CN100374905C - Projector - Google Patents

Abstract

An object of the present invention is to provide a projector that changes display characteristics according to usage environments. This projector includes a first light modulation element (60R, 60G, 60B) for modulating illumination light, and a second light modulation element ( 100), and a projection device (110) for projecting the modulated illumination light onto a screen (120); The optical path of the illuminating light is relatively moved, and the optical element moving device (1) is moved away from the above-mentioned optical path.

Description

Projector

technical field

The present invention relates to projectors.

Background technique

In recent years, the image quality of electronic display devices such as LCD (Liquid Crystal Display), EL (Electro-luminescence) display, plasma display, CRT (Cathode Ray Tube), and projector has been significantly improved. Devices with performance roughly comparable to human visual characteristics are being realized. However, in terms of the luminance dynamic range, the reproduction range is about 1 to 10 ² (nit), and the number of gradations is generally 8 bits. On the other hand, with human vision, the dynamic range of brightness that can be perceived at one time is about 10 ^-2 to 10 ⁴ (nit), and the brightness discrimination ability is 0.2 (nit). If it is converted into a gray scale number, it can be Say the equivalent of 12 bits. If you look at the displayed image of the current display device with such visual characteristics, the narrow dynamic range of brightness is very conspicuous, and the gray scale of the shadow and highlight parts is insufficient. Therefore, compared with the realism and shock of the displayed image, it is difficult. Not feeling enough.

In addition, in CG (Computer Graphics) used in movies, games, etc., the display data (hereinafter referred to as HDR (High Dynamic Range) display data) has a brightness dynamic range and gradation characteristics close to human vision, and pursues the ideal of rendering. Realistic action is going mainstream. However, since the performance of the display device for displaying this is insufficient, there is a problem that the original expressiveness of the CG content cannot be fully exhibited.

Furthermore, it is expected that a 16-bit color space will be adopted in the next-generation OS (Operating System), and the dynamic range and the number of gray scales will be greatly increased compared with the current 8-bit color space. Therefore, it is expected that there will be a high demand for realizing an electronic display device with a high dynamic range and high gradation that can effectively utilize a 16-bit color space.

Among display devices, projection-type display devices (projectors) such as liquid crystal projectors and DLP (Digital Light Processing, trademark) projectors can display large screens, and are superior in reproducing the realism and shock of displayed images. effective display device. In this field, in order to solve the above-mentioned problems, the following proposals have been made.

As a display device with a high dynamic range, for example, there is the technology disclosed in Patent Document 1, which has a light source, a second light modulation element that modulates the luminance in all wavelength regions of light, and three primary colors of RGB in the wavelength region of light. Each wavelength region modulates the brightness of the first light modulation element in its wavelength region, and the light from the light source is modulated by the second light modulation element to form a desired brightness distribution, and its optical image is in the first light modulation element A device that forms an image on the display surface, performs color modulation, and projects the light modulated twice. Each pixel of the second light modulation element and the first light modulation element is individually controlled based on the first control value and the second control value determined from the HDR display data. As the light modulation element, a transmissive modulation element having a pixel structure or a segment structure whose transmittance can be independently controlled and capable of controlling a two-dimensional transmittance distribution can be used. A representative example thereof is a liquid crystal light valve. In addition, a reflective modulator may be used instead of a transmissive modulator, and a representative example thereof includes a micromirror array device.

Now, consider the case of using a light modulation element having a transmittance of 0.2% for dark display and 60% for bright display. In the light modulation element alone, the dynamic range of luminance is 60/0.2=300.

The display device described above corresponds to a case where light modulation elements having a luminance dynamic range of 300 are optically arranged in series, and therefore a luminance dynamic range of 300×300=90000 can be realized. In addition, the same thinking holds true for the number of gradations, and by optically arranging light modulation elements with 8-bit gradation in series, it is possible to obtain a gradation number exceeding 8 bits.

Patent Document 1: Special Publication No. 2004-523001

Patent Document 2: JP-A-2001-100689

However, in a high dynamic range projector, since light is modulated by two light modulation elements arranged in series, the amount of light finally emitted from the projection device decreases, resulting in a problem that the brightness of a displayed image decreases. At this stage, it is conceivable that high dynamic range projectors are mainly used for displaying images in dark environments such as movie theaters. Therefore, the decrease in the luminance of a display image due to the arrangement of the two light modulation elements in series as described above has not been regarded as a problem.

However, in the future, it is possible to apply high dynamic range projectors to display images in bright environments such as data content. The resulting reduction in brightness of the displayed image results in insufficient brightness of the displayed image.

Contents of the invention

The present invention has been developed in view of the above-mentioned problems, and an object of the present invention is to provide a projector that changes display characteristics according to usage environments.

In order to achieve the above object, the projector of the present invention is provided with a first light modulation element for modulating illumination light, a second light modulation element for further modulating the illumination light modulated by the first light modulation element, A projector of a projection device for projecting the modulated illuminating light onto a screen, further comprising an optical element that blocks at least part of the illuminating light relative to the optical path of the illuminating light according to an external request. , and move it away from the above-mentioned optical element moving device on the optical path.

According to the projector of the present invention having such a feature, the optical element is moved away by relatively moving from the optical path of the illumination light according to a request from the outside. Therefore, it is possible to change the display characteristics of the projector with or without relatively moving the optical element from the optical path. And in the present invention, since the optical element is an element that blocks at least a part of the illuminating light, when the optical element is relatively moved from the optical path, the display characteristics of the projector will become bright, without moving the optical element When moving relatively from the optical path, although the display characteristics of the projector are slightly darkened, other display characteristics corresponding to the optical elements are improved. Thus, according to the projector of the present invention, it is possible to change the display characteristics according to the usage environment.

In addition, what moves directly to move the optical element away from the optical path may be either the optical element or the optical path of the illumination light. That is, in the projector of the present invention, the above-mentioned optical element moving device may adopt a structure in which the above-mentioned optical element is relatively moved with respect to the optical path of the above-mentioned illumination light by moving the above-mentioned optical element, and the above-mentioned optical element moving device may be By moving the optical path of the illumination light, the optical element is relatively moved with respect to the optical path of the illumination light. For example, when moving the optical element, it can be realized by using various moving mechanisms as the optical element moving device; when moving the optical path, it can be realized by using a mirror or a lens as the optical element moving device.

In addition, in the projector of the present invention, a configuration in which the above-mentioned optical element is a second light modulation element may be adopted.

By adopting such a configuration, since the optical element having a large light loss can be relatively moved from the optical path, the display characteristics of the projector when the optical element is relatively moved away from the optical path can be brightened.

In addition, in the projector of the present invention, a configuration may be adopted in which the second light modulation element is a transmissive liquid crystal light valve, and the optical element is a polarizing plate included in the second light modulation element.

By adopting such a configuration, since the optical element having the largest light loss can be moved away from the optical path, it is possible to more easily make the display characteristics of the projector brighter when the optical element is moved away from the optical path. In addition, since the polarizing plate does not need to be arranged as precisely as the second light modulation element itself or the optical path of the illumination light, it can be returned relatively easily after being removed.

In addition, when the second light modulating element is a transmissive liquid crystal light valve and the optical element is a polarizing plate as described above, it is possible to employ a configuration that, when the optical element moves away from the optical path, The liquid crystal panel included in the second light modulation element is used as a control device for full white display.

With such a configuration, since the illumination light can pass through the liquid crystal panel with almost no loss, it is possible to make the display characteristics of the projector brighter more reliably.

In addition, in the projector of the present invention, a configuration may be employed in which the optical element unifies the polarization direction of the illumination light modulated by the first light modulation element to the incident polarization direction of the second light modulation element. Orientation of the wavelength selective retardation plate.

For example, in the case of a three-panel projector that modulates each color of RGB illumination light by three first light modulation elements, the polarization direction of the illumination light modulated by each first light modulation element may be Not the same. Therefore, when the illumination lights modulated by the first light modulation elements are combined to be incident on the second light modulation element, the polarization directions of the illumination lights modulated by the first light modulation elements must be unified. Specifically, a retardation plate having wavelength selectivity (a wavelength-selective retardation plate) is arranged between the first light modulation element and the second light modulation element. The so-called wavelength-selective retardation plate is a retardation plate that only functions as a retardation plate for light of a predetermined wavelength, but does not function as a retardation plate for light of other wavelengths. By setting the illumination light whose polarization direction deviates among the illumination lights modulated by the first light modulation elements, the polarization directions of the illumination lights incident on the second light modulation elements can be unified.

However, since the illuminating light passes through such a wavelength-selective retardation plate, some energy is lost to some extent. Specifically, since the illumination light passes through the wavelength-selective retardation plate, a part of the illumination light becomes heat, and the intensity of the illumination light as a whole decreases. Therefore, for example, when the second light modulation element is moved away from the optical path of the illumination light, that is, when the wavelength selective retardation plate becomes unnecessary, by making the wavelength selective retardation plate Also moving away from the optical path of the illumination light can brighten the displayed image. Thus, in the projector of the present invention, there may be cases where the wavelength-selective retardation plate is unnecessary.

Here, as in the present invention, by adopting the configuration that the optical element that can be moved away from the optical path by the optical element moving device is a wavelength-selective retardation plate, it is possible to Brightens the displayed image.

In addition, specifically, in the projector of the present invention, a configuration may be employed in which the second light modulation element modulates the luminance of the illumination light. By employing such a configuration, the display characteristics of the projector can be adjusted to a high dynamic range without the second light modulation element moving away from the optical path of the illumination light.

In the projector of the present invention, it is possible to employ a focus adjustment device that adjusts the focal length of the projection device when the optical element is moved away from the optical path.

By adopting such a configuration, it is possible to match the focal length of the projection device according to the change of the focal length due to the movement of the optical element from the optical path. Therefore, an in-focus image can be displayed on the screen even when the optical element is moved out of the optical path.

In addition, in the projector according to the present invention, it is preferable to employ a configuration in which the focal lengths are matched by adjustment in the projection device. By employing such a configuration, it is possible to adjust the focal length of the projection device without moving the projection device itself.

In addition, the projector of the present invention may be configured to include an optical path length adjusting device that adjusts the optical path length of the illumination light when the optical element moves away from the optical path.

By adopting such a configuration, it is possible to change the optical path length of the illumination light according to the change of the focal length due to the movement of the optical element from the optical path, that is, the change of the optical path length. Therefore, even when the optical element is out of the optical path, the in-focus image can be displayed on the screen.

In addition, specifically, the optical path length adjusting device is provided with an optical path length adjusting optical element inserted into the optical path of the illumination light when the optical element moved by the optical element moving device moves away from the optical path of the illumination light, thereby being able to Adjust the light path length of the illumination light. In addition, optical glass or a dielectric multilayer film can be used as the optical path length adjustment optical element.

In addition, in the projector of the present invention, it is preferable that the optical path length adjusting optical element and the optical element are integrally formed. By adopting such a configuration, it is possible to move the optical path length adjustment optical element while moving the optical element by the optical element moving device.

In addition, when the optical path length adjusting optical element is integrally formed with the optical element, it is preferable to employ a configuration in which the optical path length adjusting optical element is attached to the optical path length adjusting optical element. The element and the above-mentioned optical element are integrally formed, and the above-mentioned optical element is attached to the step part formed on the above-mentioned optical path length adjusting optical element. By adopting such a configuration, by adjusting the height of the step portion, it is possible to easily make the optical path length when the optical element is interposed and the optical path length when only the optical path length adjusting optical element is interposed therebetween.

In addition, in the projector of the present invention, it is also possible to adopt a configuration in which the above-mentioned optical element is the above-mentioned first light modulation element.

By adopting such a configuration, since the optical element having a large light loss can be relatively moved from the optical path, the display characteristics of the projector when the optical element is relatively moved from the optical path can be made bright.

In addition, in the projector of the present invention, a structure in which the first light modulation element is a transmissive liquid crystal light valve and the optical element is a polarizing plate included in the first light modulation element may be employed.

By adopting such a configuration, since the optical element with the largest light loss can be moved away from the optical path, it is possible to more easily brighten the display characteristics of the projector when the optical element is separated from the optical path. In addition, since the polarizing plate does not need to be arranged as precisely as the first light modulation element itself or the optical path of the illumination light, it can be returned relatively easily after being removed.

In addition, specifically, in the projector of the present invention, a configuration may be employed in which the first light modulation element modulates the luminance of the illumination light. By employing such a configuration, the display characteristics of the projector can be adjusted to a high dynamic range without the first light modulation element moving relatively from the optical path of the illumination light.

In addition, in the projector of the present invention, the first light modulation element and the second light modulation element may be liquid crystal light valves, and the optical element may be an incident-side polarizing plate included in the second light modulation element. constitute.

When the first light modulation element is a liquid crystal light valve, the polarization direction of the illumination light emitted from the first light modulation element is substantially unified in one direction. Therefore, when the polarization direction is parallel to the transmission axis of the incident-side polarizing plate of the second light modulation element, it is not necessary to provide the incident-side polarizing plate.

Therefore, by adopting the above configuration, since the optical element having a large light loss can be separated from the optical path, the display characteristics of the projector can be brightened.

In addition, in the projector of the present invention, it is possible to adopt a method for changing the signal processing for driving the first light modulation element and/or the second light modulation element when the optical element is separated from the optical path. The structure of the signal processing device.

By employing such a configuration, even when the optical element moves away from the optical path, the first light modulation element and the second light modulation element can be appropriately driven, and good display characteristics can be obtained.

In addition, specifically, a configuration may be adopted in which the signal processing device changes the signal processing by changing the look-up table itself or changing addresses referred to in the look-up table.

Description of drawings

FIG. 1 is a diagram showing the main optical configuration of a projector according to a first embodiment of the present invention.

FIG. 2 is a diagram showing the configuration of a relay lens.

Fig. 3 is a cross-sectional view of a liquid crystal light valve.

Fig. 4 is a schematic configuration diagram of a moving mechanism.

FIG. 5 is a diagram showing a hardware configuration of a display control device.

FIG. 6 is a diagram showing a modified example of the projector according to the first embodiment of the present invention.

7 is a schematic configuration diagram of a moving mechanism included in a projector according to a second embodiment of the present invention.

Fig. 8 is a diagram showing the main optical configuration of a projector according to a third embodiment of the present invention.

Fig. 9 is a schematic configuration diagram of a moving mechanism.

Fig. 10 is a diagram showing the main optical configuration of a projector according to a fourth embodiment of the present invention.

Fig. 11 is a schematic configuration diagram of a moving mechanism.

Fig. 12 is a cross-sectional view of a liquid crystal light valve and an optical path length adjustment optical element.

Fig. 13 is a diagram showing the main optical configuration of a projector according to a fifth embodiment of the present invention.

Fig. 14 is a diagram showing the main optical configuration of a projector according to a sixth embodiment of the present invention.

Fig. 15 is a diagram showing the main optical configuration of a projector according to a seventh embodiment of the present invention.

Label description

PJ1, PJ3～PJ7 projectors

1 moving mechanism (optical element moving device)

5 Focus adjustment mechanism (focus adjustment device)

60B, 60G, 60R liquid crystal light valve (first light modulation element)

100 Liquid crystal light valve (second light modulation element)

101a, 101b polarizing plate

110 Projection lens (projection device)

180 Light valve driving device (control device)

300 wavelength selective retardation plate

500 Optical Path Length Adjustment Optical Elements

701 Movable mirror (optical element moving device)

801 Movable phase difference plate

802 Polarizing Beam Splitter

Detailed ways

Hereinafter, one embodiment of the projector of the present invention will be described with reference to the drawings. In addition, in the following drawings, in order to make each component into a recognizable size, the scale of each component is changed suitably.

(first embodiment)

FIG. 1 is a diagram showing the main optical configuration of a projector PJ1 according to the present embodiment.

The projector PJ1 is constituted by including an image display device and a projection lens 110, wherein the image display device has a light source 10, a uniform illumination system 20 for uniformizing the brightness distribution of light (illumination light) incident from the light source 10, and modulated The color modulating section 25 that uniformly luminances of the three primary colors of RGB in the wavelength region of light incident from the illumination system 20, the relay lens 90 that relays the light incident from the color modulating section 25, and all wavelengths of the light incident from the relay lens 90 are modulated. The brightness of the liquid crystal light valve 100 in the region; the projection lens 110 projects the incident light from the liquid crystal light valve 100 onto the screen 120 .

In addition, the light source 10 includes a lamp 11 constituted by an ultra-high pressure mercury lamp, a xenon lamp, or the like, and a reflector 12 that reflects and condenses light emitted from the lamp 11 .

In addition, in the following description, the xyz rectangular coordinate system of the entire optical system assumes that the pixel surface of the liquid crystal light valve 100 is an xy plane, and the direction of light emitted from the cross dichroic prism 80 and directed toward the projection lens 110 is Set to the z direction.

The uniform illumination system 20 includes first and second lens arrays 21 and 22 composed of fly-eye lenses and the like, a polarization conversion element 23 and a condenser lens 24 . And, the luminance distribution of the light emitted from the light source 10 is uniformized by the first and the second lens arrays 21 and 22, and the light passing through the first and the second lens arrays 21 and 22 is made to be dichroic by the polarization conversion element 23. The modulation unit is polarized in the incident polarization direction, and the polarized light is condensed by the condensing lens 24 and emitted to the color modulation unit 25 . Furthermore, the polarization conversion element 23 is composed of, for example, a PBS array and a 1/2 wavelength plate, and is an element that converts stray polarization into specific linear polarization.

The color modulator 25 includes two dichroic mirrors 30, 35, three mirrors (mirrors 36, 45, 46), five field lenses (lens 41, relay lens 42, parallelizing lens 50B) as light separating means. , 50G, 50R), three liquid crystal light valves 60B, 60G, 60R and a cross dichroic prism 80.

The dichroic mirrors 30 and 35 are elements for separating (splitting) the light (white light) from the light source 10 into RGB three primary color lights of red (R), green (G), and blue (B). The dichroic mirror 30 is an element formed on a glass plate or the like with a dichroic film that reflects the B light and the G light and transmits the R light, and reflects all the white light from the light source 10. Contains B light and G light, and allows R light to pass through. The dichroic mirror 35 is an element formed on a glass plate or the like with a dichroic film capable of reflecting the G light and transmitting the B light. Of the G light and the B light transmitted through the dichroic mirror 30, G After the light is reflected, it is transmitted to the parallelizing lens 50G, and the blue light is transmitted to the lens 41 .

The relay lens 42 is an element that transmits the light in the vicinity of the lens 41 to the vicinity of the parallelizing lens 50B, and the lens 41 has a function of making the light incident on the relay lens 42 efficiently. In addition, the B light incident on the lens 41 is transmitted to the spatially distant liquid crystal light valve 60B while maintaining its intensity distribution substantially without accompanying light loss.

The parallelizing lenses 50B, 50G, and 50R have the function of approximately parallelizing the light of each color incident on the corresponding liquid crystal light valves 60B, 60G, and 60R, so that the light transmitted through the liquid crystal light valves 60B, 60G, and 60R is efficiently incident on the relay. Function on lens 90. And, the light of the RGB three primary colors split by the dichroic mirrors 30, 35 is incident through the above-mentioned mirrors (mirrors 36, 45, 46) and lenses (lens 41, relay lens 42, parallelizing lenses 50B, 50G, 50R). onto the liquid crystal light valves 60B, 60G, 60R.

The liquid crystal light valves 60B, 60G, and 60R are made of a glass substrate on which pixel electrodes and switching elements such as thin film transistor elements and thin film diodes for driving the pixel electrodes are formed in a matrix, and a common electrode is formed on the entire surface. An active-matrix liquid crystal display element in which a TN-type liquid crystal is sandwiched between glass substrates and a polarizing plate is placed on the outside.

In addition, the liquid crystal light valves 60B, 60G, and 60R are in a normally white mode in which they are not in a white/bright (transmissive) state in a voltage-off state, and in a non-black/dark (non-transmissive) state in a voltage-applied state, or vice versa. The normally black mode is driven, and the grayscale between light and dark is simulated and controlled according to the loaded control value. The liquid crystal light valve 60B optically modulates the incident B light based on display image data, and emits modulated light including an optical image. The liquid crystal light valve 60G optically modulates the incident G light based on display image data, and emits modulated light including an optical image. The liquid crystal light valve 60R optically modulates the incident R light based on display image data, and emits modulated light including an optical image.

The cross dichroic prism 80 is composed of four right-angle prisms bonded together. Inside it, a dielectric multilayer film reflecting B light (B light reflecting dichroic film 81) and a dielectric multilayer film reflecting R light are placed. The film (R light reflection dichroic film 82 ) is formed in a cross-sectional X shape. Then, the G light from the liquid crystal light valve 60G is transmitted, the R light from the liquid crystal light valve 60R and the B light from the liquid crystal light valve 60B are deflected, and these three colors of light are combined to form a color image.

FIG. 2 is a diagram showing the configuration of the relay lens 90 .

The relay lens 90 is an element that transmits the optical images from the liquid crystal light valves 60B, 60G, and 60R synthesized by the cross dichroic prism 80 to the pixel plane of the liquid crystal light valve 100 . In addition, the relay lens 90 used in this embodiment is an inverted imaging device, so the images emitted from the liquid crystal light valves 60B, 60G, and 60R and formed on the liquid crystal light valve 100 through the relay lens 90 are like inverted images.

Moreover, the relay lens 90 shown in FIG. 2, for the sake of simple explanation, omits the description of the cross dichroic prism 80 between the liquid crystal light valves 60B, 60G, 60R and the relay lens 90, but is optically related to The configuration of the projector PJ1 shown in FIG. 1 is equivalent.

The relay lens 90 is a constant magnification imaging lens composed of a front lens group 90 a and a rear lens group 90 b arranged approximately symmetrically with respect to the aperture stop 91 . In addition, considering the viewing angle characteristics of liquid crystals, it is preferable to have telecentric characteristics on both sides. Such a relay lens 90 makes the image side focus position of the front lens group 90a coincide with the object side focus position of the aperture stop 91 and the rear lens group 90b, and is arranged on the object side focus position of the front lens group 90a. In the liquid crystal light valves 60B, 60G, and 60R, the liquid crystal light valve 100 is arranged at the image-side focus position of the rear lens group 90b. The front-stage lens group 90a and the rear-stage lens group 90b include a plurality of convex lenses and concave lenses. However, the shape, size, arrangement interval, and number of lenses, telecentricity, magnification, and other lens characteristics of the lenses can be appropriately changed according to the required characteristics, and are not limited to the example shown in FIG. 2 .

In addition, the liquid crystal light valve 100 modulates the luminance of the incident light in all wavelength regions based on the display image data, and outputs the modulated light including the final optical image to the projection lens 110 .

FIG. 3 is a cross-sectional view of the liquid crystal light valve 100 . As shown in the figure, the liquid crystal light valve 100 has a sandwich structure in which a liquid crystal panel is sandwiched between a polarizing plate 101a (optical element) and a polarizing plate 101b (optical element). Furthermore, the liquid crystal panel includes a counter substrate 102 , a counter electrode 103 , data wiring 104 , a sealing material 105 , a TFT (Thin Film Transistor) substrate 106 , and a liquid crystal layer 107 as shown in FIG. 3 .

In such a liquid crystal light valve 100 , light passing through the relay lens 90 enters from the in side in the figure, the brightness of the incident light is modulated, and then it is emitted to the out side in the figure.

In addition, as shown in FIG. 1, in the projector PJ1 of this embodiment, the moving mechanism 1 for moving the polarizing plates 101a and 101b (the optical element moves device).

FIG. 4 is a schematic configuration diagram of the moving mechanism 1 . As shown in the figure, the moving mechanism 1 includes a motor 3, a motor control circuit 2 that drives the motor 3 according to an external signal (M.S), is connected to the polarizing plates 101a and 101b included in the liquid crystal light valve 100, and can pass through the motor. 3 and the sliding gear 4 that moves along the direction a in the figure. Then, when the motor 3 is driven by the motor control circuit 2, the slide gear 4 moves in the direction a, whereby the polarizing plates 101a and 101b connected to the slide gear 4 move away from the optical path L of light (relatively move). In addition, the polarizing plates 101a and 101b are moved by driving the motor 3 in reverse rotation by the motor control circuit 2 to sandwich the liquid crystal panel again.

The projection lens 110 projects the optical image formed on the display surface of the liquid crystal light valve 100 onto the screen 120 to display a color image.

Furthermore, in the projector according to the present embodiment, a focus adjustment mechanism 5 (focus adjustment device) for changing the focal length of the projection lens 110 is connected to the projection lens 110 .

The focus adjustment mechanism 5 is a mechanism for changing the focus distance of the projection lens 110 according to the change of the focus distance that occurs when the above-mentioned moving mechanism 1 moves the polarizing plates 101a, 101b of the liquid crystal light valve 100 .

Furthermore, the liquid crystal light valves 60B, 60G, and 60R and the liquid crystal light valve 100 are the same in that they all modulate the intensity of transmitted light and include optical images corresponding to their modulation conditions, but the liquid crystal light of the latter The valve 100 modulates light (white light) in all wavelength ranges, whereas the former liquid crystal light valves 60B, 60G, and 60R modulate specific wavelength ranges that are split by the dichroic mirrors 30 and 35 as light separating means. Light (R, G, B and other colors), the two are different at this point. Therefore, the light intensity modulation by the liquid crystal light valves 60B, 60G, and 60R is simply called color modulation, and the light intensity modulation by the liquid crystal light valve 100 is called luminance modulation for distinction.

In addition, based on the same viewpoint, in the following description, the liquid crystal light valves 60B, 60G, and 60R are referred to as color modulation light valves, and the liquid crystal light valve 100 is referred to as a brightness modulation light valve for distinction.

Next, the process of light propagation in the entire projector PJ1 will be described. The white light from the light source 10 is split into three primary color lights of red (R), green (G) and blue (B) by the dichroic mirrors 30 and 35, and passes through the lenses including parallelizing lenses 50B, 50G, 50R and The mirrors are incident on the liquid crystal light valves 60B, 60G, and 60R. The various colored lights incident on the liquid crystal light valves 60B, 60G, and 60R are color-modulated according to external data corresponding to the respective wavelength regions, and emitted as modulated light including an optical image. The modulated lights from the liquid crystal light valves 60B, 60G, and 60R are respectively incident on the cross dichroic prism 80, where they are synthesized into one light beam.

After that, the light emitted from the cross dichroic prism 80 enters the liquid crystal light valve 100 via the relay lens 90 . The synthesized light incident on the liquid crystal light valve 100 is luminance-modulated based on external data corresponding to all wavelength regions, and output to the projection lens 110 as modulated light including a final optical image. Then, the projection lens 110 projects the final combined light from the liquid crystal light valve 100 onto the screen 120 to display a desired image.

In this way, in projector PJ1, the form adopted is that the optical image (image) is formed by the modulated light of the liquid crystal light valves 60B, 60G, and 60R as the first light modulator, and the optical image (image) is formed by the liquid crystal light valve as the second light modulator. The valve 100 forms the final display image, and modulates light from the light source 10 through a two-stage image forming process via two light modulation elements (a color modulation light valve and a brightness modulation light valve) arranged in series. Furthermore, as for the image forming process, for example, it is disclosed in "Helge Seetzen, Lorne A. Whitehead "A High Dynamic Range Display Using Low and High Resolution Modulators", SID Symposium 2003, PP.1450-1453 (2003)". As a result, the projector PJ1 can achieve an expansion of the dynamic range of luminance and an increase in the number of gray scales.

Furthermore, the projector PJ1 has a display control device 200 that controls the projector PJ1.

FIG. 5 is a block diagram showing the hardware configuration of the display control device 200 .

The display control device 200, as shown in FIG. 5 , includes a CPU 170 that calculates and controls the entire system based on a control program, and a ROM 172 that stores the control program of the CPU 170 in a predetermined area, and is used to store data read from the ROM 172, etc. The RAM 174 for calculation results necessary for the calculation process of the CPU 170, and the medium I/F 178 for inputting and outputting data with respect to external devices are constituted. access.

On the I/F 178, as external devices, a light valve driving device 180 for driving brightness modulation light valves and color modulation light valves, a storage device 182 for storing data, tables, etc. as files, and external devices are connected. Signal line 199 on the network. Furthermore, in the projector PJ1 of the present embodiment, the light valve driving device 180 functions as the control device of the present invention. That is, the light valve driving device 180 is driven so that when the polarizing plates 101a and 101b of the liquid crystal light valve 100 are moved, the liquid crystal panel of the liquid crystal light valve 100 becomes a full white display.

In the storage device 182, HDR display data for driving the brightness modulation light valve and the color modulation light valve, a control value registration table, and the like are stored.

In this embodiment, the projector PJ1 controls the transmittance of the liquid crystal light valves 60B, 60G, 60R and the liquid crystal light valve 100 in the display control device 200 according to the HDR video signal and RGB from the outside, and displays them on the screen 120 HDR images are displayed on the screen.

Here, HDR image data is image data capable of realizing a high-brightness dynamic range that cannot be realized in conventional image formats such as sRGB, and stores pixel values of brightness levels of display pixels for all pixels of the image. In the present embodiment, as HDR display data, a format is adopted in which a pixel value displaying a luminance level for each RGB3 primary color is stored as a floating point value for one pixel. For example, a value such as (1.2, 5.4, 2.3) is stored as a pixel value of one pixel.

In addition, the HDR image data is generated by capturing an HDR image with a high brightness dynamic range and based on the captured HDR image.

Furthermore, for the details of the generation method of HDR image data, for example, in the well-known literature "P.E.Debevec, J.Malik, "Recovering High Dynamic Range Radiance Maps from Photographs", Proceedings of ACM SIGGRAPH97, p.367-378, 1997" was made public.

In addition, in the projector PJ1 of this embodiment, for example, when there is an instruction from an external network, or when a ROM that does not store HDR image data is provided as the ROM 172, according to a request from the outside, the CPU 170 outputs a signal conveying this purpose.

Then, when this signal is input to the motor control circuit 2 of the moving mechanism 1, the motor control circuit 2 drives the motor 3, and the sliding gear 4 moves, whereby the polarizing plates 101a, 101b of the liquid crystal light valve 100 move from the optical path L of light to move away. In addition, signals from the CPU 170 are input to the focus adjustment mechanism 5 and the light valve driving device 180 in addition to the moving mechanism 1 . Then, the focus adjustment mechanism 5 adjusts the focus distance of the projection lens 110 by inputting a signal from the CPU 170, and the light valve driving unit 180 drives the liquid crystal panel of the liquid crystal light valve 100 to display a full white display by inputting a signal from the CPU 170.

In addition, in the projector PJ1 of this embodiment, the display control device 200, when the polarizing plates 101a, 101b of the liquid crystal light valve 100 are moved away from the optical path L of light, changes the parameters for driving the liquid crystal light valves 60B, 60G, and 60R. Signal processing to enable better display characteristics.

Specifically, the LUT (look-up table) when the polarizing plates 101a, 101b of the liquid crystal light valve 100 are placed on the optical path L of light, and the LUT when the polarizing plates 101a, 101b of the liquid crystal light valve 100 are moved away from the optical path L of light , is stored in the storage device 182 in advance. Then, the CPU 170 can change the signal processing for driving the liquid crystal light valves 60B, 60G, and 60R by changing the LUT stored in the storage device 182 according to the state of the polarizing plates 101 a and 101 b of the liquid crystal light valve 100 .

In addition, the signal processing data when the polarizers 101a and 101b of the liquid crystal light valve 100 are on the optical path L of light and the LUT when the polarizers 101a and 101b of the liquid crystal light valve 100 are moved away from the optical path L of light are used as 1 Each LUT is stored in the storage device 182 in advance, and the CPU 170 changes the reference base of the address of the LUT according to the state of the polarizing plates 101a, 101b of the liquid crystal light valve 100, and may also change the signal processing for driving the liquid crystal light valves 60B, 60G, and 60R.

Thus, in the projector PJ1 of this embodiment, the display control device 200 functions as the signal processing device of the present invention.

According to the projector PJ1 of this embodiment, since the polarizing plates 101a and 101b, the optical elements having the largest light loss, are moved away from the optical path L, the display characteristics of the projector PJ1 can be brightened.

Therefore, according to the projector PJ1 of this embodiment, it is possible to change the display characteristics according to the usage environment.

In addition, since the polarizing plates 101a and 101b do not have to be precisely arranged like the liquid crystal panel and the optical path of the illumination light, they can be restored relatively easily even after being moved by the moving mechanism 1 .

In addition, since the liquid crystal panel of the liquid crystal light valve 100 is completely white, light passes through the liquid crystal panel with almost no loss, so that the display characteristics of the projector can be brightened more reliably.

In addition, since the signal processing for driving the liquid crystal light valves 60B, 60G, 60R can be changed when the polarizing plates 101a, 101b of the liquid crystal light valve 100 move away from the light path L, the liquid crystal light valves 60B, 60B, 60R can be appropriately driven. 60G, 60R, and can get good display characteristics.

In addition, since the focus adjustment mechanism 5 can change the focus distance of the projection lens 110 according to the change of the focus distance caused by the relative movement of the polarizing plates 101a and 101b, it is possible to display a focused image on the screen 120.

Furthermore, when the polarizing plates 101a, 101b of the liquid crystal light valve 100 are moved away from the optical path L of light, the liquid crystal panel always displays in full white, so by using a normally white liquid crystal panel as the liquid crystal panel, the number of projectors PJ1 can be reduced. power consumption.

In addition, instead of moving both of the polarizing plates 101a and 101b of the liquid crystal light valve 100 from the optical path L, one of them may be moved from the optical path L.

For example, as shown in FIG. 6 , only the polarizing plate 101 a (incident-side polarizing plate) of the liquid crystal light valve 100 may be moved away from the optical path L by connecting only the polarizing plate 101 a (incident-side polarizing plate) to the moving mechanism 1 .

Here, the projector PJ1 according to this embodiment includes liquid crystal light valves 60B, 60G, and 60R as first light modulation elements. Therefore, the polarization directions of light emitted from the liquid crystal light valves 60B, 60G, and 60R and incident on the liquid crystal light valve 100 as the second light modulation element are substantially unified into one direction. Therefore, as long as the polarization direction of light is parallel to the transmission axis of the polarizing plate 101a, even if only the polarizing plate 101a is moved away from the optical path L, the liquid crystal light valve 100 can be driven, and the liquid crystal light valves 60B, 60G, The 60R modulated light is further modulated in brightness.

However, since the light emitted from the liquid crystal light valves 60B, 60G, and 60R reaches the liquid crystal light valve 100 through the optical system (cross dichroic prism 80, relay lens 90) in the propagation path, its polarization direction is not completely unified in one direction. Therefore, normally part of the light shielded by the polarizing plate 101a is incident on the liquid crystal light valve 100 because the polarizing plate 101a moves away from the optical path L, so that the display characteristics of the projector PJ1 can be brightened. On the other hand, since the polarization direction of the light incident on the liquid crystal light valve 100 is uneven, the brightness modulation effect of the liquid crystal light valve 100 is weak.

Specifically, when both the polarizing plates 101a and 101b are on the optical path L and the brightness is modulated by the liquid crystal light valve 100, the contrast ratio can be set to about 250000:1. On the other hand, when only the polarizing plate 101a is moved away from the optical path L and the brightness modulation is performed by the liquid crystal light valve 100, the contrast ratio is about 10000:1. Furthermore, in the case where both the polarizing plate 101a and the polarizing plate 101b are moved away from the optical path L without brightness modulation by the liquid crystal light valve 100, the contrast ratio is 500:1.

In addition, if both the polarizing plate 101a and the polarizing plate 101b are on the optical path L, and the brightness when the brightness modulation is performed by the liquid crystal light valve 100 is set to 100%, only the polarizing plate 101a is removed from the optical path L and the liquid crystal light valve 100 The brightness when the brightness modulation is performed is about 115%; the brightness when both the polarizing plate 101a and the polarizing plate 101b are removed from the optical path L without brightness modulation by the liquid crystal light valve 100 is about 150%.

(Second Embodiment)

Next, a second embodiment of the present invention will be described. In addition, in the description of the second embodiment, the description of the same parts as those of the first embodiment will be omitted or simplified.

FIG. 7 is a schematic configuration diagram of a moving mechanism included in the projector of the present embodiment. As shown in the figure, in the moving mechanism provided in the projector of this embodiment, the slide gear 4 is connected not only to the polarizing plates 101a, 101b but also to the liquid crystal light valve 100 itself.

In the projector of the present embodiment having such a configuration, the liquid crystal light valve 100 itself moves away from the optical path L when there is a request from the outside. Also, the projector of the present embodiment having such a configuration can change the display characteristics according to the usage environment, similarly to the projector PJ1 of the first embodiment described above.

(third embodiment)

Next, a third embodiment of the present invention will be described. In addition, in this 3rd Embodiment, the description of the same part as the said 1st Embodiment is abbreviate|omitted or simplified.

FIG. 8 is a diagram showing the main optical configuration of the projector PJ3 according to the present embodiment.

As shown in the figure, the projector PJ3 according to this embodiment has a configuration in which a wavelength selective retardation plate 300 is disposed between the relay lens 90 and the liquid crystal light valve 100 . In addition, as shown in the schematic configuration diagram of the moving mechanism 1 in FIG. The configuration on the wavelength selective retardation plate 300 .

For example, in the case of a three-panel projector in which the three liquid crystal light valves 60R, 60G, and 60B modulate the illumination light of each color of RGB like the projector PJ3 of this embodiment, the cross dichroic prism 80 From the viewpoint of combining efficiency, the polarization directions of the illumination light modulated by the respective liquid crystal light valves may not be unified. Therefore, when the illumination lights modulated by the liquid crystal light valves 60R, 60G, and 60B are combined to be incident on the liquid crystal light valve 100, it is necessary to change the polarization directions of the illumination lights modulated by the liquid crystal light valves 60R, 60G, and 60B to Unite.

Therefore, specifically, a wavelength-selective retardation plate 300 is disposed between the liquid crystal light valves 60R, 60G, and 60B and the liquid crystal light valve 100 .

This wavelength-selective retardation plate 300 functions as a retardation plate only for light of a predetermined wavelength (green illumination light in this embodiment), and acts as a retardation plate for light of other wavelengths (red illumination light in this embodiment). Light and blue illumination light) element that does not function as a retardation plate. Therefore, by passing the illumination light through the wavelength-selective retardation film 300, only the polarization direction of the light having a predetermined wavelength is changed, and the polarization directions of all the lights are unified. As a result, the polarization directions of all the illumination lights are unified and can be incident on the liquid crystal light valve 100 .

However, when the illumination light passes through such a wavelength-selective retardation plate 300, some energy is lost to some extent. Specifically, since the illumination light passes through the wavelength-selective retardation plate 300, a part of the illumination light becomes heat, and the intensity of the illumination light as a whole decreases.

Therefore, when the polarizing plates 101a and 101b of the liquid crystal light valve 100 are moved away from the optical path L of the illumination light like the projector PJ3 of this embodiment, that is, when the wavelength selective retardation plate 300 is unnecessary Next, by driving the moving mechanism 1, the wavelength-selective retardation plate 300 is also moved away from the optical path L of the illumination light together with the polarizing plates 101a and 101b of the liquid crystal light valve 100, so that the displayed image can be brightened.

(fourth embodiment)

Next, a fourth embodiment of the present invention will be described. In the description of the fourth embodiment, the description of the same parts as those of the first embodiment or the second embodiment will be omitted or simplified.

FIG. 10 is a diagram showing the main optical configuration of the projector PJ4 according to the present embodiment.

As shown in the figure, the projector PJ4 of the present embodiment has a structure including the optical path length adjusting optical element 500 integrally formed with the liquid crystal light valve 100, and does not include the focus adjustment mechanism provided in the projector PJ1 of the first embodiment described above. 5.

The optical path length adjustment optical element 500 is an optical element that adjusts the optical path length of illumination light, and is inserted into the optical path when the liquid crystal light valve 100 is removed from the optical path L. Specifically, even when the liquid crystal light valve 100 is moved away from the optical path L, the optical path length can be adjusted by the optical path length adjusting optical element 500 so as not to change the optical path length of the illumination light.

According to the projector PJ4 of this embodiment, even when the liquid crystal light valve 100 is moved away from the optical path L, the optical path length of the illumination light can be adjusted by the optical path length adjusting optical element 500 . Therefore, an in-focus image can be displayed on the screen 120 without adjusting the focus of the projection lens 110 by the focus adjustment mechanism.

In addition, as the optical path length adjusting optical element 500, optical glass having transparency to illumination light, dielectric multilayer glass functioning as a color filter, or the like can be used. In addition, when the dielectric multilayer glass is used as the optical path length adjustment optical element 500, the optical path length of the illumination light can be adjusted by the optical path length adjustment optical element 500, and the color temperature of the illumination light can be corrected.

In addition, in the projector PJ4 of this embodiment, as shown in the schematic configuration diagram of the moving mechanism 1 in FIG. The directions of the liquid crystal light valve 100 are connected in series and integrally formed. Therefore, the optical path length adjusting optical element 500 can be arranged on the optical path L while the liquid crystal light valve 100 is moved away from the optical path L by the moving mechanism 1 . Therefore, it is not necessary to separately provide a mechanism for moving the optical path length adjustment optical element 500 . Furthermore, in the projector PJ4 of this embodiment, the moving mechanism 1 is also included in the components of the optical path length adjusting device of the present invention, and the optical path length adjusting device 500 of the present invention is constituted by the moving mechanism 1 and the optical path length adjusting optical element 500. device.

Furthermore, when the liquid crystal light valve 100 and the optical path length adjustment optical element 500 are integrally formed, as shown in the sectional view of FIG. 100 and integrally form such a constitution.

By adopting such a configuration, by adjusting the height of the step portion 501, the optical path length when the liquid crystal light valve 100 is arranged on the optical path L and the optical path length when the optical path length adjusting optical element 500 is arranged on the optical path L can be easily adjusted. The light paths are identical in length. Also, even when an optical element other than the liquid crystal light valve 100 is used, by fitting the optical element to the step portion 501 , the positioning can be easily performed, and the replacement operation becomes easy.

(fifth embodiment)

Next, a fifth embodiment of the present invention will be described. In addition, in the description of the fifth embodiment, the description of the same parts as those of the above-mentioned first embodiment will be omitted or simplified.

FIG. 13 is a diagram showing the main optical configuration of the projector PJ5 according to the present embodiment.

As shown in the figure, in the projector PJ5 of this embodiment, the relay lens 90 and the liquid crystal light valve 100 are arranged between the condenser lens 24 and the dichroic mirror 30 . In addition, in the projector PJ5 of this embodiment, the liquid crystal light valve 100 and the relay lens 90 are arranged in this order with respect to the traveling direction of light.

In the projector PJ5 of the present embodiment having such a configuration, the light modulated in brightness by the liquid crystal light valve 100 enters the liquid crystal light valves 60R, 60G, and 60B through the relay lens 90 , and the liquid crystal light valves 60R , 60G, and 60B are color-modulated. That is, in the projector PJ5 of the present embodiment, the first light modulation element of the present invention is composed of the liquid crystal light valve 100, and the second light modulation element of the present invention is composed of the liquid crystal light valves 60R, 60G, and 60B.

Furthermore, the moving mechanism 1 is connected to the liquid crystal light valve 100 so that the liquid crystal light valve 100 can be moved away from the optical path L. As shown in FIG.

In the projector PJ5 of this embodiment, since the liquid crystal light valve 100, which is an optical element having a large light loss, can be moved from the optical path L, by moving the liquid crystal light valve 100 away from the optical path L, the The display characteristics of the projector PJ5 become bright.

In addition, as shown in FIG. 13 , a retardation plate 600 (1/2 wavelength plate) is integrally formed on the liquid crystal light valve 100 . The retardation plate 600 is an element that changes the polarization direction of incident light, and is inserted into the optical path L when the liquid crystal light valve 100 is removed from the optical path L.

The polarization direction of the light incident on the liquid crystal light valve 100 is unified by the polarization conversion element 23 , and the polarization direction is changed by being emitted from the liquid crystal light valve 100 . Here, when the liquid crystal light valve 100 is moved away from the optical path L, since the polarization direction of the light is not changed, the light cannot be incident on the subsequent liquid crystal light valves 60R, 60G, and 60B. Therefore, by inserting the retardation plate 600 into the optical path L when the liquid crystal light valve 100 is removed from the optical path L, light is converted into polarization directions that can be incident on the liquid crystal light valves 60R, 60G, and 60B.

In addition, in this embodiment, the liquid crystal light valve 100 itself is moved by the moving mechanism 1 . However, the present invention is not limited thereto, and only the polarizing plates 101 a and 101 b of the liquid crystal light valve 100 may be moved by the moving mechanism 1 .

(sixth embodiment)

Next, a sixth embodiment of the present invention will be described. In addition, in the description of the sixth embodiment, the description of the same parts as those of the above-mentioned first embodiment will be omitted or simplified.

Whereas the projectors of the first to fifth embodiments described above are configured to move the optical element and the optical path L relatively by moving the optical element, the projector of the present embodiment has a structure in which the optical element and the optical path L are moved by moving the optical path L. (Liquid crystal light valve 100) and the optical path L move relatively.

FIG. 14 is a diagram showing the main optical configuration of the projector PJ6 according to the present embodiment.

As shown in the figure, in the projector PJ6 of this embodiment, the optical path L between the condenser lens 24 and the dichroic mirror 30 is divided into an optical path L1 and an optical path L2. In the projector PJ6 of this embodiment, the light emitted from the polarization conversion element 23 is s-polarized light, and the light that can enter the liquid crystal light valves 60R, 60G, and 60B is p-polarized light.

Furthermore, the projector PJ6 of the present embodiment includes a movable mirror 701 (optical element moving device) that can move relative to the optical path L and guides light to the optical path L1 by reflecting the light on the optical path L. That is, when the movable mirror 701 is installed on the optical path L, the light is guided to the optical path L1, and when the movable mirror 701 is not installed on the optical path L, the light is guided to the optical path L2. guide light.

On the optical path L1, a plurality of relay lenses 702 and mirrors 703 are provided, and the light guided to the optical path L1 is guided to the polarizing beam splitter 704 by these optical systems.

On the other hand, on the optical path L2, a polarized beam splitter 705 for reflecting s-polarized light toward the liquid crystal light valve 100 side and a relay lens 90 are provided, and the light guided to the optical path L2 is split into polarized beams by these optical systems. The device 704 guides the light. Furthermore, in this embodiment, the liquid crystal light valve 100 is constituted by a reflective liquid crystal light valve.

The polarization beam splitter 704 is an element that guides light toward the dichroic mirror 30 by reflecting s-polarized light, and guides light toward the dichroic mirror 30 by transmitting p-polarized light.

In addition, between the polarizing beam splitter 704 and the dichroic mirror 30, there is provided a movable phase difference lens that is placed on the optical path L when light passes through the optical path L1 (when the movable mirror 701 is on the optical path L). Board 706.

In the projector PJ6 of the present embodiment having such a configuration, when the movable mirror 701 is moved onto the optical path L, the light is guided to the optical path L1. Then, the light (s-polarized light) guided to the optical path L1 is guided to a polarization beam splitter 704 through a plurality of relay lenses 702 and mirrors 703 . Here, since the polarizing beam splitter 704 is an element that guides the s-polarized light to the side of the dichroic mirror 30 by reflection, the light guided to the polarizing beam splitter 704 via the optical path L1 passes through the polarized beam The splitter 704 reflects and is guided to the side of the dichroic mirror 30 . In addition, since the movable retardation plate 706 is arranged on the optical path L when the movable mirror 701 is located on the optical path L, the light emitted from the polarized beam splitter 704 passes through the movable retardation plate 706 is changed so that p-polarized light that can be incident on the liquid crystal light valves 60R, 60G, and 60B is emitted.

On the other hand, in the case where the movable mirror 701 is moved away from the optical path L, the light is guided to the optical path L2. Then, the light guided on the optical path L2 passes through the polarizing beam splitter 705 and is guided to the liquid crystal light valve 100 , and is guided to the polarizing beam splitter 704 through the relay lens 90 after brightness modulation is performed. The light guided to the polarizing beam splitter 704 through the optical path L2 in this way is changed to p-polarized light by passing through the liquid crystal light valve 100 , and thus is guided to the side of the dichroic mirror 30 by passing through the polarizing beam splitter 704 .

In such projector PJ6 of this embodiment, by guiding light to the optical path L1, that is, by moving the optical path, it is possible to move the liquid crystal light valve 100 away from the optical path. Therefore, by guiding the light to the optical path L1, similarly to the projector of the above-mentioned first embodiment, the display characteristics can be brightened.

In addition, in the projector PJ6 of this embodiment, since the light modulated by the liquid crystal light valve 100 is modulated by each of the liquid crystal light valves 60R, 60G, and 60B, the first light modulation element of the present invention is composed of the liquid crystal light valve 100, The second light modulation element of the present invention is composed of liquid crystal light valves 60R, 60G, and 60B.

(seventh embodiment)

Next, a seventh embodiment of the present invention will be described. In addition, since this seventh embodiment is a modified example of the above-mentioned sixth embodiment, the description of the same parts as the above-mentioned sixth embodiment will be omitted or simplified.

FIG. 15 is a diagram showing the main optical configuration of the projector PJ7 according to the present embodiment.

As shown in the figure, the projector PJ7 of this embodiment includes a movable retardation plate 801 that can move relative to the optical path L instead of the movable mirror 701 included in the projector PJ6 of the sixth embodiment. and polarizing beam splitter 802. That is, in the projector PJ7 of this embodiment, the optical element moving device of the present invention is constituted by a movable retardation plate 801 and a polarizing beam splitter 802 .

The polarization beam splitter 802 guides the p-polarized light to the optical path L1 by reflecting it, and guides the s-polarized light to the optical path L2 by transmitting it.

Therefore, in the projector PJ7 of this embodiment, by disposing the movable retardation plate 801 on the optical path L, the s-polarized light emitted from the condensing lens 24 is changed into p-polarized light. Reflected by the light source 802, it is guided to the optical path L1.

On the other hand, by moving the movable retardation plate 801 away from the optical path L, the s-polarized light emitted from the condenser lens 24 passes through the polarizing beam splitter 802 and is guided to the optical path L2.

That is, according to the projector PJ7 of this embodiment, the optical path can be moved by moving the movable retardation plate 801 .

Furthermore, in this embodiment, since the light guided to the optical path L1 is p-polarized light, it is necessary to change it back to s-polarized light. Therefore, a phase difference plate 803 is provided on the optical path L1.

As above, preferred embodiments of the projector of the present invention have been described with reference to the drawings, but it is obvious that the present invention is not limited to the above-described embodiments. Various shapes, combinations, etc. of the components shown in the above-mentioned embodiments are merely examples, and various changes can be made according to design requirements and the like without departing from the scope of the present invention.

For example, in the first embodiment described above, only the polarizing plates 101a and 101b or the liquid crystal light valve 100 are moved by the moving mechanism. However, the present invention is not limited thereto, and the relay lens 90 may also be moved simultaneously with the polarizing plates 101a and 101b or the liquid crystal light valve 100 by a moving mechanism.

In addition, the moving direction and moving method of the polarizing plates 101a and 101b or the liquid crystal light valve 100 are also arbitrary.

In addition, in the above-described embodiments, a transmissive liquid crystal light valve is used as the light modulation element. However, the present invention is not limited thereto, and reflective liquid crystal light valves and micromirror array devices may also be used as light modulation elements.

In addition, for example, the present invention can also be applied to a projector in which the screen of the above-mentioned embodiment is provided on a part of the casing so as to be exposed, and the components other than the screen of the above-mentioned embodiment are accommodated inside the casing. , A so-called rear-projection projector that displays an image by projecting it from the inside of the housing onto the screen.

Claims (22)

1. A projector comprising a first light modulation element that modulates illumination light to form an image, a second light modulation element that further modulates the illumination light modulated by the first light modulation element to form an image, and A projection device for projecting the modulated illumination light above onto a screen, characterized in that: An optical element moving device is provided for moving an optical element blocking at least part of the illumination light relative to the optical path of the illumination light to move it away from the optical path in response to an external request. 2. The projector according to claim 1, wherein the optical element is the second light modulation element. 3. The projector according to claim 1, wherein the second light modulation element is a transmissive liquid crystal light valve, and the optical element is a polarizing plate included in the second light modulation element. 4. The projector according to claim 3, further comprising a control device for setting the liquid crystal panel included in the second light modulating element into full white display when the optical element is moved away from the optical path . 5. The projector according to claim 1, wherein the optical element unifies the polarization direction of the illumination light modulated by the first light modulation element into the incident polarization direction of the second light modulation element Wavelength Selective Retardation Plate. 6. The projector according to any one of claims 2 to 5, wherein the second light modulation element modulates the brightness of the illumination light. 7. The projector according to claim 1, further comprising a focus adjustment device for adjusting the focal length of the projection device when the optical element is moved away from the optical path. 8. The projector according to claim 7, wherein the focus adjustment device adjusts the focus distance by performing adjustments in the projection device. 9. The projector according to claim 1, further comprising an optical path length adjustment device for adjusting the optical path length of the illumination light when the optical element is moved away from the optical path. 10. The projector according to claim 9, wherein the optical path length adjusting device includes an optical path length adjusting optical element inserted into the optical path when the optical element is removed from the optical path. 11. The projector according to claim 10, wherein the optical path length adjustment optical element is optical glass. 12. The projector according to claim 10, wherein the optical path length adjustment optical element is a dielectric multilayer glass. 13. The projector according to claim 10, wherein the optical path length adjustment optical element and the optical element are integrally formed. 14. The projector according to claim 13, wherein the optical path length adjusting optical element and the optical element are integrally formed by affixing the optical element to the optical path length adjusting optical element, and the optical path length adjusting optical element is integrally formed. The element is pasted on the stepped portion on the optical path length adjustment optical element. 15. The projector according to claim 1, wherein the optical element is the first light modulation element. 16. The projector according to claim 1, wherein the first light modulation element is a transmissive liquid crystal light valve, and the optical element is a polarizing plate included in the first light modulation element. 17. The projector according to claim 15 or 16, wherein the first light modulation element modulates the brightness of the illumination light. 18. The projector according to claim 1, wherein the first light modulation element and the second light modulation element are liquid crystal light valves, and the optical element is an incident side of the second light modulation element. Polarizing plate. 19. The projector according to claim 1, further comprising: when the optical element is moved away from the optical path, a device for changing the driving of the first light modulation element or/and the second light modulation element is provided. Signal processing device for signal processing. 20. The projector according to claim 19, wherein the signal processing means changes the signal processing by changing the look-up table itself or changing the referenced address in the look-up table. 21. The projector according to claim 1, wherein the optical element moving device relatively moves the optical element with respect to the optical path of the illumination light by moving the optical element. 22. The projector according to claim 1, wherein the optical element moving device relatively moves the optical element with respect to the optical path of the illuminating light by moving the optical path of the illuminating light.

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