, the optical path lengths of the three axes are made equal and the brightness unevenness characteristics become the same for the three axes, thereby reducing the occurrence of color unevenness around the screen. Moreover, the optimization design of the light collection rate of the light source becomes easy. Furthermore, since the light incident on the liquid crystal panel is only polarized on one side, the heat generated by the polarizing plate of the liquid crystal panel can be reduced and temperature rise can be suppressed.

= 21 - (A4) Furthermore, the projection type liquid crystal display device according to the present invention is provided with means for moving the optical axis center of the three primary color lights from the light source away from the screen center of the liquid crystal panel. This corrects the light distribution and shading that occur in the L, projection lens, and screen, and displays an image with good white uniformity and little color unevenness.

(A5) Furthermore, in the projection type liquid crystal display device according to the present invention, each of the three liquid crystal panels includes a liquid crystal panel for correcting brightness characteristics. Luminance unevenness is corrected by a correction signal applied from the decoder part 2 to this luminance characteristic correction liquid crystal panel. This makes it possible to roughly correct luminance unevenness without significantly reducing transmittance, and improves image quality.

(A6) Also, in the projection type liquid crystal display device according to the present invention, the three liquid crystal panels are active matrix type liquid crystal panels, and form a first light shielding structure (black matrix) on the incident light side. A second light shielding structure is formed on the incident light side surface of the glass substrate. This second light shielding structure is further in contact with the cooling liquid. With such a structure, the liquid crystal panel can efficiently suppress temperature rise due to irradiation light. Further, the second light shielding structure is made of a material with high light reflectance.

This reduces heat absorption and reduces temperature rise.

(A7) Furthermore, in the projection type liquid crystal display device according to the present invention,
By providing a light refracting means on the output light side of the three liquid crystal panels, an image with the best contrast ratio in the normal direction of the display surface of the liquid crystal panel can be displayed without increasing the diameter of the projection lens. be able to.

(A8) Furthermore, in the projection type liquid crystal display device according to the present invention,
A light control glass sandwiching a liquid crystal is provided in front of the image-forming transmission screen. This allows the viewing angle to be optimally adjusted by controlling the light transmittance and light diffusivity according to the external environment and usage conditions.

Furthermore, the projection type liquid crystal display device according to the present invention has R, G
, a light source that emits the three primary colors of light of B, and the light source that emits the three primary colors of light of R,
A color separation means that separates the light into the three primary colors of G and B;
Three liquid crystal light valves arranged corresponding to the primary color lights and whose transmission amount is controlled by the three primary color video signals, a means for combining the light transmitted through the liquid crystal light valves, and one for enlarging and projecting this combined light. (B1) The projection type liquid crystal display device according to the present invention further comprises: a projection lens and a screen for forming an image of enlarged projection light;
The three liquid crystal light valves are active matrix type liquid crystal panels, and operate the signal line driving circuit and the scanning line driving circuit at several times the speed when the input video signal is in the desired display area. It can be controlled to write several lines at a time. This is L,
Multi-screens can be realized with a simple configuration without using expensive multi-screen division conversion circuits.

(B2) The light source consists of a light source lamp and a reflector.
The light source includes a reflector whose cross section including the optical axis forms a parabola and whose focal point is not constant.

The reflector is also provided with a reflector having an elliptical or polygonal aperture shape with the optical axis of the light source as its normal line.

Further, when the light valve is rectangular, the light valve is provided with an elliptical reflector having a shape of the aperture or a ratio of a major axis to a minor axis equal to the aspect ratio of the light valve.

Further, the opening surface shape is an ellipse or a polygon, the cross-sectional shape including the optical axis of the light source forms a parabola, and a finite arc length is formed between two discharge electrodes such as the light source lamp or metal halide lamp. If the reflector has a reflector, the reflector is characterized in that the focal length of the parabola is between the two discharge electrodes.

Further, when the cross-sectional shape of the light source including the optical axis forms a parabola and the light source lamp has a finite arc length between two discharge electrodes such as a metal halide lamp, the aperture surface has an elliptical shape, The distance between the aperture surface and the apex of the parabola is δ, the arc length is δ, the focal length of the parabola that intersects with the long axis of the ellipse is m1, and the focal point of the parabola that intersects with the short axis of the ellipse. Let the distance be m2, δ−m1−
m2, the long axis can be expressed as 4×√(ml×L)−1 and the short axis can be expressed as 4×J.

With this configuration, the collected light can be efficiently irradiated onto the wide aspect liquid crystal light valve, improving the light utilization rate and increasing efficiency.

(B3) Furthermore, the projection type liquid crystal display device according to the present invention has a movable mechanism in the mounting portion of the screen on which the enlarged projection light is formed by the projection lens. The first means is to have a mechanism for moving the screen in parallel in the optical axis direction. According to such a configuration, it can be installed in a thin state when not in use, so that it does not get in the way. Moreover, the set shape becomes smaller and portability is improved. Furthermore, by moving the screen part, it becomes possible to change the screen size within a certain range and to enlarge or reduce the screen size.

(B4) Alternatively, as a second means, a mechanism is provided in which the screen part can rotate in the vertical direction using a part of the set main body as a fulcrum. With such a configuration, by preparing a different type of screen in front of the projection device and projecting the image, the L
, it is possible to significantly change the screen size (larger screen), which was not possible with conventional rear projection display devices, and a display system that can be easily used for multiple purposes and allows you to enjoy impressive wide-screen images has been realized. can. Furthermore, multiple units can be combined vertically and horizontally to easily support multi-screen display.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the overall configuration of the system described in this embodiment, and its outline will be briefly described. That is, FIG. 1(a) is a sectional view of a projection type liquid crystal display device according to the present invention, FIG. 1(b) is a front view of its optical system, and FIG. 1(c) is a plan view thereof. In the figure, 4000 is a projection type liquid crystal display device according to the present invention. This projection type liquid crystal display device 4000 consists of the following main components.

400I is a light source, which is composed of a short arc high-intensity white lamp 41o1 such as a metal halide lamp, and a reflector 4100 having a paraboloid of revolution or an ellipsoid of revolution to condense the light of the lamp and emit it forward. . The collected light is extracted through a heat protection filter 4013 that removes unnecessary infrared light in order to suppress the temperature rise in the subsequent stage.

Next, this white light is dichroic mirror 4008.4
According to 009.4010, the light is color-separated into L and three primary color lights.

Here, the dichroic mirror 4008 is a blue reflecting mirror that reflects light with a wavelength of about 500 nm or less, and the dichroic mirror 409 has a wavelength of about 5DOnm to 500nm.
The dichroic mirror 4010, which is a green reflecting mirror that reflects light of 70 nm, is a red reflecting mirror that reflects light with a wavelength of about 600 nm or more. The separated blue and green light is mirror 40
11, 401.2, and is reflected by the liquid crystal panel 4002.
Guided to 4003. The reflected light from the dichroic mirror 4010 is guided to the liquid crystal panel 4004.

At this time, the light incident on each liquid crystal panel is set to be incident at a slight tilt angle so that the contrast is the best. By using such an optical arrangement and setting the center distance of each optical axis to a predetermined value, it is possible to
The lengths of the optical axis paths up to 4 (this is called optical path length) can be made equal. Here, dichroic mirror 4
010 and 4008 or mirror 41.00 have a position adjustment function, and are adapted to shift the optical axis from the center of the screen of liquid crystal panels 4002 and 4004.

The liquid crystal panels 4002, 4003, and 4004 are monochrome liquid crystal panels without color filters, and have an aspect ratio of 16:9, which corresponds to a wide screen. This liquid crystal panel is generally made of thin film transistors (TPT).
) is used for each pixel, and is used as a light valve that controls the three primary color lights using this shutter effect. This liquid crystal panel receives horizontal clock pulses (CPH), vertical clock pulses (C
PV), horizontal start pulse (STI()), vertical start pulse (STV), and a brightness correction signal (described later) are connected to terminal 40.
In addition to 21, 4022, and 4023, the three primary color lights are controlled to display an image. Here, this liquid crystal panel is provided with cooling layers 4102, 4103, and 4104 on the incident light side, and a second
The black matrix of cooling layer 4 +, 02, 41
03.

The structure is such that it is also provided on the glass surface portion facing the 4104 side. Furthermore, brightness correction panels 4112, 4113, 411
4 is provided on the incident light side of the cooling layer 4102, 4103, and 4104, and the brightness unevenness of the displayed image is corrected by the brightness correction signal from the video decoder 6800. Further, the liquid crystal panel has a light refracting means, such as a prism, placed in close contact with the output side of the liquid crystal panel, so that the light incident on the liquid crystal panel at the tilt angle is perpendicular to the display surface of the liquid crystal panel. It can be made to emit light.

4005.400L4007 is a projection lens L, which enlarges and projects the R, G, and B light image-modulated by the liquid crystal panel 4 [102, 4003, and 4004 onto the screen 401θ and synthesizes it. Here, usually both lenses 4005.40
The center of the screen of the liquid crystal panel is positioned slightly outward from the optical axis of 07. As a result, the projected image shifts to the center and images of the three primary colors overlap, so that a color image without color shift can be displayed. 4014.4015 are mirrors L, projection lenses 4005, 4006, 4007
By reflecting the light emitted from the L and bending the optical path, it works to shorten the depth dimension. 4016 is a transmission screen L, projection lens 4005.4006.4007
Forms an image of the light emitted from the This transparent screen 4016
A liquid crystal light control screen 4017 is placed in front of the screen L, so that the transmittance and diffusivity of the imaging light can be controlled and the viewing angle can be optimally adjusted.

The outline of the basic configuration of this embodiment has been briefly described above, and the details of each part will be explained below. Here, each part will be explained in the following order.

(1) From FIG. 2 to FIG. 5, [A1] Explanation regarding the configuration of the first optical arrangement means.

(2) From FIG. 6 to FIG. 7, [A2] Explanation regarding the configuration of the second optical arrangement means.

(3) From FIG. 8 to FIG. 9, [A3] Explanation regarding the configuration of the third optical arrangement means.

(4) From FIG. 10 to FIG. 16, [A41 Explanation regarding color unevenness correction means].

(5) FIG. 17 is a description of the configuration of the [A5] brightness correction liquid crystal panel.

(6) From FIG. 18 to FIG. 20, [A6] Explanation regarding the structure of a liquid crystal panel having a cooling function.

(7) FIGS. 21 to 28 explain the tilt angle correction means of the EA7 liquid crystal panel.

(8) From FIG. 29 to FIG. 33, [A8] Explanation regarding the configuration of a transmissive screen system equipped with a liquid crystal dimming screen.

[A1] First optical arrangement means (problem to be solved by the invention) FIG. 2 shows a sectional view of a conventional projection type liquid crystal display device, and FIG. 3 shows a configuration diagram of its optical system. Lamp 4 of light source 4001
The light emitted from the dichroic mirror 4008.
4009.4010, the liquid crystal panel 4002.4003 is separated into three primary color lights of R, G, and B and corresponds to each color.
．． 4004. Next, the R, G
, H video signal is modulated and the projection lens 4005.4008
．． 4007, the image is enlarged and projected onto the screen 401B.

In this case, the luminance distribution on the diagonal of the screen differs on the three axes R, G, and B, as shown in FIG. This is light source 4
001 to each LCD panel 4002, 4003.4004
This is caused by the difference in the optical path length. Tsume L, light source 40
This is because the light emitted from 01 has a certain surface illuminance distribution, and this differs depending on the incident surface of each liquid crystal panel 4002, 4003, and 4004. As a result, in the case of an arrangement as shown in the figure in which the optical path length increases in the order of B, G, and R, the luminance distribution on the B axis becomes steep L, while on the R axis it becomes gentle.

Therefore, when the white balance is adjusted at the center of the screen, the ratio of B and G components is smaller than the R component at the periphery, and a donut-shaped reddish color unevenness occurs at the periphery. The way color unevenness occurs is B and G.

It changes depending on the arrangement of R. In particular, when the screen has a wide aspect, color unevenness in the periphery tends to further increase. Also, the brightness distribution is determined by the reflector 4100 and the lamp 4.
Since the positional relationship between the parts 101 and 101 varies greatly, precision in positioning is required for installation. Tsuma L, poor manufacturability. lamp 4
Since the light emitting state of light 101 also changes over time, it similarly tends to affect the luminance distribution. As described above, the conventional system has many factors that cause subtle changes in brightness unevenness characteristics, and has a configuration in which color unevenness is likely to occur.

(Example) In order to solve the above-mentioned problem, the present invention optimizes the optical arrangement and provides a means for optical arrangement that makes the optical path lengths of three axes equal.

An embodiment of the first means will be described in detail based on the drawings. Figures 5(a) and 5(b) show the configuration diagram of the optical system of this example.
Shown below. (The figure almost overlaps with Figure 1, but I will write it again.) In this optical arrangement, the light [4001
The white light from the 41-inch lamp is incident on the blue-reflecting first dichroic mirror 4008. Here, the blue light is reflected and passes through the first mirror 4012 for the B-axis.
The light enters the liquid crystal panel 4002 of. The light transmitted through the first dichroic mirror 4008 enters a second dichroic mirror 4009 that reflects green color, and the green light is reflected here and passes through the second mirror 4011 to the second liquid crystal panel for the G axis. 4003. Furthermore, the light that has passed through the second dichroic mirror 4009 has a third dichroic mirror that reflects red.
The light is incident on the dichroic mirror 4010 and is incident on the third liquid crystal panel 4004 for the R axis. In addition, mirror 401
1.4012 may be a total reflection mirror, or a dichroic mirror may be used to improve color purity.

Here, the optical axis center distance from the lamp 4101 to the first dichroic mirror 4008 is a, and the distance from the first dichroic mirror 4008 to the second dichroic mirror 4 is
Distance to 009 b1 Second dichroic mirror 4
The optical axis center distance from 009 to the third dichroic mirror 4010 is 01 the first dichroic mirror 400.
8 to the first mirror 4012 is d1.
The optical axis center distance from the second dichroic mirror 4009 to the second mirror 4011 is el, and from the first mirror 4012 to the first liquid crystal panel 4002, and from the second mirror 4011 to the second liquid crystal panel 4003. , 3rd
Let f be the optical axis center distance from the dichroic mirror 4010 to the third liquid crystal panel 4004. In such a configuration, from the lamp 4j01 to the first liquid crystal panel 40
The optical path length from the lamp 4101 to the second liquid crystal panel 4003 is Lb, and the optical path length from the lamp 4101 to the second liquid crystal panel 4003 is L6.
Letting the optical path length from to the third liquid crystal panel 4004 be LR, it can be expressed as the following equations.

L b = a + d + f LG-a+b+e+f L, R-a+b+c+f ・=(1)
Here, if the position of each optical mirror is set so that d=b+c and e=c, equation (1) becomes Lb - LG = LR
= a + b + c + f '' (2) L, the optical path lengths of the three axes can be made equal. Therefore, the color unevenness caused by the difference in optical path length as in the past can be significantly reduced. In addition,
The shape of the reflector 4100 of the 40-inch light source and the lamp 4
When improving the light collection rate by optimizing the arc length of 101, the design is easy because optimization can be done with one optical path length.
, it becomes more efficient or more convenient.

[Effects of the Example] As described above, according to this optical arrangement, the optical path length from the light source lamp to each liquid crystal panel can be made equal, so that the brightness unevenness in the three axes has the same characteristics. Even if there is, color unevenness around the screen can be significantly reduced. Further, in designing the shape of the reflector and the arc length of the lamp, optimization is possible with a single optical path length, so precision is not required.

Therefore, it is easy to manufacture, easy to design, and can further improve efficiency and reduce unevenness in brightness. Furthermore, there is little characteristic deterioration of color unevenness due to changes in the light source over time.

[A2 Second Optical Arrangement Means Next, an embodiment of the second means will be described in detail based on the drawings. A block diagram of an optical system of an embodiment of this means is shown in FIG. White light emitted from a lamp 4101 of a light source 400 enters a dichroic prism 4200 via a heat shielding filter 4013, where it is separated into three primary colors, RlG and B. The blue light, which is the first reflected light, is reflected by the first mirror 4.
202 to the first liquid crystal panel 4002 for the B-axis, and the second reflected light, which is red light, passes through the third mirror 4204 to the third liquid crystal panel 4002 for the R-axis.
The green light enters the liquid crystal panel 4004 for the G axis, passes through the dichroic prism 4200, and enters the second liquid crystal panel 4003 for the G axis via the second mirror 4203.

Here, the mirrors 4202, 4203, and 4204 may be total reflection mirrors, or dichroic mirrors may be used to improve color purity. Each liquid crystal panel modulates the R, G, and B video signals from the video decoder 6800 and projects them onto the screen using projection lenses 4005, 4006, and 4007. Here, the optical axis center distances from the lamp 4101 to each mirror 4202, 4203, and 4204 are set equal to a, and each mirror 4202, 4203, and 4204
If the center distances of the optical axes from
It is possible to achieve equal optical path lengths such as b and L. Therefore, the color unevenness caused by the difference in optical path length as in the conventional method can be significantly reduced. In addition, the reflector 4100 of the light source 4001
When improving the light collection efficiency by optimizing the shape of the lamp 4I01 and the arc length of the lamp 4I01, the optimization can be performed with one optical path length, which facilitates design and increases efficiency. Furthermore, since this optical path length can be made shorter than in the past, higher brightness can be achieved. Furthermore, the configuration is simple and a compact optical system can be realized.
It is also effective in making the set smaller and thinner.

Furthermore, a modification of FIG. 6 is shown in FIG. In the figure, instead of the dichroic prism 4200 as a spectroscopic means,
This is an example using a cross-type dichroic mirror 4220. This method can also achieve the same effect as described above.

[Effects of Example] As described above, according to this optical arrangement, the optical path length from the light source lamp to each liquid crystal panel can be made equal, so
The brightness unevenness on the axis has the same characteristics L, and even on a wide aspect screen, color unevenness around the screen can be significantly reduced. or,
In designing the reflector shape and lamp arc length,
Since optimization can be performed using one optical path length, precision is not required. Therefore, it is easy to manufacture, easy to design, and can further improve efficiency and reduce unevenness in brightness. Even when the light source changes over time, there is little deterioration in the characteristics of color unevenness. Furthermore, since the optical path length -39~ can be shortened, high brightness can be achieved, and a compact optical system with a simple configuration can be realized.

[A3] Third optical arrangement means Next, an embodiment of the third means will be described in detail based on the drawings. A block diagram of an optical system of an embodiment of this means is shown in FIG. White light emitted from the lamp 4101 of the light source 4001 passes through a heat shield filter 4013 to a polarizing beam splitter.
It is incident on 4300. Polarizing beam splitter-4300
By this, white light is separated into P polarized light wave and S polarized light wave.

The P-polarized light wave is transmitted as it is and goes straight, and the third wave of red light is reflected.
The light enters the dichroic mirror 4306, and only the red wavelength component is reflected and enters the third liquid crystal panel 4004 for the R axis. On the other hand, the S-polarized light wave separated by the polarizing beam splitter 4300 is incident on a first dichroic mirror 4301 that transmits blue light, and the blue light is transmitted, while other wavelength components are reflected. The reflected light is the second part of the green light reflection.
The green light enters the dichroic mirror 4305, and only the green light is reflected and enters the second liquid crystal panel 4003 around the G axis. Furthermore, the blue light that has passed through the first dichroic mirror 4301 passes through the 1/4 wavelength compensator 43D2 and the 45° polarization conversion liquid crystal cell 4303, is reflected by the mirror 4304, and is again transferred to the 456 polarization conversion liquid crystal cell 4303 and the 45° polarization conversion liquid crystal cell 4303. By passing through the four-wavelength compensation plate 4302, it is converted into a P-polarized light wave. This converted P-polarized light wave is sent to the first dichroic mirror 4301 and the polarizing beam splitter 430.
0 and enters the first liquid crystal panel 4002 for the B-axis. Here, the mirror 4304 may be a total reflection mirror or a mirror with UV transmission characteristics.

According to the above configuration, the white light from the 40-inch light source is decomposed into three primary color lights and irradiated to each corresponding liquid crystal panel. These lights are modulated by R, G, and B video signals from a video decoder 6800 (not shown) in each liquid crystal panel, and are projected onto a screen by projection lenses 4005, 4006, and 4007. Here, these optical arrangements are set as follows. L, the optical axis center distance from the lamp 410 of the light source 4001 to the polarizing beam splitter 4300 is a.
, the distance between the optical axis centers of each liquid crystal panel 4002, 4003, and 4004 is set from the b1 polarizing beam splitter 4300 to the first
Let C be the distance between the optical axis center and the liquid crystal panel 4002.

Then, the first dichroic mirror 4301 is arranged at an optical axis center distance of b/2 from the polarizing beam splitter 4300, and
A mirror 4304 is placed at a distance between the optical axis centers of 2 and 2. Furthermore,
A second dichroic mirror 4305 is arranged at an optical axis center distance of c + b / 2 from the second liquid crystal panel 4003, and a third dichroic mirror 4306 is arranged at an optical axis center distance of C from the third liquid crystal panel 4004. do.

In such a configuration, the optical path length from the lamp 4101 to the B-axis first liquid crystal panel 4002 is Lb, and the lamp 4
Let LR be the optical path length from the lamp 4101 to the third liquid crystal panel 4004 for the R axis, then L b = a
+ b + b + c -a + 2 b + c
−(3) L c = a + b / 2 + b
+ b / 2 + c-a+2b+c
...(4) L ll = a + b + b
+ c - a + 2 b + c - (5),
Lb-LG = LR, and the optical path lengths from the lamp 4101 to each liquid crystal panel become equal. Therefore, the color unevenness caused by the difference in optical path length as in the conventional method can be significantly reduced. In addition, when improving the light collection rate by optimizing the shape of the reflector 4100 of the light source 4001 and the arc length of the lamp 4101, the optimization can be done with one optical path length, which facilitates design and increases efficiency. becomes easier. Furthermore, since the light incident on each liquid crystal panel is only polarized on one side,
It has the advantage that the temperature rise of the polarizing plate attached to the liquid crystal panel can be significantly suppressed compared to conventional methods.

Furthermore, a modification of FIG. 8 is shown in FIG. 9. The figure shows an example in which a λ/4 wavelength plate 4310 is used in place of the 1/4 wavelength compensator 4302 and the 45° polarization conversion liquid crystal cell 4303 to achieve the same effect. Tsume L, polarizing beam splitter-43
The S-polarized light wave from 00 is incident on the λ/4 wavelength plate 4310, and the polarization axis is rotated by 45°. Then, it is reflected by the mirror 4304, enters the λ/4 wavelength plate 431D again, and the polarization axis is further rotated by 45 degrees, so that it is converted into a P-polarized light wave. converted P
The polarized light is transmitted by the first dichroic mirror 43 that transmits blue light.
01 and polarized beam spree 43 = transmitted through the vine 4300 and the first liquid crystal panel 40 for the B axis
02. Even with such a configuration, equal optical path lengths can be achieved by using the same optical arrangement as in FIG. 8.

[Effects of the Example] As described above, according to this optical arrangement, the optical path lengths from the light source lamp to each liquid crystal panel become equal, so that the brightness unevenness in the three axes becomes the same characteristic, resulting in a wide aspect screen. However, color unevenness around the screen can be significantly reduced. Further, in designing the shape of the reflector and the arc length of the lamp, optimization is possible with a single optical path length, so precision is not required.

Therefore, it is easy to manufacture, easy to design, and can further improve efficiency and reduce unevenness in brightness. There is little characteristic deterioration of color unevenness due to changes in the light source over time. Furthermore, since the light incident on the liquid crystal is only polarized on one side, the rise in temperature of the polarizing plate can be significantly suppressed, thereby preventing a decrease in contrast due to deterioration of the polarizing plate and malfunction due to an increase in the temperature of the liquid crystal panel itself.

[A41 Color unevenness correction mechanism (problem to be solved by the invention) As shown in Figure 3, in the conventional optical arrangement, in order to superimpose R, G, and B images on the screen, the light from the left and right projection lenses is The center of the liquid crystal panel is offset by d with respect to the axis. This shift amount d is the projection lens interval D1
If the projection lens magnification is A, then d=D/A. or,
In order to downsize the set, a wide-angle projection lens is often used. However, in principle, the projection lens is
As shown in Figure 0 (a), the amount of light surrounding the center of the optical axis becomes darker in proportion to the fourth power of the cosine of the angle of view (cosine fourth power law).
. When such a lens is used in the above-mentioned off-center position,
On the screen, as shown in No. 440(b), the light intensity distribution of 3 is different, and the color L is stronger in blue on the right side and more red on the left side.

Furthermore, since the reflector 4100 of the light source 4001 generally uses a rotating blade mirror, and the arc length of the lamp 4101 is finite, the distribution of the focused light is not uniform.
As shown in FIG. 11, the periphery is often dark compared to the center.

Furthermore, the transmissive screen 4016 is generally shown in FIG. 12(a).
), (b) (This drawing is published by the Institute of Electronics, Information and Communication Engineers paper EID86.
It is composed of a Fresnel lens and a lenticular lens shown in (see 30), but the Fresnel lens causes a loss as shown in the black area in the figure and the amount of light decreases. This loss increases at the periphery where the angle of incidence on the screen is large. Therefore,
The screen light amount ratio of the three axes is as shown in FIG. 12(C).

In addition, if the angle of incidence i from the three lenses to the screen is large, a color shift will occur due to the viewing angle characteristics of the screen, as shown in FIG.

The synergistic result of these light amount distribution characteristics causes uneven light distribution on the screen, which leads to deterioration of white uniformity and color unevenness. These phenomena become more severe with wide aspect screens.

This is because the angle of view is wide and the angle of incidence of light on the screen becomes larger at the periphery.

(Example) In order to solve the above-mentioned problem, an adjusting means for shifting the center of the luminous flux of the three primary colors from the center of the liquid crystal panel was provided. An example is shown in FIG. The figure shows an example applied to the optical arrangement shown in FIG. In the figure, move mirrors 4010 and 4012 to the left and right
It has a mechanism that allows it to be moved a long distance. This is L, mirror 40
10.The optical axis of the light reflected by 4012 is
Since the adjustment can be made off the center of 02.4004, the light distribution on the projection lens and screen can be corrected, and the white uniformity on the screen can be adjusted to be optimal.

For example, if the uneven light distribution due to the projection lens shown in Figure 10 is dominant, the light distribution with the center of R on the right side and the center of B on the left side as shown in Figure 15 will affect the liquid crystal panel. You just need to adjust it so that it is incident on .

FIG. 16 is an example of the optical arrangement shown in FIG. 6. In this optical arrangement, it is necessary to make all three projection lenses off-center the liquid crystal panel, so as shown in the figure, to correct the light distribution, mirrors 4202 and 4204 are moved horizontally by H, and mirror 4203 is moved vertically. so that only H can move. By using such means, it is possible to correct the light distribution on the projection lens and the screen, and it is possible to adjust the white uniformity on the screen to be optimal.

[Effects of the Example] As described above, the occurrence of color unevenness due to deterioration of white uniformity can be easily corrected with a simple configuration that does not require additional parts, and also without the need for electrical correction. This is a very effective method.

[A5] Brightness correction liquid crystal panel (The problem that the invention seeks to solve).

Conventional projection type liquid crystal display devices have a problem in that white uniformity cannot be achieved. The phenomenon will be explained below.

In an illumination system using a parabolic mirror of revolution or the like, it is common for the periphery to be somewhat dark compared to the center, as shown in FIG.

Furthermore, in principle, a wide-angle projection lens has a dark amount of light around the center of the optical axis in proportion to the fourth power of the angle of view (cosine fourth power law), as shown in FIG. 10(a).

With a lens having an angle of view of 30 degrees or more, the amount of light that reaches the periphery of the screen is only about 50 to 60 percent of the light that reaches the center, resulting in a noticeable decrease in brightness at the periphery of the screen. Lens 3 with such characteristics
With the book off-center, the liquid crystal image is projected using the left, center, and right sides of the lens as shown by the arrows in the figure, but on the screen, the right side as shown in Figure 1.0(b) Blue is stronger, and red is stronger on the left side.

Furthermore, although the transmission screen 4017 generally uses a Fresnel lens and a lenticular lens (see FIGS. 12(a) and 12(b)), even a Fresnel lens causes a decrease in the amount of peripheral light.

The cause is a decrease in the aperture ratio of the Fresnel lens at the periphery of the screen. In FIGS. 12(a) and 12(b), the black areas are areas that do not function as lenses and cause loss, and the incident angle becomes smaller around the periphery of the screen, so loss increases. Therefore, the light intensity ratio of the screen according to Fresnel is shown in Figure 12 (
It will look like C).

Since the R lens is on the right side, there is a lot of loss at the left end, and the opposite is true for the B lens.

The sum of all these light intensity distribution characteristics is the overall light distribution characteristic L, and the ratio of RGB varies depending on the intensity of the distribution of each characteristic, which causes color unevenness. . For example, if the distribution of the three primary colors depending on the light intensity ratio of the lens (see Figure 10(b)) is the most dominant among other characteristics, blue will be strong on the right side of the screen and red will be strong on the left side.

A commonly used method for correcting such brightness unevenness is to apply correction to the input video signal.

However, this method reduces the contrast of the displayed image. L, liquid crystal panels originally have a narrower dynamic range than CRTs, so it is better to drive the video signal over a full range, but with the method described above, the full range drive is performed using a signal obtained by adding a correction signal to the video signal. The video signal level will decrease. As a result, the image loses its contrast.

The present invention eliminates the uneven distribution of RGB that occurs on the screen due to the cause described in 1 above, without reducing the contrast.
The purpose is to reduce color unevenness caused by this and improve white uniformity.

(Example) A drive circuit for a liquid crystal panel will be explained with reference to FIG. 17, and a measure for improving white uniformity, which is one of the features of this proposal, will be explained.

4002, 4003, and 4004 are active matrix liquid crystal panels in which each pixel is provided with a thin film transistor. For example, the aspect ratio is 169 and the number of pixels is 960x48.
0, and is compatible with NTSC (7) second generation EDTV video display. Red, green, and blue video signals Vl? input from the video decoder 6800, respectively. ,VC,VB
It works as a light valve for the image light that is displayed and projected onto the screen.

4112, 4113, and 4114 are simple matrix liquid crystal panels for brightness correction according to the present invention. It works to narrow down the light in bright areas to cancel out uneven brightness and brightness gradients that occur in lighting systems, lenses, screens, etc.

The aspect ratio is the same <1.6:9, and the number of pixels is set to 36×15 since it is fine if it is coarse. This increases the aperture ratio and increases the light transmittance.

45001 is a PLL-VCO and is an LCD for sampling 960 pixels during one horizontal effective display period based on the horizontal synchronizing signal HD input with twice the frequency of normal NTSC.
Drive source clock CLK (approximately 36.7MH in this example)
z) and outputs it.

45002 is a 1/32 frequency divider L, which divides the 36.7 MHz clock into 1.15 MHz. This allows horizontal 3
Obtain the clock for the 0 pixel LCDs 4112 to 4114.

45003 is also a 1/32 frequency divider, L, horizontal synchronization signal HD
As input, L CD 4112 to 41 every 32 scanning lines
14 column electrode drives are moved down one line.

45004 is a V address generation circuit which counts up the column address every clock input from the frequency divider 45003 every 32 times HD.

45005 is an H address generation circuit, which is a PLL/VCO
The clock from 45001 is divided into 1/3 by frequency divider 45002.
2 and count up the row address using that clock.

45006 is a read-only memory (ROM) which inputs the column address from the address generator 45004 and the row address from the address generator 45005, and outputs a brightness correction signal written in advance. A pulse modulation unit 45009 modulates the pulse width to match the brightness correction signal and outputs it to the X drivers 411 and 21 of the LCD, thereby correcting the brightness of the designated pixel area. Note that these signal processing is performed by the video decoder 6800, and only the signals necessary for driving the liquid crystal panel are sent to the terminals 4021, 4022, and 402.
3 (Figure 1).

For example, as shown in Figure 11, the brightness correction signal written in advance in the ROM is used to lower the brightness at the center of the brightness correction liquid crystal panel when the light distribution characteristics of the light collection system are such that the periphery becomes darker than the center. , is a signal that increases the brightness of the peripheral area.

In addition, as shown in Figure 1.0(b), if the combination of the light intensity ratios of the three projection lenses results in stronger blue on the right side of the screen and stronger red on the left side, the B-axis brightness correction liquid crystal panel This signal lowers the brightness on the right side and lowers the brightness on the left side of the R-axis brightness correction liquid crystal panel.

Similarly, as shown in Figure 12 (C), if the light amount ratio of the transmissive screen is such that the B loss is large on the right side of the screen and the R loss is large on the left side, then the left side of the liquid crystal panel for brightness correction on the B axis is This signal lowers the brightness of the right side of the R-axis brightness correction liquid crystal panel.

In this way, in the overall light distribution characteristic including all of these light quantity distribution characteristics, a signal for correcting the uneven distribution of RGB on the screen and the color unevenness caused by it is written in the ROM in advance at the production stage.

Further, in terms of the structure, the brightness correction liquid crystal panel is arranged in front of the video display liquid crystal panel so that the light source light enters the brightness correction liquid crystal panel and the video display liquid crystal panel in this order.

Although the brightness correction liquid crystal panel requires a high aperture ratio and has coarse pixels, a simple matrix panel with 30×15 pixels and low cost is sufficient.

[Effects of Example] RG generated on the screen by the brightness correction liquid crystal panel
It becomes possible to reduce the uneven distribution of B and the color unevenness caused by it, and to improve white uniformity. Then, the original image can be displayed satisfactorily without reducing the contrast as before.

[A6] Liquid crystal panel with improved cooling function (problem to be solved by the invention) FIG. 18 shows a simple structure of a conventional liquid crystal panel. In the figure, 4600 is a transparent first glass substrate, 4601
is also the second glass substrate, 4602 is a thin film transistor (hereinafter referred to as TPT), 4603 is a pixel transparent electrode, 46
04 is a light shielding structure (black matrix), 4605
represents the liquid crystal material.

Generally, amorphous silicon (hereinafter referred to as a-3i) is often used as a gate electrode material for TPT. However, since a-3i has a photoelectric effect, when the TPT is irradiated with light, the off-state current increases and the on-off resistance ratio of the TPT decreases. Therefore, a black matrix is provided on the inner surface of the second glass substrate on the incident light side for the purpose of blocking light from the TPT and leaking light between the pixel electrodes.

Generally, this black matrix occupies about half the area of a cell in a liquid crystal panel. In other words, approximately 50% of the light irradiated to the liquid crystal panel is absorbed by the black matrix and converted into heat. This causes the temperature of the liquid crystal material to rise. Liquid crystal materials are subject to severe temperature conditions, and their performance deteriorates as the temperature rises.

(Example) An example of the present invention is shown in FIG. 19. Number 18 in the diagram
The same numbers as in the figure indicate the same elements. In the present invention, a black matrix 4606, which is a second light shielding structure, is newly provided on the surface of the second glass substrate on the incident light side. Therefore, the incident light is completely absorbed by the second black matrix, so the temperature of the second black matrix 4606 increases, but since the glass 4601 has a high thermal conductivity, heat is not easily transferred to the liquid crystal material. Therefore, unlike the conventional method, the liquid crystal material is not directly heated. For example, by providing an air cooling fan 4607, it is possible to directly cool the black matrix and effectively prevent the temperature of the liquid crystal material from increasing by 1. Further, in consideration of diffuse reflection on the glass and the angle of incidence of the incident light, the black matrix 4604 is provided in the conventional manner to sufficiently suppress the light irradiated to the TPT. The temperature of the black matrix 4604 hardly increases because most of the incident light is absorbed by the black matrix 4606.

Another embodiment is shown in FIG. In FIG. 19 of the above embodiment, an air cooling fan is used for cooling, but although the fan has a high cooling effect, noise becomes a problem. In this embodiment, the third glass substrate 4609 is provided, and the black matrix 4604 is cooled by immersing it in a cooling liquid 4608. When using an air-cooling fan, a location for installing the fan is required, but using a cooling liquid has the advantage that it can be used as a unit including the liquid crystal panel.

Further, as another embodiment, if the second black matrix is made of a material having a high light reflectance, such as aluminum, there is an advantage that heat generation of the second black matrix is reduced and temperature rise can be prevented.

[Effects of Examples] As explained above in the Examples, by providing the second black matrix on the surface of the glass on the light incident side, the liquid crystal material is not directly heated, and the air cooling fan/cooling Cooling can be done efficiently using liquids.

Furthermore, if a material with high light reflectivity is used for this, the heat generation of the second black matrix is reduced, and as a result, the temperature rise of the liquid crystal material can be reduced, and deterioration of the liquid crystal material due to temperature rise can be prevented. Furthermore, deterioration of display image quality can also be prevented.

[Al1 Tilt Angle Correction Method (Problem to be Solved by the Invention) Generally, a liquid crystal panel using TN mode liquid crystal is used as an image display liquid crystal panel. however,
As shown in FIG. 21, the contrast changes depending on the viewing angle. The best contrast point is not on the normal line of the liquid crystal panel, but at a position a few positions away. Normally, in a TN mode liquid crystal, an alignment film is provided to align liquid crystal molecules in a certain direction, but a tilt called a pretilt is formed to stabilize the operation of the liquid crystal. Therefore, the best contrast characteristic point of the liquid crystal panel exists on a line L which is tilted several positions from the normal line of the display surface (referred to as the tilt angle) due to the influence of the pretilt.

Generally, the tilt angle is approximately 5 degrees in the vertical direction, and in order to obtain high-contrast image quality, it is necessary to tilt the liquid crystal panel by the amount of the tilt angle or change the viewing position.

FIG. 22 shows the relationship between the liquid crystal panel 4701 and incident light.

4702 is the light source light, and 4703 is the incident angle of the light source light 4702 with respect to the normal line 4704 of the display surface of the liquid crystal panel 4701.

If this angle of incidence is made to match the tilt angle, an image with the best contrast ratio can be obtained.

When the liquid crystal panel 4701 is not tilted as shown in FIG. 23(a), the old liquid crystal panel 47 is not tilted with respect to the optical axis of the optical system as shown in FIG. The optical system is shown when tilted with respect to the axis.

Note that simply tilting the liquid crystal panel is not preferable because the projected image will be distorted. In the figure, reference numeral 4710 indicates a projection lens, which is assumed here to be an ideal thin lens with no thickness for the sake of clarity.

4711 is the optical axis of the optical component, 4715 is the projection lens 47
10 is the entrance pupil, 4712 is the entrance pupil position, 4713 is the back focus of the projection lens 4710, and 4702 is the light source light.

Here, of the light source light 4702 to the projection lens 4710, only the light irradiated to the entrance pupil 4715 can reach the screen, and if the optical system is telecentric and the light source light 4702 is very close to parallel light, the entrance pupil position 4712 is Must be very long.

Next, as shown in FIG. 23(b), the optical axis 4714 of the light source is set at the tilt angle 47
Consider the case of tilting by a distance of 0.03. L, when the liquid crystal panel is moved so that the light source optical axis is tilted by the tilt angle 4703 with respect to the -60= entrance pupil 4715 without changing the back focus 4713, the light source light 4702 becomes the light on the projection lens 4710. In order to project the source light 4702 onto the screen through a position that is far away from the axis 47]1, it is necessary to increase the diameter of the projection lens 4710. This results in an increase in the size of the optical system. Furthermore, since the center part of the projection lens is not used and is used in an offset state, the maximum brightness point of the projected image shifts from the center of the screen, resulting in an unbalanced brightness distribution and unnatural brightness unevenness. There are some drawbacks. Therefore, there has been a desire for a method that can display images with the best contrast by tilting the liquid crystal panel without increasing the size of optical system components.

(Example) FIG. 24 shows an example of the present invention. 4701 is a liquid crystal panel, 4702 is a light source, 4720 is a liquid crystal, and a light refraction means (hereinafter referred to as a prism) installed on the exit side of the panel.
4703 is the incident angle of the light source, 47°22 is the prism 47
20 is the refracted light of the light source light 4702, 4711 is the normal line to the display surface of the liquid crystal, and 4714 is the optical axis of the light source.

Light source light 4702 incident on the liquid crystal panel 47 inches is refracted by a prism 4720 and reaches the viewer. Here, when the incident angle 4703 is equal to the tilt angle, the refracted light 47
The prism 4720 is set so that the prism 22 is parallel to the normal line of the display surface of the liquid crystal panel 47 inches. This makes it possible to obtain an image with the best contrast ratio when observed from the normal direction of the display surface of the liquid crystal panel 4701.

FIG. 25 shows an optical system when the means of the present invention is used in a projection type liquid crystal display device. Prism 4 which is the light refracting means
By using 720, the projection lens 4710 can be placed on the normal line 4711 of the 47-inch liquid crystal display panel, so the projection lens can be the same size as the conventional one, making it possible to downsize the optical system. can. Furthermore, since the center of the projection lens can be used, the maximum brightness point of the projected image is located at the center of the screen, resulting in a well-balanced brightness distribution.

FIGS. 26 and 27 show other embodiments of the light refracting means according to the present invention. The liquid crystal panel 4701 is usually configured as an active matrix type in which a switch element such as a thin film transistor (TPT) is provided for each pixel, and is used as a light valve that controls light by its shutter effect. A prism 47 is placed on the output side of such a liquid crystal panel 47H.
20, the prism 4720 is placed at the 26th prism.
In the figure, a fine prism 4720 is formed correspondingly to each pixel column, and in FIG. 27, a fine prism 4720 is formed correspondingly to each pixel. Even in such a configuration, the effects described above can be achieved.

FIG. 28 shows an example of a three-panel projection type image display device using the tilt angle correction method of the present invention. The figure shows an example in which the optical arrangement shown in FIG. 8 is applied.

R, G, B liquid crystal panels 4002, 4003.400
A prism 4731 is provided on the output side of 4 with the light refracting means and 9.
, 4782°4733 are arranged. Here, as mentioned above, in order to use the liquid crystal panel as the maximum contrast point, the optical axis 47 of the projection lens 4005, 4008, 4007
11, the optical axis 4714 of the light source 4001 is tilted by the tilt angle 4703.

Then, the light that passes through the prisms 4731, 4732, and 4738 and the liquid crystal panel is transmitted through the projection lens 4005.
400B.

Accordingly, the liquid crystal panels 4002, 4003, and 4004 can be used with the best contrast without increasing the size of the projection lenses 4005, 4006, and 4007, and a good projected image can be obtained.

In this case, when light including multiple wavelengths is refracted, it is wavelength-resolved due to the difference in refractive index for each wavelength.

This is the tilt angle correction prism 4781, 473.
The same applies to 2°4733L, and if the image on the liquid crystal panel is wavelength-resolved and projected onto the screen, this is not preferable because it causes image deterioration. However, the above 3
In the plate projection type video device, prisms 4731, 4
Each wavelength range of the incident light to 732.4733 is selected and narrowed by dichroic mirrors 4301.4305.4306 L, and the wavelength decomposition due to the difference in refractive index for each wavelength described above can be ignored and there is no problem.

[Effects of the Example] With the liquid crystal display device proposed by our school, an image with the best contrast can be obtained without tilting the liquid crystal display panel, and the optical components in the projection type image display device do not become larger. . Moreover, since the center portion of the projection lens can be used, the maximum brightness point of the projected image is located at the center of the screen, and a well-balanced brightness distribution can be obtained.

[A8 Dimming Screen (Problem to be Solved by the Invention) In general, a rear projection type image display device needs to display a high-brightness image in consideration of use in a bright place.

To achieve this, the screen was made directional so that more light was transmitted when viewed from the front of the screen, thereby achieving high brightness. Therefore, when viewed from a certain angle, the brightness is lower than when viewed from the front, which is a so-called viewing angle characteristic. FIG. 12 shows a screen configuration using a conventional lenticular lens and Fresnel lens, and FIG. 29 shows the horizontal viewing angle characteristics of the conventional screen. The pitch of the lenticular lenses of the screen used in conventional video projectors is approximately 1 mm, and the horizontal viewing angle is ±70 at half-value angle (the angle at which the front brightness falls to 50%).
°There is. In particular, in the case of a projection type liquid crystal display device, moiré tends to occur due to the pitch relationship between the pixels of the liquid crystal panel and the lenticular lenses, so the pitch of the lenticular lenses needs to be fine pitched, for example, 0.4 mm. However, due to this fine pitch, L
, it becomes difficult to expand the horizontal viewing angle as in the past. This is because designing a lenticular lens becomes difficult as the definition becomes higher. As a result, the brightness at the front becomes large, but the brightness from an angle other than the front becomes small. L: Center brightness and viewing angle are not compatible. In particular, when displaying a 16:9 wide aspect image, there is a problem that the viewing angle must be widened because there is a high possibility that the image will be viewed from an angle.

(Example) FIG. 30 shows an example of the present invention. A light control glass 4 is placed in front of a transmission screen 4017 consisting of a lenticular lens and a Fresnel lens of the projection type liquid crystal display device 4000.
805 are placed in close contact with each other to vary the degree of light diffusion and transmittance.

FIG. 31 shows a configuration diagram of the light control glass 4805.

A polymer liquid crystal 4807 is sandwiched between two glass plates 4806 and a transparent electrode 4808 from the front and back, and the orientation distribution of the liquid crystal is electrically controlled by applying a voltage to the electrode 4808. When no voltage is applied from the AC voltage source 4809, the liquid crystal is oriented irregularly, so light passing through the transmissive screen 4017 is irregularly refracted and diffused. Next, as voltage is gradually applied by the voltage adjustment circuit 4810, the orientation distribution of the liquid crystal begins to align, and the transmissive screen 40]
The diffusion of light passing through 7 is reduced and the transmittance is increased. This allows the degree of light diffusion and light transmittance to be changed arbitrarily.
The viewing angle can be expanded. FIG. 32 shows the viewing angle characteristics when the degree of light diffusion is increased by using a light control glass.

Dimming reduces the gain of the screen, but it can also widen the viewing angle.

As another application example, FIG. 33 shows a method of automatically controlling the viewing angle characteristics of the screen according to the external environment. A light detection device is installed in a projection display device to detect the illuminance of external light and control the balance between screen gain and viewing angle. When the illuminance of outside light is low, the screen gain is lowered and the brightness is adjusted to widen the viewing angle. Conversely, when the illuminance of external light is high, the viewing angle is narrowed and the screen gain is adjusted to increase. In the figure, a light detection unit 4814 using a light sensor or the like is installed around the screen of the housing of the projection display device to detect the intensity of external light. The intensity of the detected light is determined by the dimming control unit 4815.
Here, a control voltage that changes according to the control algorithm described above is generated to control the voltage adjustment circuit 4810. A voltage adjustment circuit 4810 controls the voltage value of the AC voltage source and applies it to the electrode 4808 of the dimming glass screen. According to such a configuration, when the illuminance of external light is low, the applied voltage is lowered to increase the irregularity of the alignment distribution of the liquid crystal and scatter the light transmitted through the screen. Conversely, when the illuminance of external light is high, the applied voltage is increased to increase the regularity of the alignment distribution of the liquid crystal and increase the light transmittance of the screen. As described above, the light is adjusted to control the balance between the screen gain and viewing angle of the transmissive screen, and to set conditions for easy viewing.

Note that the terminal 4816 is connected to the user control unit 900 shown in FIG.
0 (described in detail later) is added, the user can cancel the automatic mode and make any settings manually.Also, in the above example, the case of liquid crystal was explained, but this Of course, it is not limited.

[Effects of the Embodiments] As described above, according to the present invention, by controlling the transmitted light of the rear projection display device, it is possible to control the viewing angle characteristics of the screen and expand the viewing angle. becomes. This allows many people to view the video. Enlarging the viewing angle is particularly effective when displaying a 16:9 wide aspect image. In addition, by adjusting the light according to the intensity of external lighting, it is possible to select the screen gain and viewing angle that adapt to changes in the environment, allowing you to select conditions for easier viewing.

Furthermore, other embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 34 shows the overall configuration of the system for explaining this embodiment. First, a brief overview will be given. That is, FIG. 34 is a sectional view of a projection type liquid crystal display device according to the present invention.
consists of the following as its main components:

50 inches is a liquid crystal projector main body, and the light from this liquid crystal projector main body is refracted twice through a first mirror 5002 and a second mirror 5003, and a wide screen transmissive screen 5004 with an aspect ratio of 16:9 is formed. Enlarge and project the image. screen 5
004 is attached to a movable screen housing part 5005 as a first movable means so that it can be moved back and forth.Also, as shown in FIG. It is attached to the rotating screen housing part 5050 as a movable means, so that it can also be projected onto a second large screen.

FIG. 35 shows a configuration example of a liquid crystal projector main body 5001.

5010 is a light source consisting of a lamp 5011 and a reflector 5012. The white light emitted by the lamp 5011 is
The light is collected by a reflector 5012 and output as substantially parallel high-intensity light. This reflector 5012 has an aperture, an ellipsoid, or a polygon shape in consideration of the aspect ratio of 16:9 of the liquid crystal panel that is the irradiation target, and is designed to improve the light utilization efficiency. The emitted light is a total reflection mirror 5013
The heat rays are removed by a heat shielding filter 5014, and only visible light enters a red reflective dichroic mirror 5015. The red light is separated by a red reflection dichroic mirror 5015 and enters the R-axis liquid crystal panel 5021 via a total reflection mirror 5016.

On the other hand, the light transmitted through the red reflective dichroic mirror 5015 enters the blue reflective dichroic mirror 5018,
Here, the blue light is separated and enters the B-axis circumferential liquid crystal panel 5022. The remaining green light that has passed through the blue reflective dichroic mirror 5018 is incident on the G-axis angle liquid crystal panel 5023. The three primary color lights obtained by such a color separation means are modulated by a video signal in a corresponding liquid crystal panel.

R-axis liquid crystal panel 5021 and B-axis liquid crystal panel 5022
The light transmitted through the red-transmitting dichroic mirror 5017
The light transmitted through the G-axis angle liquid crystal panel 5023 is combined with the R1B light by a green reflection dichroic mirror 5020 via a total reflection mirror 5019. This combined light is enlarged and projected onto the screen 5004 by the projection lens 5024. The projection lens 5024 has an electric zoom function and an electric focus function under the control of a projection lens drive circuit 5030, and a control signal from the user control unit 6 is sent to the terminal 5029 in accordance with the movement of the screen 5004.
In addition, L, screen size, and focus can be adjusted.

Various drive signals 1 for driving the liquid crystal panel are sent to a terminal 502.
It is input from 7. The drive signal is horizontal clock pulse CP
, , Vertical clock pulse CPv, horizontal start pulse ST, , Vertical start pulse ST v and R, G, B
The primary color signals are L, and these signals are sent to the video decoder 680.
Supplied from 0.

The outline of the basic configuration of this embodiment has been described above, and further detailed embodiments of each part will be described below.

Here, each part will be explained in the following order.

(1) FIGS. 36 to 41 are explanations regarding [B1] multi-screen compatible liquid crystal panel configuration.

(2) FIGS. 42 to 48 are explanations regarding the structure of [B2] wide screen compatible reflector.

(3) FIG. 49 is a description of the configuration of the [B3] first screen movable mechanism means.

(4) From FIG. 50 to FIG. 51, [B4] Explanation regarding the configuration of the second screen movable mechanism means.

[B]] Multi-screen compatible liquid crystal panel (invention or problem to be solved) Conventionally, there was a way to realize a large screen by using multiple projection display devices of about 408' to 60' for various exhibitions. . FIG. 36 is an example of a combination of two projection display devices vertically and two horizontally. The projection display device may be a CRT type or a liquid crystal type. Here, the case of the liquid crystal type will be described. In this way, to display one image on four display devices, the original
Converting one video signal into four parts and terminals 5109 to 51.
Enter 12. For this purpose, a complicated signal conversion device as shown in FIG. 537 is required. In the figure, terminal 5115
The input video signal is separated into a luminance signal Y and a color signal by a video chroma processing circuit 5116. These signals are A
After digital conversion by D converters 5117 and 511g, data is input to field memories 5119 to 5122 and data corresponding to the 4 VI areas of upper left, upper right, lower left, and lower right are read out at 4 times the writing speed, and 4 The signal is supplied to DA converters 5123 to 5123 corresponding to the divided areas.

The luminance signal and color signal converted into analog signals are outputted as a composite video signal by video chroma modulation circuits 5131 to 5134. A conversion device having such a configuration uses a field memory, etc., and is therefore complicated and expensive.

(Embodiment) FIG. 38 shows an embodiment of the multi-screen configuration of the present invention. For the sake of simplicity, an example of a multi-screen display when a total of four screens, two vertically and two horizontally, are used will be described. Further, the projection device is a projection type liquid crystal display device using liquid crystal.

In the figure, only one system of drive signals applied to the terminal 51o9 is required. The input drive signal is a projection type liquid crystal display device (projector) 5101,5]02゜5103.
5104 in parallel to the main body, and the image is sent to screen 5.
105.5108.5107 and 51.08, respectively. In this case, the signal cable 5 is connected between each projection device main body.
By connecting through 140.5141.5142, multi-image display can be performed without using a signal conversion device as in the past.

Although the projection type liquid crystal display device has a configuration as shown in FIG. 35 described above, the electrical connections and operations of the four projection type liquid crystal display devices will now be explained using FIG. 39. 502]-
1 to 502]-4 is a liquid crystal module (panel) L,
In this case, for example, the R-axis circumferential panel in FIG. 35 is used. Since it is actually a three primary color display (color display), there are three systems of the configuration shown in FIG. 5150.5+51.5
Reference numeral 152.5153 denotes a liquid crystal cell substrate L, with electrodes arranged vertically and horizontally in a matrix, and each intersection serving as a display pixel. 5154, 5155, 5156, and 5157 are signal line drive circuits that drive the vertical signal lines, so-called X drivers, which sample the L and R video signals and hold them for one horizontal scanning period, and drive the vertical signal lines of the liquid crystal cell. Output to electrode.

5158.5159.5] [io, 51BI is a scanning line driving device that drives horizontal scanning lines, so-called X driver L, which applies write pulses to horizontal scanning electrodes of liquid crystal cells in synchronization with horizontal scanning of signals. Output. 51B2,51
83°5184.5165 is a liquid crystal module controller that outputs the timing signals necessary for the L and X drivers and the X driver. This controller receives the aforementioned horizontal clock pulses cp, . . . , vertical clock pulses cpv as various drive signals from an input terminal 5028.

Horizontal start pulse ST, , vertical start pulse ST
v and the primary color signal (R) are input.

Next, the configuration and operation of the liquid crystal cell, the X driver, and the X driver will be explained using FIGS. 40 and 41. Reference numeral 5150 denotes a liquid crystal cell L, in which electrodes are provided in a matrix shape vertically and horizontally, and a liquid crystal pixel 5 is provided at each intersection.
179, thin film transistor (TPT) 5177,
An additional capacitor 5178 is connected.

Therefore, when a signal level to be written to each pixel is output to the vertical signal line, if a write pulse is output to the horizontal scanning line, the TPT in that one horizontal column turns on.
The liquid crystal pixels and the additional capacitance are charged with the pixel size, and the display of that column is performed. By repeating this operation in order from the top, one screen's worth of display is completed.

5154 is an X driver (L), 5170 is a shift register (L), and when the horizontal start pulse STH is first input, an on signal is output from the left end, and the shift clock C
Each time K is input, it shifts one step to the right. When the right shift is completed for the number of horizontal pixels, a carry-out CO signal is output.

5171 is a level converter and shift register 5
Shift the TTL level signal from 1.70 to a level suitable for driving the liquid crystal.

5172 is a sample and hold circuit that converts the L and input R signals to the sampling timing from the shift register.
The pulses are used to sequentially sample from the left during one horizontal scanning period, and the level is held. To explain in more detail using FIG. 41, 5180 is a switch circuit which opens in response to an on signal from a shift register and stores the signal potential of the R line in a storage capacitor 5181.

5173 is a buffer driver L, output instruction signal O
The pixel signal held for one line by E is output to the signal line of the liquid crystal cell. The inside is composed of an amplifier 5182 as shown in the figure.

Returning to FIG. 40, L and 5174 are the shift registers of the X driver.While the gate width data D input at the start of display is high, continue inputting /%A, and shift input at the timing of horizontal scanning. The clock shifts down one step at a time. 5175 is a level shifter L, 517
B is a buffer driver that drives the scanning line of the liquid crystal cell. If the scanning width data D is kept high for two shift periods, the scanning lines will continue to be turned on two lines at a time thereafter.

Returning to FIG. 39 again for further explanation, the input signals bO, bl of the controllers 5162-5165.

b2. b3 is a terminal for instructing the screen magnification mode; L;
For example, if all 0 indicates normal display without enlargement, and if b1 = 1 and all other 0 indicates enlargement of 2 times vertically and horizontally, then the shift clock CK for sampling timing output to the X driver will be multiplied by 78-2. output the scanning width data D for 2 lines, and output the Y driver shift clock C during horizontal blanking.
If K is output twice, the upper left portion of the original video signal will be displayed in a state in which it is enlarged twice both horizontally and vertically.

When sampling reaches the center of the video signal, a carry-out signal CO is output from the X driver 5154, giving an instruction to the controller 5163 to start operation. Therefore, the X driver 5155 begins sampling the R signal at twice the speed, and displays the upper right portion of the image.

When the image is displayed up to the top and bottom center of the screen, a carry-out signal c is sent from Y drivers 5158 and 5159.

is output to controllers 5184 and 5185, and the LCD in the lower half of the screen starts operating.

The lower half of the screen operates in the same way, displaying the original video signal on four screens.

Furthermore, the case where the images are stacked in three vertically and horizontally three layers or more is also possible using the screen enlargement ratio mode bO-b3.

Further, in this embodiment, although the case of the projection type display bag holder has been explained, it is possible to use a direct view type display device as well.

[Effects of the Example] As described above, if the liquid crystal module configuration is adopted as in this example, while maintaining the normal single screen display function,
Multi-screens of a liquid crystal display device can be realized at low cost with a simple configuration without using an expensive multi-screen division conversion circuit, large-screen display is easily possible, and multipurpose usability is greatly improved. Further, even if the projection type liquid crystal display device form of the present invention as shown in FIG. 50 is used, a multi-screen can be easily configured.
It can respond to various market needs in a variety of ways.

[B2 High Condensing Rate Reflector (Problem to be Solved by the Invention) In a conventional projection type liquid crystal display device, the aperture surface of the reflector 5012 shown in FIG. 35 is circular, and the liquid crystal panel 5021. ．． Since the aspect ratio of 5(122 and 5023) is rectangular, a part of the light collected from the reflector 5012 was not irradiated onto the liquid crystal panel, but was irradiated onto the surrounding area and turned into heat.

For example, in Figure 42, the shape of the liquid crystal panel corresponds to the aspect ratio of wide-screen HDTV or high-definition television.
6 rectangles 5200 L, reflector 5012
When the irradiation surface of the emitted light is its circumscribed circle 5201, the area ratio of the rectangle 5200 to the circumscribed circle 5201 is 5.
It is 4.41%. This is LCD panel 5021.502
2.5023 indicates the utilization rate of light incident on L,
This improvement has been sought as an effective means for increasing the brightness and efficiency of projection display devices.

(Example) FIG. 43 shows the shape of a reflector of the present invention, and FIG. 44 shows the relationship between its opening surface and the shape of a liquid crystal panel. 44th
In the figure, 5201 is an aperture surface of a reflector according to the present invention, and 5200 is a liquid crystal panel display surface with an aspect ratio of 16:9. The aperture surface 5201 has an elliptical shape L circumscribing the display surface of the liquid crystal panel 5200, and the ratio of the major axis bb' to the minor axis aa' is set to the aspect ratio of the liquid crystal panel. In this case, the area ratio between the liquid crystal panel display surface 5200 and the opening surface of the reflector 52 inches is 63.7%.
, the light utilization rate is improved to 54.41% in FIG.

Next, as another example, a reflector having a shape in which all cross sections including the optical axis are paraboloids L and the focus of each paraboloid is not located at a fixed position will be described.

In the reflector with an elliptical opening shown in FIG. 43, FIG. 524 shows a cross section along the short axis aa', and FIG. 525 shows a cross section along the long axis bb'. 5011 is a high brightness white light emitting lamp such as a metal halide lamp, L, 50
12 is a reflector 25202, 5203 is a lamp 50
There are 11 discharge electrodes L, and this interval is called the arc length. h
-h' is the optical axis of the light source consisting of the lamp 5o11 and the reflector -5012. Each cross section including the optical axis h-h' of the elliptical reflector 5012 is represented by a parabola, and the 46th
The focus of the parabola in the cross section of the figure is f1, and the focus of the cross section in FIG. 525 is f2.

At this time, the foci of all other parabolas are f1~f
It will exist between the two.

Here, when the aperture surface is a perfect circle, the focus of the parabola of each cross section is constant L, and if the lamp 5011 is an ideal point light source, when the point light source is made to coincide with the focus, the light is focused by the reflector. The light becomes ideal parallel light. However, as shown in FIG. 46, since actual lamps including metal halide lamps have a finite arc length, it is not necessary to focus each parabola on one point. Rather, if the focal points are dispersed appropriately between the discharge electrodes, unevenness in the density distribution of the condensed light beam tends to be less likely to occur. Therefore, by continuously changing the shape of each parabola while placing the focus of each parabola between the two discharge electrodes 5202 and 5203, the shape of the aperture surface can be set to a shape other than a perfect circle.

Furthermore, in an elliptical reflector, the focal point fl.

By placing f2 between the discharge electrodes 5202.52013, the focal point of the parabola of all cross sections constituting the reflector exists between the discharge electrodes 52025203, and the focal point f
By matching 1 and f2 with the discharge electrodes 5202 and 5203, the aperture ratio can be improved.

Here, in FIG. 48, a parabola 5204 represents a cross section including the optical axis of the reflector. When the focal point is f, the relationship between X+Y is y-±2J'7...(1) L is L, this is L, and the length n of the aperture surface is when the distance from the vertex is m. It becomes n-45・(2).

In FIGS. 46 and 47, focus f1. ．． When f2 and the discharge electrodes 5202 and 5203 are aligned, the focus f
1, f2 focal length m1, m2, discharge electrode 5202.
5203 spacing is 6, and the distance from the reflector aperture surface to the vertex of the parabola is L, the shape of the aperture surface is the long axis b-b
' is 4×νrY1 "〒3koL)-1 minor axis is 4X (m
2×L).

Furthermore, as a means for efficiently irradiating light to the display section of a liquid crystal panel, it is also possible to use an aperture surface as shown in FIG. 45 or a polygon whose cross section including the optical axis forms a parabola. The figure shows an example in which the aspect ratio is set to 16:9, which is the same as the liquid crystal panel. In this case, as described above, it cannot be set so that all the focal points of the parabolas in each cross section are located within the discharge electrodes 5202 and 5203 of the lamp. Toe L, focus f1, f2
The larger the distance between L, the longer the arc length that matches this L.
, which is not practical in making lamps. However, even if the focal points f1 and f2 are slightly deviated from the discharge electrodes, the unevenness of the illuminance distribution of the focused light will only increase slightly, and almost all the light from the light source will be able to enter the liquid crystal panel, resulting in a significant improvement in the utilization rate. do.

Incidentally, in the above embodiment, the case of liquid crystal was explained, but it is needless to say that the present invention is not limited to this.

[Effects of Examples] As described above, according to the reflector of the present invention, it is possible to effectively irradiate the panel with light from the lamp, thereby reducing the brightness of a projection display device with a wide aspect screen. and efficiency can be improved.

[B3] First screen movable means (problem to be solved by the invention) In a conventional three-lens rear projection display device using a CRT or liquid crystal panel, a function is provided to enlarge the screen L and reduce the screen. This required a large-scale and expensive signal processing circuit, and although it was possible to enlarge the screen area, it was impossible to increase the screen size itself. In order to construct a rear projection display device with such functions at low cost, the first method is to adopt a Luns type projection optical system and provide a movable mechanism that moves the screen parallel to the optical axis. If it can be enlarged and reduced in size, it can be installed in a thin state when not in use, making the set smaller and improving portability. Further, as a second means, a lens type is adopted as the projection optical system, and the screen part is provided with a mechanism that can rotate and open in the vertical direction using a part of the set main body as a fulcrum.

With such a configuration, it is possible to provide a separate screen and project on a large screen. It is possible to realize a display system that can be used in many ways, making it possible to significantly change the screen size (enlarge the screen), which was not possible with conventional rear projection display devices.

(Example) An embodiment of the first means will be described in detail based on the drawings.

A structural diagram of this embodiment is shown in FIG. 34.

In this structural diagram, a Luns type liquid crystal projector main body 5001
The projected image light emitted from the projection liquid crystal display device 50 is reflected by the first mirror 5002 and the second mirror 5003.
00 and is enlarged and projected onto a transmission screen 5004 attached to a movable screen housing section 5005 that is movable parallel to the optical axis of the projected image light. By pulling out the movable screen housing section 5005 to the front, the projection distance from the projection lens to the transmissive screen 5004 is increased, and the screen size is increased. and,
A control signal from the user control unit 9000 in FIG. 52 to adjust the focus at the user's desired screen size,
As shown in FIG. 35, the control signal is input to a control signal input terminal 5029 and is applied to a projection lens drive circuit 5030 to control the focus of the projection lens 5024 and the zoom of the screen.

Therefore, when increasing the screen size, the movable screen housing section 5005 is pulled out and the user control section 710
Focus by inputting 0.

In addition, when reducing the screen size, the user control unit 7]
00 to set the zoom position of the projection lens and 87 = orcus. In addition, it is also possible to use the zoom function to make the display smaller than the screen size of the transmissive screen 5004. If you use this type of display, you can obtain a bright screen even though the screen size is small, and also reduce the size of the pixels of the liquid crystal panel. It is possible to display high-quality images with no noticeable roughness.

Incidentally, in the above embodiment, the case of liquid crystal was explained, but it is needless to say that the present invention is not limited to this.

[Effects of the Embodiment] According to the above configuration, it can be installed in a thin state when not in use, so it does not become a hindrance. Moreover, the set shape can be made smaller and portability is improved. Furthermore, it has the advantage that the screen can be enlarged or reduced by moving the screen.

[B4] Second screen movable means (Example) An embodiment of the second means will be described in detail based on the drawings.

A structural diagram of this embodiment is shown in FIG. 50.

In this structural diagram, a Luns type liquid crystal projector main body 5001
The projected image light emitted from the is reflected by a first mirror 5002 and a second mirror 5003 and is expanded to a transmission screen 5Ω04 attached to a retractable screen housing part 5050 that rotates using a part of the main body as a fulcrum. Projected.

When using a large screen for projection, rotate the retractable screen housing section 5050 to open the second screen 5051.
can be projected on.

As the second screen 5051, a reflective screen is used for front projection, and a transmissive screen is used for rear projection. By setting the position of the second screen 5051, it is possible to enlarge the screen simply by adjusting the focus of the projection lens and the screen size using a control signal from the user control unit 7100 shown in FIG.

With this configuration, it is possible to significantly increase the screen size, which was not possible with conventional rear projection display devices.
, when not in use, it can be installed in a thin state. Additionally, multiple units can be arranged vertically and horizontally to support a multi-screen configuration.

In the above embodiments, the case of liquid crystal has been described, but it is needless to say that the present invention is not limited to this.

[Effects of the embodiment] According to the above configuration, it can normally be used as a rear projection type, and by opening the screen part, the L
, it is possible to project onto another type of large screen, making it possible to significantly change the screen size (enlarge the screen). or,
It is also possible to arrange multiple units vertically and horizontally to create a multi-configuration.
, it is possible to create a display system that can be used for multiple purposes, such as an event hall where a large number of people can enjoy powerful images at the same time.

Below, the video decoder 6800 and the user control unit 71
00 will be explained.

FIG. 52 is an overall block diagram of the receiving section in one embodiment of the present invention. A radio frequency (RF) signal from an antenna is introduced into the input terminal 6100 and supplied to the RF input processing section 6300. The audio signal obtained by the RF manual processing section 6300 is supplied to the selector 6400. This selector 6400 can also select an external audio signal. The output audio signal from the selector 6400 is
The audio signal is amplified by the audio amplifier B500 and supplied to the speaker 6600. The video signal obtained from RF input processing section 6300 is input to selector 8700. selector 67
00 can also select an external video signal.

The video signal selected by the selector 6700 is input again to the RF input processing section 6300 where it undergoes received signal correction (for example, ghost cancellation processing), and is input to the video decoder 6800 and the synchronization control section 6900. Video decoder 68
00 indicates the input video signal method (intermediate method, current method)
Then, processing according to the control by the user is performed, and the input video signal is decoded. The R, G, B signals, synchronization signals, brightness correction signals, etc. obtained as a result of decoding are sent to the display 7000.
supplied to

The synchronization control unit 6900 uses a control signal included in the video signal to generate a predetermined synchronization signal and an identification signal indicating the format and type of the video signal. Synchronization signal is video decoder 6800
The signal is input to and used for decoding the video signal.

The user control unit 7100 controls the operating modes of the system according to user operations, and includes a selector 91
= [The signals selected at 1400 and 6700 can be switched. Further, in response to an identification signal indicating the type of video signal from the synchronization control unit 6900 and an identification signal indicating the type of audio signal from the RF input processing unit, L and an indicator provide a processing mode switching signal to the video decoder 6800. 6
200, the video and audio modes are displayed.

Further, when the user performs an operation to select an external input other than an RF signal, the user control unit 7100 sends a signal to control the video ghost canceller of the RF input processing unit 8300 to a through state.

[Brief explanation of the drawing]

FIG. 1 is a basic configuration diagram of a first projection type liquid crystal display device of the present invention, FIG. 2 is a sectional view of a conventional projection type liquid crystal display device, and FIG.
The figure shows the configuration of a conventional optical system. Figure 4 shows the brightness unevenness characteristics of the conventional optical system. Figure 5 shows the optical system configuration of the projection type liquid crystal display device of the present invention. Figure 6 shows the projection type liquid crystal display of the present invention. FIG. 7 is a diagram showing the configuration of another optical system of the projection type liquid crystal display device of the present invention, and FIG. 8 is a diagram showing the configuration of another optical system of the projection type liquid crystal display device of the present invention. , FIG. 9 is a diagram showing a modified configuration of another optical system of the projection type liquid crystal display device of the present invention, FIG. 10 is a light amount ratio characteristic of a conventional projection lens, and FIG. 11 is a light distribution characteristic of a conventional condensing system. Fig. 12 is an explanatory diagram of the structure, principle, and light amount ratio of a conventional screen, Fig. 13 is a diagram of the principle and characteristics of color shift generation, Fig. 14 is a diagram of the optical system configuration of the present invention, and Fig. 15 is a diagram of the present invention. A light distribution characteristic diagram of the condensing system after implementation, FIG. 16 is a diagram showing another embodiment of the optical system configuration diagram of the present invention, FIG. 17 is a diagram of the drive circuit configuration diagram of the brightness correction liquid crystal panel of the present invention, Figure 18 is a conventional liquid crystal panel configuration diagram, Figure 19
20 is a diagram showing another embodiment of the liquid crystal panel configuration of the present invention, FIG. 21 is a viewing angle characteristic diagram of the liquid crystal panel, and FIG. FIG. 23 is an explanatory diagram of the optical system of a projection type liquid crystal display device, FIG. 24 is a diagram showing a negative tilt correction means of the present invention, and FIG. 25 is a diagram showing a projection type to which tilt color correction of the present invention is applied. An explanatory diagram of the optical system of a liquid crystal display device, FIG. 26 is a diagram showing another embodiment of the negative tilt correction means of the present invention, and FIG. 27 is a diagram showing another embodiment of the negative tilt correction means of the present invention. figure,
Fig. 28 is a diagram showing an embodiment of a projection type liquid crystal display device to which tilt color correction of the present invention is applied, Fig. 29 is a conventional screen viewing angle characteristic diagram, Fig. 30 is a screen configuration diagram of the present invention, and Fig. 31 32 is a diagram showing the configuration of a dimming screen, FIG. 32 is a view angle characteristic of the screen configuration according to the present invention, FIG. 33 is a diagram showing a configuration diagram of automatic screen viewing angle control according to the present invention, and FIG. 34 is a diagram showing the second projection type liquid crystal display according to the present invention. A basic configuration diagram of the display device, FIG. 35 is a basic configuration diagram of the liquid crystal projector main body, FIG. 36 shows an example of multi-screen display using a conventional projection type liquid crystal display device, and FIG. 37 shows conventional multi-screen signal conversion. 38 is a diagram showing an example of a multi-screen display by the projection type liquid crystal display device of the present invention; FIG. 39 is a diagram showing an example of multi-display driving of the projection type liquid crystal display device of the present invention. , FIG. 40 is a diagram showing a configuration example of a liquid crystal module of a projection type liquid crystal display device of the present invention, FIG. 41 is a configuration diagram of an X driver of a liquid crystal module of a projection type liquid crystal display device of the present invention, and FIG. An explanatory diagram of the utilization rate, FIG. 43 is a first configuration diagram of a reflector of a projection type to 94- liquid crystal display device of the present invention, and FIG. 44 is a diagram explaining the action of a reflector of a projection type liquid crystal display device of the present invention. , FIG. 45 is a second configuration diagram of the reflector of the projection type liquid crystal display device of the present invention, FIG. 46 is a short-axis sectional view of the reflector of the projection type liquid crystal display device of the present invention, and FIG. 47 is a second configuration diagram of the reflector of the projection type liquid crystal display device of the present invention. FIG. 48 is a long sleeve sectional view of a reflector of a liquid crystal display device, FIG. 48 is an X+Y coordinate diagram of a cross-sectional parabola of a reflector of a projection type liquid crystal display device of the present invention, and FIG. 49 is a first screen means of a projection type liquid crystal display device of the present invention. 5. Detailed mechanical diagram of the moving parts; FIG. 50 is a side view of the second screen movable means of the projection type liquid crystal display device of the present invention; FIG. 51 is a diagram of the second screen movable portion of the projection type liquid crystal display device of the present invention. Detailed mechanical diagram, FIG. 52 is an overall block diagram of the receiving section in an embodiment of the present invention. 4000...Projection type liquid crystal display device, 4001...Light source, 4002-4004...Liquid crystal panel, 4005-
4007...Projection lens, 4008-4010...
Dichroic mirror, 4011. ．． 4012゜401
4.4015・Total reflection mirror, 4013...Heatproof filter, 4016...Projection type screen, transmission type screen, 4017...Liquid crystal dimming screen, 4100
...Reflector-14101...Lamp, 4102
~4104...Cooling layer, 4112~4114...Brightness correction liquid crystal panel, 4200...Dichroic prism, 40021...X driver, 40022...X driver, 45001...PLL VCo, 4500
2゜45003...1/32 frequency division, 45004...
V address generation counter, 45005...H address generation counter, 4500B...ROM, 45007
...V counter, 45008...H counter, 45
009...Pulse modulation, 4 days 21...X driver, 4
1122...X driver, 51.70.5174...
・・Shift register, 51.71・・Level converter, 5172・・Sample hold circuit, 5175・Comparator, 5173.5176・・Buffer driver, 6100・・Input terminal, 6200・・・Indicator, 6300・・・RF input processing unit, [1400,870
0...Selector, 6500...Audio amplifier, 6600...
...Speaker, 6800...Video decoder, 6900
...Synchronization control unit, 7000...Display, 7100
...User control section. Applicant's representative Patent attorney Takehiko Suzue Figure (a.
Mouth (1 piece Children's baboon group crest standing Peiko Fig. 11 - Consideration counterfeit 1hi (digital doo H 乍 - (a) 12th: 12th b (c) 1 and ≦ Nu i multiple (b) Mouth 320 Kazushimitsu Screen 9-Kun City Oto 33 Figure 45r5 Figure 47 Figure 46 Koshirae 48 Figure 5404=

Claims (29)

[Claims] (1) A single light source that emits white light including three primary color lights,
color separation means for separating incident light from the light source into three primary color lights; and three color separation means arranged corresponding to the three primary color lights from the color separation means.
In a rear projection type liquid crystal display device comprising one liquid crystal panel and three projection lenses for enlarging and projecting the light emitted from the liquid crystal panel onto a transmission screen, the color separation means includes first, second, and third color separation means. comprising a dichroic mirror and first and second mirrors, the first mirror being arranged so that light is incident on the first liquid crystal panel in the traveling direction of the light reflected by the first dichroic mirror; The second mirror is arranged so that light is incident on the second liquid crystal panel in the traveling direction of the light reflected by the second dichroic mirror, and the third dichroic mirror is arranged so that the light transmitted by the second dichroic mirror is incident on the second liquid crystal panel. The third liquid crystal panel is arranged such that light enters the third liquid crystal panel in the traveling direction of the third liquid crystal panel, and the optical axis center distance from the first dichroic mirror to the second mirror is The optical axis center distance from the second dichroic mirror to the second mirror is equal, and the optical axis center distance from the second dichroic mirror to the second mirror is equal to the optical axis center distance from the second dichroic mirror to the second mirror. A projection type liquid crystal display device, characterized in that the optical arrangement is made such that the optical axis center distances to the third dichroic mirror are equal, and the optical path lengths from the light source to the three liquid crystal panels are equal. (2) a single light source that emits white light including three primary colors;
color separation means for separating incident light from the light source into three primary color lights; and three color separation means arranged corresponding to the three primary color lights from the color separation means.
In a rear projection type liquid crystal display device comprising one liquid crystal panel and three projection lenses for enlarging and projecting the light emitted from the liquid crystal panel onto a transmission screen, the color separation means includes a dichroic prism and a first and a second lens.
, a third mirror, the three liquid crystal panels and the projection lens are arranged in a delta shape, and the first mirror faces the first liquid crystal panel in the traveling direction of the first reflected light by the dichroic prism. the second mirror is arranged so that light enters the second liquid crystal panel in the traveling direction of the light transmitted through the dichroic prism, and the third mirror The optical arrangement is arranged such that light is incident on the third liquid crystal panel in the traveling direction of the second reflected light from the prism, and the optical axis center distances from the dichroic prism to the three liquid crystal panels are equal to each other. A projection type liquid crystal display device, characterized in that optical path lengths from the light source to the three liquid crystal panels are equal. (3) The projection type liquid crystal display device according to claim 2, wherein a dichroic cross mirror is used in place of the dichroic prism. (4) a single light source that emits white light including three primary colors;
color separation means for separating incident light from the light source into three primary color lights; and three color separation means arranged corresponding to the three primary color lights from the color separation means.
In a rear projection type liquid crystal display device comprising two liquid crystal panels and three projection lenses that magnify and project light emitted from the liquid crystal panels onto a transmissive screen, the three liquid crystal panels and three projection lenses are arranged at equal intervals. and the color separation means is arranged in a polarizing beam splitter and a polarizing beam splitter.
It includes a four-wavelength compensator, a 45-degree polarization conversion liquid crystal panel, a mirror, and first, second, and third dichroic mirrors, and the first dichroic mirror is arranged in the traveling direction of the reflected light of the polarizing beam splitter.
a dichroic mirror, and the quarter wavelength compensator, the 45-degree polarization conversion liquid crystal panel, and the mirror are arranged in the traveling direction of the transmitted light of the first dichroic mirror; The traveling direction of the reflected light from the first dichroic mirror is arranged so that it passes through a 1/4 wavelength compensator, a 45-degree polarization conversion liquid crystal panel, and a polarizing beam splitter, and returns to the first liquid crystal panel, and is incident on the first liquid crystal panel. The second dichroic mirror is arranged so that light enters the second liquid crystal panel, and the third dichroic mirror is arranged so that light enters the third liquid crystal panel in the traveling direction of the transmitted light of the polarizing beam splitter. from the polarizing beam splitter to the first polarizing beam splitter.
The optical arrangement is such that the optical axis center distance from the first dichroic mirror to the first dichroic mirror and the optical axis center distance from the first dichroic mirror to the mirror are equal to 1/2 of the projection lens arrangement interval. A projection type liquid crystal display device characterized in that the optical path lengths to three liquid crystal panels are made equal. (5) The projection type liquid crystal display device according to claim 4, characterized in that a λ/4 wavelength plate is used in place of the 1/4 wavelength compensating plate and the 45 degree polarization conversion liquid crystal panel. (6) a single light source that emits white light including three primary colors;
color separation means for separating incident light from the light source into three primary color lights; and three color separation means arranged corresponding to the three primary color lights from the color separation means.
In a rear projection type liquid crystal display device comprising two liquid crystal panels and three projection lenses that magnify and project the light emitted from the liquid crystal panel onto a transmissive screen, the display center of the liquid crystal panel and the optical axis center of the light source A projection type liquid crystal display device characterized in that the optical arrangement is such that the two do not match. (7) a single light source that emits white light including three primary colors;
color separation means for separating incident light from the light source into three primary color lights; and three color separation means arranged corresponding to the three primary color lights from the color separation means.
A projection type liquid crystal display device comprising one liquid crystal panel and three projection lenses for enlarging and projecting the light emitted from the liquid crystal panel onto a transmissive screen, comprising a brightness correction liquid crystal panel on the incident light side of the liquid crystal panel. A projection type liquid crystal display device characterized by: (8) Claim 7, characterized in that the brightness correction liquid crystal panel is constituted by a simple matrix type liquid crystal panel.
Projection type liquid crystal display device as described in . (9) a single light source that emits white light including three primary colors;
color separation means for separating incident light from the light source into three primary color lights; and three color separation means arranged corresponding to the three primary color lights from the color separation means.
A projection type liquid crystal display device comprising two liquid crystal panels and a projection lens for enlarging and projecting light emitted from the liquid crystal panel onto a screen, the liquid crystal panel comprising a first glass substrate on which a thin film transistor is formed, and a first glass substrate on which a thin film transistor is formed; A structure in which a liquid crystal material is sandwiched between a glass substrate and a second glass substrate on which a light shielding structure is formed facing the glass substrate, the first glass substrate being on the output light side, and the second glass substrate having a light shielding structure formed thereon. A projection type liquid crystal display device, characterized in that a second glass substrate is disposed on the incident light side, and a second light shielding structure is formed on a surface of the second glass substrate on the incident light side. (10) The projection type liquid crystal display device according to claim 9, wherein the second light shielding structure forming surface is in contact with a cooling liquid. (11) The projection type liquid crystal display device according to claim 9, wherein the second light shielding structure is made of a material with high light reflectance. (12) A single light source that emits white light including three primary color lights, a color separation means for separating incident light from the light source into three primary color lights, and a color separation means corresponding to the three primary color lights from the color separation means. In a projection type liquid crystal display device comprising three arranged liquid crystal panels and a projection lens that enlarges and projects the light emitted from the liquid crystal panels onto a screen, the liquid crystal panel is provided with a light refracting means on a side surface of the emitted light. A projection type liquid crystal display device characterized by: (13) The projection type liquid crystal display device according to claim 12, wherein the light refraction means are arranged in correspondence to each display pixel row of the liquid crystal panel. (14) The first aspect of the invention is characterized in that the light refraction means are arranged correspondingly to each display pixel of the liquid crystal panel.
The projection type liquid crystal display device according to item 2. (15) A single light source that emits white light including three primary color lights, a color separation means for separating incident light from the light source into three primary color lights, and a color separation means corresponding to the three primary color lights from the color separation means. In a rear projection display device comprising three arranged panels and three projection lenses that magnify and project the light emitted from the panels onto a transmissive screen, the front surface of the transmissive screen can be arbitrarily illuminated by an applied voltage. 1. A projection display device comprising a dimming means capable of changing transmittance and light diffusivity. (16) The projection type display device according to claim 15, wherein the light control means is a light control glass having a structure in which a liquid crystal material is sandwiched therebetween. (17) The projection type display according to claim 15, comprising an external light detection means and a dimming control means, and controlling the dimming means by changing the applied voltage according to external light. Device. (18) A single light source that emits white light including three primary color lights, a color separation means that separates the incident light from the light source into the three primary color lights, and a color separation means that corresponds to the three primary color lights from the color separation means. three arranged liquid crystal panels, a color synthesis means for synthesizing the three primary color lights emitted from the liquid crystal panels, and a single projection lens for enlarging and projecting the emitted light from the color synthesis means onto a transmission screen; In the rear projection type liquid crystal display device comprising the transmissive screen, the liquid crystal panel has a matrix of electrodes in the vertical and horizontal directions, a signal line driving circuit that drives the vertical signal lines, and a scanning circuit that drives the horizontal scanning lines. a line drive circuit, the signal line drive circuit can be driven at several times the normal speed, and end signal output means indicating that writing to the edge of the screen has been completed;
and an operation start instruction means capable of controlling the start of driving, and the scanning line driving circuit is capable of driving to output scanning signals for several lines at a speed several times the normal speed, and when writing to the edge of the screen is completed. What is claimed is: 1. A projection type liquid crystal display device, comprising: a termination signal output means for indicating the start of driving; and an operation start instruction means capable of controlling the start of driving. (19) A single light source consisting of a discharge lamp that emits white light, a reflector that reflects and emits the emitted light, color separation means that separates the incident light from the light source into three primary color lights, and the color In a projection type display device comprising three panels arranged corresponding to the three primary color lights from the decomposition means, a projection lens for enlarging and projecting the emitted light from the panels onto a screen, and the screen, the reflector is A projection type display device characterized in that a cross section including the optical axis of the light source forms a parabola, and the focal point is not constant. (20) The projection display device according to claim 19, wherein the reflector has an elliptical aperture shape with the optical axis of the light source as the normal line. (21) The projection display device according to claim 19, wherein the reflector has a polygonal aperture shape with the optical axis of the light source being the normal line. (22) When the display area of the panel is rectangular, the shape of the aperture of the reflector is an ellipse having a ratio of a major axis to a minor axis equal to an aspect ratio of the rectangle. 21. The projection display device according to item 20. (23) The scope of the present invention is characterized in that when the aperture shape of the reflector is elliptical and the cross section including the optical axis of the light source forms a parabola, the focal point is located between the discharge electrodes of the discharge lamp. 21. The projection display device according to item 20. (24) The scope of the present invention is characterized in that when the shape of the aperture of the reflector is polygonal and the cross section including the optical axis of the light source forms a parabola, the focal point is located between the discharge electrodes of the discharge lamp. 22. The projection display device according to item 21. (25) When the shape of the aperture of the reflector is elliptical and the cross section including the optical axis of the light source forms a parabola, the distance between the aperture and the apex of the parabola is L, the arc length is δ, and the cross section including the optical axis of the light source is a parabola. The focal length of the parabola that intersects the long axis of the ellipse is m
1. When the focal length of the parabola that intersects the short axis is m2, δ=m1-m2, and the long axis is 4×√(m1×L),
24. The projection type display device according to claim 23, wherein the short axis is expressed by 4×√(m2×L). (26) A single light source that emits white light including three primary color lights, a color separation means that separates the incident light from the light source into the three primary color lights, and a color separation means that corresponds to the three primary color lights from the color separation means. three arranged panels, a color synthesis means for synthesizing the three primary color lights emitted from the panels, a single projection lens for enlarging and projecting the emitted light from the color synthesis means onto a transmissive screen, and What is claimed is: 1. A rear projection display device comprising a transparent screen and a rear projection display device, characterized in that the casing portion to which the transmissive screen is attached is provided with a sliding mechanism that moves in parallel in the direction of the projection optical axis. (27) The projection display device according to claim 26, wherein the sliding mechanism includes a rail in the main body and a plurality of rotating rollers that sandwich the rail in the casing. . (28) A single light source that emits white light including three primary color lights, a color separation means that separates the incident light from the light source into the three primary color lights, and a color separation means that corresponds to the three primary color lights from the color separation means. three arranged panels, a color synthesis means for synthesizing the three primary color lights emitted from the panels, a single projection lens for enlarging and projecting the emitted light from the color synthesis means onto a transmissive screen, and What is claimed is: 1. A rear projection display device comprising a molded screen, wherein a casing portion to which the transmissive screen is attached is provided with a rotation mechanism so that projection can be performed on a surface other than the transmissive screen. (29) The rotation mechanism is characterized in that a shaft passes through the center of rotation of the main body, and protrusions provided on the casing and the main body are connected by a spring, and are held during rotation. A projection type display device according to claim 28.