JP2010243584A - Image display device and image display method - Google Patents

Abstract

An image display apparatus and an image display method capable of improving display resolution while preventing image quality deterioration such that an image looks blurred.
The projector includes a light source that emits light including a plurality of color lights, and a plurality of liquid crystal lights in which a plurality of pixels are arranged in a matrix and the light emitted from the light source is modulated for each color light. Valves 24R, 24G, and 24B (light modulation elements), and a projection optical system 3 that projects light modulated by the plurality of light modulation elements onto the screen 34 (projected surface). Among the plurality of pixel images, the position of at least one pixel image is shifted from the position of the other pixel image, and the image of the intra-pixel light transmitting portion in the at least one pixel image and the intra-pixel light in the other pixel image The image of the transmission part is not superimposed.
[Selection] Figure 1

Description

  The present invention relates to an image display device and an image display method.

  In a projection-type image display device such as a projector, when the image display device includes a light modulation element such as a liquid crystal light valve, the resolution of the image projected on the screen is the resolution of the light modulation element (the number of horizontal pixels, vertical Usually, it matches the number of pixels. The “resolution of the image projected on the screen” is hereinafter referred to as “display resolution”. On the other hand, as a method for improving the display resolution without changing the resolution of the light modulation elements, the number of light modulation elements is increased and the position of the image of each pixel formed by each light modulation element is shifted on the screen for projection. There is a way.

  For example, a total of six liquid crystal panels are used, two for each color of red (R), green (G), and blue (B), and each pixel of the first liquid crystal panel (R, G, B) is used. A liquid crystal projector apparatus having a configuration in which the display of each pixel of the second liquid crystal panel (R ′, G ′, B ′) is shifted by ½ pixel pitch with respect to the display has been proposed (for example, the following patents) Reference 1). In addition, two liquid crystal panels for green light modulation, a total of four liquid crystal panels are used, and the display of the first green pixel and the display of the second green pixel are shifted by a ½ pixel pitch. A liquid crystal projector device has also been proposed (see, for example, Patent Document 2 below).

JP-A-5-323270 JP 2003-322854 A

  However, in the liquid crystal projector devices disclosed in Patent Documents 1 and 2, although a sense of improvement in resolution can be obtained, there has been a problem of image quality deterioration in which the sharpness of the image is lowered and the image looks blurred.

  The present invention has been made to solve the above-described problems, and provides an image display device and an image display method capable of improving display resolution while preventing image quality deterioration such that an image looks blurred. With the goal.

  In order to achieve the above object, an image display device according to the present invention includes a light source that emits light including a plurality of colored lights having different wavelength ranges, and a light that is emitted from the light source in which a plurality of pixels are arranged in a matrix. A plurality of light modulation elements that modulate the light for each color light, and a projection optical system that projects the light modulated by the plurality of light modulation elements onto the projection surface, and is projected onto the projection surface. Among the plurality of pixel images of the plurality of light modulation elements, the position of at least one pixel image is deviated from the position of the other pixel image, and the image of the in-pixel light transmission portion in the at least one pixel image It is characterized in that the image of the intra-pixel light transmission part in the other pixel image is not superimposed.

  As a result of studying the cause of image blurring in the conventional image display device, the present inventors found that the cause is that the pixels in the shifted positional relationship overlap each other, thereby I found out that the sharpness is lost. In the image display device of the present invention, the position of at least one pixel image out of the plurality of pixel images of the plurality of light modulation elements projected on the projection surface is shifted from the position of the other pixel image, and The image of the in-pixel light transmission part in at least one pixel image and the image of the in-pixel light transmission part in other pixel images are not superimposed. Therefore, it is possible to provide an image display device that can ensure the sharpness of the edge portion of the display pattern, and can improve the display resolution while preventing image quality deterioration such as image blurring.

In the image display device of the present invention, the horizontal pitch between two adjacent intra-pixel light transmission part images in the other pixel image is W, and the vertical pitch between the two adjacent intra-pixel light transmission part images. Is defined as H, and the area of the in-pixel light transmission portion image in the at least one pixel image is defined as S, and the light transmission portion area ratio is defined as S / (W × H), the light transmission portion area ratio S / (W × H ) Is desirably 0.25 or less.
If the shape of the in-pixel light transmission part image is a rectangle, when the light transmission part area ratio S / (W × H) is 0.25, the inside of the four pixels adjacent to each other in the horizontal direction and the vertical direction in the other pixel images. At the center between the light transmission portion images, the in-pixel light transmission portion image in at least one pixel image is just fitted so that the corner portions thereof are in contact with each other. Therefore, when the light transmission area ratio S / (W × H) is 0.25 or less, it is possible to reliably realize a configuration in which the in-pixel light transmission images are not overlapped.

In the image display device of the present invention, the plurality of light modulation elements are provided with a light shielding film having a pixel opening corresponding to the pixel, and a plurality of microlenses are arrayed on a light incident side of the plurality of light modulation elements. The microlens array arranged in a shape is provided, and the light incident on the microlens array is in a state in which a light beam incident on each of the microlenses is condensed in a range smaller than the pixel opening. A configuration that transmits the light modulation element can be employed.
According to this configuration, by changing the curvature (focal length) of each microlens constituting the microlens array, the light flux incident on each microlens is collected regardless of the size of the pixel opening. The size of the in-pixel light transmission portion image can be adjusted as appropriate. Therefore, the configuration of the present invention can be realized without particularly changing the design of the light shielding film such as a black matrix provided in the light modulation element.

Alternatively, in the image display device of the present invention, the plurality of light modulation elements includes a light shielding film having a pixel opening corresponding to the pixel, and light incident on each of the plurality of light modulation elements is the pixel. A configuration that allows the entire region in the opening to pass through can be employed.
According to this configuration, contrary to the above configuration, the size of the light transmitting portion image in the pixel is defined by the pixel opening of the light shielding film of the light modulation element, so the light transmitting portion area ratio satisfies the above condition. The design of the present invention can be realized without using a microlens array as long as the pixel aperture is designed to satisfy the above condition.

In the image display device according to the aspect of the invention, the plurality of color lights are red light, green light, and blue light, and the plurality of light modulation elements modulates the red light. A red light modulation element, a first green light modulation element that modulates the green light, a second green light modulation element, and a first blue light modulation that modulates the blue light. An element and a second blue light modulation element, and in the first red light modulation element, the first green light modulation element, and the first blue light modulation element. The position of the pixel image is shifted from the position of the pixel image in the second light modulator for red light, the second light modulator for green light, and the second light modulator for blue light. Configuration can be adopted.
According to this configuration, since the two pixel images having the shifted positional relationship are each composed of a pixel image by red light, a pixel image by green light, and a pixel image by blue light, an image with excellent color balance can be obtained. Can do.

Alternatively, in the image display device of the present invention, the plurality of color lights are red light, green light, and blue light, and the plurality of light modulation elements are a light modulation element for red light that modulates the red light and the green light. A light modulating element for green light that modulates light and a light modulating element for blue light that modulates blue light, the light modulating element for red light, the light modulating element for green light, and the light for blue light Among the modulation elements, a configuration in which the position of the pixel image in one of the light modulation elements and the position of the pixel image in the remaining two light modulation elements are shifted can be employed.
According to this configuration, the configuration of the present invention is realized by using a general image display device including three light modulation elements, a red light modulation element, a green light modulation element, and a blue light modulation element. it can.

  The image display method of the present invention includes a light source that emits light including a plurality of color lights having different wavelength ranges, a plurality of pixels arranged in a matrix, and a plurality of light sources that modulate the light emitted from the light source for each color light. An image display method using an image display device comprising: a light modulation element; and a projection optical system that projects light modulated by the plurality of light modulation elements onto a projection surface, the image display method comprising: Among the plurality of pixel images of the plurality of light modulation elements to be projected to the position, the position of at least one pixel image is shifted from the position of the other pixel image, and the in-pixel light transmission portion in the at least one pixel image and the It is characterized by not overlapping the in-pixel light transmission part in other pixel images.

  In the image display method of the present invention, since the in-pixel light transmission part in at least one pixel image and the in-pixel light transmission part in another pixel image are not overlapped, the sharpness of the edge portion of the display pattern is ensured, It is possible to improve display resolution while preventing image quality deterioration such as image blurring.

1 is a schematic configuration diagram of a projector according to a first embodiment of the invention. It is sectional drawing which shows one form of the liquid crystal light valve of this projector. It is a figure which shows the image which shifted the position of the pixel image in this embodiment. It is a figure for demonstrating the light transmissive part area ratio. It is a graph which shows the relationship between a spatial frequency and amplitude ratio when changing the light transmissive part area ratio. It is a figure which shows the effect of the projector of this embodiment. It is a schematic block diagram of the projector of 2nd Embodiment of this invention. It is a figure which shows the image which shifted the position of the pixel image in this embodiment. It is a figure which shows the other image which shifted the position of the pixel image. It is a figure which shows the other image which shifted the position of the pixel image. It is sectional drawing which shows the other form of a liquid crystal light valve.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
The image display apparatus according to the present embodiment is a configuration example of a so-called six-plate projector having six sets of liquid crystal light valves, two sets for each of three colors R, G, and B.
FIG. 1 is a schematic configuration diagram of a projector according to the present embodiment. FIG. 2 is a cross-sectional view showing an embodiment of the liquid crystal light valve of the projector according to the present embodiment. 3A and 3B are diagrams showing an image in which the position of the pixel image on the screen is shifted in the present embodiment. FIG. 3A shows the present embodiment, and FIG. 3B shows a conventional example. FIG. 4 is a diagram for explaining the light transmitting portion area ratio. FIG. 5 is a graph showing the relationship between the spatial frequency and the amplitude ratio when the light transmission area ratio is changed. 6A and 6B are diagrams illustrating effects of the projector according to the present embodiment. FIG. 6A is an original display pattern, FIG. 6B is a conventional display pattern, and FIG. 6C is a display pattern according to the present embodiment. , Respectively.
In each of the following drawings, in order to make the components easy to see, the ratios and scales of the dimensions may be varied depending on the components.

As shown in FIG. 1, the projector 1 according to the present embodiment modulates light emitted from a light source according to an input image signal and forms image light, and two image forming optical systems 2A and 2B. A projection optical system 3 that projects the image light formed by the forming optical systems 2A and 2B.
The image forming optical systems 2A and 2B include an image forming optical system 2A arranged so that an emission direction of the formed image light and a projection direction of the image light by the projection optical system 3 are substantially parallel to each other. The image forming optical system 2B is disposed so that the emission direction and the projection direction of the image light by the projection optical system 3 are substantially orthogonal to each other. Each of the image forming optical systems 2A and 2B includes an illumination optical system 4, a color separation optical system 5, a relay optical system 6, and electro-optical devices 7A and 7B.

The illumination optical system 4 forms an image of light emitted from the light source 9 in an illuminated area, and includes a light source 9, a first lens array 11, a second lens array 12, and a superimposing lens 13. ing.
Although not shown, the light source 9 is a light source lamp that emits a radial light beam, a reflector that reflects the radiated light emitted from the light source lamp and converges it at a predetermined position, and the light converged by the reflector is an illumination optical axis. And a collimating concave lens that collimates with respect to A.

  The first lens array 11 and the second lens array 12 have a configuration in which small lenses corresponding to each other are arranged in a matrix, and the first lens array 11 transmits light incident from the light source 9 into a plurality of portions. The light is divided and imaged in the vicinity of the second lens array 12. In addition, the second lens array 12 forms an image emitted from each small lens of the first lens array 11 together with the superimposing lens 13 located in the subsequent stage of the optical path, on the liquid crystal panel of the electro-optical devices 7A and 7B described later. Image the area. Each partial light emitted from the second lens array 12 is linearly polarized light having substantially one type of polarization direction by a polarization conversion element (not shown) disposed between the second lens array 12 and the superimposing lens 13. Is converted to The linearly polarized light converted by the polarization conversion element in the image forming optical system 2A and the linearly polarized light converted by the polarization conversion element in the image forming optical system 2B are linearly polarized light having different types of polarization directions. Yes.

  The color separation optical system 5 includes two dichroic mirrors 15 and 16 and a reflection mirror 17, and a plurality of partial lights emitted from the illumination optical system 4 by the dichroic mirrors 15 and 16 are converted into red light ( R light), green light (G light), and blue light (B light). The relay optical system 6 includes an incident side lens 19, a relay lens 20, and reflection mirrors 21 and 22, and is separated by the color separation optical system 5, and blue light having a longer optical path than other color lights is used for blue light. It has a function of leading to the liquid crystal light valve 24B.

  At this time, the dichroic mirror 15 of the color separation optical system 5 transmits the red light component of the light emitted from the illumination optical system 4, while reflecting the green light component and the blue light component. The red light transmitted through the dichroic mirror 15 is reflected by the reflection mirror 17 and passes through the field lens 25 to reach the red light liquid crystal light valve 24R. The field lens 25 converts each partial light emitted from the second lens array 12 into light parallel to the central axis (principal ray). The same applies to the field lens 25 provided on the light incident side of the liquid crystal light valve 24G for green light and the liquid crystal light valve 24B for blue light.

  Of the green light and blue light reflected by the dichroic mirror 15, the green light is reflected by the dichroic mirror 16, passes through the field lens 25, and reaches the green light liquid crystal light valve 24G. On the other hand, the blue light passes through the dichroic mirror 16, passes through the relay optical system 6, and further passes through the field lens 25 to reach the blue light liquid crystal light valve 24B.

The electro-optical devices 7A and 7B modulate incident light according to an image signal to form image light. The emission direction of the formed image light and the projection direction of the image light by the projection optical system 3 are substantially the same. A parallel-side electro-optical device 7A arranged so as to be parallel, and a vertical-side electro-optical device 7B arranged so that the emission direction of the formed image light and the projection direction of the image light by the projection optical system 3 are substantially orthogonal to each other. And is composed of.
Each of the electro-optical devices 7A and 7B includes three liquid crystal light valves (a liquid crystal light valve for red light 24R, a liquid crystal light valve for green light 24G, and a liquid crystal light valve for blue light 24B), and the liquid crystal light valves 24R and 24G. , 24B, an incident side polarizing plate (not shown) arranged on the light incident side, an emission side polarizing plate (not shown) arranged on the light emitting side of each liquid crystal light valve, and a cross dichroic prism 26 (color combining optics). System).

  The incident side polarizing plate transmits only polarized light having a polarization direction substantially the same as the polarization direction aligned by the polarization conversion element among the color lights separated by the color separation optical system 5 and absorbs other light. The liquid crystal light valves 24R, 24G, and 24B as the light modulation elements are controlled in the alignment state of the liquid crystal in the liquid crystal panel 28 according to the input image signal, so that the polarization direction of the polarized light incident from the incident side polarizing plate. Modulate. The exit-side polarizing plate transmits polarized light in a certain direction (for example, light having a polarization axis perpendicular to the light transmission axis of the incident-side polarizing plate) out of the light emitted through the liquid crystal panel 28, and the other Absorbs light.

  A cross dichroic prism 26 serving as a color synthesis optical system combines the color lights emitted from the emission-side polarizing plates to form image light. The cross dichroic prism 26 has a substantially square shape in plan view in which four right angle prisms are bonded together, and two dielectric multilayer films are formed on the interface where the right angle prisms are bonded together. These dielectric multilayer films transmit green light emitted from the liquid crystal light valve 24G, and reflect red light and blue light emitted from the liquid crystal light valves 24R and 24B. Thereby, image light (color image) in which red light, green light, and blue light are combined is formed.

  The projection optical system 3 includes a polarization beam splitter 31 (hereinafter abbreviated as PBS) and a projection lens 32. The PBS 31 is formed by bonding two right-angle prisms, and transmits light in one polarization direction and reflects light in the other polarization direction through a dielectric polarizing film formed at the interface where the right-angle prisms are bonded. Let In the present embodiment, the image light emitted from the image forming optical system 2A is transmitted through the dielectric polarizing film, and the image light emitted from the image forming optical system 2B is reflected by the dielectric polarizing film, and the projection lens 32 respectively. Led to. The projection lens 32 is configured as a combined lens in which a plurality of lenses are housed in a cylindrical lens barrel (not shown), and enlarges and projects image light emitted from the PBS 31 onto a projection surface such as a screen 34.

  As shown in FIG. 2, the liquid crystal light valves 24R, 24G, and 24B of the present embodiment include a liquid crystal panel 28 and a microlens array 29 arranged on the light incident side of the liquid crystal panel 28. The liquid crystal panel 28 has a configuration in which a liquid crystal layer as an electro-optical material is sealed between a pair of transparent glass substrates 36 and 37. The liquid crystal panel 28 has an image forming region in which a plurality of pixels P are arranged in a matrix, and includes a black matrix 38 (light-shielding film) that partitions the plurality of pixels P arranged in a matrix. . The black matrix 38 also has a function of shielding data lines, scanning lines, thin film transistors (hereinafter abbreviated as TFTs) and the like formed on the active matrix substrate of the pair of glass substrates 36 and 37. ing. Therefore, the black matrix 38 is formed in a lattice shape on the liquid crystal layer side surface of one of the glass substrates 36 and 37 using a light-shielding metal film such as chromium, and is provided corresponding to each pixel P. Light passes through the pixel opening Pa, contributing to image formation.

  Here, as shown in FIG. 2, the light incident on the microlens array 29 is collected by the microlenses 40 so that the light flux Lp incident on each microlens 40 is smaller than the pixel opening Pa. In this state, the liquid crystal panel 28 is transmitted. Thereby, the image by the light which finally passed through each pixel opening Pa projected on the screen 34 becomes smaller than the image when the pixel opening Pa is projected as it is. Hereinafter, the “image on the screen generated by the light transmitted through each pixel opening” is referred to as an “in-pixel light transmitting portion image”.

  In this embodiment, as shown in FIG. 3A, the in-pixel light transmission portion images R1, G1, B1 by the three liquid crystal light valves 24R, 24G, 24B in the parallel-side electro-optical device 7A, and the vertical-side electro-optics. In-pixel light transmission portion images R2, G2, and B2 by the three liquid crystal light valves 24R, 24G, and 24B in the device 7B are oblique to the arrangement direction (horizontal direction and vertical direction) of the in-pixel light transmission portion images. It is off. This is because the two sets of intra-pixel light transmission portion images R1, G1, B1, R2, G2, and B2 are shifted obliquely while projecting an image on the screen 34. This can be realized by adjusting the relative position with respect to the electro-optical device 7B and then assembling these electro-optical devices 7A and 7B in the housing of the projector 1.

  On the other hand, FIG. 3B is a diagram illustrating a state in which the pixel image is shifted in a conventional projector having a configuration in which the pixel image is shifted. In the conventional projector, the in-pixel light transmitting portion images R1, G1, B1, R2, G2, and B2 that are in a shifted positional relationship are overlapped in this manner. This seems to be the cause of image blurring. On the other hand, in the projector 1 of the present embodiment, the in-pixel light transmission part images R1, G1, B1 by the three liquid crystal light valves 24R, 24G, 24B in the parallel side electro-optical device 7A, and the three in the vertical side electro-optical device 7B. The in-pixel light transmission portion images R2, G2, and B2 by the two liquid crystal light valves 24R, 24G, and 24B are not superimposed.

  Here, as shown in FIG. 4, for example, the pitch in the horizontal direction between two adjacent intra-pixel light transmitting portion images R1, G1, B1 in the liquid crystal light valves 24R, 24G, 24B on the parallel electro-optical device 7A side is set. W, the vertical pitch between two adjacent in-pixel light transmission part images R1, G1, B1 is H, and the in-pixel light transmission part image R2 in the liquid crystal light valves 24R, 24G, 24B on the vertical electro-optical device 7B side. , G2, B2 is defined as S, and the light transmission area ratio is defined as S / (W × H). In-pixel light transmission portion images R1, G1, and B1 by the liquid crystal light valves 24R, 24G, and 24B in the parallel-side electro-optical device 7A, and In-pixel light transmission portions by the liquid crystal light valves 24R, 24G, and 24B in the vertical-side electro-optical device 7B. In order not to overlap the images R2, G2, and B2, the light transmission area ratio S / (W × H) needs to be 0.25 or less.

  For example, assuming that the shapes of the in-pixel light transmission part images R1, G1, B1, R2, G2, and B2 are square, when the light transmission part area ratio S / (W × H) is 0.25, the parallel-side electric The liquid crystal light on the vertical electro-optical device 7B side is located at the center between the four in-pixel light transmission part images R1, G1, B1 in the liquid crystal light valves 24R, 24G, 24B on the optical device 7A side. The in-pixel light transmission portion images R2, G2, and B2 in the bulbs 24R, 24G, and 24B are just fitted so that the corner portions thereof are in contact with each other. Therefore, when the light transmission area ratio S / (W × H) is 0.25 or less, the in-pixel light transmission area images R1, G1, B1, R2, G2, and B2 do not overlap each other.

  As described above, according to the projector 1 of the present embodiment, since the in-pixel light transmission portion images R1, G1, B1, R2, G2, and B2 that are in the shifted positional relationship do not overlap each other, The sharpness of the portion is ensured, and the display resolution can be improved while preventing image quality deterioration such as image blurring. In the present embodiment, since the liquid crystal light valves 24R, 24G, and 24B are provided with the microlens array 29, if the curvature (focal length) of each microlens 40 constituting the microlens array 29 is changed, the pixels Regardless of the size of the opening Pa, the size of the in-pixel light transmitting portion images R1, G1, B1, R2, G2, and B2 on the screen 34 can be adjusted as appropriate. Therefore, it is not necessary to change the design of the black matrix 38 in the liquid crystal panel 28. Furthermore, each of the two in-pixel light transmitting portion images R1, G1, B1, R2, G2, and B2 having a shifted positional relationship is configured by an image by red light, an image by green light, and an image by blue light. An image with excellent color balance can be obtained.

The inventors of the present invention evaluated the sharpness of the display pattern by changing the light transmission area ratio S / (W × H). FIG. 5 shows a simulation result of the frequency characteristics of the projector, where the horizontal axis represents the frequency of the input signal and the vertical axis represents the amplitude ratio.
First, a discrete signal input to each pixel in the spatial domain and an interpolation function at a predetermined light transmission area ratio are set, and then Fourier transform is performed using the discrete signal and the interpolation function. It is possible to calculate the frequency characteristic of the amplitude ratio as shown in FIG. The amplitude ratio has a value of 1 when the input signal can be reproduced 100%, and the smaller the value is, the more the input signal cannot be reproduced faithfully, and the sharpness of the display pattern decreases. As a result of the change of the interpolation function in accordance with the change in the light transmission area ratio, the frequency characteristic of the amplitude ratio changes. As can be seen from FIG. 5, as the light transmission area ratio S / (W × H) is reduced from 100% to 20%, the frequency characteristic of the amplitude ratio takes a value close to 1, and the sharpness of the display pattern Can be confirmed.

  FIGS. 6A to 6C are enlarged views of the actual display pattern. The original display pattern (in a state where no pixel shift is performed) is the letter “m” shown in FIG. It is. On the other hand, as shown in FIG. 6B, when the light transmission area ratio is 72%, the sharpness of the edge of the character is lost and the character looks blurred. On the other hand, as shown in FIG. 6C, when the light transmission area ratio is 25%, which is the range of the present embodiment, the sharpness of the edge portion of the character is improved, and FIG. The characters are clearly visible.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS.
The image display apparatus according to this embodiment is a configuration example of a three-plate projector.
FIG. 7 is a schematic configuration diagram of the projector according to the present embodiment. 8 and 9 are diagrams showing images obtained by shifting the position of the pixel image in the present embodiment.
In FIG. 7, the same components as those in FIG. 1 of the first embodiment are denoted by the same reference numerals, and detailed description may be omitted.

  As shown in FIG. 7, the projector 51 of this embodiment includes an illumination optical system 52, a color separation optical system 5, a relay optical system 6, liquid crystal light valves 24R, 24G, and 24B (light modulation means), a cross A dichroic prism 26 (color combining means) and a projection lens 3 (projection optical system) are provided. The illumination optical system 52 includes a light source 9, a first lens array 11 and a second lens array 12, and a polarization conversion element 53.

  The color separation optical system 5 includes dichroic mirrors 15 and 16. Of the light emitted from the light source 9, the red light LR passes through the dichroic mirror 15, while the green light LG and the blue light LB are reflected by the dichroic mirror 15. Of the green light LG and blue light LB reflected by the dichroic mirror 15, the blue light LB passes through the dichroic mirror 16, and the green light LG is reflected by the dichroic mirror 16.

  The red light LR that has passed through the dichroic mirror 15 is reflected by the reflection mirror 17 and enters the liquid crystal light valve 24R for red light through the field lens 25. The green light LG reflected by the dichroic mirror 16 passes through the field lens 25 and enters the green light liquid crystal light valve 24G. The blue light LB transmitted through the dichroic mirror 16 enters the blue light liquid crystal light valve 24B via the relay optical system 6.

  Each of the liquid crystal light valves 24R, 24G, and 24B includes a transmissive liquid crystal panel 28 and a microlens array 29 provided on the light incident side of the liquid crystal panel 28, as in the first embodiment. In addition, on the light incident side and the light exit side of the liquid crystal light valves 24R, 24G, and 24B, an incident side polarizing plate and an exit side polarizing plate are provided, respectively. The red light LR, the green light LG, and the blue light LB modulated by the liquid crystal light valves 24R, 24G, and 24B are incident on the cross dichroic prism 26, and the three color lights are combined into a combined light L. The combined light L enters the projection lens 3 and is enlarged and projected onto the screen 34 (projected surface) by the projection lens 3.

  In the first embodiment, since there are six sets of liquid crystal light valves, two sets for each color light of R, G, and B, each of the two intra-pixel light transmitting portion images in the shifted positional relationship is red light. Image, green light image, and blue light image. On the other hand, in the present embodiment, there are three sets of liquid crystal light valves 24R, 24G, and 24B, one set for each color light of R, G, and B. Therefore, as shown in FIG. In contrast, the in-pixel light transmission portion image R by the red light liquid crystal light valve 24R and the in-pixel light transmission portion image B by the blue light liquid crystal light valve 24B, and the in-pixel light transmission portion image by the green light liquid crystal light valve 24G. Only G is shifted in an oblique direction with respect to the arrangement direction (horizontal direction, vertical direction) of the in-pixel light transmission portion image.

  Further, in the conventional projector, as shown in FIG. 8B, the intra-pixel light transmission portion images R, G, and B that are in a shifted positional relationship are superimposed, whereas the projector 51 of the present embodiment. As shown in FIG. 8A, the in-pixel light transmission portion image R by the red light liquid crystal light valve 24R and the in-pixel light transmission portion image B by the blue light liquid crystal light valve 24B overlap each other. However, the in-pixel light transmission part image R by the green light liquid crystal light valve 24G is not superimposed on the in-pixel light transmission part images R and B. In the case of the present embodiment as well, as in the first embodiment, the light transmission area ratio S / (W × H) is set to 0.25 or less.

  Also in the projector 51 of the present embodiment, the in-pixel light transmission portion images R, G, and B that are in a shifted positional relationship are not superimposed on each other, so that the display resolution can be improved while preventing image quality deterioration such as image blurring. The same effects as in the first embodiment can be obtained. In the present embodiment, since the present invention is applied to a so-called three-plate projector having three sets of liquid crystal light valves 24R, 24G, and 24B, the apparatus configuration is complicated as in the first embodiment. Therefore, the effect of the present invention can be sufficiently obtained.

  Of the three sets of liquid crystal light valves 24R, 24G, and 24B, the liquid crystal light valve that is to shift the in-pixel light transmission portion images R, G, and B is not limited to the green light liquid crystal light valve 24G. The liquid crystal light valve 24R for red light may be used, or the liquid crystal light valve 24B for blue light may be used. However, since green has the highest visibility for the human eye, as in the above configuration, the in-pixel light transmission portion image R by the red light liquid crystal light valve 24R and the pixel by the blue light liquid crystal light valve 24B. The difference in luminance among the in-pixel light transmitting portion images R, G, and B constituting the image is that the in-pixel light transmitting portion image G by the green light liquid crystal light valve 24G is shifted with respect to the inside light transmitting portion image B. Is desirable in the sense that becomes smaller.

  In both the first embodiment and the second embodiment, the in-pixel light transmission part image is obliquely shifted with respect to the arrangement direction of the in-pixel light transmission part image. With this configuration, it is possible to more effectively obtain a sense of improved resolution that matches the visual characteristics of the human eye. However, the direction in which the in-pixel light transmissive portion image is shifted is not necessarily limited to the oblique direction with respect to the arrangement direction of the in-pixel light transmissive portion image. Direction).

  For example, as shown in FIG. 9A, the in-pixel light transmitting portion images R, G, and B are shifted in the horizontal direction of the screen, and the in-pixel light transmitting portion image R by the red light liquid crystal light valve 24R and the green light are displayed. The in-pixel light transmission portion image G by the liquid crystal light valve 24G and the in-pixel light transmission portion image B by the blue light liquid crystal light valve 24B may not be completely overlapped. In the case of this configuration, the light transmission area ratio S / (W × H) is about 0.11, and the light transmission area ratio S / (W × H) satisfies the condition of 0.25 or less. Also in this configuration, the display resolution can be improved while preventing image quality deterioration such as image blurring as compared with the conventional case in which the intra-pixel light transmission portion image shown in FIG. 9B is superimposed.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the first embodiment, an example of a six-plate projector is shown, and in the second embodiment, an example of a three-plate projector is shown, but the number of light modulation elements is not limited thereto. For example, two sets of liquid crystal light valves for green light having the highest visibility are used, and as shown in FIG. 10A, the light transmission portion image R in the pixel by the liquid crystal light valve for red light and the liquid crystal light valve for blue light are used. The in-pixel light transmission part image B and the in-pixel light transmission part image G1 by the first green light liquid crystal light valve are superimposed, and only the in-pixel light transmission part image G2 by the second green light liquid crystal light valve is obliquely displayed. It is good also as a structure which is not shifted and superimposed. Even in this configuration, the display resolution can be reduced while preventing image quality deterioration such as image blurring, as compared with the conventional case in which the in-pixel light transmission portion images R, G1, G2, and B shown in FIG. Can be improved.

  In the above-described embodiment, the light of the liquid crystal panel constituting the liquid crystal light valve is used as means for reducing the in-pixel light transmission portion image so that the light transmission portion area ratio S / (W × H) is 0.25 or less. Although the configuration in which the microlens array is arranged on the incident side is illustrated, the configuration is not limited to this configuration. For example, as shown in FIG. 11, a lattice-shaped light shielding film 64 is also provided on the substrate 63 on the opposite side of the substrate 62 on the side of the liquid crystal panel 60 on which the black matrix 61 is provided, and from the pixel opening Pa1 of the black matrix 61. Alternatively, a configuration in which the pixel opening Pa2 of the newly provided light shielding film 64 is reduced may be employed. According to this configuration, since the size of the in-pixel light transmission part image is defined by the pixel opening Pa2 of the light shielding film 64, the pixel opening Pa2 is designed so that the light transmission part area ratio satisfies the above condition. As long as only the microlens array is used, the effects of the present invention can be obtained.

  In the above-described embodiment, the example in which the in-pixel light transmitting portion images are shifted and disposed at two positions has been described. However, the in-pixel light transmitting portion images may be disposed at three or more positions. In addition, although an example in which a transmissive liquid crystal light valve is used as the light modulation element has been described, a reflective liquid crystal light valve, a digital micromirror device (DMD), or the like can also be used. . The specific configuration of each part of the projector described in the above embodiment can be changed as appropriate.

  DESCRIPTION OF SYMBOLS 1,51 ... Projector (image display apparatus), 3 ... Projection optical system, 9 ... Light source, 24R, 24G, 24B ... Liquid crystal light valve (light modulation element), 29 ... Micro lens array, 34 ... Screen (projection surface) 38, 61 ... Black matrix (light shielding film), 40 ... Microlens, P ... Pixel, Pa, Pa1, Pa2 ... Pixel opening, R, G, B, R1, G1, B1, R2, G2, B2 ... Pixel Internal light transmission part image.

Claims (7)

A light source that emits light including a plurality of colored lights having different wavelength ranges;
A plurality of pixels arranged in a matrix, and a plurality of light modulation elements for modulating the light emitted from the light source for each color light;
A projection optical system that projects light modulated by the plurality of light modulation elements onto a projection surface;
Among the plurality of pixel images of the plurality of light modulation elements projected onto the projection surface, the position of at least one pixel image is shifted from the position of another pixel image, and the at least one pixel image. An image display device characterized in that the image of the in-pixel light transmission part in FIG. 5 and the image of the in-pixel light transmission part in the other pixel image are not superimposed.   In the other pixel image, a horizontal pitch between two adjacent in-pixel light transmitting portion images is W, a vertical pitch between the two adjacent in-pixel light transmitting portion images is H, and the at least one pixel. If the area of the in-pixel light transmission part image in the image is defined as S and the light transmission part area ratio is defined as S / (W × H), the light transmission part area ratio S / (W × H) is 0.25 or less. The image display apparatus according to claim 1. The plurality of light modulation elements are provided with a light shielding film having a pixel opening corresponding to each pixel,
A microlens array in which a plurality of microlenses are arranged in an array on the light incident side of the plurality of light modulation elements is provided,
The light incident on the microlens array is transmitted through the light modulation element in a state where a light beam incident on each of the microlenses is condensed in a range smaller than the pixel opening. The image display device according to claim 2. The plurality of light modulation elements are provided with a light shielding film having a pixel opening corresponding to each pixel,
The image display apparatus according to claim 2, wherein light incident on each of the plurality of light modulation elements is transmitted through the entire area of the pixel opening. The plurality of color lights are red light, green light, blue light,
The plurality of light modulation elements include a first light modulation element for red light and a second light modulation element for red light that modulate the red light, and a first light modulation element for green light that modulates the green light. And a second light modulation element for green light, and a first light modulation element for blue light and a second light modulation element for blue light that modulate the blue light,
Positions of pixel images in the first red light modulation element, the first green light modulation element, and the first blue light modulation element, and the second red light modulation element The position of the pixel image in the second light modulation element for green light and the second light modulation element for blue light is shifted from each other. The image display device described. The plurality of color lights are red light, green light, blue light,
The plurality of light modulation elements are: a red light modulation element that modulates the red light; a green light modulation element that modulates the green light; and a blue light modulation element that modulates the blue light; Consists of
The position of the pixel image in any one of the light modulation element for red light, the light modulation element for green light, and the light modulation element for blue light, and the pixel image in the remaining two light modulation elements The image display apparatus according to claim 1, wherein the position is deviated from the position of the image display apparatus. A light source that emits light including a plurality of color lights having different wavelength ranges, a plurality of pixels arranged in a matrix, a plurality of light modulation elements that modulate the light emitted from the light source for each color light, and the plurality of light sources A projection optical system for projecting light modulated by a light modulation element onto a projection surface, and an image display method using an image display device comprising:
Among the plurality of pixel images of the plurality of light modulation elements projected onto the projection surface, the position of at least one pixel image is shifted from the position of another pixel image, and the pixel in the at least one pixel image An image display method, wherein an image of a light transmission part and an image of an intra-pixel light transmission part in the other pixel image are not superimposed.

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