JP2007256829A - Projection display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the reduction in light using efficiency due to a change in an aspect ratio of a screen, in a projection display apparatus. <P>SOLUTION: The projection display apparatus 100 includes: a light source 105; an illuminating optical system 104 that modulates the light emitted from the light source 105 to illuminating-light; a display panel 102 that modulates the light from the illuminating optical system 104 to an optical image corresponding to a video signal; and a projection lens 101 for enlarging and projecting the light from the display panel 102 in a prescribed projection range. The illuminating optical system 104 includes a first optical modulation element 120 and a second optical modulation element 130 including a plurality of movable mirrors 121 and 131 arranged in a matrix state, for adjusting the aspect ratio of the illuminated area of the display panel 102 in accordance with the information on the aspect ratio of the video signal. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a projection display device, and more particularly to a projection display device using a light valve such as a liquid crystal panel or a semiconductor device equipped with a plurality of mirrors operated by electrical signals.

Projection-type display devices are used for presentations, home theaters, and the like because their screens can be easily enlarged. This type of projection display device mainly includes a light source, an illumination optical system for making light from the light source uniform, and a liquid crystal panel that modulates the light from the illumination optical system into an optical image corresponding to a video signal. The light valve, a projection lens for enlarging and projecting an optical image formed by the light valve, and a screen on which light from the projection lens is projected (see, for example, Patent Document 1).
JP-A-3-111806

In this type of light valve type projection display apparatus, the light valve is irradiated with uniform light from the illumination optical system, and the transmittance and reflectance of the light valve are changed in accordance with the video signal. As a result, an optical image corresponding to the video signal is formed by the light valve, and the video is reproduced on the screen via the projection lens. That is, in this projection display device, an optical image as a luminance distribution is formed by partially narrowing uniform illumination light to reproduce an image.
The illumination optical system is configured to efficiently guide the light beam from the light source to the light valve without unevenness. For this reason, it has the following two functions.
(1) A circular light beam emitted from the light source is converted into a short shape on the light valve.
(2) The light beam emitted from the light source is divided into a matrix and superimposed again and guided onto the light valve.
In order to realize these two functions, for example, there is a method using a fly-eye lens 1 and a fly-eye lens 2 (see, for example, FIG. 10 of Patent Document 1). The fly-eye lenses 1 and 2 have minute lenses arranged in a matrix. In the fly-eye lens 1, light from a light source is divided into a plurality of light beams by the minute lens, and is divided in the fly-eye lens 2. The reflected light beam is guided in a superimposed manner by the micro lens over the entire surface to be illuminated. In order to realize the function (1), the shape of one minute lens of the fly-eye lens 1 is set to be similar to the short shape of the light valve. Further, in order to realize the function (2), the optical axis center of one minute lens of the fly-eye lens 2 is adjusted so as to match the optical axis center of the corresponding minute lens of the fly-eye lens 1.

However, the aspect ratio (aspect ratio) of the screen may change depending on the type of video to be displayed (for example, movie software is Vista size, cinema size, 16: 9, 4: 3, etc.). For example, when a projection display device is configured with a light valve having an aspect ratio of 4: 3, when displaying video software with an aspect ratio of 16: 9, a signal with black bands above and below Is input to the light valve, so that a 16: 9 image can be projected on the screen. At this time, since the light is always cut by the light valve in the black belt portion, the light from the light source cannot be efficiently projected onto the screen.
As described above, in the conventional light valve type projection display device, if the change is made to the change in the aspect ratio of the screen, the light utilization efficiency of the entire device is lowered.
An object of the present invention is to prevent a decrease in light utilization efficiency associated with a change in screen aspect ratio in a projection display device.

A projection display device according to a first aspect of the present invention includes a light source, an illumination optical system that modulates light from the light source into illumination light, and a light valve that modulates light from the illumination optical system into an optical image according to a video signal. And a projection optical system for enlarging and projecting light from the light valve. The illumination optical system has a modulation optical system including a plurality of movable mirrors arranged in a matrix and adjusting the aspect ratio of the illuminated area of the light valve according to the aspect ratio information of the video signal.
In this projection display device, light from a light source is converted into illumination light by an illumination optical system and is incident on a light valve. The illumination light is modulated into an optical image corresponding to the video signal by the light bubble, and this optical image is enlarged and projected by the projection optical system to reproduce the video.
Here, the illuminated area of the light valve is adjusted by the movable mirror of the modulation optical system in accordance with the aspect ratio information of the video signal. For this reason, for example, in both cases where the video aspect ratio is 4: 3 and 16: 9, illumination light can be irradiated only to a region where an optical image is formed on the light valve. As a result, the projection display device can irradiate illumination light only in a necessary area even when the aspect ratio of the screen changes, and prevents a decrease in light utilization efficiency due to a change in the aspect ratio of the screen. Can do.
Here, the aspect ratio information of the video signal means aspect ratio information of an area that contributes to the reproduction of the video.

A projection display device according to a second invention is the projection display device according to the first invention, wherein the modulation optical system includes a plurality of movable mirrors and modulates light from the light source according to the projection range, and a plurality of movable A second light modulation element that includes a mirror and further modulates light from the first light modulation element according to the projection range.
According to a third aspect of the present invention, there is provided a projection display apparatus according to the first or second aspect, further comprising: an enlarging optical system that is disposed on an optical path between the modulation optical system and the light valve and expands light from the modulation optical system I have.
In this case, the movable range of the movable mirror included in the modulation optical system can be reduced, and the modulation optical system can be downsized.
A projection display device according to a fourth aspect of the present invention is the reflection mirror according to the third aspect, wherein the magnifying optical system has a predetermined curvature.
In a projection display device according to a fifth aspect of the present invention, in any one of the first to fourth aspects, the angle and the height of the movable mirror are variable to arbitrary values.

  In the projection display device according to the present invention, since the illumination optical system has a modulation optical system including a plurality of movable mirrors, the illuminated area can be adjusted according to the aspect ratio information of the video signal. Thereby, even if the aspect ratio of the screen changes, the illumination light can be irradiated only to a necessary region, and a decrease in light utilization efficiency accompanying a change in the aspect ratio of the screen can be prevented.

Embodiments of the present invention will be described with reference to the drawings.
[1] Overall Configuration FIG. 1 shows an example of a schematic configuration diagram of a projection display apparatus 100 as a first embodiment of the present invention. Here, a single-plate type (color filter type) projection display device will be described as an example.
The projection display apparatus 100 mainly includes a light source 105, an illumination optical system 104 that modulates light from the light source 105 into illumination light, and a field mirror 103 as an expansion optical system that expands the light from the illumination optical system 104. A display panel 102 as a light valve that modulates the light from the field mirror 103 into an optical image corresponding to the video signal, a projection lens 101 as a projection optical system that magnifies and projects the light from the display panel 102, and a projection lens And a screen 106 on which light from 101 is projected.
The light source 105 includes a lamp 115 that emits light when a voltage is applied, and a reflector 116 that collects light from the lamp 115. Examples of the lamp 115 include an ultrahigh pressure mercury lamp.
The projection display apparatus 100 is characterized in that the illuminated area is adjusted in the illumination optical system 104 in accordance with the aspect ratio information of the video signal. Specifically, the illumination optical system 104 includes a first light modulation element 120 as a part of a modulation optical system that modulates light from the light source 105, and modulation optics that further modulates light from the first light modulation element 120. It comprises a second light modulation element 130 as a part of the system. The configurations of the first light modulation element 120 and the second light modulation element 130 will be described later.

The field mirror 103 is a mirror that expands the light from the second light modulation element 130 of the illumination optical system 104, and the reflection surface is configured by a curved surface. The display panel 102 is an element for modulating the light from the field mirror 103 into an optical image corresponding to the video signal. For example, a reflective liquid crystal panel or a semiconductor device equipped with a plurality of movable mirrors operated by electric signals is used. Can be mentioned. In the present embodiment, the aspect ratio of the display panel 102 is set to 4: 3. The projection lens 101 enlarges and projects the optical image formed by the display panel 102 onto the screen 106.
[2] About the 1st light modulation element 120 and the 2nd light modulation element 130 Here, the 1st light modulation element 120 and the 2nd light modulation element 130 are demonstrated using FIG. 2 and FIG. FIG. 2 is a schematic plan view of the first light modulation element 120 and the second light modulation element 130, and FIG. 3 is an operation explanatory diagram of the movable mirrors 121 and 131 constituting the first light modulation element 120 and the second light modulation element 130. Show.
As shown in FIG. 2, the first light modulation element 120 and the second light modulation element 130 include a plurality of movable mirrors 121 and 131 arranged in a matrix and a mechanism for supporting and driving the movable mirrors 121 and 131. It is comprised from the board | substrates 122 and 132. FIG. The movable mirrors 121 and 131 are composed of minute rectangular plane mirrors, and are provided as many as the number of pixels of the display panel 102, for example. In FIG. 2, for the sake of convenience, the number of movable mirrors 121 is set to be smaller than the actually conceivable quantity.

As shown in FIG. 3, the angle and height of each movable mirror 121 and 131 with respect to the substrates 122 and 132 can be adjusted to arbitrary values within a predetermined range.
With the above configuration, the first light modulation element 120 and the second light modulation element 130 can arbitrarily change the shape of the entire reflection surface, and can arbitrarily adjust the illumination range and illuminance. For example, by adjusting the shapes of the reflection surfaces of the first light modulation element 120 and the second light modulation element 130 to fly eye mirrors, the first light modulation element 120 and the second light modulation element 130 can be used to form two conventional fly eyes. Similar to the lens, the light from the light source 105 can be made uniform.
In addition, about modulation optical systems, such as the 1st light modulation element 120 and the 2nd light modulation element 130, what is described, for example in patent 3657259 etc. can be considered. Therefore, detailed description of the movable mirrors 121 and 131 and the substrates 122 and 132 is omitted here.
[3] Each Drive Unit As shown in FIG. 1, the projection display apparatus 100 includes a lamp drive unit 151 that drives the light source 105 and a light modulation element drive unit that drives the movable mirror 121 of the first light modulation element 120. 152, a display panel driving unit 153 that drives the display panel 102, and a CPU 154, a ROM 155, and a RAM 156 for controlling and calculating the operation of each driving unit.

The lamp driving unit 151 is connected to the lamp 115 and applies a voltage to the lamp 115 to cause the lamp 115 to emit light. The light modulation element driving unit 152 is connected to the substrates 122 and 132 of the first light modulation element 120 and the second light modulation element 130, and a voltage is applied to the support part of the movable mirrors 121 and 131 to each movable mirror. The angles and heights of 121 and 131 are adjusted separately. Here, one light modulation element driving unit 152 is provided for the two light modulation elements 120 and 130, but the driving unit may be provided separately. The display panel driving unit 153 applies a voltage to each pixel of the display panel 102 in accordance with video signals sequentially sent from the outside, and modulates light from the illumination optical system 104 into an optical image. The display panel driving unit 153 has a display memory for storing, for example, sequentially sent video signals.
The CPU 154 includes a circuit that controls the operation of each of the driving units 151, 152, and 153, or a circuit that performs an operation based on information acquired from the outside, and the ROM 155, RAM 156, and each driving unit via the bus 158. 151, 152, and 153. For example, a video output device 157 capable of outputting a video signal is connected to the bus 158.
[4] Operation The operation of the projection display apparatus 100 will be described with reference to FIGS. FIG. 4 is a schematic configuration diagram of the first light modulation element 120 and the second light modulation element 130 corresponding to the aspect ratio 4: 3, and FIG. 5 is a diagram illustrating the first light modulation element 120 and the second light corresponding to the aspect ratio 16: 9. The schematic block diagram of the modulation element 130 is shown. 4 and 5 are schematic sectional views of the first light modulation element 120 and the second light modulation element 130. FIG.

As shown in FIG. 1, the light from the light source 105 is converted into uniform light by the lens group 111 of the illumination optical system 104, and is uniformly irradiated to the first light modulation element 120. The light incident on the first light modulation element 120 is reflected by the individual movable mirrors 121. The light reflected by the movable mirror 121 enters the display panel 102. For example, when the display panel 102 is a transmissive liquid crystal panel, the voltage from the display panel driving unit 153 is applied to the liquid crystal layer according to the sequentially transmitted video signals, and the light from the first light modulation element 120 is displayed. The light is modulated into an optical image as a luminance distribution on the panel 102. The light transmitted through the display panel 102 is enlarged and projected onto the screen 106 by the projection lens 101, and an image is reproduced on the screen 106.
On the other hand, video signals sequentially sent from the video output device 157 are temporarily stored in the RAM 156. Image aspect ratio information is acquired by the CPU 154 from the stored video signal. The ROM 155 stores a plurality of drive data for driving the first light modulation element 120 and the second light modulation element 130 into a predetermined reflecting surface shape. For example, the CPU 154 generates drive data corresponding to the aspect ratio. Selected. The angles and heights of the movable mirrors 121 and 131 of the first light modulation element 120 and the second light modulation element 130 are adjusted by the light modulation element driving unit 152 based on the selected drive data.

For example, when the aspect ratio of the reproduced video is 4: 3 which is the same as the aspect ratio of the display panel 102, the first drive data corresponding to the aspect ratio 4: 3 is selected by the CPU 154. As shown in FIG. 4, based on the first drive data, the first light modulation element 120 and the second light modulation element 130 are angled by the movable mirrors 121 and 131 so as to form a 3 × 3 fly-eye mirror. And height is adjusted. In this case, one reflecting surface 123, 133 has a similar shape (aspect ratio is 4: 3) of the display panel 102. The light from the light source 105 is divided into nine light beams by the plurality of reflection surfaces 123 of the first light modulation element 120, and the divided light beams are superimposed on the display panel 102 by the reflection surface 133 of the second light modulation element 130. Is irradiated. Thereby, an image having an aspect ratio of 4: 3 is reproduced on the screen 106 via the display panel 102 and the projection lens 101.
When the aspect ratio of the reproduced video is 16: 9, the CPU 154 selects the second drive data corresponding to the aspect ratio 16: 9. As shown in FIG. 5, based on the second drive data, the first light modulation element 120 and the second light modulation element 130 are arranged to form a 4 × 3 fly-eye mirror. Height is adjusted. One reflective surface 124, 134 has an aspect ratio of 16: 9. The light from the light source 105 is divided into 12 light beams by the plurality of reflection surfaces 124 of the first light modulation element 120, and the divided light beams are superimposed on the display panel 102 by the reflection surface 134 of the second light modulation element 130. Is irradiated. At this time, the aspect ratio of the illuminated area on the display panel 102 is 16: 9 which is similar to the reflective surfaces 124 and 134. Therefore, an image with an aspect ratio of 16: 9 is reproduced on the screen 106 via the display panel 102 and the projection lens 101. In other words, since a video signal having an aspect ratio of 16: 9 is input to the display panel 102, areas that do not contribute to video reproduction can be formed above and below the display panel 102 and the screen 106. Since the aspect ratio of the illuminated area is adjusted to 16: 9 by the two-light modulation element 130, the illumination light from the illumination optical system 104 is not irradiated to the area that does not contribute to the reproduction of the image on the display panel 102.

[5] Effect As described above, in the projection display apparatus 100, when the aspect ratio of the image is 4: 3, the first light modulation element 120 is set so that the aspect ratio of the illuminated area is 4: 3. And is adjusted by the second light modulation element 130. When the aspect ratio of the video is 16: 9, the first light modulation element 120 and the second light modulation element 130 are adjusted so that the aspect ratio of the illuminated area is 16: 9. For this reason, in the projection display apparatus 100, illumination light can be irradiated only to a necessary area on the display panel 102 even if the aspect ratio of the image changes, and the light utilization efficiency associated with the change in the aspect ratio of the screen. Can be prevented.
[6] Other Embodiments The present invention is not limited to the above-described embodiments, and various changes or modifications can be made without departing from the spirit of the invention.
For example, in the present embodiment, the illumination optical system 104 includes the first light modulation element 120 and the second light modulation element 130, but a lens or the like may be included in addition to these elements.
From the viewpoint of improving image quality, it is desirable that the number of movable mirrors 121 be the same as the number of pixels of the display panel 102 or more than the number of pixels of the display panel 102. However, the present invention is not limited to this. Absent.

  Further, the projection display device 100 is not limited to a single plate type color filter type, for example, a single plate type color sequential method (with a lot lens and a color wheel) or a three plate type projection display device. Also good. In the case of the single-plate color sequential method, the operations of the movable mirrors 121 and 131 of the first light modulation element 120 and the second light modulation element 130 are synchronized with the timing of R, G, and B color modulation. In the case of the three-plate type, a display panel and a micromirror array MEMS element are provided for each of R, G, and B components.

  The projection display device of the present invention can prevent a decrease in light utilization efficiency due to a change in the aspect ratio of the screen, and thus is useful in a field where a projection display device with high light utilization efficiency is required.

1 is a schematic configuration diagram of a projection display apparatus 100 according to a first embodiment of the present invention. FIG. 3 is a schematic plan view of a first light modulation element 120 and a second light modulation element 130. Operation | movement explanatory drawing of the movable mirrors 121 and 131 which comprise the 1st light modulation element 120 and the 2nd light modulation element 130. FIG. The schematic block diagram of the 1st light modulation element 120 and the 2nd light modulation element 130 corresponding to aspect ratio 4: 3. The schematic block diagram of the 1st light modulation element 120 and the 2nd light modulation element 130 corresponding to aspect ratio 16: 9.

Explanation of symbols

100 Projection Display Device 101 Projection Lens (Projection Optical System)
102 Display panel (light valve)
103 Field mirror 104 Illumination optical system 105 Light source 106 Screen 120 First light modulation element 121 Movable mirror 122 Substrate 130 Second light modulation element 131 Movable mirror 132 Substrate

Claims (5)

A light source;
An illumination optical system that modulates light from the front light source into illumination light;
A light valve that modulates light from the illumination optical system into an optical image according to a video signal;
A projection optical system for enlarging and projecting light from the light valve,
The illumination optical system has a modulation optical system including a plurality of movable mirrors arranged in a matrix and adjusting the aspect ratio of the illuminated region of the light valve according to the aspect ratio information of the video signal.
Projection display device. The modulation optical system includes a plurality of the movable mirrors, a first light modulation element that modulates light from the light source according to the projection range, and a plurality of the movable mirrors according to the projection range. A second light modulation element for further modulating light from the light modulation element,
The projection display device according to claim 1. The optical system further includes a magnifying optical system that is disposed on an optical path between the modulation optical system and the light valve and that expands light from the modulation optical system.
The projection display device according to claim 1. The magnifying optical system is a reflecting mirror having a predetermined curvature.
The projection display device according to claim 3. The angle and height of the movable mirror are variable to an arbitrary value.
The projection display device according to claim 1.

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