JP4654579B2 - Optical system light propagation structure and optical display device, optical system light propagation method, and optical display device display method - Google Patents

Description

  The present invention relates to a structure, an apparatus, and a method applied to an optical system that modulates light from a light source via a plurality of light modulation elements, and in particular, improves imaging accuracy without increasing cost. The present invention relates to a light propagation structure and an optical display device of an optical system suitable for performing high-precision modulation, a light propagation method of the optical system, and a display method of the optical display device.

In recent years, LCD (Liquid Crystal Display), EL, plasma display, CRT (Cathode Ray Tube), projectors, and other optical display devices have seen remarkable improvements in image quality, and the resolution and color gamut have achieved performance that is almost comparable to human visual characteristics. It is being done. However, looking at the luminance dynamic range, the reproduction range, remains in at most 1 to 10 ² [nit] extent, also the number of gradations is 8 bits are common. On the other hand, human visual perception has a luminance dynamic range perceived at a time of about 10 ⁻² to 10 ⁴ [nit], and the luminance discrimination capability is about 0.2 [nit], which is the number of gradations. Is converted to 12 bits. Looking at the display image of the current optical display device through such visual characteristics, the narrowness of the luminance dynamic range is conspicuous, and in addition, the reality and power of the display image are insufficient due to the lack of gradation in the shadow part and highlight part. Will feel unsatisfactory.

  Further, in computer graphics (hereinafter abbreviated as CG) used in movies, games, etc., display data (hereinafter referred to as HDR (High Dynamic Range) display data) that represents a luminance dynamic range and gradation number close to human vision. The movement of pursuing the reality of depiction is being mainstream. However, since the performance of the optical display device that displays it is insufficient, there is a problem that the expressive power inherent in the CG content cannot be fully exhibited.

Further, the next OS (Operating System) is scheduled to adopt a 16-bit color space, and the luminance dynamic range and the number of gradations are dramatically increased as compared with the current 8-bit color space. Therefore, it is desired to realize an optical display device that can make use of the 16-bit color space.
Among optical display devices, projection display devices such as liquid crystal projectors and DLP projectors are capable of displaying on a large screen and are effective in reproducing the reality and power of display images. In this field, the following proposals have been made to solve the above problems.

  As a projection display device with a high dynamic range, for example, there is a technique disclosed in Patent Document 1, which includes a light source, a first light modulation element that modulates luminance in the entire wavelength region of light, and a wavelength region of light. Among these, each wavelength region of the RGB three primary colors is provided with a second light modulation element that modulates the luminance of the wavelength region, and the light from the light source is modulated by the first light modulation element to form a desired luminance distribution, and its optical image Is imaged on the pixel surface of the second light modulation element, color-modulated, and second-order modulated light is projected. Each pixel of the first light modulation element and the second light modulation element is individually controlled based on the first control value and the second control value determined from the HDR display data. As the light modulation element, a transmittance modulation element having a pixel structure or a segment structure whose transmittance can be controlled independently and capable of controlling a two-dimensional transmittance distribution is used. A typical example is a liquid crystal light valve. Further, a reflectance modulation element may be used instead of the transmittance modulation element, and a representative example thereof is DMD.

  Consider a case where a light modulation element having a dark display transmittance of 0.2% and a bright display transmittance of 60% is used. With a single light modulation element, the luminance dynamic range is 60 / 0.2 = 300. Since the conventional projection display apparatus corresponds to optically arranging light modulation elements having a luminance dynamic range of 300 in series, a luminance dynamic range of 300 × 300 = 90000 can be realized. The same idea holds for the number of gradations, and an 8-bit gradation light modulation element is optically arranged in series, whereby a gradation number exceeding 8 bits can be obtained.

In addition, as a projection display device that realizes a high luminance dynamic range, for example, a display device disclosed in Patent Document 2 is known.
In the invention described in Patent Document 2, a light source, a first light modulation element, a light separation unit that separates light from the first light modulation element into light of RGB three primary colors, and light separated by the light separation unit respectively enter A plurality of second light modulation elements and a cross prism for combining the light from each second light modulation element, and modulating light from the light source via the first light modulation element and each second light modulation element; An image is displayed. In the invention described in Patent Document 2, the first light modulation element is imaged on the second light modulation element by an optical lens constituting an illumination optical system.
JP-A-9-116840 Japanese Patent Laid-Open No. 2001-1000068

  However, in the invention described in Patent Document 1, a light separation unit is provided between the first light modulation element and the second light modulation element, and the first light modulation element and the second light modulation element are separated from each other. Since there is no imaging means such as a lens in the meantime, there is a problem that it is difficult to accurately form an optical image of the first light modulation element on the pixel surface of the second light modulation element. In the invention described in Patent Document 2, the imaging accuracy can be improved to some extent by using high-precision optical parts such as lenses and mirrors constituting the illumination optical system. There was a problem that the cost would increase if it was composed of parts.

FIG. 20 is a diagram illustrating the configuration of the optical paths of the first light modulation element and the second light modulation element in the projection display device described in Patent Document 2. Although other optical elements such as mirrors are also arranged on the actual optical path, these optical elements are omitted in FIG. 20 for easy understanding of the following description.
In the optical system of FIG. 20, the first light modulation element 130 for luminance modulation is disposed on the light source side with the fly-eye lenses 112a and 112b interposed therebetween, and the color modulation element is disposed on the opposite side of the light source with the fly-eye lenses 112a and 112b interposed therebetween. The second light modulation element 140 is arranged. In this optical system, an optical image of each element lens constituting the fly-eye lens 112 a close to the first light modulation element 130 is formed on the pixel surface of the second light modulation element 140. Therefore, in order to obtain a desired luminance distribution, this luminance distribution must be formed for each element lens. By the way, the fly-eye lenses 112a and 112b are optical elements used for the purpose of uniforming the luminance distribution, and for that purpose, it is desirable that the number of element lenses is large. Then, the size of each element lens is inevitably smaller than each pixel size of the second light modulation element 140. Specifically, those having a size of about 1/3 to 1/5 are used. Now, considering that the pixels of the second light modulation element 140 and the pixels of the first light modulation element 130 have a one-to-one correspondence, the pixel density of the first light modulation element 130 is the pixel of the second light modulation element 140. 3-5 times the density is required. However, the current light modulation element (for example, a liquid crystal light valve) has a pixel density close to the upper limit of the microfabrication technology for high definition, and considering that point, the first light modulation element 130 It is difficult to achieve a pixel density of 3 to 5 times. Accordingly, the accuracy of the luminance distribution that can be formed by the first light modulation element 130 must be 3 to 5 times as coarse as the pixel density of the second light modulation element 140. Furthermore, since the optical image of each element lens is formed on the pixel surface of the second light modulation element 140 by at most two lenses, the fly-eye lens 112b and the condenser lens 12d that are far from the first light modulation element 130, Sufficient aberration correction cannot be performed and it must be considerably blurred. Therefore, the conventional projection display device has a problem that it is difficult to perform high-precision brightness adjustment.

  Therefore, the present invention has been made paying attention to such an unsolved problem of the conventional technique, and improves the imaging accuracy and performs high-precision modulation without increasing the cost. It is an object of the present invention to provide a light propagation structure and an optical display device suitable for an optical system, a light propagation method for an optical system, and a display method for an optical display device.

[Invention 1] In order to achieve the above object, the light propagation structure of the optical system of Invention 1 comprises:
Light from a light source is modulated via a first light modulation element having a plurality of pixels whose light propagation characteristics can be independently controlled and a second light modulation element having a plurality of pixels whose light propagation characteristics can be independently controlled. A structure applied to an optical system,
Condensing means is provided between the first light modulation element and the second light modulation element, and the first light modulation element and the second light modulation element are arranged close to each other.

  With such a configuration, when the first light modulation element is disposed on the light source side, the light from the light source is primarily modulated by the first light modulation element, and an optical image of the first light modulation element is collected. The light is transmitted to the second light modulation element via the light means. At this time, since the optical image of the first light modulation element is condensed by the light condensing means and formed on the pixel surface of the second light modulation element, the second image is obtained while suppressing a decrease in luminance due to light diffusion or the like. It is transmitted to the light modulation element. The light from the first light modulation element is secondarily modulated by the second light modulation element.

  Thereby, since the light from the light source is modulated via the first light modulation element and the second light modulation element, an effect that a relatively high luminance dynamic range and gradation number can be realized is obtained. Further, the first light modulation element and the second light modulation element are arranged close to each other, and an optical image of the first light modulation element is formed on the pixel surface of the second light modulation element via the light collecting means. An optical image of the one light modulation element can be formed on the pixel surface of the second light modulation element with a relatively high accuracy, and the pixel surface of the first light modulation element does not have to be made small, so that a relatively high accuracy can be obtained. Modulation can be performed. Accordingly, an effect that the possibility that the image quality is deteriorated can be reduced as compared with the conventional case. Furthermore, since it is not necessary to use highly accurate optical components for the illumination optical system, an effect of suppressing an increase in cost can be obtained.

Here, the light propagation characteristic refers to a characteristic that affects the propagation of light, and includes, for example, light transmittance, reflectance, refractive index, and other propagation characteristics. The same applies to the optical display devices of the inventions 2, 6 and 7, the optical propagation method of the optical system of the invention 13, and the display methods of the optical display devices of the inventions 14, 18 and 19.
The light source may be any medium that generates light. For example, the light source may be a light source built in an optical system such as a lamp, or may be a sun or indoor light. It may be an external light source. The same applies to the optical propagation method of the optical system according to the thirteenth aspect of the invention.

  The first light modulation element may have any configuration as long as it is a light modulation element having a plurality of pixels whose light propagation characteristics can be independently controlled. A single plate type composed of elements or a multi-plate type composed of a plurality of light modulation elements may be used. As a function, for example, the luminance of the entire wavelength region of light may be modulated, or the luminance of the specific wavelength region may be modulated for a plurality of different specific wavelength regions out of the wavelength region of light. It may be. The same applies to the second light modulation element. The same applies to the optical display devices of the inventions 2, 6 and 7, the optical propagation method of the optical system of the invention 13, and the display methods of the optical display devices of the inventions 14, 18 and 19.

[Invention 2] On the other hand, in order to achieve the above object, an optical display device of Invention 2 comprises:
A light source, a first light modulation element having a plurality of pixels that receive light from the light source and whose light propagation characteristics can be controlled independently; and light incident from the first light modulation element and having light propagation characteristics A device for displaying an image by modulating light from the light source via the first light modulation element and the second light modulation element. There,
Condensing means comprising a microlens array is provided on the emission side of the first light modulation element, and the first light modulation element and the second light modulation element are arranged close to each other.

  With such a configuration, in the optical display device, the light from the light source is first-order modulated by the first light modulation element, and the optical image of the first light modulation element passes through the microlens array. Is transmitted to. At this time, since the optical image of the first light modulation element is condensed by the microlens array and formed on the pixel surface of the second light modulation element, the second image is suppressed while suppressing a decrease in luminance due to light diffusion or the like. It is transmitted to the light modulation element. The light from the first light modulation element is secondarily modulated by the second light modulation element.

  Thereby, since the light from the light source is modulated via the first light modulation element and the second light modulation element, an effect that a relatively high luminance dynamic range and gradation number can be realized is obtained. Further, the first light modulation element and the second light modulation element are arranged close to each other, and an optical image of the first light modulation element is formed on the pixel surface of the second light modulation element via the microlens array. An optical image of the one light modulation element can be formed on the pixel surface of the second light modulation element with a relatively high accuracy, and the pixel surface of the first light modulation element does not have to be made small, so that a relatively high accuracy can be obtained. Modulation can be performed. Accordingly, an effect that the possibility that the image quality is deteriorated can be reduced as compared with the conventional case. Furthermore, since it is not necessary to use highly accurate optical components for the illumination optical system, an effect of suppressing an increase in cost can be obtained.

[Invention 3] Furthermore, the optical display device of Invention 3 is the optical display device of Invention 2,
A second condensing unit comprising a microlens array is provided on the incident side of the second light modulation element.
With such a configuration, in the optical display device, the light from the light source is primarily modulated by the first light modulation element, and the optical image of the first light modulation element is transmitted through the two microlens arrays to the second light. It is transmitted to the modulation element.

  Thereby, since the two microlens arrays are provided, the light collecting performance can be further improved. Accordingly, a decrease in luminance due to light diffusion or the like can be further suppressed, so that an effect of improving the luminance of the display image can be obtained. In addition, there is an effect that the optical image of the first light modulation element can be formed on the pixel surface of the second light modulation element with relatively high accuracy.

[Invention 4] Furthermore, the optical display device of Invention 4 is the optical display device of Invention 3,
The lens diameter of the microlens array of the condensing means is the same or substantially the same as the pixel of the first light modulation element, and the lens diameter of the microlens array of the second light modulation element is the same as that of the second light modulation element. It is characterized by having the same or almost the same size as the pixel.
With such a configuration, the optical image of each pixel of the first light modulation element is emitted to the second light modulation element via the element lens of the condensing means corresponding to the pixel. Further, the optical image of the first light modulation element is incident on each pixel of the second light modulation element via the element lens of the second light collecting unit corresponding to the pixel.

Thereby, the condensing performance can be further improved. Accordingly, a decrease in luminance due to light diffusion or the like can be further suppressed, so that an effect of improving the luminance of the display image can be obtained. In addition, there is an effect that the optical image of the first light modulation element can be formed on the pixel surface of the second light modulation element with relatively high accuracy.
[Invention 5] Furthermore, the optical display device of Invention 5 is the optical display device of Invention 2,
A second condensing unit comprising a selfoc lens is provided between the first light modulation element and the second light modulation element.

With such a configuration, in the optical display device, the light from the light source is primarily modulated by the first light modulation element, and the optical image of the first light modulation element passes through the microlens array and the Selfoc lens. 2 is transmitted to the light modulation element.
Thereby, since the microlens array and the Selfoc lens are provided, the light collecting performance can be further improved. Accordingly, a decrease in luminance due to light diffusion or the like can be further suppressed, so that an effect of improving the luminance of the display image can be obtained. In addition, there is an effect that the optical image of the first light modulation element can be formed on the pixel surface of the second light modulation element with relatively high accuracy.

[Invention 6] Furthermore, the optical display device of Invention 6 comprises:
A light source, a first light modulation element having a plurality of pixels that receive light from the light source and whose light propagation characteristics can be controlled independently; and light incident from the first light modulation element and having light propagation characteristics A device for displaying an image by modulating light from the light source via the first light modulation element and the second light modulation element. There,
Condensing means comprising a microlens array is provided on the incident side of the second light modulation element, and the first light modulation element and the second light modulation element are arranged close to each other.

  With such a configuration, in the optical display device, the light from the light source is first-order modulated by the first light modulation element, and the optical image of the first light modulation element passes through the microlens array. Is transmitted to. At this time, since the optical image of the first light modulation element is condensed by the microlens array and formed on the pixel surface of the second light modulation element, the second image is suppressed while suppressing a decrease in luminance due to light diffusion or the like. It is transmitted to the light modulation element. The light from the first light modulation element is secondarily modulated by the second light modulation element.

  Thereby, since the light from the light source is modulated via the first light modulation element and the second light modulation element, an effect that a relatively high luminance dynamic range and gradation number can be realized is obtained. Further, the first light modulation element and the second light modulation element are arranged close to each other, and an optical image of the first light modulation element is formed on the pixel surface of the second light modulation element via the microlens array. An optical image of the one light modulation element can be formed on the pixel surface of the second light modulation element with a relatively high accuracy, and the pixel surface of the first light modulation element does not have to be made small, so that a relatively high accuracy can be obtained. Modulation can be performed. Accordingly, an effect that the possibility that the image quality is deteriorated can be reduced as compared with the conventional case. Furthermore, since it is not necessary to use highly accurate optical components for the illumination optical system, an effect of suppressing an increase in cost can be obtained.

[Invention 7] Furthermore, the optical display device of Invention 7 includes:
A light source, a first light modulation element having a plurality of pixels that receive light from the light source and whose light propagation characteristics can be controlled independently; and light incident from the first light modulation element and having light propagation characteristics A device for displaying an image by modulating light from the light source via the first light modulation element and the second light modulation element. There,
Condensing means comprising a Selfoc lens is provided between the first light modulation element and the second light modulation element, and the first light modulation element and the second light modulation element are arranged close to each other. And

  With such a configuration, in the optical display device, the light from the light source is primarily modulated by the first light modulation element, and the optical image of the first light modulation element passes through the SELFOC lens and the second light modulation element. Is transmitted to. At this time, the optical image of the first light modulation element is condensed by the SELFOC lens and formed on the pixel surface of the second light modulation element, so that the second decrease while suppressing a decrease in luminance due to light diffusion or the like. It is transmitted to the light modulation element. The light from the first light modulation element is secondarily modulated by the second light modulation element.

  Thereby, since the light from the light source is modulated via the first light modulation element and the second light modulation element, an effect that a relatively high luminance dynamic range and gradation number can be realized is obtained. In addition, the first light modulation element and the second light modulation element are arranged close to each other, and an optical image of the first light modulation element is formed on the pixel surface of the second light modulation element via the SELFOC lens. An optical image of the one light modulation element can be formed on the pixel surface of the second light modulation element with a relatively high accuracy, and the pixel surface of the first light modulation element does not have to be made small, so that a relatively high accuracy can be obtained. Modulation can be performed. Accordingly, an effect that the possibility that the image quality is deteriorated can be reduced as compared with the conventional case. Furthermore, since it is not necessary to use highly accurate optical components for the illumination optical system, an effect of suppressing an increase in cost can be obtained.

[Invention 8] Furthermore, the optical display device of Invention 8 is the optical display device of any one of Inventions 2 to 7,
The first light modulation element, the light condensing unit, and the second light modulation element are bonded and integrated.
With such a configuration, since the first light modulation element, the condensing unit, and the second light modulation element are in close contact with each other, it is possible to further suppress a decrease in luminance due to light diffusion or the like. Therefore, the effect that the brightness | luminance of a display image can be improved is acquired.

[Invention 9] Furthermore, the optical display device of Invention 9 is the optical display device of any one of Inventions 2 to 8,
Furthermore, light separating means for separating the light from the light source into light of a plurality of different specific wavelength regions, a plurality of light modulating means for entering the light separated by the light separating means, and a light from each of the light modulating means Photosynthesis means for synthesizing light,
The light modulation means includes the first light modulation element, the condensing means, and the second light modulation element.

  With such a configuration, the light from the light source is separated into light of a plurality of specific wavelength regions by the light separation means, and the separated light is incident on each light modulation means. In each light modulation means, the light from the light source is primarily modulated by the first light modulation element, and the optical image of the first light modulation element is transmitted to the second light modulation element via the light collecting means. At this time, since the optical image of the first light modulation element is condensed by the light condensing means and formed on the pixel surface of the second light modulation element, the second image is obtained while suppressing a decrease in luminance due to light diffusion or the like. It is transmitted to the light modulation element. Then, the light from the first light modulation element is secondarily modulated by the second light modulation element, and the light from each second light modulation element is combined by the light combining means to display an image.

As a result, since the modulation is performed for each specific wavelength region, the image quality can be improved as compared with a case where the modulation is performed all over the entire wavelength region of light.
Here, the specific wavelength region is not limited to be set for each of the RGB three primary colors, but can be arbitrarily set as necessary. However, if it is set for each of the RGB primary colors, the existing liquid crystal light valve can be used as it is, which is advantageous in terms of cost. Hereinafter, the same applies to the display method of the optical display device of the invention 21.

[Invention 10] Furthermore, the optical display device of Invention 10 is the optical display device of Invention 9,
Luminance distribution equalizing means for equalizing the luminance distribution of light from the light source is provided on the optical path between the light source and the light separating means.
With such a configuration, the luminance distribution of the light from the light source is made uniform by the luminance distribution uniformizing means and is incident on the light separating means.

Thereby, the effect that the possibility that luminance unevenness occurs can be reduced is obtained.
Here, the luminance may be a physical radiance that does not consider human visual characteristics (Radiance = W / (sr · m ² )), or a luminance that considers human visual characteristics (luminance = cd / m ² ) may be used as an index. The same applies to the display method of the optical display device of the invention 22 below.

[Invention 11] Furthermore, the optical display device of Invention 11 is the optical display device of Invention 10,
The luminance distribution uniformizing unit includes a polarization conversion element that polarizes light from the light source in accordance with a polarization direction in which the first light modulation element can be incident.
With such a configuration, the light from the light source is polarized by the polarization conversion element in accordance with the incident polarization direction of the first light modulation element, and the polarized light is incident on the first light modulation element.

As a result, a large amount of light from the light source becomes a modulation target of the first light modulation element, so that an effect of improving the luminance of the display image can be obtained.
[Invention 12] Furthermore, the optical display device of Invention 12 is the optical display device of any one of Inventions 2 to 11,
The first light modulation element and the second light modulation element are liquid crystal light valves.
With such a configuration, since an existing optical component can be used, an effect of further suppressing an increase in cost can be obtained.

[Invention 13] On the other hand, in order to achieve the above object, the light propagation method of the optical system of Invention 13 includes:
Light from a light source is modulated via a first light modulation element having a plurality of pixels whose light propagation characteristics can be independently controlled and a second light modulation element having a plurality of pixels whose light propagation characteristics can be independently controlled. A method applied to an optical system,
The first light modulation element and the second light modulation element are arranged close to each other, and in the optical path between the first light modulation element and the second light modulation element, the first light modulation element is disposed on the first light modulation element via a condensing unit. An optical image is formed on the pixel surface of the second light modulation element.
Thereby, the same effect as the light propagation structure of the optical system of the invention 1 can be obtained.

[Invention 14] On the other hand, in order to achieve the above object, a display method of an optical display device according to Invention 14 includes:
A light source, a first light modulation element having a plurality of pixels that receive light from the light source and whose light propagation characteristics can be controlled independently; and light incident from the first light modulation element and having light propagation characteristics And a second light modulation element having a plurality of independently controllable pixels, and an optical display for displaying an image by modulating light from the light source via the first light modulation element and the second light modulation element A device display method comprising:
The first light modulation element and the second light modulation element are arranged close to each other, and a micro provided on the emission side of the first light modulation element in the optical path of the first light modulation element and the second light modulation element An optical image of the first light modulation element is formed on a pixel surface of the second light modulation element via a light collecting unit including a lens array.
Thereby, an effect equivalent to that of the optical display device of aspect 2 is obtained.

[Invention 15] Further, the display method of the optical display device of the invention 15 is the display method of the optical display device of the invention 14,
In the optical path of the first light modulation element and the second light modulation element, the light collection means and the second light collection means comprising a microlens array provided on the incident side of the second light modulation element An optical image of one light modulation element is formed on a pixel surface of the second light modulation element.
Thereby, the same effect as the light propagation structure of the optical system of the invention 3 can be obtained.

[Invention 16] Furthermore, the display method of the optical display device of the invention 16 is the display method of the optical display device of the invention 15,
The lens diameter of the microlens array of the condensing means is the same or substantially the same as the pixel of the first light modulation element, and the lens diameter of the microlens array of the second light modulation element is the same as that of the second light modulation element. It is characterized by having the same or almost the same size as the pixel.
Thereby, the same effect as the light propagation structure of the optical system of the invention 4 can be obtained.

[Invention 17] Further, the display method of the optical display device of the invention 17 is the display method of the optical display device of the invention 14,
In the optical path of the first light modulation element and the second light modulation element, an optical image of the first light modulation element is converted into the second light via the light collection means and second light collection means including a SELFOC lens. The image is formed on the pixel surface of the modulation element.
Thereby, the same effect as the light propagation structure of the optical system according to the fifth aspect of the invention can be obtained.

[Invention 18] Furthermore, the display method of the optical display device of Invention 18 includes:
A light source, a first light modulation element having a plurality of pixels that receive light from the light source and whose light propagation characteristics can be controlled independently; and light incident from the first light modulation element and having light propagation characteristics And a second light modulation element having a plurality of independently controllable pixels, and an optical display for displaying an image by modulating light from the light source via the first light modulation element and the second light modulation element A device display method comprising:
The first light modulation element and the second light modulation element are arranged close to each other, and a micro provided on the incident side of the second light modulation element in the optical path of the first light modulation element and the second light modulation element An optical image of the first light modulation element is formed on a pixel surface of the second light modulation element via a light collecting unit including a lens array.
Thereby, an effect equivalent to that of the optical display device of aspect 6 is obtained.

[Invention 19] Furthermore, the display method of the optical display device of Invention 19 includes
A light source, a first light modulation element having a plurality of pixels that receive light from the light source and whose light propagation characteristics can be controlled independently; and light incident from the first light modulation element and having light propagation characteristics And a second light modulation element having a plurality of independently controllable pixels, and an optical display for displaying an image by modulating light from the light source via the first light modulation element and the second light modulation element A device display method comprising:
The first light modulation element and the second light modulation element are disposed close to each other, and the first light modulation element and the second light modulation element are disposed in the optical path of the first light modulation element and the second light modulation element via a condensing unit including a Selfoc lens. An optical image of one light modulation element is formed on a pixel surface of the second light modulation element.
Thereby, an effect equivalent to that of the optical display device of aspect 7 is obtained.

[Invention 20] Furthermore, the display method of the optical display device of the invention 20 is the display method of the optical display device of any of the inventions 14 to 19,
The first light modulation element, the light condensing unit, and the second light modulation element are bonded and integrated.
Thereby, an effect equivalent to that of the optical display device of aspect 8 is obtained.

[Invention 21] Furthermore, the display method of the optical display device of the invention 21 is the display method of the optical display device of any of the inventions 14 to 20,
The optical display device further includes a light separation unit that separates light from the light source into light of a plurality of different specific wavelength regions, a plurality of light modulation units that respectively enter the light separated by the light separation unit, A light combining means for combining the light from each light modulation means,
The light modulation means includes the first light modulation element, the condensing means, and the second light modulation element.
Thereby, an effect equivalent to that of the optical display device of aspect 9 is obtained.

[Invention 22] Furthermore, the display method of the optical display device of the invention 22 is the display method of the optical display device of the invention 21,
In the optical path between the light source and the light separating unit, the luminance distribution of the light from the light source is made uniform through a luminance distribution uniforming unit.
Thereby, an effect equivalent to that of the optical display device of aspect 10 is obtained.

[Invention 23] Furthermore, the display method of the optical display device of the invention 23 is the display method of the optical display device of the invention 22,
In the optical path between the light source and the light separating means, the light from the light source is polarized through a polarization conversion element according to the incident polarization direction of the first light modulation element.
Thereby, the same effect as that of the optical display device of the eleventh aspect can be obtained.

[Invention 24] Furthermore, the display method of the optical display device of the invention 24 is the display method of the optical display device of any of the inventions 14 to 23,
The first light modulation element and the second light modulation element are liquid crystal light valves.
Thereby, an effect equivalent to that of the optical display device of aspect 12 is obtained.

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 to FIG. 11 are diagrams showing a first embodiment of a light propagation structure of an optical system and an optical display device, and a light propagation method of the optical system and a display method of the optical display device according to the present invention.
In the present embodiment, a light propagation structure of an optical system and an optical display device, and a light propagation method of the optical system and a display method of the optical display device according to the present invention are applied to a projection display device 100 as shown in FIG. It is applied.

First, the configuration of the projection display device 100 will be described with reference to FIG.
FIG. 1 is a block diagram illustrating a hardware configuration of the projection display apparatus 100.
As shown in FIG. 1, the projection display device 100 includes a light source 10, a luminance distribution uniformizing unit 12 that uniformizes a luminance distribution of light incident from the light source 10, and a light incident from the luminance distribution uniforming unit 12. The light modulation unit 18 that modulates the luminances of the three primary colors of RGB in the wavelength region and the projection unit 20 that projects light incident from the light modulation unit 18 onto a screen (not shown).

The light source 10 includes a lamp 10a such as a high-pressure mercury lamp and a reflector 10b that reflects light emitted from the lamp 10a.
The light modulation unit 18 includes three light modulation element groups 40R, 40G, and 40B in which a plurality of pixels whose transmittance can be independently controlled are arranged in a matrix, and five field lenses 42R, 42G, 42B _{1 to} 42B _3. And two dichroic mirrors 44a and 44b, three mirrors 46a, 46b and 46c, and a dichroic prism 48. First, it lights the dichroic mirror 44a from uniform luminance distribution section 12, as well as spectral red, green and blue RGB3 primary by 44b, via the field lens 42R, 42G, and 42B ₁ ~42B ₃ and mirror 46a~46c The light is incident on the light modulation element groups 40R to 40B. Then, the luminance of the RGB three primary colors is spectrally modulated by each of the light modulation element groups 40R to 40B, and the modulated RGB three primary colors are condensed by the dichroic prism 48 and emitted to the projection unit 20.

  The luminance distribution uniformizing unit 12 includes two fly-eye lenses 12a and 12b, a polarization conversion element 12c, and a condenser lens 12d. Then, the brightness distribution of the light from the light source 10 is made uniform by the fly-eye lenses 12a and 12b, and the uniformed light is polarized by the polarization conversion element 12c in the polarization direction where the light modulation element groups 40R to 40B can enter, and polarized light. Is condensed by the condenser lens 12 d and emitted to the light modulation unit 18.

  For example, the polarization conversion element 12c includes a PBS array and a half-wave plate. The wave plate is a birefringent element in which a phase difference occurs between S-polarized light and P-polarized light when light having a specific wavelength passes. The artificial quartz crystal is polished by setting the thickness corresponding to each specific wavelength, and bonded so that the optical axes of the respective crystals are orthogonal to each other. The half-wave plate converts linearly polarized light into linearly polarized light orthogonal to the half-wave plate, and makes its phase difference 180 ° (π).

Next, the configuration of the light modulation element groups 40R to 40B will be described in detail with reference to FIG. Since all of the light modulation element groups 40R to 40B have the same configuration, only the light modulation element group 40R will be described below, and the description of the light modulation element groups 40G and 40B will be omitted.
FIG. 2 is a cross-sectional view of the light modulation element group 40R in the optical axis direction.

As shown in FIG. 2, the light modulation element group 40R includes a liquid crystal light valve 50R in which a plurality of pixels whose transmittance can be controlled independently is arranged in a matrix, and a plurality of pixels whose transmittance can be controlled independently. And a liquid crystal light valve 52R having a higher resolution than the liquid crystal light valve 50R.
The liquid crystal light valve 50R includes a polarizing plate 501, a counter substrate 502, a counter electrode 503, a data wiring 504, a sealing material 505, a panel substrate 506, a liquid crystal 507, and a microlens array 508. On the incident side of the panel substrate 506 (the side on which light from the light source 10 is incident), a control voltage is applied to pixel electrodes and pixel electrodes (not shown) arranged at predetermined intervals from the data wiring 504 to each pixel. Active elements (not shown) are formed, and a counter electrode 503 is formed on the counter substrate 502. A liquid crystal 507 is filled between the panel substrate 506 and the counter substrate 502, and the liquid crystal 507 is sealed with a sealing material 505. A polarizing plate 501 is bonded to the incident side of the counter substrate 502. On the other hand, a microlens array 508 is bonded to the emission side of the panel substrate 506 (the side from which light from the light source 10 is emitted) with the convex direction facing the emission side. The microlens array 508 can be manufactured by, for example, a manufacturing method disclosed in Japanese Patent Application Laid-Open No. 2000-305472.

  The liquid crystal light valve 52 </ b> R includes a polarizing plate 521, a counter substrate 522, a counter electrode 523, a data wiring 524, a sealing material 525, a panel substrate 526, a liquid crystal 527, and a polarizing plate 531. On the incident side of the panel substrate 526, a data line 524 to each pixel, a pixel electrode arranged at a predetermined interval, and an active element (not shown) for applying a control voltage to the pixel electrode (not shown) are formed. In addition, a counter electrode 523 is formed on the counter substrate 522. A liquid crystal 527 is filled between the panel substrate 526 and the counter substrate 522, and the liquid crystal 527 is sealed with a sealing material 525. A polarizing plate 521 is bonded to the incident side of the counter substrate 522. On the other hand, a polarizing plate 531 is bonded to the emission side of the panel substrate 526.

  Light from the luminance distribution uniformizing unit 12 is incident from the left (in direction) in FIG. 2 and is primarily modulated by the liquid crystal light valve 50R, and an optical image of the liquid crystal light valve 50R is transmitted through the microlens array 508. It is transmitted to the liquid crystal light valve 52R. At this time, since the optical image of the liquid crystal light valve 50R is condensed by the micro lens array 508 and formed on the pixel surface of the liquid crystal light valve 52R, the liquid crystal light valve is suppressed while suppressing a decrease in luminance due to light diffusion or the like. 52R. Then, the light from the liquid crystal light valve 50R is second-order modulated by the liquid crystal light valve 52R, emitted to the right (out direction) in FIG. 2, and transmitted to the dichroic prism 48.

The liquid crystal light valves 50R and 52R are in a normally white mode in which a white / bright (transmission) state is applied when a voltage is applied, and a black / dark (non-transmission) state is applied when no voltage is applied, or vice versa. It is driven, and the gradation between light and dark is analog controlled according to the given control value.
Although not shown, in the following description, the light modulation element group 40G corresponds to the liquid crystal light valves 50R and 52R, the liquid crystal light valves 50G and 52G, and the light modulation element group 40B includes the liquid crystal light valves 50R and 50R. Those corresponding to 52R are referred to as liquid crystal light valves 50B and 52B.

  On the other hand, the projection display device 100 includes a display control device 200 (not shown) that controls the liquid crystal light valves 50R to 50B and the liquid crystal light valves 52R to 52B. Hereinafter, the liquid crystal light valves 52R to 52B are collectively referred to as color modulation light valves, and the liquid crystal light valves 50R to 50B are referred to as luminance modulation light valves in order to distinguish them from the color modulation light valves. In the present embodiment, the color modulation light valve determines the display resolution (refers to the resolution perceived by the observer when the observer views the display image of the projection display device 100).

Next, the configuration of the display control apparatus 200 will be described in detail with reference to FIGS.
FIG. 3 is a block diagram illustrating a hardware configuration of the display control apparatus 200.
As shown in FIG. 3, the display control device 200 reads out from the CPU 70 that controls the calculation and the entire system based on the control program, the ROM 72 that stores the control program of the CPU 70 in a predetermined area, the ROM 72, and the like. It is composed of a RAM 74 for storing data and calculation results required in the calculation process of the CPU 70, and an I / F 78 that mediates input / output of data to / from an external device, and these are used for transferring data. They are connected to each other via a bus 79 which is a signal line so as to be able to exchange data.

The I / F 78 is connected to an external network 199 as an external device, a light valve driving device 80 that drives the luminance modulation light valve and the color modulation light valve, a storage device 82 that stores data, tables, and the like as files. The signal line for connecting is connected.
The storage device 82 stores HDR display data.
The HDR display data is image data capable of realizing a high luminance dynamic range that cannot be realized by a conventional image format such as sRGB, and stores pixel values indicating pixel luminance levels for all pixels of the image. Currently, it is used to synthesize CG objects into actual scenery, especially in the CG world. Although there are various image formats, there are many formats in which pixel values are stored in a floating-point format in order to realize a higher luminance dynamic range than conventional image formats such as sRGB. As values to be stored, physical radiance not considering human visual characteristics (Radiance = W / (sr · m ² )) or luminance considering human visual characteristics (luminance = cd / m ² ). It is also a feature that it is a value regarding. In the present embodiment, the HDR display data uses a format in which pixel values indicating radiance levels for each of the three primary colors of RGB are stored as floating point values for one pixel. For example, the value (1.2, 5.4, 2.3) is stored as the pixel value of one pixel.

  The HDR display data is generated based on a HDR image having a high luminance dynamic range and a captured HDR image. However, with current film cameras and digital still cameras, HDR images with a high luminance dynamic range in nature cannot be taken at a time. Therefore, one HDR image is generated from a plurality of photographed images whose exposure is changed by some method. For details of the method for generating HDR display data, see, for example, publicly known document 1 “PEDebevec, J. Malik,“ Recovering High Dynamic Range Radiance Maps from Photographs ”, Proceedings of ACM SIGGRAPH97, pp.367-378 (1997). It is published in.

Assuming that the luminance level of the pixel p in the HDR display data is Rp, the transmittance of the pixel corresponding to the pixel p of the luminance modulation light valve is T1, and the transmittance of the pixel corresponding to the pixel p of the color modulation light valve is T2, (1) and (2) hold.

Rp = Tp × Rs (1)
Tp = T1 × T2 × G (2)

However, in the above formulas (1) and (2), Rs is the luminance of the light source 10 and G is a gain, both of which are constants. Tp is a light modulation rate.

From the above equations (1) and (2), it can be seen that there are an infinite number of combinations of T1 and T2 for the pixel p. However, T1 and T2 may not be arbitrarily determined. Since the image quality may deteriorate depending on the method of determination, T1 and T2 need to be appropriately determined in consideration of the image quality.
When the luminance modulation light valve and the color modulation light valve have different resolutions, for one pixel p1 of the luminance modulation light valve, the pixel p1 overlaps with a plurality of pixels of the color modulation light valve on the optical path, and conversely, the color modulation For one pixel p2 of the light valve, the pixel p2 may overlap with a plurality of pixels of the luminance modulation light valve on the optical path. Here, when calculating the transmittance T1 for the pixel p1 of the luminance modulation light valve, if the transmittance T2 of a plurality of overlapping pixels of the color modulation light valve is determined, an average value of the transmittance T2 is calculated. Considering the calculated average value and the like as the transmittance T2 of the pixel corresponding to the pixel p1 of the color modulation light valve, it is conceivable to calculate the transmittance T1 by the above equations (1) and (2). However, since the average value or the like is regarded as the transmittance T2 of the color modulation light valve, an error is inevitably generated there. This error occurs regardless of the order of determination whether the transmittance T1 of the luminance modulation light valve is determined first or the transmittance T2 of the color modulation light valve is determined first. The modulation light valve and the color modulation light valve that determine the display resolution have a large visual influence, so it is better to minimize the error.

  Therefore, let us examine how the magnitude of the error changes depending on the order of determination. First, consider determining the transmittance T2 of the color modulation light valve first. The transmittance T1 of the pixel p1 of the luminance modulation light valve is calculated by calculating the average value of the transmittance T2 of a plurality of overlapping pixels of the color modulation light valve, etc., based on the calculated average value and the HDR display data (1 ) And (2). As a result, when viewed from the pixel p1 of the luminance modulation light valve, the transmittance T1 has an error with respect to the transmittance T2 of a plurality of overlapping pixels of the color modulation light valve, but the degree of error is an average value or the like. This is the degree of error caused by statistical calculations. On the other hand, when viewed from the pixel p2 of the color modulation light valve, the transmittance T2 is equal to the average value of the transmittance T1 of a plurality of overlapping pixels of the luminance modulation light valve. Thus, a large error may occur that does not satisfy the above equations (1) and (2). This is because even if the relationship (a relationship satisfying the above equations (1) and (2)) with a plurality of overlapping pixels of the color modulation light valve is defined based on the pixel p1, the opposite relationship is not necessarily established. It is thought to be caused. Therefore, the error of the transmittance T2 of the color modulation light valve is likely to be larger.

The same applies to the reverse case, and when the transmittance T1 of the luminance modulation light valve is determined first, there is a high possibility that the error of the transmittance T1 of the luminance modulation light valve will be larger.
From the above, from the viewpoint of improving the image quality, it is concluded that the influence of the error may be less if the transmittance is determined later among the luminance modulation light valve and the color modulation light valve, but the transmittance is determined later. can get. In this embodiment, since the color modulation light valve determines the display resolution, the transmittance T2 of the color modulation light valve is determined later.

Further, the storage device 82 stores control value registration tables 400R, 400G, and 400B in which the control values of the luminance modulation light valves are registered for each of the three primary colors RGB.
FIG. 4 is a diagram illustrating a data structure of the control value registration table 400R.
In the control value registration table 400R, as shown in FIG. 4, one record is registered for each control value of the luminance modulation light valve. Each record includes a field in which the control value of the luminance modulation light valve is registered and a field in which the transmittance of the pixel of the luminance modulation light valve (liquid crystal light valve 50R) corresponding to red is registered.

  In the example of FIG. 4, “0” is registered as the control value and “0.004” is registered as the transmittance in the first row record. This indicates that when the control value “0” is output to the pixel of the luminance modulation light valve, the transmittance of the pixel becomes 0.4%. FIG. 4 shows an example in which the number of gradations of the luminance modulation light valve is 4 bits (0 to 15 values). However, in practice, there is a record corresponding to the number of gradations of the luminance modulation light valve. be registered. For example, when the number of gradations is 8 bits, 256 records are registered.

  The data structure of the control value registration tables 400G and 400B is not particularly shown, but has the same data structure as the control value registration table 400R. However, the control value registration table 400R differs from the control value registration table 400R in that the control value registration table 400G registers the transmittance of the pixels of the luminance modulation light valve (liquid crystal light valve 50G) corresponding to green, and the control value registration table 400B corresponds to blue. The pixel transmittance of the luminance modulation light valve (liquid crystal light valve 50B) is registered.

In addition, the storage device 82 stores control value registration tables 420R, 420G, and 420B in which the control values of the color modulation light valves are registered for each of the RGB three primary colors.
FIG. 5 is a diagram illustrating a data structure of the control value registration table 420R.
In the control value registration table 420R, as shown in FIG. 5, one record is registered for each control value of the color modulation light valve. Each record includes a field in which the control value of the color modulation light valve is registered, and a field in which the transmittance of the pixel of the color modulation light valve (liquid crystal light valve 52R) corresponding to red is registered.

  In the example of FIG. 5, “0” is registered as the control value and “0.004” is registered as the transmittance in the first row record. This indicates that when the control value “0” is output to the pixel of the color modulation light valve, the transmittance of the pixel is 0.4%. FIG. 5 shows an example in which the number of gradations of the color modulation light valve is 4 bits (0 to 15 values). However, in actuality, there is a record corresponding to the number of gradations of the color modulation light valve. be registered. For example, when the number of gradations is 8 bits, 256 records are registered.

  The data structure of the control value registration tables 420G and 420B is not particularly shown, but has the same data structure as the control value registration table 420R. However, the control value registration table 420R is different from the control value registration table 420R in that the control value registration table 420G registers the transmittance of the pixel of the color modulation light valve (liquid crystal light valve 52G) corresponding to green, and the control value registration table 420B corresponds to blue. The pixel transmittance of the color modulation light valve (liquid crystal light valve 52B) is registered.

Next, the configuration of the CPU 70 and the processing executed by the CPU 70 will be described.
The CPU 70 includes a microprocessing unit (MPU) or the like, starts a predetermined program stored in a predetermined area of the ROM 72, and executes display control processing shown in the flowchart of FIG. 6 according to the program. .
FIG. 6 is a flowchart showing the display control process.

The display control process is a process of determining the control values of the luminance modulation light valve and the color modulation light valve based on the HDR display data, and driving the luminance modulation light valve and the color modulation light valve based on the determined control value. When executed by the CPU 70, as shown in FIG. 6, first, the process proceeds to step S100.
In step S100, the HDR display data is read from the storage device 82.

  In step S102, the read HDR display data is analyzed, and a histogram of pixel values, a maximum value, a minimum value, an average value, and the like of the luminance level are calculated. This analysis result is for use in automatic image correction such as brightening a dark scene, darkening a scene that is too bright, or coordinating intermediate contrast, or for tone mapping.

Next, the process proceeds to step S104, and tone mapping is performed on the luminance level of the HDR display data to the luminance dynamic range of the projection display device 100 based on the analysis result of step S102.
FIG. 7 is a diagram for explaining tone mapping processing.
As a result of analyzing the HDR display data, it is assumed that the minimum value of the luminance level included in the HDR display data is Smin and the maximum value is Smax. Further, it is assumed that the minimum value of the luminance dynamic range of the projection display device 100 is Dmin and the maximum value is Dmax. In the example of FIG. 7, since Smin is smaller than Dmin and Smax is larger than Dmax, HDR display data cannot be appropriately displayed as it is. Therefore, normalization is performed so that the histogram of Smin to Smax falls within the range of Dmin to Dmax.

Details of tone mapping are disclosed in, for example, publicly known document 2 “F. Drago, K. Myszkowski, T. Annen, N. Chiba,“ Adaptive Logarithmic Mapping For Displaying High Contrast Scenes ”, Eurographics 2003, (2003)”. It is posted.
Next, the process proceeds to step S106, and the HDR image is resized (enlarged or reduced) in accordance with the resolution of the color modulation light valve. At this time, the HDR image is resized while maintaining the aspect ratio of the HDR image. Examples of the resizing method include an average value method, an intermediate value method, and a nearest neighbor method (nearest neighbor method).

Next, the process proceeds to step S108, and based on the luminance level Rp of each pixel of the resized image and the luminance Rs of the light source 10, the light modulation rate Tp is calculated for each pixel of the resized image by the above equation (1).
Next, the process proceeds to step S110, where an initial value (for example, 0.2) is given as the transmittance T2 of each pixel of the color modulation light valve, and the transmittance T2 of each pixel of the color modulation light valve is provisionally determined.

  Next, the process proceeds to step S112, and based on the calculated light modulation rate Tp, the provisionally determined transmittance T2 and the gain G, the transmission of the luminance modulation light valve in units of pixels of the color modulation light valve according to the above equation (2). The rate T1 ′ is calculated. Here, since the color modulation light valve is composed of the three liquid crystal light valves 52R to 52B, the transmittance T1 'is calculated for each of the three primary colors of RGB for the same pixel.

Next, the process proceeds to step S114, and for each pixel of the luminance modulation light valve, the weighted average value of the transmittance T1 ′ calculated for the pixel of the color modulation light valve that overlaps the pixel on the optical path is used as the transmittance T1 of the pixel. Calculate as Weighting is performed based on the area ratio of overlapping pixels.
Next, the process proceeds to step S116, and for each pixel of the luminance modulation light valve, a control value corresponding to the transmittance T1 calculated for that pixel is read from the control value registration tables 400R to 400B, and the read control value is read from the pixel. Is determined as the control value. In the reading of the control value, the transmittance that most closely approximates the calculated transmittance T1 is searched from the control value registration tables 400R to 400B, and the control value corresponding to the transmittance found by the search is read. This search is performed using, for example, a binary search method, thereby realizing a high-speed search.

  Next, the process proceeds to step S118, and for each pixel of the color modulation light valve, the weighted average value of the transmittance T1 determined for the pixel of the luminance modulation light valve that overlaps the pixel on the optical path is calculated, and the calculated average value Based on the light modulation rate Tp and the gain G calculated in step S108, the transmittance T2 of the pixel is calculated by the above equation (2). Weighting is performed based on the area ratio of overlapping pixels.

  Next, the process proceeds to step S120, and for each pixel of the color modulation light valve, a control value corresponding to the transmittance T2 calculated for the pixel is read from the control value registration tables 420R to 420B, and the read control value is read from the pixel. Is determined as the control value. In the reading of the control value, the transmittance that most closely approximates the calculated transmittance T2 is searched from the control value registration tables 420R to 420B, and the control value corresponding to the transmittance found by the search is read. This search is performed using, for example, a binary search method, thereby realizing a high-speed search.

Next, the process proceeds to step S122, the control values determined in steps S116 and S120 are output to the light valve driving device 80, the brightness modulation light valve and the color modulation light valve are each driven to project a display image, and a series of operations are performed. End the process and return to the original process.
Next, the operation of the present embodiment will be described with reference to FIGS.
In the following, all of the color modulation light valves have a resolution of 18 horizontal pixels × 12 vertical pixels and a gradation number of 4 bits, and the luminance modulation light valves have a resolution of 15 horizontal pixels × 10 vertical pixels and a 4-bit resolution. An explanation will be given taking as an example the case of having the number of gradations.

  In the display control device 200, the HDR display data is read through steps S100 to S104, the read HDR display data is analyzed, and the luminance level of the HDR display data is determined based on the analysis result. Tone-mapped to 100 luminance dynamic range. Next, through step S106, the HDR image is resized in accordance with the resolution of the color modulation light valve.

  Next, through step S108, the light modulation rate Tp is calculated for each pixel of the resized image. For example, the light modulation rate Tp of the pixel p in the resized image is such that the luminance level Rp (R, G, B) of the pixel p is (1.2, 5.4, 2.3) and the luminance Rs (R, R, If (G, B) is (10000, 10000, 10000), then (1.2, 5.4, 2.3) / (10000, 10000, 10000) = (0.00012, 0.00054, 0.00023).

FIG. 8 is a diagram showing a case where the transmittance T2 of the color modulation light valve is provisionally determined.
Next, through step S110, the transmittance T2 of each pixel of the color modulation light valve is provisionally determined. When the pixels in the upper left four sections of the color modulation light valve are p21 (upper left), p22 (upper right), p23 (lower left), and p24 (lower right), the transmittance T2 of the pixels p21 to p24 is shown in FIG. Thus, an initial value T20 is given.

FIG. 9 is a diagram illustrating a case where the transmittance T1 ′ of the luminance modulation light valve is calculated for each pixel of the color modulation light valve.
Next, through step S112, the transmittance T1 ′ of the luminance modulation light valve is calculated for each pixel of the color modulation light valve. When attention is paid to the pixels p21 to p24, the transmittances T11 to T14 of the luminance modulation light valves corresponding thereto correspond to the light modulation rates of the pixels p21 to p24 as Tp1 to Tp4 and the gain G as "1" as shown in FIG. It can be calculated by the following formulas (3) to (6).

Calculate using actual numerical values. When Tp1 = 0.00012, Tp2 = 0.05, Tp3 = 0.02, Tp4 = 0.01, and T20 = 0.1, T11 = 0.0012, T12 = 0.5, T13 = 0.2, and T14 = 0.1 according to the following equations (3) to (6). Become.

T11 = Tp1 / T20 (3)
T12 = Tp2 / T20 (4)
T13 = Tp3 / T20 (5)
T14 = Tp4 / T20 (6)

FIG. 10 is a diagram illustrating a case where the transmittance T1 of each pixel of the luminance modulation light valve is determined.

  Next, through step S114, the transmittance T1 of each pixel of the luminance modulation light valve is determined. When the pixels in the upper left four sections of the luminance modulation light valve are p11 (upper left), p12 (upper right), p13 (lower left), and p14 (lower right), the pixel p11 has a color as shown in FIG. Since the modulation light valve and the luminance modulation light valve have different resolutions, they overlap with the pixels p21 to p24 on the optical path. Since the resolution of the color modulation light valve is 18 × 12 and the resolution of the luminance modulation light valve is 15 × 10, the pixel p11 can be divided into a 6 × 6 rectangular area from the least common multiple. Then, the overlapping area ratio between the pixel p11 and the pixels p21 to p24 is 25: 5: 5: 1 as shown in FIG. Therefore, the transmittance T15 of the pixel p11 can be calculated by the following equation (7) as shown in FIG.

Calculate using actual numerical values. When T11 = 0.0012, T12 = 0.5, T13 = 0.2, and T14 = 0.002, T15 = 0.008 according to the following equation (7).

T15 = (T11 × 25 + T12 × 5 + T13 × 5 + T14 × 1) / 36 (7)

Similarly to the pixel p11, the transmittances T16 to T18 of the pixels p12 to p14 can be obtained by calculating a weighted average value based on the area ratio.

  Next, through step S116, for each pixel of the luminance modulation light valve, a control value corresponding to the transmittance T1 calculated for the pixel is read from the control value registration tables 400R to 400B, and the read control value is read out. Is determined as the control value of the pixel. For example, since T15 = 0.008, referring to the control value registration table 400R, 0.09 is the closest approximation as shown in FIG. Therefore, “8” is read from the control value registration table 400R as the control value of the pixel p11.

FIG. 11 is a diagram illustrating a case where the transmittance T2 of each pixel of the color modulation light valve is determined.
Next, through step S118, the transmittance T2 of each pixel of the color modulation light valve is determined. As shown in FIG. 11A, the pixel p24 overlaps the pixels p11 to p14 on the optical path because the resolutions of the color modulation light valve and the luminance modulation light valve are different. Since the resolution of the color modulation light valve is 18 × 12 and the resolution of the luminance modulation light valve is 15 × 10, the pixel p24 can be divided into 5 × 5 rectangular regions from the least common multiple thereof. Then, the overlapping area ratio of the pixel p24 and the pixels p11 to p14 is 1: 4: 4: 16 as shown in FIG. Therefore, when attention is paid to the pixel p24, the transmittance T19 of the luminance modulation light valve corresponding to the pixel p24 can be calculated by the following equation (8). Then, the transmittance T24 of the pixel p24 can be calculated by the following equation (9) as shown in FIG. 11C when the gain G is “1”.

Calculate using actual numerical values. When T15 = 0.09, T16 = 0.33, T17 = 0.15, T18 = 0.06, and Tp4 = 0.01, T19 = 0.1188 and T24 = 0.0842 are obtained from the following equations (8) and (9).

T19 = (T15 × 1 + T16 × 4 + T17 × 4 + T18 × 16) / 25 (8)
T24 = Tp4 / T19 (9)

Similarly to the pixel p24, the transmittances T21 to T23 of the pixels p21 to p23 can be obtained by calculating a weighted average value based on the area ratio.

  Next, through step S120, for each pixel of the color modulation light valve, a control value corresponding to the transmittance T2 calculated for the pixel is read from the control value registration tables 420R to 420B, and the read control value is read out. Is determined as the control value of the pixel. For example, when T24 = 0.0842 for the pixel p24 of the color modulation light valve, referring to the control value registration table 420R, 0.07 is the closest value as shown in FIG. Therefore, “7” is read from the control value registration table 420R as the control value of the pixel p24.

Then, through step S122, the determined control value is output to the light valve driving device 80. Thereby, the luminance modulation light valve and the color modulation light valve are driven, and an optical image is formed on the pixel surface of the luminance modulation light valve and the color modulation light valve.
In the projection display device 100, the luminance distribution uniformizing unit 12 equalizes the luminance distribution of light from the light source 10, and the dichroic mirrors 44a and 44b convert the light from the luminance distribution uniforming unit 12 into light of RGB three primary colors. The light is separated and incident on the color modulation elements 40R to 40B. The light from the luminance distribution uniformizing unit 12 is primarily modulated by the luminance modulation light valve, and an optical image of the luminance modulation light valve is transmitted to the color modulation light valve via the microlens array 508. At this time, since the optical image of the luminance modulation light valve is condensed by the microlens array 508 and formed on the pixel surface of the color modulation light valve, the color modulation light is suppressed while suppressing a decrease in luminance due to light diffusion or the like. It is transmitted to the valve. The light from the luminance modulation light valve is secondarily modulated by the color modulation light valve, and the light from the color modulation light valve is synthesized by the dichroic prism 48 to display an image.

Thus, in this embodiment, the microlens array 508 is provided on the emission side of the luminance modulation light valve, and the luminance modulation light valve and the color modulation light valve are arranged close to each other.
Thereby, since the light from the light source 10 is modulated through the luminance modulation light valve and the color modulation light valve, a relatively high luminance dynamic range and number of gradations can be realized. Further, since the luminance modulation light valve and the color modulation light valve are arranged close to each other and an optical image of the luminance modulation light valve is formed on the pixel surface of the color modulation light valve via the microlens array 508, the luminance modulation light valve Can be formed on the pixel surface of the color modulation light valve with relatively high accuracy, and the pixel surface of the luminance modulation light valve need not be made small, so that relatively high-precision modulation can be performed. . Therefore, it is possible to reduce the possibility that the image quality is deteriorated as compared with the conventional case. Furthermore, since it is not necessary to use high-precision optical components for the illumination optical system, an increase in cost can be suppressed.

Furthermore, in this embodiment, the luminance modulation light valve, the microlens array 508, and the color modulation light valve are bonded and integrated.
Thereby, since the luminance modulation light valve, the microlens array 508, and the color modulation light valve are in close contact with each other, a decrease in luminance due to light diffusion or the like can be further suppressed. Therefore, the brightness of the display image can be improved.

  Further, in the present embodiment, dichroic mirrors 44a and 44b that separate light from the light source 10 into RGB three primary colors, a plurality of light modulation element groups 40R to 40B that respectively receive the separated light, and each light modulation element And dichroic prisms 48 that combine the light from the groups 40R to 40B. The light modulation element groups 40R to 40B include a luminance modulation light valve, a microlens array 508, and a color modulation light valve.

Thereby, since the modulation is performed for each of the RGB three primary colors, the image quality can be improved as compared with the case where the modulation is performed all over the entire wavelength region of light.
Further, in the present embodiment, the luminance distribution uniformizing unit 12 that equalizes the luminance distribution of the light from the light source 10 is provided on the optical path between the light source 10 and the light modulating unit 18.
This can reduce the possibility of uneven brightness.

Further, in the present embodiment, the luminance distribution uniformizing unit 12 includes a polarization conversion element 12c that polarizes the light from the light source 10 in the incident polarization direction of the luminance modulation light valve.
As a result, most of the amount of light from the light source 10 is to be modulated by the luminance modulation light valve, so that the luminance of the display image can be improved.
Furthermore, in the present embodiment, the luminance modulation light valve and the color modulation light valve are liquid crystal light valves.

Thereby, since an existing optical component can be used, an increase in cost can be further suppressed.
Furthermore, in this embodiment, the transmittance T2 of each pixel of the color modulation light valve is provisionally determined, and the transmittance T1 of each pixel of the luminance modulation light valve is determined based on the provisionally determined transmittance T2 and the HDR display data. The control value of each pixel of the luminance modulation light valve is determined based on the determined transmittance T1, and the transmittance T2 of each pixel of the color modulation light valve is determined based on the determined transmittance T1 and the HDR display data. The control value for each pixel of the color modulation light valve is determined based on the determined transmittance T2.

Thereby, since the transmittance T2 of the color modulation light valve that determines the display resolution is determined later, the influence of the error can be suppressed, and the possibility that the image quality is deteriorated can be reduced. Furthermore, since it is not necessary to maintain the number of gradation tables corresponding to the number of gradations, even if the number of gradations is increased, the size and generation time of the gradation table do not increase so much.
Further, in the present embodiment, the transmittance T1 ′ of the luminance modulation light valve is calculated for each pixel of the color modulation light valve based on the provisionally determined transmittance T2 and HDR display data, and the calculated transmittance T1 ′ is obtained. Based on this, the transmittance T1 of each pixel of the luminance modulation light valve is calculated.

  When the luminance modulation light valve and the color modulation light valve have different resolutions, rather than directly calculating the transmittance T1 of each pixel of the luminance modulation light valve based on the temporarily determined transmittance T2, it is temporarily determined. It is easier to calculate the transmittance T1 ′ of each pixel of the luminance modulation light valve after calculating the luminance T1 ′ of the luminance modulation light valve on a pixel basis of the color modulation light valve based on the transmitted transmittance T2. become. Therefore, when the luminance modulation light valve and the color modulation light valve have different resolutions, the transmittance T1 of each pixel of the luminance modulation light valve can be calculated relatively easily.

Further, in the present embodiment, for each pixel of the luminance modulation light valve, the transmittance T1 of the pixel is calculated based on the transmittance T1 ′ calculated for the pixel of the color modulation light valve that overlaps the pixel on the optical path. It is supposed to be.
Accordingly, when the luminance modulation light valve and the color modulation light valve have different resolutions, the transmittance T1 of each pixel of the luminance modulation light valve is the transmittance of the pixel of the color modulation light valve that overlaps the pixel in the optical path. Since it is a relatively appropriate value for T2, the possibility of image quality deterioration can be further reduced. Further, the transmittance T1 of each pixel of the luminance modulation light valve can be calculated more easily.

Furthermore, in this embodiment, for each pixel of the luminance modulation light valve, the weighted average value of the transmittance T1 ′ calculated for the pixel of the color modulation light valve that overlaps the pixel on the optical path is used as the transmittance T1 of the pixel. Is calculated as
Accordingly, when the luminance modulation light valve and the color modulation light valve have different resolutions, the transmittance T1 of each pixel of the luminance modulation light valve is the transmittance of the pixel of the color modulation light valve that overlaps the pixel in the optical path. Since it becomes a more appropriate value with respect to T2, the possibility that the image quality deteriorates can be further reduced. Further, the transmittance T1 of each pixel of the luminance modulation light valve can be calculated more easily.

Further, in the present embodiment, for each pixel of the color modulation light valve, the transmittance T2 of the pixel is calculated based on the transmittance T1 determined for the pixel of the luminance modulation light valve that overlaps the pixel on the optical path. It is like that.
Accordingly, when the luminance modulation light valve and the color modulation light valve have different resolutions, the transmittance T2 of each pixel of the color modulation light valve is the transmittance of the pixel of the luminance modulation light valve that overlaps the pixel in the optical path. Since it is a relatively appropriate value for T1, the possibility of image quality degradation can be further reduced. Further, the transmittance T2 of each pixel of the color modulation light valve can be calculated relatively easily.

Furthermore, in this embodiment, for each pixel of the color modulation light valve, a weighted average value of the transmittance T1 determined for the pixel of the luminance modulation light valve that overlaps the pixel on the optical path is calculated, and based on the average value Then, the transmittance T2 of the pixel is calculated.
Accordingly, when the luminance modulation light valve and the color modulation light valve have different resolutions, the transmittance T2 of each pixel of the color modulation light valve is the transmittance of the pixel of the luminance modulation light valve that overlaps the pixel in the optical path. Since it becomes a more appropriate value with respect to T1, the possibility that the image quality is deteriorated can be further reduced. In addition, the transmittance T2 of each pixel of the color modulation light valve can be calculated more easily.

Further, in the present embodiment, a luminance modulation light valve is used as the first-stage light modulation element, and a color modulation light valve is used as the second-stage light modulation element.
Thus, since only one light modulation element needs to be added to the conventional projection display device, the projection display device 100 can be configured relatively easily.
In the first embodiment, the luminance modulation light valve corresponds to the first light modulation element of the invention 1, 2, 8, 9, 11 to 14, 20, 21, 23 or 24, and the color modulation light valve is This corresponds to the second light modulation element of the invention 1, 2, 8, 9, 12 to 14, 20, 21 or 24. The luminance distribution uniformizing unit 12 corresponds to the luminance distribution uniforming means of the invention 10, 11 or 22, and the light modulation element groups 40R to 40B correspond to the light modulation means of the invention 9 or 21, and the dichroic mirror 44a. , 44b correspond to the light separating means of the inventions 9, 10, 21 to 23.

In the first embodiment, the dichroic prism 48 corresponds to the light synthesizing means of the invention 9 or 21, and the microlens array 508 is the invention 1, 2, 8, 9, 13, 14, 20, or 21. It corresponds to the light collecting means.
Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 12 is a diagram showing a second embodiment of a light propagation structure of an optical system and an optical display device, and a light propagation method of the optical system and a display method of the optical display device according to the present invention.

  In the present embodiment, a light propagation structure of an optical system and an optical display device, and a light propagation method of the optical system and a display method of the optical display device according to the present invention are applied to a projection display device 100 as shown in FIG. What is applied is different from the first embodiment in the configuration of the light modulation element groups 40R to 40B. Hereinafter, only the parts different from the first embodiment will be described, and the same parts as those in the first embodiment will be denoted by the same reference numerals and the description thereof will be omitted.

The configuration of the light modulation element groups 40R to 40B will be described in detail with reference to FIG. Since all of the light modulation element groups 40R to 40B have the same configuration, only the light modulation element group 40R will be described below, and the description of the light modulation element groups 40G and 40B will be omitted.
FIG. 12 is a cross-sectional view of the light modulation element group 40R in the optical axis direction.
The light modulation element group 40R includes liquid crystal light valves 50R and 52R as shown in FIG.

  The liquid crystal light valve 50R includes a polarizing plate 501, a counter substrate 502, a counter electrode 503, a data wiring 504, a sealing material 505, a panel substrate 506, a liquid crystal 507, and a polarizing plate 511. On the incident side of the panel substrate 506, a pixel electrode and an active element (not shown) for applying a control voltage to the pixel electrode (not shown) arranged at a predetermined interval from the data wiring 504 are formed and opposed to each other. An electrode 503 is formed on the counter substrate 502. A liquid crystal 507 is filled between the panel substrate 506 and the counter substrate 502, and the liquid crystal 507 is sealed with a sealing material 505. A polarizing plate 501 is bonded to the incident side of the counter substrate 502. On the other hand, a polarizing plate 511 is bonded to the emission side of the panel substrate 506.

  The liquid crystal light valve 52R includes a microlens array 528, a counter substrate 522, a counter electrode 523, a data wiring 524, a sealing material 525, a panel substrate 526, a liquid crystal 527, and a polarizing plate 531. On the incident side of the panel substrate 526, pixel electrodes arranged at a predetermined interval from the data wiring 524 and active elements (not shown) for applying a control voltage to the pixel electrodes (not shown) are formed and opposed to each other. An electrode 523 is formed over the counter substrate 522. A liquid crystal 527 is filled between the panel substrate 526 and the counter substrate 522, and the liquid crystal 527 is sealed with a sealing material 525. A microlens array 528 is bonded to the incident side of the counter substrate 522 with the convex direction facing the incident side. On the other hand, a polarizing plate 531 is bonded to the emission side of the panel substrate 526.

Next, the operation of the present embodiment will be described.
In the projection display device 100, the luminance distribution uniformizing unit 12 equalizes the luminance distribution of light from the light source 10, and the dichroic mirrors 44a and 44b convert the light from the luminance distribution uniforming unit 12 into light of RGB three primary colors. The light is separated and incident on the color modulation elements 40R to 40B. The light from the luminance distribution uniformizing unit 12 is primarily modulated by the luminance modulation light valve, and an optical image of the luminance modulation light valve is transmitted to the color modulation light valve via the microlens array 528. At this time, since the optical image of the luminance modulation light valve is condensed by the microlens array 528 and formed on the pixel surface of the color modulation light valve, the color modulation light is suppressed while suppressing a decrease in luminance due to light diffusion or the like. It is transmitted to the valve. The light from the luminance modulation light valve is secondarily modulated by the color modulation light valve, and the light from the color modulation light valve is synthesized by the dichroic prism 48 to display an image.

In this way, in the present embodiment, the microlens array 528 is provided on the incident side of the color modulation light valve, and the luminance modulation light valve and the color modulation light valve are arranged close to each other.
Thereby, since the light from the light source 10 is modulated through the luminance modulation light valve and the color modulation light valve, a relatively high luminance dynamic range and number of gradations can be realized. In addition, the luminance modulation light valve and the color modulation light valve are arranged close to each other, and an optical image of the luminance modulation light valve is formed on the pixel surface of the color modulation light valve via the microlens array 528. Can be formed on the pixel surface of the color modulation light valve with relatively high accuracy, and the pixel surface of the luminance modulation light valve need not be made small, so that relatively high-precision modulation can be performed. . Therefore, it is possible to reduce the possibility that the image quality is deteriorated as compared with the conventional case. Furthermore, since it is not necessary to use high-precision optical components for the illumination optical system, an increase in cost can be suppressed.

  In the second embodiment, the luminance modulation light valve corresponds to the first light modulation element of the invention 1, 6, 8, 9, 11 to 13, 18, 20, 21, 23 or 24, and the color modulation light. The valve corresponds to the second light modulation element of the invention 1, 6, 8, 9, 12, 13, 18, 20, 21 or 24. The luminance distribution uniformizing unit 12 corresponds to the luminance distribution uniforming means of the invention 10, 11 or 22, and the light modulation element groups 40R to 40B correspond to the light modulation means of the invention 9 or 21, and the dichroic mirror 44a. , 44b correspond to the light separating means of the inventions 9, 10, 21 to 23.

In the second embodiment, the dichroic prism 48 corresponds to the light synthesizing means of the invention 9 or 21, and the microlens array 528 is the invention 1, 6, 8, 9, 13, 18, 20, or 21. It corresponds to the light collecting means.
Next, a third embodiment of the present invention will be described with reference to the drawings. FIG. 13 is a diagram showing a third embodiment of a light propagation structure of an optical system and an optical display device, and a light propagation method of the optical system and a display method of the optical display device according to the present invention.

  In the present embodiment, a light propagation structure of an optical system and an optical display device, and a light propagation method of the optical system and a display method of the optical display device according to the present invention are applied to a projection display device 100 as shown in FIG. What is applied is different from the first embodiment in the configuration of the light modulation element groups 40R to 40B. Hereinafter, only the parts different from the first embodiment will be described, and the same parts as those in the first embodiment will be denoted by the same reference numerals and the description thereof will be omitted.

The configuration of the light modulation element groups 40R to 40B will be described in detail with reference to FIG. Since all of the light modulation element groups 40R to 40B have the same configuration, only the light modulation element group 40R will be described below, and the description of the light modulation element groups 40G and 40B will be omitted.
FIG. 13 is a cross-sectional view of the light modulation element group 40R in the optical axis direction.
As shown in FIG. 13, the light modulation element group 40R includes liquid crystal light valves 50R and 52R, and a SELFOC lens 54 provided between the liquid crystal light valves 50R and 52R.

  The liquid crystal light valve 50R includes a polarizing plate 501, a counter substrate 502, a counter electrode 503, a data wiring 504, a sealing material 505, a panel substrate 506, a liquid crystal 507, and a polarizing plate 511. On the incident side of the panel substrate 506, a pixel electrode and an active element (not shown) for applying a control voltage to the pixel electrode (not shown) arranged at a predetermined interval from the data wiring 504 are formed and opposed to each other. An electrode 503 is formed on the counter substrate 502. A liquid crystal 507 is filled between the panel substrate 506 and the counter substrate 502, and the liquid crystal 507 is sealed with a sealing material 505. A polarizing plate 501 is bonded to the incident side of the counter substrate 502. On the other hand, a polarizing plate 511 is bonded to the emission side of the panel substrate 506.

  The liquid crystal light valve 52R includes a counter substrate 522, a counter electrode 523, a data wiring 524, a sealing material 525, a panel substrate 526, a liquid crystal 527, and a polarizing plate 531. On the incident side of the panel substrate 526, pixel electrodes arranged at a predetermined interval from the data wiring 524 and active elements (not shown) for applying a control voltage to the pixel electrodes (not shown) are formed and opposed to each other. An electrode 523 is formed over the counter substrate 522. A liquid crystal 527 is filled between the panel substrate 526 and the counter substrate 522, and the liquid crystal 527 is sealed with a sealing material 525. On the other hand, a polarizing plate 531 is bonded to the emission side of the panel substrate 526.

A selfoc lens 54 is disposed between the liquid crystal light valve 50R and the liquid crystal light valve 52R, and is optically coupled.
Next, the operation of the present embodiment will be described.
In the projection display device 100, the luminance distribution uniformizing unit 12 equalizes the luminance distribution of light from the light source 10, and the dichroic mirrors 44a and 44b convert the light from the luminance distribution uniforming unit 12 into light of RGB three primary colors. The light is separated and incident on the color modulation elements 40R to 40B. The light from the luminance distribution uniformizing unit 12 is primarily modulated by the luminance modulation light valve, and an optical image of the luminance modulation light valve is transmitted to the color modulation light valve via the Selfoc lens 54. At this time, since the optical image of the luminance modulation light valve is condensed by the Selfoc lens 54 and formed on the pixel surface of the color modulation light valve, the color modulation light is suppressed while suppressing a decrease in luminance due to light diffusion or the like. It is transmitted to the valve. The light from the luminance modulation light valve is secondarily modulated by the color modulation light valve, and the light from the color modulation light valve is synthesized by the dichroic prism 48 to display an image.

In this manner, in the present embodiment, the Selfoc lens 54 is provided between the luminance modulation light valve and the color modulation light valve, and the luminance modulation light valve and the color modulation light valve are arranged close to each other.
Thereby, since the light from the light source 10 is modulated through the luminance modulation light valve and the color modulation light valve, a relatively high luminance dynamic range and number of gradations can be realized. In addition, since the luminance modulation light valve and the color modulation light valve are arranged close to each other and an optical image of the luminance modulation light valve is formed on the pixel surface of the color modulation light valve via the Selfoc lens 54, the luminance modulation light valve Can be formed on the pixel surface of the color modulation light valve with relatively high accuracy, and the pixel surface of the luminance modulation light valve need not be made small, so that relatively high-precision modulation can be performed. . Therefore, it is possible to reduce the possibility that the image quality is deteriorated as compared with the conventional case. Furthermore, since it is not necessary to use high-precision optical components for the illumination optical system, an increase in cost can be suppressed.

  In the third embodiment, the luminance modulation light valve corresponds to the first light modulation element of the invention 1, 7 to 9, 11 to 13, 19 to 21, 23 or 24, and the color modulation light valve is an invention. The luminance distribution uniformizing unit 12 corresponds to the luminance distribution uniformizing means according to the tenth, eleventh, or twenty-second aspect of the invention, corresponding to the second light modulation element of 1, 7 to 9, 12, 13, 19 to 21 or 24. . The light modulation element groups 40R to 40B correspond to the light modulation means of the invention 9 or 21, the dichroic mirrors 44a and 44b correspond to the light separation means of the inventions 9, 10, 21 to 23, and the dichroic prism 48 is This corresponds to the photosynthesis means of the invention 9 or 21.

In the third embodiment, the SELFOC lens 54 corresponds to the light condensing means of inventions 1, 7 to 9, 13, 19 to 21.
In the first embodiment, the microlens array 508 is provided on the emission side of the luminance modulation light valve. However, the present invention is not limited to this, and the microlens array is provided on the incident side of the color modulation light valve. Can be configured. Specifically, the following configuration can be employed.

FIG. 14 is a cross-sectional view of the light modulation element group 40R in the optical axis direction.
As shown in FIG. 14, the liquid crystal light valve 52R includes a polarizing plate 521, a microlens array 528, a counter substrate 522, a counter electrode 523, a data wiring 524, a sealing material 525, a panel substrate 526, a liquid crystal 527, and a polarizing plate 531. It is configured. On the incident side of the panel substrate 526, pixel electrodes arranged at a predetermined interval from the data wiring 524 and active elements (not shown) for applying a control voltage to the pixel electrodes (not shown) are formed and opposed to each other. An electrode 523 is formed over the counter substrate 522. A liquid crystal 527 is filled between the panel substrate 526 and the counter substrate 522, and the liquid crystal 527 is sealed with a sealing material 525. A microlens array 528 is embedded in the counter substrate 522 with the convex direction facing the emission side. A polarizing plate 521 is bonded to the incident side of the counter substrate 522. On the other hand, a polarizing plate 531 is bonded to the emission side of the panel substrate 526.

The liquid crystal light valve 50R has the same configuration as that of the first embodiment.
Accordingly, the two microlens arrays 508 and 528 are provided, and the lens diameters of the microlens arrays 508 and 528 are the same or substantially the same, so that the light collecting performance can be further improved. Accordingly, a decrease in luminance due to light diffusion or the like can be further suppressed, and the luminance of the display image can be improved. In addition, the optical image of the luminance modulation light valve can be formed on the pixel surface of the color modulation light valve with higher accuracy.

In this case, the luminance modulation light valve corresponds to the first light modulation element of the fifteenth invention, the color modulation light valve corresponds to the second light modulation element of the third or fifteenth invention, and the microlens array 508 corresponds to the fifteenth invention. The microlens array 528 corresponds to the second light collecting means of the invention 3 or 15.
In the third embodiment, the Selfoc lens 54 is provided between the luminance modulation light valve and the color modulation light valve. However, the present invention is not limited to this, and the incident side of the color modulation light valve is also microscopic. A lens array can be provided. Specifically, the following configuration can be employed.

FIG. 15 is a cross-sectional view of the light modulation element group 40R in the optical axis direction.
As shown in FIG. 15, the liquid crystal light valve 52R includes a polarizing plate 521, a microlens array 528, a counter substrate 522, a counter electrode 523, a data wiring 524, a sealing material 525, a panel substrate 526, a liquid crystal 527, and a polarizing plate 531. It is configured. On the incident side of the panel substrate 526, pixel electrodes arranged at a predetermined interval from the data wiring 524 and active elements (not shown) for applying a control voltage to the pixel electrodes (not shown) are formed and opposed to each other. An electrode 523 is formed over the counter substrate 522. A liquid crystal 527 is filled between the panel substrate 526 and the counter substrate 522, and the liquid crystal 527 is sealed with a sealing material 525. A microlens array 528 is embedded in the counter substrate 522 with the convex direction facing the emission side. A polarizing plate 521 is bonded to the incident side of the counter substrate 522. On the other hand, a polarizing plate 531 is bonded to the emission side of the panel substrate 526.

The liquid crystal light valve 50R has the same configuration as that of the third embodiment.
Thereby, since the SELFOC lens 54 and the microlens array 528 are provided, the light collecting performance can be further improved. Accordingly, a decrease in luminance due to light diffusion or the like can be further suppressed, and the luminance of the display image can be improved. In addition, the optical image of the luminance modulation light valve can be formed on the pixel surface of the color modulation light valve with higher accuracy.

In this case, the luminance modulation light valve corresponds to the first light modulation element of the invention 5 or 17, the color modulation light valve corresponds to the second light modulation element of the invention 5 or 17, and the microlens array 508 includes: Corresponding to the light collecting means of the seventeenth aspect, the SELFOC lens 54 corresponds to the second light collecting means of the fifth or seventeenth aspect.
In the first to third embodiments, the case where the color modulation light valve and the luminance modulation light valve have different resolutions has been described. In this case, as shown in the example of FIG. When adopting a configuration in which a microlens array is provided on the emission side and the incident side of the color modulation light valve, it is preferable to make the lens diameters different from each other. Specifically, the following configuration can be employed.

FIG. 16 is a cross-sectional view of the light modulation element group 40R in the optical axis direction.
In FIG. 16, a microlens array 508 is provided on the exit side of the luminance modulation light valve, and a microlens array 528 is provided on the entrance side of the color modulation light valve. The lens diameter of the microlens array 508 has the same or almost the same size as the pixel of the luminance modulation light valve. Further, the lens diameter of the microlens array 528 has the same or almost the same size as the pixel of the color modulation light valve.

  As a result, two microlens arrays 508 and 528 are provided, the lens diameter of the microlens array 508 is the same as or substantially the same as the pixel of the luminance modulation light valve, and the lens diameter of the microlens array 528 is changed to the color modulation light. Since the size is the same as or substantially the same as the pixel size of the bulb, the light collection performance can be further improved. Accordingly, a decrease in luminance due to light diffusion or the like can be further suppressed, and the luminance of the display image can be improved. In addition, the optical image of the luminance modulation light valve can be formed on the pixel surface of the color modulation light valve with higher accuracy.

  In this case, the luminance modulation light valve corresponds to the first light modulation element of the invention 4, 15 or 16, and the color modulation light valve corresponds to the second light modulation element of the invention 3, 4, 15 or 16. The microlens array 508 corresponds to the light collecting means of the invention 4, 15 or 16. The microlens array 528 corresponds to the second light collecting means of the invention 3, 4, 15 or 16.

  In the first to third embodiments, the projection display apparatus 100 is configured with the light modulation unit 18 as a three-plate type (a method in which modulation is performed by the three light modulation element groups 40R to 40B). Not limited to this, as shown in FIG. 17, the light modulation unit 18 may be configured as a single plate type (a method in which modulation is performed by one light modulation element group 40). A single-plate color modulation light valve can be configured by, for example, providing a liquid crystal light valve with a color filter. In this case, the light modulation element that determines the display resolution may be either a luminance modulation light valve or a color modulation light valve.

FIG. 17 is a block diagram showing a hardware configuration when the projection display device 100 is configured as a single plate type.
In the first to third embodiments, the light modulation element arranged at the front stage as viewed from the light source 10 is a luminance modulation light valve, and the light modulation element arranged at the rear stage from the light source 10 is a color modulation light. Although it is configured as a bulb, the present invention is not limited to this, and the light modulation element arranged in the previous stage when viewed from the light source 10 is configured as a color modulation light valve, and the light modulation element disposed in the subsequent stage as viewed from the light source 10 is configured as a luminance modulation light valve. You can also

  In the first to third embodiments, the liquid crystal light valves 50R to 50B and 52R to 52B are configured using active matrix liquid crystal display elements. However, the present invention is not limited to this, and the liquid crystal light valves 50R to 50R are used. 50B and 52R to 52B can be configured using passive matrix type liquid crystal display elements and segment type liquid crystal display elements. An active matrix type liquid crystal display element has an advantage that precise gradation display can be performed, and a passive matrix type liquid crystal display element and a segment type liquid crystal display element have an advantage that they can be manufactured at low cost.

  In the first to third embodiments, the color modulation light valve is configured as a light modulation element that determines the display resolution. However, the present invention is not limited to this, and the luminance modulation light valve determines the display resolution. It can also be configured as a light modulation element. In this case, the transmittance T1 of each pixel of the luminance modulation light valve is determined after determining the transmittance T1 of each pixel of the color modulation light valve (the transmittance of the light modulation element determined previously is T1). The transmittance of the light modulation element to be determined later is T2.)

  In the first to third embodiments, the control values for the luminance modulation light valve and the color modulation light valve are determined based on the HDR display data. However, the normal 8-bit RGB image data for each color is used. Is used, the value of 0 to 255 in normal RGB image data is not a physical quantity of luminance but a relative value of 0 to 255. Therefore, in order to display the display device of the present invention based on normal RGB image data, the physical luminance Rp to be displayed or the transmittance Tp of the entire display device must be determined from the normal RGB image. .

FIG. 18 is a diagram illustrating the data structure of the input value registration table 440.
Therefore, by using the input value registration table 440 of FIG. 18, it is possible to convert the input value of 0 to 255 of the normal RGB image into the physical transmittance Tp, and the transmittance Tp of this table. It is possible to easily change the display appearance (gradation characteristics) of a normal RGB image depending on the setting method. Since the transmittance Tp in this table is Tp in the above equation (2), once this value is determined, a plurality of processes are performed by performing the same processing as in the first to third embodiments. The transmittances T1 and T2 of the light modulation element are determined and can be displayed.

FIG. 19 is a diagram showing the data structure of the input value registration table 460.
The input value registration table 460 in FIG. 19 uses the luminance Rp instead of the transmittance Tp. Since the luminance Rp in this table is Rp in the above equation (1), once this value is determined, a plurality of light beams are obtained by performing the same processing as in the first to third embodiments. The transmittances T1 and T2 of the modulation elements are determined and can be displayed.

In the first to third embodiments, for each pixel of the color modulation light valve, the weighted average value of the transmittance T1 determined for the pixel of the luminance modulation light valve that overlaps the pixel on the optical path is calculated. The transmittance T2 of the pixel is calculated based on the average value. However, the present invention is not limited to this, and for each pixel of the color modulation light valve, the luminance modulation light valve that overlaps the pixel on the optical path is used. Based on the control value determined for the pixel, the transmittance T1 _table corresponding to the control value is read from the control value registration tables 400R to 400B, the weighted average value of the read transmittance T1 _table is calculated, and the average value is calculated. The transmissivity T2 of the pixel can also be calculated based on this.

  In the first to third embodiments, the average value of the transmittance T1 ′ calculated for each of the three primary colors of RGB for the same pixel is calculated as T1 ′ of the pixel. Not limited to this, the transmittance T1 ′ is calculated as it is for each of the three primary colors RGB, and in step S114, the average value of the transmittance T1 calculated for each of the three primary colors of the same pixel is calculated as T1 of the pixel. You can also.

  In the first to third embodiments, for each pixel of the color modulation light valve, the weighted average value of the transmittance T1 determined for the pixel of the luminance modulation light valve that overlaps the pixel on the optical path is calculated. The transmittance T2 of the pixel is calculated based on the average value. However, the present invention is not limited to this, and for each pixel of the color modulation light valve, the luminance modulation light valve that overlaps the pixel on the optical path is used. A maximum value, a minimum value, or an average value of the transmittance T1 determined for the pixel may be calculated, and the transmittance T2 of the pixel may be calculated based on the calculated value.

In the first to third embodiments, the projection display device 100 is configured by providing the transmissive light modulation element. However, the present invention is not limited to this, and the luminance modulation light valve or the color modulation light valve is not limited to the DMD. A reflection type light modulation element such as (Digital Mirror Device) can also be used. In this case, the reflectance is determined based on the HDR display data.
In the first to third embodiments, the light modulation element having a small number of pixels and the number of gradations is used to simplify the description. However, the light modulation element having a large number of pixels and the number of gradations is used. Even in the case of using, processing can be performed in the same manner as in the first to third embodiments.

In the first to third embodiments, the gain G = 1.0 is set to simplify the description. However, the gain G is not 1.0 depending on the hardware configuration. In consideration of the actual calculation cost, it is preferable to register the control value and the transmittance in the control value registration table in a manner including the influence of the gain G.
In the first to third embodiments, the case where the control program stored in advance in the ROM 72 is executed in executing the processing shown in the flowchart of FIG. 6 is not limited to this. The program may be read from the storage medium storing the program showing these procedures into the RAM 74 and executed.

  Here, the storage medium is a semiconductor storage medium such as RAM or ROM, a magnetic storage type storage medium such as FD or HD, an optical reading type storage medium such as CD, CDV, LD, or DVD, or a magnetic storage type such as MO. / Optical reading type storage medium, including any storage medium that can be read by a computer regardless of electronic, magnetic, optical, or other reading methods.

  In the first to third embodiments, the optical propagation structure and optical display device of the optical system according to the present invention, the optical propagation method of the optical system, and the display method of the optical display device are shown in FIG. As described above, the present invention is applied to the projection display device 100. However, the present invention is not limited to this, and can be applied to other cases without departing from the gist of the present invention.

2 is a block diagram showing a hardware configuration of a projection display apparatus 100. FIG. It is sectional drawing of the optical axis direction of the light modulation element group 40R. 3 is a block diagram illustrating a hardware configuration of a display control device 200. FIG. It is a figure which shows the data structure of the control value registration table 400R. It is a figure which shows the data structure of the control value registration table 420R. It is a flowchart which shows a display control process. It is a figure for demonstrating a tone mapping process. It is a figure which shows the case where the transmittance | permeability T2 of a color modulation light valve is provisionally determined. It is a figure which shows the case where the transmittance | permeability T1 'of a brightness | luminance modulation light valve is calculated per pixel of a color modulation light valve. It is a figure which shows the case where the transmittance | permeability T1 of each pixel of a brightness | luminance modulation light valve is determined. It is a figure which shows the case where the transmittance | permeability T2 of each pixel of a color modulation light valve is determined. It is sectional drawing of the optical axis direction of the light modulation element group 40R. It is sectional drawing of the optical axis direction of the light modulation element group 40R. It is sectional drawing of the optical axis direction of the light modulation element group 40R. It is sectional drawing of the optical axis direction of the light modulation element group 40R. It is sectional drawing of the optical axis direction of the light modulation element group 40R. It is a block diagram which shows the hardware constitutions at the time of comprising the projection type display apparatus 100 as a single plate type. It is a figure which shows the data structure of the input value registration table. It is a figure which shows the data structure of the input value registration table 460. It is a figure which shows the structure of the optical path of the 1st light modulation element in a projection type display apparatus of patent document 2, and a 2nd light modulation element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Projection type display apparatus, 10 ... Light source, 10a ... Lamp, 10b ... Reflector, 12 ... Luminance distribution equalization part, 12a, 12b ... Fly eye lens, 12c ... Polarization conversion element, 12d ... Condensing lens, 18 ... Light modulation unit, 40R to 40B ... light modulation element _{group, 42R, 42G, 42B 1 ~42B} 3 ... field lenses, 44a, 44b ... dichroic mirror, 46a through 46c ... mirror, 48 ... dichroic prism, 20 ... projection section, 50R～ 50B, 52R to 52B ... Liquid crystal light valve, 54 ... Selfoc lens, 501, 511, 531 ... Polarizing plate, 502, 503, 522, 523 ... Counter electrode, 504, 524 ... Data wiring, 505, 525 ... Sealing material , 506, 526 ... Panel substrate, 507, 527 ... Liquid crystal, 508, 528 ... My Lorenz array, 70 ... CPU, 72 ... ROM, 74 ... RAM, 78 ... I / F, 79 ... Bus, 80 ... Light valve driving device, 82 ... Storage device, 199 ... Network, 400R-400B, 420R-420B ... Control value registration table, 440, 460 ... Input value registration table, 112a, 112b ... Fly-eye lens, 112d ... Condensing lens, 130 ... First light modulation element, 140 ... Second light modulation element

Claims (8)

Light from a light source is modulated via a first light modulation element having a plurality of pixels whose light propagation characteristics can be independently controlled and a second light modulation element having a plurality of pixels whose light propagation characteristics can be independently controlled. A structure applied to a projection display device ,
The first light modulation element is provided on a side where light from a light source is incident, and first condensing means including a microlens array having a lens diameter that is the same as or substantially the same as a pixel of the first light modulation element A second condensing means, which is provided on the emission side of the one light modulation element and includes a microlens array having a lens diameter that is the same as or substantially the same as the pixel of the second light modulation element, is incident on the second light modulation element. is provided on the first optical modulation elements and in close proximity to the second optical modulation element disposed projection display device the resolution of the second optical modulation element may be higher than the resolution of the first light modulation element use light propagation structure. A light source, a first light modulation element having a plurality of pixels that receive light from the light source and whose light propagation characteristics can be controlled independently; and light incident from the first light modulation element and having light propagation characteristics A device for displaying an image by modulating light from the light source via the first light modulation element and the second light modulation element. There,
First condensing means comprising a microlens array having a lens diameter that is the same as or substantially the same as the pixel of the first light modulation element is provided on the emission side of the first light modulation element, and Rutotomoni provided with the second focusing means comprising a microlens array lens diameter and the pixel in the same or substantially the same size on the incident side of the second optical modulation element, the first light modulation element and the second light modulator A projection type display device, wherein the elements are arranged close to each other, and the resolution of the second light modulation element is higher than the resolution of the first light modulation element. Oite to claim 2,
The projection display device, wherein the first light modulation element, the first light condensing means , the second light condensing means, and the second light modulation element are bonded and integrated. According to claim 2 or 3,
And light separating means for separating light from the light source into light of a plurality of different specific wavelength regions,
A plurality of light modulation means for entering the light separated by the light separation means, and a light combining means for combining the light from each of the light modulation means,
The projection display device, wherein the light modulation means includes the first light modulation element, the first light collection means , the second light collection means, and the second light modulation element. In claim 4 ,
A projection-type display device comprising: a luminance distribution uniformizing unit configured to uniform a luminance distribution of light from the light source on an optical path between the light source and the light separating unit. In claim 5 ,
The luminance distribution uniformizing means is a projection type display device characterized by having a polarization conversion element that polarized light according to the light from the light source incident allows the polarization direction of the first optical modulation element. In any of claims 2 to 6 ,
The projection display device, wherein the first light modulation element and the second light modulation element are liquid crystal light valves. Light from a light source is modulated via a first light modulation element having a plurality of pixels whose light propagation characteristics can be independently controlled and a second light modulation element having a plurality of pixels whose light propagation characteristics can be independently controlled.
A method applied to a projection display device ,
The first light modulator device and in close proximity to the second optical modulation element are arranged, the higher resolution than the resolution of the first optical modulation element having said second optical modulation element, wherein the first optical modulation element in the optical path of the second optical modulation element, the first focus-consisting of the microlens array of the said lens diameter of the pixel in the same or substantially the same size as the first optical modulation elements provided on the exit side of the first light modulation element wherein through the means, and a second focusing means comprising a microlens array of the size lens diameter of the pixel in the same or substantially the same second optical modulation and the second optical modulation elements provided on the incident side of the element An optical propagation method for a projection display device , wherein an optical image of a first light modulation element is formed on a pixel surface of the second light modulation element.

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