JP2006178174A - Image display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display apparatus in which a low cost, a large number of pixels, a high definition image, and a high contrast ratio are achieved. <P>SOLUTION: The image display apparatus includes at least a light source, a polarized beam splitter, an optical deflection element, a reflection type space light modulation element and a projection lens. The polarized beam splitter to which linearly polarized light from the light source is made incident is disposed in the direction of the vibration of the electric field of the linearly polarized beam so as to be parallel to the polarized-beam splitting function face of the polarized beam splitter. In addition, the reflection type space light modulation element is disposed in the direction of the vibration of the electric field of the linearly polarized beam so as not to coincide with the horizontal and vertical directions of the the side of a square pixel of the reflection type space light modulation element. Further, the optical deflection element deflects the linearly polarized beam within a plane parallel to the direction of the vibration of the electric field of the linearly polarized beam. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image display device, and more particularly to a technology that enables a projector device to have a high number of pixels, high image quality, and low cost.

  In current projector apparatuses, increasing the number of pixels (high-definition image), improving the contrast ratio, that is, high-quality image quality, and cost reduction are problems. Regarding the increase in the number of pixels, the production of the pixels of the spatial light modulation elements, the improvement of the contrast ratio, mainly the design of the optical elements and the projection optical system, and the cost, mainly the number of spatial light modulation elements used. is doing.

  The system is divided according to the number of spatial light modulation elements used in the projector apparatus. A three-plate system using three spatial light modulators for three colors of red (R), green (G), and blue (B), and a spatial light modulator for two of R, G, and B 2 plate system using one spatial light modulation element for the remaining one color, single plate system using one spatial light modulation element by irradiating R, G, B in time division (field sequential) There is. The cost can be reduced as the number of spatial light modulators used is smaller. However, there is a problem that the lower the number of spatial light modulation elements used, the lower the image quality. Therefore, one of the problems is to realize high quality image quality in a low cost single plate system.

  There is an optical system called an Off-Axis optical system (system) in which illumination light is incident on a reflective liquid crystal spatial light modulator from an oblique direction. In this system, an existing polarizer and analyzer are used instead of a polarizing beam splitter (PBS), and illumination light incident from a light source and video light emitted from a reflective spatial light modulator are separated. Since inexpensive polarizers and analyzers are used instead of PBS, the cost can be reduced. In this optical system, the design of a decentered optical system and further cost reduction are the issues, but a design using a normal optical system effective for cost reduction is also proposed in Non-Patent Document 1. . However, even in this method, the increase in the number of pixels is one of the common problems with other optical systems.

  On the other hand, in order to increase the number of pixels of the spatial light modulator, there is a method in which the pixels are physically made small, but the cost increases. On the other hand, there is a method of apparently increasing the number of pixels using an optical method. An element that deflects (shifts) the optical path is introduced into the optical system of the projector apparatus, and the switching of the deflection is synchronized with the switching of the image display of the spatial light modulation element, at least at a frequency at which the observer does not feel flicker. By doing so, an image having a larger number of pixels than the number of pixels of the spatial light modulation element is projected on the screen (observation surface). The apparent increase in pixels is because an afterimage of the observer's eyes is used. Techniques relating to such optical path deflection are disclosed in Patent Documents 1 to 3. Briefly, linearly polarized light incident on the liquid crystal element is deflected in the horizontal direction with respect to the direction of vibration of the electric field, two liquid crystal elements are used, and the directions of deflection are orthogonal to each other in two vertical and horizontal directions. The number of pixels is increased by a factor of four by shifting by an amount corresponding to half the pitch (distance between pixels).

  Spatial light modulation elements are roughly classified into two types, a transmission type and a reflection type. A reflective spatial light modulator can produce an electrical circuit such as a drive circuit below the reflective electrode (pixel) than a transmissive spatial light modulator, thus improving the aperture ratio and reducing the pixel size. High quality image quality can be achieved.

  Further, Patent Document 4 proposes a driving method and a display device that use a wobbling element to shift pixels and improve the horizontal resolution. The device disclosed in Patent Document 4 includes a display element (p-Si TFT LCD), a λ / 2 plate, and a wobbling element that shifts pixels diagonally. The wobbling element is a combination of a phase modulation optical element and a quartz birefringent medium. Here, the display element is a transmissive spatial light modulation element.

Further, according to Patent Document 5, there is a partial overlap between pixels increased by light deflection at a distance corresponding to half the pixel pitch. There is a pixel reduction technique as a technique for reducing this overlap and realizing higher quality image quality. In this method, the pixels are optically reduced, and the reduced image (or hollow image) is projected onto the screen as the object surface of the projection lens. The element used is a microlens array or a micro concave mirror, and the size is the same as the pixel.
JP 2003-057689 A JP 2003-280041 A Japanese Patent Laid-Open No. 2003-090991 Japanese Patent Laid-Open No. 11-259039 JP 2003-248189 A “Optical-System Designs for LCoS Front Projects”, Matthew Bone, Information Display 1/01, 2001, pp. 10-14.

  However, none of the above-described conventional examples can realize high-quality image quality in a low-cost single-plate system.

  The present invention has been made to solve this problem, and an object thereof is to provide an image display device capable of increasing the number of pixels, a high-definition image, and a high contrast ratio at low cost.

  In order to solve the above problems, the image display apparatus of the present invention includes at least a light source, a polarization separation element, a light deflection element, a reflective spatial light modulation element, and a projection lens. The polarization separation element to which the linearly polarized light from the light source is incident is provided so as to be parallel to the plane having the polarization separation function in the polarization separation element with respect to the direction of vibration of the linearly polarized electric field. The reflective spatial light modulator is provided so that the horizontal direction and the vertical direction of the side of the square pixel of the reflective spatial light modulator do not coincide with the direction of vibration of the linearly polarized electric field. Yes. Further, the light deflection element deflects the linearly polarized light in a plane parallel to the direction of vibration of the linearly polarized electric field. Therefore, by shifting the reflected light from the reflective spatial light modulation element obliquely with respect to the pixels, the apparent number of pixels can be increased, a high contrast ratio is possible, and the single plate type reduces the number of pixels. A costly image display device can be provided.

  Another image display apparatus of the present invention includes at least a light source, a polarization separation element, a first phase shifter, a light deflection element, a reflective spatial light modulation element, and a projection lens. The polarization separation element to which the linearly polarized light from the light source is incident is provided so as to be parallel to the plane having the polarization separation function in the polarization separation element with respect to the direction of vibration of the linearly polarized electric field. Further, the first phase shifter is provided by rotating the slow axis of the first phase shifter by a predetermined angle with respect to the direction of vibration of the electric field of linearly polarized light. Further, the light deflection element deflects the linearly polarized light in a plane parallel to the direction of vibration of the linearly polarized electric field. Therefore, an image display device with a high number of pixels and low cost can be provided.

  Further, another image display device of the present invention includes at least a light source, a first polarizer, a light deflecting element, a reflective spatial light modulator, a second polarizer, and a projection lens. Then, the first polarizer to which the linearly polarized light from the light source is incident transmits linearly polarized light having a vibration direction in which the vibration direction of the electric field is parallel to the direction of the transmission axis of the first polarizer. The reflective spatial light modulator has an array of square pixels, modulates the direction of oscillation of the linearly polarized electric field incident on each pixel, emits it, and transmits linearly polarized light that passes through the first polarizer. It is provided so that the horizontal and vertical directions of the pixel sides do not coincide with the vibration direction of the electric field. Further, the light deflecting element deflects the optical path with respect to the vibration direction of a predetermined electric field of the light modulated and emitted by the reflective spatial light modulator. The second polarizer is provided such that the transmission axis of the second polarizer is parallel to the vibration direction of a predetermined electric field. Therefore, it is possible to shift the pixels by considering the relationship between the installation of the two conventional polarizers, the reflective spatial light modulator and the direction of vibration of the electric field of linearly polarized light, and using the light deflector. Therefore, the apparent number of pixels can be increased, and a low-cost image display device can be provided.

  Another image display device of the present invention includes at least a light source, a polarization separation element, a first light deflection element, a reflective spatial light modulation element, a first phase shifter, a second light deflection element, and a projection lens. is doing. The first and second light deflection elements have a function of deflecting light within the vibration plane of the linearly polarized electric field. The first phase shifter is provided between the optical paths of the first optical deflection element and the second optical deflection element, and linearly polarized light whose slow axis of the first phase shifter is incident on the first phase shifter. It is provided so as not to be horizontal and vertical with respect to the vibration surface of the electric field. Therefore, by combining oblique deflection and lateral deflection, an apparent number of pixels can be increased and a high-definition image display device can be provided.

  Furthermore, another image display device of the present invention includes a light source, a first polarizer, a first light deflection element, a reflective spatial light modulation element, a first phase shifter, a second light deflection element, a second light deflection element, It has at least a polarizer and a projection lens. The first and second light deflection elements have a function of deflecting light within the vibration plane of the linearly polarized electric field. The first phase shifter is provided between the optical paths of the first optical deflection element and the second optical deflection element, and the slow axis of the first phase shifter is a straight line that enters the first phase shifter. It is provided so as not to be horizontal and vertical to the plane of vibration of the polarized electric field. Furthermore, the first polarizer and the second polarizer are provided so that the transmission axis of the first polarizer and the transmission axis of the second polarizer are orthogonal to each other. Therefore, since the transmission axes of the two polarizers are crossed Nicols, the image display device with higher contrast can be provided.

  The first phase shifter is preferably a half-wave plate. Furthermore, by providing a second phase shifter that is a quarter-wave plate between the optical paths of the polarization separation element and the light deflection element, phase compensation can be performed and a higher contrast ratio can be realized.

  Furthermore, the angle between the direction of vibration of the linearly polarized electric field and the horizontal and vertical directions of the sides of the square pixels in the reflective spatial light modulator is 45 °, so that the number of pixels can be increased. An image display device with higher image quality can be provided.

  In addition, the angle formed by the slow axis of the first phase shifter and the direction of vibration of the electric field of linearly polarized light is 22.5 °, so that 45 ° oblique deflection is possible, resulting in higher quality image quality. Image display apparatus can be provided.

  Furthermore, light of three colors of red, green, and blue is incident on the spatial light modulation element in a time-sharing manner, and the light deflection element deflects only one of the three colors of light. Therefore, the switching of the light deflection element may be performed at a low speed, and the cost can be further reduced. In addition, the light deflection element can provide an image display device of a higher quality image by deflecting only the green light having the maximum specific visibility among the three colors of light.

  Further, since the reflective spatial light modulator has a microlens, the image is optically reduced, so that an image display device for a high-definition image can be provided.

  Furthermore, since the square pixel of the reflective spatial light modulator is concave, an image display device for a higher definition image can be provided by utilizing the small aberration characteristic of the concave mirror.

  Further, since the vibration direction of the predetermined electric field is a direction orthogonal to the transmission axis of the first polarizer, it is possible to provide an image display device capable of high pixel count, higher quality image quality, and lower cost.

  Further, a third phase is set in a state where the slow axis is rotated with respect to the vibration direction of the electric field of the linearly polarized light after the first polarizer exits after the light traveling direction of the first polarizer. By providing the phase shifter, it is possible to provide an image display device capable of high pixel count, higher quality image quality, and lower cost.

  Further, since the first polarizer, the second polarizer, or the polarization separation element is a wire grid polarizer, a higher contrast ratio can be realized.

  Furthermore, the light deflection element is provided between the optical path between the spatial light modulation element and the second polarizer, so that an image display device capable of a high contrast ratio and a lower cost can be provided.

  According to the present invention, in consideration of the relationship between the installation of the polarization separation element and the spatial light modulation element and the direction of vibration of the electric field of linearly polarized light, and by using the light deflection element, diagonal pixel shift is possible, Therefore, the apparent number of pixels can be increased, and since it is a single plate type, a low-cost projector device can be provided. Compared to the conventional technique of performing pixel shift in the horizontal direction and pixel shift in the vertical direction to perform diagonal pixel shift, the conventional pixel shift in the diagonal direction is performed by two pixel shifts. In the method, pixel shift in an oblique direction can be realized by one pixel shift. In accordance with the fact that pixel shifting in an oblique direction can be performed with one pixel shift, two conventional optical deflection elements are required. In this method, one optical deflection element is sufficient, and the device can be simplified. . Further, for example, in order to set the display on the screen to 60 Hz, when two light deflection elements are provided, a 240 Hz reflection type spatial light modulation element is required, whereas only one light modulation element is provided. May be a 120 Hz reflective spatial light modulator. That is, a low-cost reflective spatial light modulator can be used.

  FIG. 1 is a configuration diagram showing an outline of an image display apparatus according to a first embodiment of the present invention. The image display apparatus 10 according to the present embodiment shown in the figure includes a light source 11, a polarizer 12, a polarization separation element 13, a quarter wavelength plate 14 as a phase shifter, a light deflection element 15, and a reflective spatial light modulation element. 16 and the projection lens 17 are comprised. A screen (observation surface) 19 is on the light exit side of the projection lens 17. The light source 11 is a white light source such as an ultra-high pressure mercury lamp, and is a white lamp that emits unpolarized white light. Unpolarized white light emitted from the light source 11 is converted into linearly polarized light by the polarizer 12. In the coordinates shown in FIG. 1 (y-axis is perpendicular to the drawing), the direction of vibration of the linearly polarized electric field is assumed to be parallel to the y-axis. Further, a color separation optical system such as a color wheel, which will be described later, may be inserted between the light source 11 and the polarization separation element 13 to extract the three primary colors R, G, and B from white light in a time division manner. Furthermore, the polarizer 12 is not limited to a single polarizing element, and may be a polarization conversion optical system including a plurality of optical / polarizing elements. In addition, the white lamp of the light source 11 has a unique light distribution. When the light is irradiated onto the spatial light modulator 16 and projected onto the screen 19 as it is, an image with different brightness is obtained depending on the location reflecting the light distribution. It is desirable that a uniform illumination optical system such as a fly-eye lens pair or an integrator rod for reducing this is interposed between the light source 11 and the polarization separation element 13. The polarization separation element 13 (PBS: Polarization Beam Splitter) has a surface 18 having a polarization separation function for separating two different polarizations (p-polarized light and s-polarized light), and the surface 18 has a multilayer film made of an inorganic material. Is formed. The quarter-wave plate 14 is for phase compensation and for realizing a higher contrast ratio. When the linearly polarized light passes through each optical element, the extinction ratio is lowered and the contrast ratio of the projector apparatus is lowered due to slight elliptical polarization or rotation of the vibration surface of the electric field. This quarter-wave plate 14 is used to eliminate this. The plane 18 having a polarization separation function is parallel to the y-axis and is also parallel to the direction of vibration of the incident linearly polarized electric field.

  Here, the configuration of the light deflection element in FIG. 1 will be described with reference to FIG. 2 which is a schematic sectional view of the light deflection element. The optical deflection element 15 shown in FIG. 2 is an optical deflection element using a liquid crystal element. The light deflecting element 15 includes two transparent glass substrates 15-1 and 15-2, and liquid crystal molecules 15-3 are distributed between the transparent glass substrates 15-1 and 15-2. Transparent electrodes (not shown) are formed on the transparent glass substrates 15-1 and 15-2, and a voltage is applied to the liquid crystal molecules 15-3 through the transparent electrodes. Therefore, as shown in FIGS. 2B to 2C, the alignment direction of the liquid crystal molecules can be changed depending on the presence or absence of voltage and the height. Due to this difference in orientation direction, it is possible to deflect the optical path of linearly polarized light (p-polarized light) in which the direction of vibration of the electric field is parallel to the incident x axis. In addition, the light deflecting element 15 is linearly moved as shown in FIG. 2C with respect to linearly polarized light (s-polarized light) whose electric field vibration direction is parallel to the y-axis (perpendicular to the paper surface) direction. Therefore, in FIG. 1, the linearly polarized light transmitted through the quarter-wave plate 14 enters the spatial light modulator 16 without being deflected. The material of the liquid crystal molecules 15-3 of the light deflection element is preferably a ferroelectric liquid crystal because high speed light deflection is required, but a conventional nematic liquid crystal or the like may be used as long as the light deflection speed can be reduced.

  Next, FIG. 3 is a schematic diagram showing the configuration of the spatial light modulation element of FIG. In the figure, the spatial light modulator 16 has square pixels (pixel electrodes) arrayed, coordinates 21 are determined by the direction of the sides of the square pixels, and coordinates 22 are those shown in FIGS. Xyz coordinates (z axis is perpendicular to the drawing). This coordinate 21 is obtained by rotating the coordinate 22 around the z-axis. In addition, the direction of vibration of the electric field of the incident linearly polarized light 23 is parallel to the y axis, and does not coincide with the horizontal direction and the vertical direction of the square pixel. Here, the spatial light modulation element 16 is a reflection type using a liquid crystal, and the incident linearly polarized light 23 is transmitted through the liquid crystal layer, reflected by the pixel electrode, and takes an optical path through the liquid crystal layer. In this optical path, when the liquid crystal of the spatial light modulator 16 is off, the incident linearly polarized light 23 is emitted with its electric field vibration rotated by 90 °, and when it is on, the electric field vibration direction is changed. Instead, it is emitted. It is assumed that a liquid crystal that performs such switching is used. In addition, a rubbing layer for controlling the alignment of the liquid crystal is provided above and below the liquid crystal layer. One rubbing direction of the rubbing layer is, for example, twisted nematic liquid crystal having a twist angle of 45 °, which coincides with the direction of light deflection, and the other rubbing direction is orthogonal. Here, it is preferable to align one side of the rubbing direction with the vibration plane of the electric field of the incident linearly polarized light. When the liquid crystal of the spatial light modulator 16 is on, the vibration direction of the electric field of the linearly polarized light 23 does not change and is parallel to the y-axis, so that the light is transmitted through the light deflecting element 15 without being deflected, and then 1 The light is transmitted through the / 4 wavelength plate 14 and reflected by the surface 18 having the polarization function of the polarization separation element, and returns to the light source. For this reason, the screen 19 displays black. On the other hand, when the liquid crystal of the spatial light modulator 16 is off, the direction of vibration of the electric field of the linearly polarized light 23 is parallel to the x-axis, and the light is deflected depending on the presence / absence of the voltage applied to the light deflector 15 and the height. After passing through the four-wave plate 14 and then passing through the polarization separation function of the polarization separation element, the light passes through the projection lens 17 and is displayed white (bright) on the screen. Here, it is assumed that the light deflection element 15 is installed so that the deflection direction thereof coincides with the vibration direction of the electric field of the linearly polarized light 23. Further, the thickness and applied voltage of the light deflection element 15 in FIG. 1 are adjusted so that the amount of light deflection is about half the pitch of the pixels on the screen.

  Therefore, on the screen, images different in two projection locations shown in FIGS. 4A and 4B are displayed with time shifted slightly (time division). If the display time of (a) and (b) in FIG. 4 is very short (for example, 60 Hz or more at which the observer does not feel flicker at the frequency), the observer is as shown in FIG. You will see an image with a doubled number of pixels. In addition, the pixel shifting by the above-described conventional wobbling element uses two elements, ie, a phase modulation optical element and a quartz birefringence medium. However, in the present invention, only an optical deflecting element using liquid crystal may be used, and the size of the apparatus can be reduced. And cost reduction.

  Next, FIG. 5 is a block diagram showing an outline of an image display apparatus according to the second embodiment of the present invention. In the figure, the same components as those in FIG. 1 indicate the same components. The image display device 30 of the present embodiment shown in the figure uses a wire grid polarizer (grid polarizer) 31 as a polarization separation element, and omits the quarter wavelength plate 14 of FIG. is there. The wire grid polarizer 31 can have a higher extinction ratio than a birefringent polarizer or a polarizer using dichroism, and can obtain a high contrast ratio even if a quarter-wave plate is omitted. it can. Here, as shown in FIGS. 6A and 6B, schematic diagrams of the wire grid polarizer 31, the wire grid polarizer 31 includes a light-transmitting optical member 31-1 and a thin metal wire 31. -2 are formed at equal intervals. The pitch p of the metal thin wire 31-2 is a fraction of the wavelength of about 400 nm to 650 nm. The increase in the number of pixels is the same as in the first embodiment, and is omitted here.

  Next, FIG. 7 is a schematic diagram showing another configuration of the spatial light modulator of FIG. In the spatial light modulation element shown in (a) of the figure, the direction of light deflection at the xy coordinates is assumed to be the diagonal direction of the square pixel 41 of the spatial light modulation element. The direction of vibration of the linearly polarized electric field is parallel to the y-axis. When the light deflection direction is close to 0 ° (horizontal) instead of 45 °, it becomes close to light deflection in one direction, and the number of pixels is improved only in one direction. On the other hand, if the angle is 45 °, the amount of deflection in the x and y axes is the same in light deflection, and it is close to performing the deflection in the x and y directions independently, and an effect close to a four times increase in the number of pixels. Can be obtained. FIG. 7B shows a twisted positional relationship between the polarization beam splitter 51 and the square pixel array 52 of the spatial light modulation elements. The linearly polarized light 53 is parallel to the y axis. At this time, the optical system excluding the spatial light modulator needs to rotate around the z axis (perpendicular to the paper surface). As shown in FIG. 7C, the polarizing beam splitter 51 and the linearly polarized light 53 are rotated about the z axis, and the horizontal and vertical sides of the square pixel coincide with the xy axis. The relative positional relationship is the same. However, it is necessary to design the optical elements having such a twisted positional relationship so as to fit in the housing of the projector apparatus.

  FIG. 8 is a diagram showing a conceptual configuration of an image display apparatus according to the third embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same components. The image display device 60 shown in FIG. 6A is provided with a half-wave plate 61 as a component different from the image display device 10 of the first embodiment shown in FIG. The direction of vibration of the linearly polarized electric field is parallel to the y-axis when it exits the quarter-wave plate 14. FIG. 9 shows the operation of the half-wave plate 61 as the second phase shifter. They are arranged as shown in FIG. Further, the slow axis 62 of the half-wave plate 61 is shown in FIG. Now, the direction of vibration of the electric field of the linearly polarized light (after exiting the quarter-wave plate) incident on the half-wave plate 61 is the direction 63, and the angle formed by this and the slow axis 62 is θ. The direction of vibration of the incident linearly polarized electric field is rotated by θ by the action of the half-wave plate 61, and when exiting the half-wave plate 61, the direction of vibration of the linearly polarized electric field at the time of incidence is viewed. It is rotating 2θ. The light enters the pixel of the spatial light modulator at an angle of 2θ. The subsequent steps are the same as those described in the first embodiment, and an effect of increasing the number of pixels can be obtained. In the first embodiment, the square pixel array of the spatial light modulator and the polarization beam splitter have a twisted positional relationship (see FIGS. 6B and 6C). In the embodiment, as shown in FIG. 10, the polarization beam splitter 71 and the spatial light modulation element square pixel array 72 are not in a twisted positional relationship, and the direction 73 of the linearly polarized electric field is vibrated. Is inclined from the x (y) axis. In this embodiment, a half-wave plate need only be installed in a conventional optical system with its slow axis adjusted, and the cost can be further reduced.

  FIG. 11 is a diagram showing the configuration of an image display apparatus according to the fourth embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 5 denote the same components. The image display device 80 of the fourth embodiment shown in FIG. 11 differs from the image display device 30 of the second embodiment of FIG. 5 in that a half-wave plate 81 is provided. Also in this embodiment, the wire grid polarizer 31 is used as the polarization separation element, and the quarter wavelength plate is omitted. By using the wire grid polarizer 31, a high contrast ratio can be achieved. The angle formed at the time of incidence (θ in FIG. 9) between the slow axis of the half-wave plate 81 and the direction of vibration of the electric field of linearly polarized light is 22.5 °, and the angle at the time of emission (the electric field of linearly polarized light at the time of incidence). Is 45 °, and the direction of light deflection by the light deflection element is 45 ° when viewed from the x (y) axis. As described above, the effect of increasing the maximum number of pixels can be obtained with the same amount of deflection from the x and y axes. Further, the amount of deflection on the screen becomes half of the diagonal line of the pixel pitch. This effect is close to the effect of deflecting half the pixel pitch in both the x and y directions. The maximum effect in deflection in one oblique direction is obtained, and a higher definition image is possible.

  Next, FIG. 12 is a schematic diagram showing an example of a color separation optical system. As shown in the figure, an example of a color separation optical system is a color wheel 92 having a disk made of red, green, and red filters that rotate about a rotation axis 95. The white light 94 emitted from the light source 91 is separated into three primary colors of red, blue, and green light by a color wheel 92 in a time division manner. The light deflection element 93 performs light deflection on the separated light beams 96 of the three primary colors, but it is necessary to switch the liquid crystal off and on at high speed. By deflecting light of only one of the three colors, the switching speed of the light deflection element 93 is reduced to 1/3. There is a vertical alignment type liquid crystal that responds at high speed, but it is not yet used in liquid crystal displays. If the speed is reduced to 1/3, a conventional twisted nematic liquid crystal or the like can be used, and the cost can be further reduced. Here, the light deflecting color is green. This is because green light has the highest specific visibility for the observer, and it is considered that the effect of increasing the number of pixels is more advantageous when the light is deflected than the other two colors. Therefore, in FIG. 4C, it can be seen that there is an overlap between pixels in the image superimposed by light deflection. Since an afterimage is used, the effect of increasing the number of pixels can be obtained even if it remains as it is. However, if pixels are reduced as shown in FIG. 13A and then light deflected and superimposed as shown in FIG. 13B, a higher definition image can be obtained. As a method of reducing the pixels in this way, there is a method of providing a microlens array in accordance with the pixel arrangement of the spatial light modulator.

  A cross-sectional view thereof is shown in FIG. A reflective spatial light modulator 100 shown in FIG. 1A includes a microlens array 101, a resin (adhesion) layer 102, a cover glass 103, a liquid crystal layer 104, a pixel electrode (pixel) 105, and a semiconductor substrate 106. Next, FIG. 14B shows the principle of pixel reduction. Incident light 107 is collected by the microlens 108, reflected by the pixel electrode 105, and further collected by the microlens 108 and emitted. In this process, there is a position 109 where the luminous flux becomes narrower. If this position 109 is the object plane of the projection lens, it is possible to project the reduced pixels shown in FIG. 13A on the screen. Note that the position 109 here is the position where the luminous flux becomes narrower, but the incident light has a divergence angle and there is also a light distribution of the light source, so when the position shifted from this is the object surface of the projection lens In some cases, an appropriate reduced pixel can be obtained.

  A reflective spatial light modulator 110 shown in FIG. 15 includes a cover glass 111, a pair of transparent electrodes 112 and 114, a liquid crystal layer 113, a semiconductor substrate 117, a concave reflective pixel 116, and a transparent member 115 filling the concave surface. It consists of Incident light is collected by a concave mirror. The function of reducing the pixels is the same as that of the example of the microlens shown in FIG. 13, but the use of a concave mirror can reduce chromatic aberration and increase the radius of curvature, thereby reducing spherical aberration and higher quality. Can provide a good image.

  FIG. 16 is a diagram showing the configuration of an image display apparatus according to the fifth embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same components. The image display device 120 of the fifth embodiment shown in FIG. 16 includes a light source 11, a first polarizer 121, a light deflection element 15, a reflective spatial light modulation element 16, a second deflector 122, and a projection lens. 17 is comprised. The first polarizer 121 and the second polarizer 122 are a so-called polarizer and analyzer. The light source 11 is a white lamp as in the above embodiments, and emits non-polarized light.

  Next, changes in the vibration direction of the electric field of each optical system or linearly polarized electric field and optical path deflection in the fifth embodiment shown in FIG. 16 will be described with reference to FIG. 17A shows the first polarizer 121, and its transmission axis 121-1 has xy coordinates (the z axis is perpendicular to the drawing. These coordinates are shown in FIGS. c) and (d) are also common to the y-axis). The light from the light source 11 in FIG. 16 is linearly polarized light whose transmission axis direction (y-axis) and the vibration direction of the electric field are parallel when it passes through the first polarizer 121. FIG. 17B shows the light deflection element 15 whose deflection direction is 15-4 (parallel to the x-axis). The optical deflection element 15 can deflect the optical path when linearly polarized light in the direction of vibration of the electric field parallel to the deflection direction 15-4 is incident on this element, while the direction of vibration of the electric field perpendicular to the deflection direction 15-4. When the linearly polarized light is incident, the optical path cannot be deflected as described above. Since the vibration direction of the electric field of the linearly polarized light transmitted through the first polarizer 121 is perpendicular to the deflection direction of the light deflecting element 15, the linearly polarized light passes through the light deflecting element without being deflected. The vibration direction of the electric field of linearly polarized light after passing through the light deflecting element 15 is parallel to the x-axis. FIG. 17C shows a reflective spatial light modulation element 16 and a square pixel arrangement as in FIG. The horizontal and vertical directions of the sides of the square pixel coincide with the x-axis and y-axis directions. The vibration direction of the electric field of linearly polarized light incident on the pixel is parallel to the y-axis, that is, the direction 16-1 in FIG. This linearly polarized light enters the pixel of the reflective spatial light modulator 16, is reflected by the reflective pixel electrode, passes through the process of being emitted after the optical path is reversed. In this process, by the modulation function of the reflective spatial light modulator 16, the oscillation direction of the linearly polarized electric field is rotated by 90 ° and emitted in the direction 16-2 in FIG. Further, when the light is not modulated, the light is emitted in the state 16-1 in FIG. The reflective spatial light modulation element 16 can perform this modulation for each pixel, and one of the directions 16-1 and 16-2 differs depending on the pixel, and this depends on an image to be displayed. Here, one pixel is described. FIG. 17D shows the second polarizer 122, which has a transmission axis 122-1. In the case of linearly polarized light emitted from the reflective spatial light modulator 16 and the direction of vibration of the electric field is the direction 16-2, it passes through the second polarizer 122, reaches the screen 19 via the projection lens 17 of FIG. When this is a bright state (white display) and the vibration direction of the electric field is in the direction 16-1, it cannot pass through the second polarizing element 122, is absorbed and reflected here, and does not reach the screen 19. This is a dark state (black display).

  In addition, the vibration direction of the predetermined electric field and the transmission axis of the first polarizer 121 in FIG. 16 are orthogonal to each other. This is a so-called crossed Nicol arrangement, and linearly polarized light with a predetermined electric field vibration can be extracted with high accuracy. Further, FIG. 18 shows a case where the vibration direction of the predetermined electric field and the transmission axis of the first polarizer 121 are not orthogonal. At this time, it may be deflected by the light deflecting element at the time of incidence, but there is no problem in the display image because it does not have image information. In this case, since the transmission axes of the first polarizer 121 and the second polarizer 122 are in the same direction, an element in which these two polarizers are integrated may be used. Further, by rotating the deflection direction of the first polarizers 121 and 122 by 90 °, it is possible to shift in the y-axis direction.

  Next, the effect of increasing the number of pixels by the optical deflection element is shown in FIG. FIG. 19A shows a case where all pixels are displayed in white. As described above, when the deflection direction of the optical deflecting element is parallel to the x-axis and the entire white table of FIG. 19A is deflected, the x position is shifted from the position 0 as shown in FIG. 19B. Display shifts to a position shifted in the axial direction. At this time, the amount of deflection is adjusted so that the amount of deviation is half the size of one pixel on the screen, depending on the refractive index, thickness, type of liquid crystal of the light deflecting element, and the magnitude of the applied voltage of the liquid crystal. Adjust. By switching (a) and (b) in FIG. 19 at high speed, the number of pixels apparently increases by a factor of two, that is, by a factor of two. The appearance is due to an afterimage of the observer. The display switching speed is preferably 60 Hz or higher so that the observer does not feel flicker. Further, as the liquid crystal material used for the light deflection element, a vertical alignment type liquid crystal that can be switched at high speed is preferable.

  Next, another change in the vibration direction of each element of the optical system or linearly polarized electric field and deflection of another optical path in the fifth embodiment shown in FIG. 16 will be described with reference to FIG. 20A shows the first polarizer 121, the transmission axis 121-1 of which is an xy coordinate (the z axis is perpendicular to the drawing and coincides with the optical path, and this coordinate is the same as FIG. 20). (B), (c), and (d) are also common to each other). When the light from the light source is transmitted through the first polarizer 121, the direction of the transmission axis and the direction of vibration of the electric field are linearly polarized light. Next, (b) of FIG. 20 shows the optical deflection element 15, and its deflection direction is 15-4. When linearly polarized light in the vibration direction of the electric field parallel to this direction is incident on this element, the light is deflected in this direction along the optical axis (z-axis). Further, when linearly polarized light in the vibration direction of the electric field perpendicular to this direction is incident, the light is not deflected. Here, the oscillation direction of the electric field of the linearly polarized light that has passed through the first polarizer 121 is parallel to the direction 121-1, which is orthogonal to the deflection direction 15-4 of the light deflection element 15, so that the light is deflected. Without passing through the light deflection element 15. FIG. 20C shows the reflective spatial light modulator 16 in which square pixels are arranged. At this time, the horizontal and vertical directions of the sides of the square pixel coincide with the xy coordinates. Further, the vibration direction of the linearly polarized electric field incident on the square pixel does not coincide with the horizontal and vertical directions. In this description, the vibration direction of the incident linearly polarized electric field is the direction 121-1 shown in FIG. Due to the modulation function of the reflective spatial light modulator 16, the vibration direction of the incident linearly polarized electric field is the direction 16-1 that is not different from the incident time in FIG. 20C, or the direction rotated 90 degrees from the incident time. Take either one of 16-2. FIG. 20D shows a second polarizer (analyzer) 122, which has a transmission axis 122-1, which is the transmission axis of the first polarizer 121 in FIG. It is orthogonal to 121-1. The linearly polarized light emitted from the reflective spatial light modulation element 16 is transmitted through the light deflection element 15 and the second polarizer 122 when the direction of vibration of the electric field is the direction 16-2 in FIG. (Because the transmission axis of the polarizer coincides with the vibration direction of the electric field of linearly polarized light), the light reaches the screen via the projection lens 17 of FIG. This is a bright state. Further, the optical path can be deflected by the deflection function of the optical deflection element 15. On the other hand, when the direction of vibration of the linearly polarized electric field emitted from the reflective spatial light modulator 16 is the direction 16-1, the transmission axis and the deflection direction are orthogonal to each other after passing through the light deflection element 15 and the analyzer. It is absorbed and reflected by the analyzer and does not reach the projection lens 17 or the screen. This is a dark state. As described above, in FIG. 17, the deflection is in the x- or y-axis direction, but in FIG. 20, the oblique deflection is possible. Further, regarding the arrangement of the optical deflection elements, the x-axis (or y-axis) in FIG. 2 is assumed to coincide with the deflection direction 15-4 of the optical deflection element 15 in FIG. The effect of increasing the number of pixels by the light deflection in the oblique direction has been described with reference to FIG.

  In addition, the direction of light deflection is the diagonal direction of the square pixel of the spatial light modulator (45 ° from the x-axis or y-axis). When the light deflection direction is close to 0 ° (horizontal) instead of 45 °, it becomes close to light deflection in one direction, and the number of pixels is improved only in one direction. On the other hand, if the angle is 45 °, the amount of deflection in the x and y axes is the same in light deflection, and it is close to performing the deflection in the x and y directions independently, and an effect close to a four times increase in the number of pixels. Can be obtained. Further, since it is the diagonal direction of the square pixel, it may be deflected in the directions of 135 °, 225 °, and 315 ° equivalent to 45 °. At this time, each component of the optical system is arranged so as to correspond to the deflection direction.

FIG. 21 is a diagram showing a configuration of an image display apparatus according to the sixth embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 16 denote the same components. The image display apparatus 130 of the sixth embodiment shown in FIG. 21 includes a light source 11, a first polarizer 121, a phase shifter 131 that is a half-wave plate, a light deflector 15, and a reflective spatial light modulator. 16, the 2nd deflector 122, and the projection lens 17 are comprised.
Next, changes in the vibration direction of the electric field of each optical system or linearly polarized electric field and deflection of the optical path in the sixth embodiment shown in FIG. 21 will be described with reference to FIG. FIG. 22A shows a first polarizer 121, which has a transmission axis 121-1. The vibration direction of the electric field of the linearly polarized light after passing through the first polarizer 121 is parallel to the y axis. A phase shifter (half-wave plate) 131 shown in FIG. 22B has a slow axis 132. The direction of vibration of the linearly polarized electric field when incident on the half-wave plate is direction 133, and the direction of vibration of the linearly polarized electric field after exiting the half-wave plate is direction 134. If the angle formed by the vibration direction 133 of the electric field at the time of incidence and the slow axis 132 is θ, the angle formed by the vibration direction 133 of the electric field at the time of incidence and the vibration direction 134 of the electric field at the time of emission is 2θ (1 / Depending on the function of the two-wave plate). (C) of FIG. 22 is the optical deflection | deviation element 15, and the optical deflection direction is the direction 15-4. The direction of vibration of the linearly polarized electric field emitted from the half-wave plate is the direction 134, and is orthogonal to the light deflection direction 15-4. At this time, the light is not deflected. FIG. 22D shows the reflective spatial light modulator 16 and its square pixel array. The horizontal and vertical directions of the sides of the square pixel do not coincide with the xy direction. When linearly polarized light in the vibration direction of the electric field in the direction 134 in FIG. 22B is incident on the pixel of the reflective spatial light modulator 16, the vibration direction of the linearly polarized electric field is illustrated by the modulation function of the spatial light modulator 15. 22 (d), the electric field vibration direction 16-1 and the electric field vibration direction 16-2. At this time, it is assumed that the vibration direction 16-1 of the electric field coincides with the direction 134 in FIG. Next, the linearly polarized light in the electric field vibration direction 16-1 or the electric field vibration direction 16-2 in FIG. 22D passes through the light deflection element 15. At this time, the linearly polarized light in the electric field vibration direction 16-2 is deflected, and the linearly polarized light in the electric field vibration direction 16-1 is not deflected. Next, the linearly polarized light in the vibration direction of the two electric fields passes through the phase shifter 131 that is a half-wave plate. At this time, the linearly polarized light whose electric field vibration direction is the electric field vibration direction 16-1 is the linearly polarized light whose electric field vibration direction is parallel to the y-axis by the function of the half-wave plate, and the electric field vibration direction is the electric field vibration direction. The linearly polarized light in the vibration direction 16-2 is linearly polarized light whose electric field vibration direction is parallel to the x-axis. (E) of FIG. 22 is the 2nd polarizer 122, and the transmission axis 122-1 is parallel to the x-axis. Linearly polarized light parallel to the x-axis emitted from the phase shifter 131 which is a half-wave plate is transmitted through the second polarizer 122 and reaches the screen 19 through the projection lens 17 of FIG. 21 (bright state). The linearly polarized light parallel to the y-axis emitted from the phase shifter 131 which is a two-wavelength plate is absorbed and reflected by the second polarizer 122 and does not reach the projection lens 17 and the screen 19 (dark state).
The angle (θ in FIG. 22B) between the slow axis 132 of the phase shifter 131 which is a half-wave plate and the vibration direction of the electric field of linearly polarized light is 22.5 °, and is emitted. The angle of time (from the vibration direction of the electric field of linearly polarized light at the time of incidence) is set to 45 °, and the direction of light deflection by the light deflection element is set to 45 ° when viewed from the x (y) axis. As described above, the effect of increasing the maximum number of pixels can be obtained with the same amount of deflection from the x and y axes. Also, it may be 112.5 °, 202.5 °, or 292.5 ° equivalent to 22.5 °.

  FIG. 23 is a diagram showing the configuration of an image display apparatus according to the seventh embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 16 denote the same components. In the image display device 140 according to the seventh embodiment shown in FIG. 23, the light deflection element 15 is provided only on the optical path (return path) between the spatial light modulation element 16 and the second polarizer 122. According to the present embodiment, extra members are not included in the optical system, and not only the extinction ratio and contrast ratio are improved, but also the size of the light deflection element is about half the size. Furthermore, cost reduction can be achieved.

  FIG. 24 is a diagram showing the configuration of an image display apparatus according to the eighth embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 21 denote the same components. In the image display apparatus 150 of the eighth embodiment shown in FIG. 24, the light deflection element 15 is provided only on the optical path (return path) between the reflective spatial light modulation element 16 and the phase shifter 131. According to the present embodiment, extra members are not included in the optical system, and not only the extinction ratio and contrast ratio are improved, but also the size of the light deflection element is about half the size. Furthermore, cost reduction can be achieved.

  FIG. 25 is a diagram showing the configuration of an image display apparatus according to the ninth embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same components. The image display device 160 of the ninth embodiment shown in FIG. 25 includes a light source 11, a polarizer 12, a polarization separation element 13, a first light deflection element 161, a phase shifter 162, a second light deflection element 163, The reflective spatial light modulator 16 and the projection lens 17 are included. According to the image display device 160 of the present embodiment having such a configuration, unpolarized white light emitted from the light source 11 is converted into linearly polarized light (s-polarized light) by the polarizer 12, and the s-polarized light is polarized. The light enters the separation element 13. Then, the s-polarized light reflected by the plane 18 for separating polarized light and emitted from the polarization separating element 13 enters the first light deflecting element 161, exits without being deflected, and enters the phase shifter 162. Here, the phase shifter 162 is a half-wave plate. As shown in FIG. 9, the linearly polarized light emitted from the phase shifter 162 is 2θ from the time of incidence, and the vibration surface of the electric field rotates. The second optical deflecting element 163 is installed so that the deflecting surface thereof is perpendicular to the plane of vibration of the electric field of the linearly polarized light that is emitted, and thus the linearly polarized light that is emitted from the phase shifter 162 is the second optical deflection. The light enters the element 163, passes through without being deflected, and enters the spatial light modulation element 16. Then, the linearly polarized light whose electric field is not modulated by the liquid crystal is emitted from the spatial light modulator 16, then enters the second light deflector 163, exits without being deflected, and enters the phase shifter 162. Incident. This phase shifter 162 rotates the vibration surface of the electric field by 2θ, which is opposite to the above, and becomes s-polarized light, which is incident on the first light deflection element 161. Depending on the voltage applied to the liquid crystal of the first light deflecting element 161, the light exits without being deflected and enters the polarization separating element 13. Then, the light is reflected by the surface 18 having a polarization function of the polarization separation element 13 and returns to the light source 11. For this reason, the light does not reach the screen 19, and thus dark (black) display is provided on the screen 19. On the other hand, linearly polarized light whose electric field is modulated by the liquid crystal is emitted from the spatial light modulator 16, then enters the second light deflector 163, is deflected and exits, and then enters the phase shifter 162. . This phase shifter 162 rotates the vibration surface of the electric field by 2θ, which is opposite to the above, and becomes p-polarized light, which is incident on the first light deflection element 161. Depending on the voltage applied to the liquid crystal of the first light deflecting element 161, it is deflected and emitted, and enters the polarization separating element 13. Then, the light passes through the surface 18 having a polarization function of the polarization separation element 13 and reaches the screen 19 through the projection lens 17. For this reason, the display is bright (white) on the screen 19.

  Thus, the linearly polarized light is deflected by the applied voltage of the liquid crystal by the first light deflecting element 161 and the second light deflecting element 162. When the light is deflected by the two light deflecting elements, the light can reach four different positions on the screen 19, so that the image of the pixel can be projected. Here, the case where nine pixels of bright display are projected on the screen will be described as an example. From FIG. 26A when not deflected, the second optical deflection element as shown in FIG. And the amount of deflection becomes half the pixel pitch on the screen. Alternatively, as shown in FIG. 26C, the light is deflected laterally by the first light deflection element. Further, as shown in FIG. 26 (d), the second light deflector deflects obliquely in the opposite direction to FIG. 26 (b). In this way, if the series of deflections from (a) to (d) of FIG. 26 is performed at a high speed of 60 Hz or higher at which the observer does not feel flicker, the observer feels that he is seeing a smooth image. In particular, it is effective in reducing noticeable jaggies when an oblique line image is displayed. In addition, an image corresponding to a 4-fold increase in the number of pixels in this case can be expected.

  FIG. 27 is a timing chart showing waveforms of voltages applied to the first and second deflection elements and the spatial light modulation element. Here, it is assumed that the first light deflecting element is deflected in an oblique direction, and the second light deflecting element is deflected in a horizontal (left / right) direction. With the two light deflection elements, four different deflections are possible: (diagonally lower, left), (diagonally upper, left), (diagonally upper, right), (diagonally upper, right). During this time, the spatial light modulator flashes four times. As shown in FIG. 27C, this is one field, that is, four subfields. This is called 4-subfield driving. FIG. 28 represents this as one pixel projected on the screen, and FIG. 26 shows the surrounding pixels together. In FIG. 27, the applied voltage of the two light deflection elements is expressed as a rectangular wave, and the applied voltage of the spatial light modulation element is expressed as a δ function, but it is appropriate and not limited to this.

  Further, FIG. 29 is a timing chart showing another waveform of the voltage applied to the first and second deflection elements and the spatial light modulation element. This figure is called three-subfield driving. In FIG. 27, the driving is performed such that the voltage application times of the diagonally upper and lower deflections, and the right and left deflections are equalized, but in FIG. 29, these are not equalized. That is, as shown in FIG. 30, the oblique deflection is performed only when it is on the left. Even with such deflection, the screen can be filled with projection pixels without gaps, and the shape of the pixels becomes a triangle, but high definition of the pixels can be achieved. In addition, the driving frequency of the first and second light deflection elements and the spatial light modulation element can be reduced to 3/4 of the four subfield driving by the three subfield driving. For this reason, it is possible to use a conventional inexpensive liquid crystal material that is slower in reaction, and the cost can be reduced, and the load is reduced and the durability is improved by lowering the driving frequency. Further, by changing the angle in the oblique direction and the magnitude of the deflection, it becomes possible to deflect the triangle as close as shown in FIG.

  FIG. 31 is a diagram showing a configuration of an image display apparatus according to the tenth embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 25 denote the same components. The phase shifter 162, which is a half-wave plate, may be disposed between the first light deflecting element 161 and the second light deflecting element 163 and can be arranged as shown in FIG. In the image display device 170 of the tenth embodiment shown in FIG. 31, the configuration in which the light polarization separation element 13 is between the second light deflection element 163 and the phase shifter 162 and the first light deflection element 161. However, as described above, the phase shifter 162 that is a half-wave plate is disposed between the first optical deflection element 161 and the second optical deflection element 163. Similar to the ninth embodiment, the effect of increasing the definition of an image can be obtained.

  FIG. 32 is a diagram showing a state in which the spatial light modulator is arranged around the optical axis. In the image display device shown in FIGS. 25 and 31, only the reflective spatial light modulator is rotated, and the rotation angle is 2θ. In this case, the vibration plane of the linearly polarized electric field incident on the pixel is parallel (or perpendicular) to the side of the pixel. This is the relationship between the position of the pixel and the incident linearly polarized light in the prior art. For this reason, the conventional reflective spatial light modulator can be used without changing the rubbing layer or the like. The image on the screen is projected obliquely from the x and y axes as shown in FIG. However, this is not a problem if a mechanism for rotating the entire apparatus is provided. FIG. 33 shows only one pixel.

  FIG. 34 is a diagram showing a configuration of an image display apparatus according to the eleventh embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 25 denote the same components. The image display apparatus 180 according to the present embodiment shown in the figure has a configuration in which a wire grid polarizer (grid polarizer) 181 is used as a polarization separation element. The wire grid polarizer 181 can have a higher extinction ratio than a birefringent polarizer or a dichroic polarizer.

  FIG. 35 is a diagram showing the configuration of an image display apparatus according to the twelfth embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 25 denote the same components. The image display apparatus 190 according to the twelfth embodiment shown in the figure includes a light source 11, a first polarizer 191, a phase shifter 162 that is a half-wave plate, a first light deflecting element 161, and a reflective space. The light modulation element 16, the second light deflection element 163, and the second polarizer 192 are included. The second polarizer 192 is a so-called analyzer, and the transmission axis of the second polarizer 192 is orthogonal to the transmission axis of the first polarizer 191 (crossed Nicols). This optical system is off-axis. According to the image display device of the twelfth embodiment having such a configuration, when non-polarized light is emitted from the light source 11 and passes through the first polarizer 191, it becomes linearly polarized light. At this time, the vibration plane of the electric field of linearly polarized light is made parallel to the y-axis. Next, the slow axis of the phase shifter 162, which is a half-wave plate, is at a position rotated about the z axis from the y axis, and does not coincide with either the x axis or the y axis. The linearly polarized light incident on the phase shifter 162, which is a half-wave plate, becomes linearly polarized light having a vibration surface of an electric field rotated by 2θ from the y-axis, is transmitted through the first light deflecting element 161, and is reflected-type spatial light modulation. Incident on the element 16. When the linearly polarized light reflected by the pixel is not modulated by the reflective spatial light modulator 16, it passes through the first light deflector 161, and the phase shifter 162 rotates the vibration surface of the electric field by 2θ opposite to the above. , Linearly polarized light parallel to the y-axis. Then, the light passes through the second light polarizing element 163 and is reflected and absorbed by the second polarizer 192. The direction of the transmission axis of the second polarizer 192 is parallel to the x-axis, and linearly polarized light whose electric field vibration plane is parallel to the y-axis cannot be transmitted. At this time, light cannot reach the screen, and dark display (black display) occurs. On the other hand, the linearly polarized light whose electric field vibration plane is modulated by the spatial light modulator 16 has the electric field vibration plane perpendicular to the direction 64 in FIG. This linearly polarized light is transmitted through the first light deflecting element 161 and rotated by 2θ opposite to the above in the phase shifter 162 to become linearly polarized light whose electric field vibration plane is parallel to the x axis. The linearly polarized light passes through the second light deflecting element 163 and then passes through the second polarizer 192 to reach the screen 19 to be bright display (black display). Further, in this process, the first light deflecting element 161 and the second light deflecting element 163 can be deflected, and when all of them are deflected, four sub-field driving as described above, that is, four on the screen 19 are performed. Different positions can be taken. For this reason, an improvement in image quality due to an increase in the apparent number of pixels is achieved. Further, the above-described 3-subfield driving is also possible. Further, in such an off-axis optical system, a polarizer and an analyzer are used, and the cost is low because a conventional polarizer is used. In addition, in the configuration of the polarizer and the analyzer, a high extinction ratio can be obtained and a high contrast ratio can be achieved. When the angle formed by the slow axis of the phase shifter 162 that is a half-wave plate and the vibration plane of the electric field of the linearly polarized light incident on the phase shifter 162 is 22.5 °, the side of the square pixel The angle between the incident linearly polarized electric field and the vibration plane of the electric field is 45 °, which becomes a square diagonal line and light deflection on the diagonal line. Further, if the distance is shifted to a distance corresponding to half of the diagonal line of the pixel pitch, the number of pixels can be increased, a high contrast and a higher definition image can be displayed.

  FIG. 36 is a diagram showing a state of a projection pixel when pixel reduction is performed and both deflection in one oblique direction and one lateral direction are performed. As shown in the figure, when both the oblique and lateral deflections are performed, it is possible to project a pixel image without a gap, which substantially increases the number of pixels by four times, and reduces the reduction of the pixels by 1/2. When it is set to about the level, a higher definition image is obtained.

  The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications and substitutions are possible as long as they are described within the scope of the claims.

1 is a configuration diagram showing an outline of an image display apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic sectional view of the configuration of the light deflection element in FIG. 1. It is a schematic diagram which shows the structure of the spatial light modulation element of FIG. It is a figure which shows the mode of the screen display by the image display apparatus of a 1st embodiment. It is a block diagram which shows the outline of the image display apparatus which concerns on the 2nd Example of this invention. It is a schematic diagram which shows the structure of a wire grid polarizer. It is a schematic diagram which shows another structure of the spatial light modulation element of FIG. It is a figure which shows the notional structure of the image display apparatus of the 3rd Example of this invention. It is a figure which shows the effect | action of a half-wave plate. It is a figure which shows the arrangement | sequence of the square pixel of the polarizing beam splitter and spatial light modulation element in the example of 3rd Embodiment. It is a figure which shows the structure of the image display apparatus which concerns on the 4th Embodiment of this invention. It is the schematic which shows an example of a color separation optical system. It is a figure which shows the mode of a screen display when light is deflected by reducing a pixel. It is sectional drawing which shows the structure of the reflection type spatial light modulation element using a micro lens array. It is sectional drawing which shows another structure of the reflection type spatial light modulation element using a micro lens array. It is a figure which shows the structure of the image display apparatus which concerns on the 5th Example of this invention. It is a figure which shows the mode of the change of the vibration direction of each element of an optical system in the example of 5th Embodiment or a linearly polarized electric field, and the deflection | deviation of an optical path. It is a figure which shows another mode of the change of the vibration direction of each element of the optical system in the example of 5th Embodiment or a linearly polarized electric field, and the deflection | deviation of an optical path. It is a figure which shows the mode of the pixel number increase by an optical deflection | deviation element. It is a figure which shows another mode of the change of the vibration direction of each element of the optical system in the example of 5th Embodiment or a linearly polarized electric field, and the deflection | deviation of an optical path. It is a figure which shows the structure of the image display apparatus which concerns on the 6th Example of this invention. It is a figure which shows the mode of each element of the optical system in a 6th embodiment, the change of the vibration direction of the electric field of linearly polarized light, and the deflection | deviation of an optical path. It is a figure which shows the structure of the image display apparatus which concerns on the 7th Example of this invention. It is a figure which shows the structure of the image display apparatus which concerns on the 8th Embodiment of this invention. It is a figure which shows the structure of the image display apparatus which concerns on the 9th Example of this invention. It is a figure which shows an example which projected 9 pixels of bright display on the screen. It is a timing chart which shows the waveform of the applied voltage of a 1st, 2nd deflection | deviation element and a spatial light modulation element. It is a figure which shows the mode of the deflection | deviation of 1 pixel projected on the screen by 4 subfield drive. It is a timing chart which shows another waveform of the applied voltage of a 1st, 2nd deflection | deviation element and a spatial light modulation element. It is a figure which shows the mode of the deflection | deviation of 1 pixel projected on the screen by 3 subfield drive. It is a figure which shows the structure of the image display apparatus which concerns on the 10th Embodiment of this invention. It is a figure which shows a mode that the spatial light modulation element was arrange | positioned rotated to the optical axis. It is a figure which shows the mode of the display of 1 pixel on a screen by the spatial light modulation element of FIG. It is a figure which shows the structure of the image display apparatus which concerns on the 11th Example of this invention. It is a figure which shows the structure of the image display apparatus which concerns on the 12th Embodiment of this invention. It is a figure which shows the mode of the projection pixel at the time of performing both diagonal one direction and horizontal deflection | deviation.

Explanation of symbols

10; Image display device, 11; Light source, 12; Polarizer,
13; polarization separation element; 14; quarter wave plate; 15; light deflection element;
16; spatial light modulation element, 17; projection lens, 18; surface,
19; Screen.

Claims (18)

At least a light source, a polarization separation element, a light deflection element, a reflective spatial light modulation element, and a projection lens;
The polarization separation element on which linearly polarized light from the light source is incident is provided so as to be parallel to a plane having a polarization separation function in the polarization separation element with respect to the direction of vibration of the electric field of the linearly polarized light,
The reflective spatial light modulator is provided so as not to coincide with the horizontal and vertical directions of the sides of the square pixels of the reflective spatial light modulator with respect to the direction of vibration of the linearly polarized electric field. ,
The image display device, wherein the light deflection element deflects the linearly polarized light in a plane parallel to a direction of vibration of the electric field of the linearly polarized light. Having at least a light source, a polarization separation element, a first phase shifter, a light deflection element, a reflective spatial light modulation element, and a projection lens;
The polarization separation element on which linearly polarized light from the light source is incident is provided so as to be parallel to a plane having a polarization separation function in the polarization separation element with respect to the direction of vibration of the electric field of the linearly polarized light,
The first phase shifter is provided by rotating the slow axis of the first phase shifter by a predetermined angle with respect to the vibration direction of the electric field of the linearly polarized light,
The image display device, wherein the light deflection element deflects the linearly polarized light in a plane parallel to a direction of vibration of the linearly polarized light. At least a light source, a first polarizer, a light deflection element, a reflective spatial light modulation element, a second polarizer and a projection lens;
The first polarizer to which the linearly polarized light from the light source is incident transmits linearly polarized light having a vibration direction in which the vibration direction of the electric field is parallel to the direction of the transmission axis of the first polarizer,
The reflective spatial light modulator has an array of square pixels, modulates the direction of vibration of the linearly polarized electric field incident on each pixel, emits it, and transmits linearly polarized light that passes through the first polarizer. Provided so that the horizontal and vertical directions of the sides of the pixel do not match the vibration direction of the electric field,
The light deflection element deflects an optical path with respect to a vibration direction of a predetermined electric field of light modulated and emitted by the reflective spatial light modulation element,
The image display apparatus, wherein the second polarizer is provided so that a transmission axis of the second polarizer is parallel to a vibration direction of the predetermined electric field. At least a light source, a polarization separation element, a first light deflection element, a reflective spatial light modulation element, a first phase shifter, a second light deflection element, and a projection lens;
The first and second light deflection elements have a function of deflecting light within a plane of vibration of a linearly polarized electric field,
The first phase shifter is provided between optical paths of the first optical deflection element and the second optical deflection element, and a slow axis of the first phase shifter is connected to the first phase shifter. An image display device provided so as not to be horizontal and vertical with respect to a vibration plane of an incident electric field of linearly polarized light. A light source, a first polarizer, a first light deflection element, a reflective spatial light modulation element, a first phase shifter, a second light deflection element, a second polarizer, and a projection lens;
The first and second light deflection elements have a function of deflecting light within a plane of vibration of a linearly polarized electric field,
The first phase shifter is provided between optical paths of the first optical deflection element and the second optical deflection element, and a slow axis of the first phase shifter is connected to the first phase shifter. Provided so as not to be horizontal and vertical to the vibration plane of the incident linearly polarized electric field,
The first polarizer and the second polarizer are provided so that a transmission axis of the first polarizer and a transmission axis of the second polarizer are orthogonal to each other. .   The image display apparatus according to claim 2, wherein the first phase shifter is a half-wave plate.   The image display apparatus according to claim 1, wherein a second phase shifter is provided between optical paths of the polarization separation element and the light deflection element.   The image display device according to claim 7, wherein the second phase shifter is a ¼ wavelength plate.   The angle formed by the direction of vibration of the linearly polarized electric field and the horizontal and vertical directions of the sides of the square pixel in the reflective spatial light modulator is 45 °. Image display device.   The image display apparatus according to claim 2, wherein an angle formed between a slow axis of the first phase shifter and a direction of vibration of the electric field of the linearly polarized light is 22.5 °.   Red, green, and blue light is incident on the spatial light modulator in a time-sharing manner, and the light deflector deflects only one of the three colors of light. The image display device according to claim 1.   The image display device according to claim 11, wherein the light deflection element deflects only green light of the three colors of light.   The image display device according to claim 1, wherein the reflective spatial light modulator has a microlens.   The image display device according to claim 1, wherein the square pixels of the reflective spatial light modulator are concave.   The image display apparatus according to claim 3, wherein the vibration direction of the predetermined electric field is a direction orthogonal to a transmission axis of the first polarizer.   The third phase is set in a state where the slow axis is rotated with respect to the vibration direction of the electric field of the linearly polarized light after the first polarizer exits after the light traveling direction of the first polarizer. The image display device according to claim 3, wherein a phase shifter is provided.   The image display device according to claim 3, wherein the first polarizer, the second polarizer, or the polarization separation element is a wire grid polarizer.   The image display device according to claim 3, wherein the light deflection element is provided between an optical path between the spatial light modulation element and the second polarizer.

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