JP2008107445A - Projector and modulation control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of faithfully reproducing a specific color. <P>SOLUTION: Three light valves 104, 106 and 108 receive light emitted from a light source 100, and modulate the light of each one color out of three primary colors RGB. A fourth light valve 111 receives the light emitted from the light source 100 and modulates the light of the specific color expressed by points in a triangle on an xy chromaticity diagram with three primary colors RGB as vertexes. A projection lens 114 receives the light modulated by the three light valves respectively and the light modulated by the fourth light valve 111, and projects the light. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a projector and a modulation control method, and more particularly to a projector and a modulation control method with high color reproducibility.

In recent years, IT has been advanced in the medical field, and not only documents but also photographs have been digitized. The display image quality required at that time is very high, and specifications such as resolution, gradation, color unevenness, color reproducibility, color gamut and the like are required to be higher than those of consumer displays.
In a conventional display, two projectors are stacked (for example, refer to Patent Document 1), a color wheel of four or more primary colors and a light valve are combined (for example, refer to Patent Document 2), or an existing three primary color light valve. By adding one primary color light valve to the above configuration, four or more primary colors are additively mixed to expand the displayable color gamut (see, for example).
JP 2000-338950 A JP 2004-286963 A Shmuel Roth, Walt Caldwell, “64.4: Four Primary Color Projection Display”, SID Symposium Digest of Technical Papers, May 2005, Volume 36, Issue 1, pp. 1818-1821

  However, with a conventional display, although the displayable color gamut is wide, coloration and color unevenness occurs in the monochrome display portion, and subtle shades such as skin color cannot be faithfully reproduced. There is a problem that a specific color cannot be faithfully reproduced.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a projector and a modulation control method capable of faithfully reproducing a specific color.

  The present invention has been made to solve the above-described problems. A projector according to the present invention receives a light source and light emitted from the light source, and modulates light of each of three colors. A specific color modulation element that receives light emitted from the light source and modulates light of a fourth color represented by a point in a triangle on the xy chromaticity diagram having the three colors as vertices; And a projection lens that receives light modulated by each of the three modulation elements and light modulated by the specific color modulation element and projects these lights.

  Thereby, the projector of the present invention modulates the light of the fourth color, so that the fourth color can be faithfully reproduced.

  The projector according to the present invention is the projector described above, and determines whether or not a predetermined color range including the fourth color includes a color of a predetermined pixel of the input image signal. When it is determined that the color of the predetermined pixel is included, control means for modulating at least the predetermined pixel with the specific color modulation element is provided.

  Thus, the projector of the present invention modulates the light of the fourth color when the color of the predetermined pixel is included in a predetermined color range including the fourth color. Is included in a predetermined color range including the fourth color, the color can be faithfully reproduced.

  The projector according to the aspect of the invention is the projector described above, wherein the color range is an area in the vicinity of the fourth color point in the xy chromaticity diagram, and the control unit is configured to change the color of the predetermined pixel. 3 is determined, the color of the predetermined pixel is 3 in the xy chromaticity diagram with the point of any two of the three colors and the point of the fourth color as vertices. It is determined which of the three triangles is within, and the predetermined pixel is selected from the two modulation elements corresponding to the color of the triangle of the determination result among the three modulation elements, and the specific Modulating with a color modulation element.

  Accordingly, when the color of the image signal is included in the region in the vicinity of the point of the fourth color in the xy chromaticity diagram, the projector according to the present invention has two modulation elements of the three primary colors RGB and the specific color. Since the modulation is performed by the modulation element, the color of the image signal close to the fourth color can be faithfully reproduced.

  The projector according to the aspect of the invention is the projector described above, wherein the control unit modulates a pixel included in the color range among the predetermined pixels with the specific color modulation element. Pixels not included in the color range are modulated by the three modulation elements.

  The projector according to the present invention is any one of the projectors described above, wherein the three colors are red, green, and blue, and the fourth color is a skin color.

  As a result, the projector of the present invention modulates the flesh color light with the specific color modulation element, so that the flesh color can be faithfully reproduced.

  The projector according to the present invention is any one of the projectors described above, wherein the three colors are red, green, and blue, and the fourth color is white.

  As a result, the projector of the present invention modulates white light with the specific color modulation element, so that white can be faithfully reproduced.

  Further, the projector according to the present invention is any one of the above-described projectors, and when the luminance of the display image is required, the control unit may set the specific color modulation element for all display pixels. Control is performed so that the amount of emitted light is maximized.

  Thus, the projector according to the present invention can use the light incident on the special color modulation element to increase the luminance of the display image, so that a display image with high luminance can be obtained.

  Further, the projector according to the present invention is any one of the projectors described above, and the control unit converts the predetermined pixel into the three modulation elements and the specific color when gradation of a display image is required. Modulation is performed by four modulation elements including a modulation element.

  As a result, the projector of the present invention modulates with the three modulation elements and the specific color modulation element, so that a display image with a high number of gradations can be obtained.

  The projector according to the present invention is any one of the projectors described above, wherein the light emitted from the light source is polarized and separated, and light having one polarization direction is incident on the special modulation element, and the other polarization direction is incident. Polarizing and combining the polarization separating means installed so that light can be inserted and removed at a position where the light is incident on the three modulation elements, and the light modulated by the specific color modulation element and the light modulated by the three modulation elements. And a polarization beam combining means installed so as to be inserted and removed at a position where the polarized light beam is incident on the projection lens.

  As a result, the projector according to the present invention operates as one of the projectors described above when the polarization separation unit and the polarization synthesis unit are inserted, and has three colors when the polarization separation unit and the polarization synthesis unit are removed. In addition, when operating as a projector that modulates with three colors, all three light elements can be irradiated with light from the light source, so that the light from the light source can be used efficiently. be able to.

  The projector according to the present invention is any one of the projectors described above, and includes a color filter installed on the optical path of the light incident on the specific color modulation element in a replaceable or removable manner. .

  Thereby, the projector of the present invention can change the color that can be faithfully reproduced by changing the color of the light modulated by the special color modulation element.

  In addition, the modulation control method of the present invention receives a light source, three modulation elements that receive light emitted from the light source, and modulates one color of each of the three colors, and light emitted from the light source. , A specific color modulation element that modulates the light of the fourth color represented by a point in the triangle on the xy chromaticity diagram with the three colors as vertices, the light modulated by each of the three modulation elements, and the specific A modulation control method for a projector comprising a projection lens that receives light modulated by a color modulation element and projects these lights, and a control means for controlling the transmittance of the three modulation elements and the specific color modulation element. The control means determines whether or not a predetermined color range including the fourth color includes the color of a predetermined pixel of the input image signal; and In the first process, the control means determines that the color of the predetermined pixel When it is determined that the rare, characterized in that it comprises a second step of modulating at least said predetermined pixel in the particular color modulation element.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic block diagram showing a configuration of a projection optical system unit in a projector according to the first embodiment of the present invention. Reference numeral 100 denotes a light source comprising a lamp such as a high-pressure mercury lamp and a uniformizing means for uniformizing light emitted from the lamp. 101 is a polarization separation element (polarization separation means) such as a PBS (Polarized Beam Splitter) that separates P-polarized light and S-polarized light by transmitting P-polarized light and reflecting S-polarized light out of the light emitted from the light source 100. ). 102 receives the P-polarized light separated by the polarization separation element 101, transmits the R (red) component light, and converts the remaining G (green) component and B (blue) component light into cyan light. It is an R (Red) C (Cyan) separation element that reflects. Reference numeral 103 denotes a mirror that reflects the R component light transmitted through the RC separation element 102. Reference numeral 104 denotes an R light valve (modulation element) that performs R component color modulation by transmitting R component light reflected by the mirror 103 at a transmittance set for each pixel by a control system described later. .

  Reference numeral 105 denotes a G (Green) B (Blue) separation element that receives cyan light reflected by the RC separation element 102, reflects only the G component light, and transmits the remaining B component light. Reference numeral 106 denotes a G light valve (modulation element) that performs color modulation of the G component by transmitting the G component light reflected by the GB separation element 105 at a transmittance set for each pixel by a control system described later. It is. Reference numeral 107 denotes an RG composite that transmits the R component light and reflects the G component light, thereby combining the R component light color-modulated by the R light valve and the G component light color-modulated by the G light valve. It is an element.

  Reference numeral 108 denotes a B light valve (modulation element) that performs color modulation of the B component by transmitting the B component light transmitted by the GB separation element 105 at a transmittance set for each pixel by a control system described later. It is. Reference numeral 109 denotes a mirror that reflects the B component light color-modulated by the B light valve 108. 110 reflects the B component light reflected by the mirror 109 and transmits the yellow light composed of the R component and the G component synthesized by the RG synthesis element 107, thereby synthesizing these lights B (Blue) ) Y (Yellow) composite element.

  Reference numeral 111 denotes a fourth light valve (special color modulation element) that performs modulation by transmitting S-polarized light separated by the polarization separation element 101 at a transmittance set for each pixel by a control system described later. White light as the fourth color is incident on the fourth light valve 111. Reference numeral 112 denotes a mirror that reflects the S-polarized light modulated by the fourth light valve 111. Reference numeral 113 denotes a polarization combining element (polarization combining means) that combines the light by reflecting the S-polarized light reflected by the mirror 112 and transmitting the light combined by the BY combining element (P-polarized light). Reference numeral 114 denotes a projection lens that projects the light combined by the polarization combining element 113 onto a screen (not shown).

  FIG. 2 is a schematic block diagram showing the configuration of the projection optical system unit in the projector according to the present embodiment. In the figure, portions corresponding to the respective portions in FIG. An image input unit 120 receives an image signal input to the projector according to the present embodiment. A color analysis unit 121 receives an image signal received by the image input unit 120 and determines the transmittance of each light valve (a value obtained by dividing the amount of emitted light by the amount of incident light) based on the color of each pixel of the image signal. (Control means). Although described in detail using the flowchart of FIG. 3, the color analysis unit 121 is white (achromatic) (that is, the color of light modulated by the fourth light valve) for each pixel of the received image signal. If it is white, the transmittance of the R light valve 104, the G light valve 106, and the B light valve 108 is set to “0”, and the transmittance of the fourth light valve 111 is set to the pixel. The value depends on the brightness. When the color is not white, the transmittance of the R light valve 104, the G light valve 106, and the B light valve 108 is set to a value corresponding to the color and luminance of the pixel, and the transmittance of the fourth light valve 111 is set to “ 0 ”.

  122, the drive voltage at which the transmittance of the R light valve 104, the G light valve 106, and the B light valve 108 becomes the transmittance of each light valve determined by the color analysis unit 121 is determined for each light valve. It is an RGB light valve drive unit that drives each light valve with a drive voltage. A fourth light valve driving unit 123 determines a driving voltage at which the transmittance of the fourth light valve 111 is the transmittance determined by the color analyzing unit 121 and drives the fourth light valve 111 with the driving voltage. is there. In the drawing, reference numeral 124 denotes an RGB light valve that collectively represents the R light valve 104, the G light valve 106, and the B light valve 108 for convenience.

  FIG. 3 is a flowchart for explaining the operation of the color analysis unit 121. The color analysis unit 121 processes each pixel of the image signal according to the flowchart. First, the color analysis unit 121 extracts information about a certain pixel from the image signal received by the image input unit 120, and R (red), G (green), and B (blue) components of the color of the pixel. It is determined whether or not the luminances of all are equal (Sa1). Thereby, it is determined whether or not the color of the pixel is white. Here, assuming that the color of the pixel is white, the color analysis unit 121 determines that the luminances of the R component, the G component, and the B component are all equal, and proceeds to step Sa4. In step Sa4, the color analysis unit 121 hides the R light valve 104, the G light valve 106, and the B light valve 108. That is, the color analyzing unit 121 sets the transmittance of the R light valve 104, the G light valve 106, and the B light valve 108 to “0” so as to block light. Next, the color analyzing unit 121 modulates the fourth light valve 111 to display white (Sa5). That is, for the fourth light valve 111, the color analysis unit 121 sets the transmittance value so that the amount of emitted light is an amount corresponding to the luminance of the pixel.

  If the color of the pixel is not white, the color analysis unit 121 determines in step Sa1 that the luminances of the R component, the G component, and the B component are not all equal, and the process proceeds to step Sa2. To do. In step Sa2, the color analysis unit 121 hides the fourth light valve. That is, the color analysis unit 121 sets the transmittance of the fourth light valve to “0” so as to block light. Next, the color analyzing unit 121 modulates the R light valve 104, the G light valve 106, and the B light valve 108 to display the color of the pixel (Sa3). That is, for the R light valve 104, the G light valve 106, and the B light valve 108, the color analysis unit 121 sets the transmittance value so that the amount of emitted light is an amount corresponding to the color and luminance of the pixel.

As a result, the white (that is, achromatic) region of the image is displayed only with the light transmitted through the fourth light valve 111, so that an image with no color unevenness is displayed in the achromatic region. be able to.
Note that when the gradation of the display image is required, that is, when it is desired to increase the number of gradations as compared with the case of normal use (when operating as in the present embodiment), the color analysis unit 121 performs R By determining the transmittance of each light valve so that all of the light valve 104, the G light valve 106, the B light valve 108, and the fourth light valve 111 are modulated, the gradation is doubled in monochrome display. be able to.

  In addition, when high luminance is required, that is, when it is desired to display high luminance as compared with normal use (when operating as in the present embodiment), the color analysis unit 121 performs the first operation for all pixels. Each light valve is configured such that the transmittance of the four light valves 111 is set to a constant value (for example, the emission amount is maximum), and white pixels are also modulated by the R light valve 104, the G light valve 106, and the B light valve 108. By determining the transmittance, an image with increased brightness can be displayed.

  In addition, a color filter that transmits white (achromatic) light, which is the fourth color, may be installed in the optical path between the polarization separation element 101 and the fourth light valve 111. Depending on the type of light source, there may be many specific color components. By placing a color filter that transmits white (achromatic) light, which is the fourth color, accurate white (achromatic) Can be realized. Moreover, the color may be accurately reproduced by setting the color filter to an arbitrary color other than white.

  Further, by installing the polarization separating element 101 and the polarization combining element 113 in FIG. 1 so as to be electrically removed / inserted, the projector according to the present embodiment and the projector of RGB three primary colors can be switched. At this time, at the time of removal to become a projector of RGB three primary colors, the amount of light incident on the R light valve 104, the G light valve 106, and the B light valve 108 is twice as much as that at the time of insertion of the projector of this embodiment. A bright image can be displayed. Note that only the polarization separation element 101 of the polarization separation element 101 and the polarization composition element 113 may be removed and inserted.

[Second Embodiment]
The second embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a schematic block diagram showing the configuration of the projection optical system unit in the projector according to the second embodiment of the present invention. In the figure, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. Reference numeral 201 denotes a flesh color filter that is installed in the optical path between the polarization separation element 101 and the fourth light valve 111 and is the fourth color. The flesh-colored light that has passed through the color filter 201 is incident on the fourth light valve 111. The color filter 201 will be described with reference to FIG.

  FIG. 5 is a schematic block diagram showing the configuration of the projection optical system unit in the projector according to the present embodiment. In the figure, parts corresponding to those in FIGS. 2 and 4 are denoted by the same reference numerals, and description thereof is omitted. Reference numeral 221 denotes a color analysis unit (control unit) that receives an image signal received by the image input unit 120 and determines the transmittance of each light valve based on the color of each pixel of the image signal. The color analysis unit 221 will be described in detail using the flowchart of FIG. 6, but the color analysis unit 221 has a predetermined color range in which the pixel color includes skin color, that is, the color of light modulated by the fourth light valve 111. It is determined whether or not it is included. If included, at least the fourth light valve 111 is modulated.

FIG. 6 is a flowchart for explaining the operation of the color analysis unit 221. The color analysis unit 221 processes each pixel of the image signal according to the flowchart. First, the color analysis unit 221 extracts information about a certain pixel from the image signal received by the image input unit 120, performs gamma processing on the RGB value of the pixel, and then performs an XYZ value of the CIE (International Lighting Commission) color system. (Sb1). In this embodiment, RGB values are each represented by 8 bits (0 to 255), and the color analysis unit 221 performs gamma processing using the following equations (1), (2), and (3). .
r = (R / 255) ^ 2.2 (1)
g = (G / 255) ^ 2.2 (2)
b = (B / 255) ^ 2.2 (3)
Here, the values R, G, and B are the values of the R component, the G component, and the B component of the image signal, respectively, and the values r, g, and b are the R component, the G component, and the B component after the gamma processing, respectively. Value. “^” Is an operator representing a power.

The color analysis unit 221 uses the following formulas (4), (5), and (6) for the values r, g, and b calculated in the formulas (1), (2), and (3), and XYZ. Convert to value.
X = 0.607r + 0.174g + 0.200b (4)
Y = 0.299r + 0.587 g + 0.114b (5)
Z = 0.000r + 0.066g + 1.116b (6)
Next, the color analysis unit 221 calculates the x value and the y value of the xy chromaticity from the XYZ values calculated in step Sb1 using the following expressions (7) and (8) (Sb2).
x = X / (X + Y + Z) (7)
y = Y / (X + Y + Z) (8)

  The color analysis unit 221 determines whether or not the xy chromaticity calculated in step Sb2 is a skin color (Sb3). In the present embodiment, the x value of the chromaticity of the skin color is set to “0.447”, the y value is set to “0.484”, and an xy chromaticity diagram as shown in FIG. 8 is used as a predetermined color range including the skin color. A region in the vicinity of the skin color (skin color region H) is used. The skin color region H has an x value and a y value within the range of “± 0.030” from the chromaticity of the skin color, and the color analysis unit 221 has the xy chromaticity calculated in step Sb2 within the range. At some point, it is determined to be skin tone. Here, it is assumed that the xy chromaticity is within the range and the skin color is determined. Then, the process proceeds to step Sb6, and the color analysis unit 221 uses a total of three light valves, that is, two light valves of the R light valve 104, the G light valve 106, and the B light valve 108 and the fourth light valve 111. The transmittance for displaying the skin color of the XYZ value calculated in step Sb1 is calculated. The remaining one of the R light valve 104, the G light valve 106, and the B light valve 108 has a transmittance of “0”.

  The color analysis unit 221 selects two light valves from the R light valve 104, the G light valve 106, and the B light valve 108 as follows. In the xy chromaticity diagram as shown in FIG. 8, the color analysis unit 221 includes RGB three primary color points (points R, G, and R) corresponding to the three light valves of the R light valve 104, the G light valve 106, and the B light valve 108. B) and the xy calculated in step Sb2 in any one of the three triangles having the vertex of the point of any two colors and the point of the skin color of the transmitted light of the color filter 201 (point C). It is determined whether a skin color of chromaticity exists. Next, the color analysis unit 221 displays the skin color of the XYZ values calculated in step Sb1 for the transmittances of the two light valves and the fourth light valve 111 corresponding to the color of the vertex of the triangle as a result of this determination. Calculate as follows.

  The method for calculating the transmittance by the color analysis unit 221 will be described by taking as an example the case of using the R light valve 104, the G light valve 106, and the fourth light valve 111. Only when the transmittance of the R light valve 104 is “1” (ie, 100%), the XYZ values of the colors displayed are Xr, Yr, Zr, and similarly the XYZ values of the G light valve 106 are Xg, Yg, Zg. The XYZ values of the fourth light valve 111 are Xc, Yc, Zc, and the XYZ values of the skin color to be displayed are X, Y, Z. At this time, if the transmittances of the R light valve 104, the G light valve 106, and the fourth light valve 111 are α, β, and γ, respectively, Equation (9) is established. α, β, and γ can be calculated by Expression (10) obtained by modifying Expression (9).

  The color analysis unit 221 uses the G light valve 106, the B light valve 108, and the fourth light valve 111, or the R light valve 104, the B light valve 108, and the fourth light valve 111. The transmittance of each light valve is calculated in the same manner as when modulation is performed by the R light valve 104, the G light valve 106, and the fourth light valve 111 described above. Note that the color analysis unit 221 may store a matrix corresponding to the inverse matrix in Expression (10), and perform calculation based on these matrices.

  On the other hand, if the color analysis unit 221 determines that the xy chromaticity of the pixel does not satisfy the condition of Step Sb3 described above and is not a skin color in Step Sb3, the process proceeds to Step Sb4. In step Sb4, the color analysis unit 221 sets the transmittance of the fourth light valve 111 to “0”. Next, in step Sb5, the color analysis unit 221 calculates the transmittance of the R light valve 104, the G light valve 106, and the B light valve 108 that display the color of the pixel.

  FIG. 7 is a characteristic example of spectral transmittance of the color filter 201 with the horizontal axis indicating the wavelength and the vertical axis indicating the transmittance. As shown in FIG. 7, the color filter 201 has a spectral transmittance characteristic simulating the spectral distribution of human skin. For this reason, by using the color filter 201, the skin color can be reproduced at the spectral level. In order to make use of the spectral transmittance characteristics of the color filter 201, it is desirable to use a lamp having a broad emission spectrum, such as a xenon lamp, as the lamp of the light source 100.

  In the present embodiment, the color filter 201 has been described as having spectral transmittance characteristics imitating the spectral distribution of human skin, assuming it is used in the medical field, but is used in other fields. If there is, a color filter 201 having a color specific to the field may be used. For example, in the agricultural field, a green or yellow color filter may be used, and in other fields, a white color filter may be used, or the color of the light source is used as it is and no color filter is used. Also good. In this case, the color analysis unit 221 needs to change the determination condition in step Sb3 and the calculation parameter in step Sb4 according to the color of the color filter.

In the present embodiment, the skin color region H may be displayed using only the fourth light valve 111 (the G light valve 106, the B light valve 108, and the fourth light valve 111 have a transmittance of 0). .
Further, when the gradation of the display image is required, that is, when it is desired to increase the number of gradations as compared with the case of normal use (when operating as in the present embodiment), the color analysis unit 121 performs R The number of gradations may be increased by determining the transmittance of each light valve so that all of the light valve 104, the G light valve 106, the B light valve 108, and the fourth light valve 111 are modulated.

  In addition, when high luminance is required, that is, when it is desired to display high luminance as compared with normal use (when operating as in the present embodiment), the color analysis unit 121 performs the first operation for all pixels. The light transmittance of each of the four light valves 111 is set to a constant value (for example, the emission amount is maximum), and white pixels are also modulated by the R light valve 104, the G light valve 106, and the B light valve 108. An image with increased brightness may be displayed by determining the transmittance.

  The light source 100 includes two light sources, one of which irradiates the fourth light valve via the color filter 201, and the other of the light source 100 via the RC separation element 102, the R light valve 104 and the G light valve. 106 and the B light valve 108 may be irradiated. In this case, it is desirable to use a lamp having a broad emission spectrum such as a xenon lamp as the lamp of the light source that irradiates the fourth light bulb.

  In addition, when the color filter 201 is installed and inserted so as to be electrically removed and inserted, the color analysis unit 221 of this embodiment operates, and when it is removed, the color analysis unit of the first embodiment. By causing 121 to operate, the projector according to the present embodiment and the projector according to the first embodiment may be selectable. Further, a plurality of color filters having different colors may be removed / inserted using a color wheel or the like. At this time, the color analysis unit 221 changes the determination condition in step Sb and the parameter used for calculation in step Sb4 according to the color of the inserted color filter.

  In the first and second embodiments, the color analysis unit 121 and the color analysis unit 221 have been described as calculating the transmittance of each light valve. However, the color analysis unit 121 and the color analysis unit 221 are storage units. And storing the transmittance of each light valve corresponding to each value of the image signal in the storage unit, and referring to the storage unit, the transmittance of each light valve corresponding to the value of the input image signal May be read out.

  Further, a program for realizing the functions of the color analysis unit 121 in FIG. 2 and the color analysis unit 221 in FIG. 5 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system. The processing of each unit may be performed by executing. Here, the “computer system” includes an OS and hardware such as peripheral devices.

Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design and the like within a scope not departing from the gist of the present invention.

  The present invention is suitable for use in projectors in fields where the required display image quality is very high, such as the medical field, but is not limited thereto.

It is a schematic block diagram which shows the structure of the projection optical system part of the projector by 1st Embodiment of this invention. It is a schematic block diagram which shows the structure of the projection optical system part of the projector by the same embodiment. 4 is a flowchart for explaining the operation of a color analysis unit 121 according to the embodiment. It is a schematic block diagram which shows the structure of the projection optical system part among the projectors by 2nd Embodiment of this invention. It is a schematic block diagram which shows the structure of the projection optical system part of the projector by the same embodiment. 6 is a flowchart for explaining the operation of a color analysis unit 221 according to the embodiment. It is an example of the characteristic of the spectral transmittance of the color filter 201 by the embodiment. FIG. 4 is an xy chromaticity diagram showing a displayable color range according to the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Light source 101 ... Polarization separation element 102 ... RC separation element 103 ... Mirror 104 ... R light valve 105 ... GB separation element 106 ... G light valve 107 ... RG composition element 108 ... B light valve 109 ... Mirror 110 ... BY composition element 111 ... 4th light valve 112 ... Mirror 113 ... Polarization composition element 114 ... Projection lens 120 ... Image input part 121, 221 ... Color analysis part 122 ... RGB light valve drive part 123 ... 4th light valve drive part 124 ... RGB light valve

Claims (11)

A light source;
Three modulation elements that receive light emitted from the light source and modulate light of each one of the three colors;
A specific color modulation element that receives light emitted from the light source and modulates light of a fourth color represented by a point in a triangle on the xy chromaticity diagram having the three colors as vertices;
A projector comprising: a projection lens that receives light modulated by each of the three modulation elements and light modulated by the specific color modulation element and projects these lights.   It is determined whether or not a predetermined color range including the fourth color includes a predetermined pixel color of the input image signal, and it is determined that the predetermined pixel color is included. The projector according to claim 1, further comprising a control unit that modulates at least the predetermined pixel with the specific color modulation element. The color range is a region near the fourth color point in the xy chromaticity diagram,
When it is determined that the color of the predetermined pixel is included, the control unit determines that the color of the predetermined pixel is a point of any two of the three colors and the first color in the xy chromaticity diagram. It is determined which of the three triangles having the vertex of the four colors as a vertex, and the predetermined pixel is set to the color of the vertex of the triangle of the determination result among the three modulation elements. The projector according to claim 2, wherein modulation is performed by using the two corresponding modulation elements and the specific color modulation element.   The control means modulates the pixels included in the color range among the predetermined pixels with the specific color modulation element, and the pixels not included in the color range among the predetermined pixels include the three modulation elements. The projector according to claim 2, wherein the projector modulates the light. The three colors are red, green and blue,
The projector according to any one of claims 1 to 4, wherein the fourth color is a skin color. The three colors are red, green and blue,
The projector according to claim 1, wherein the fourth color is white. The control means controls the specific color modulation element so that the amount of emitted light is maximized for all display pixels when high brightness of the display image is required. The projector according to claim 4.   The control means modulates the predetermined pixel with four modulation elements, that is, the three modulation elements and the specific color modulation element, when gradation of a display image is required. The projector according to any one of claims 1 to 6. The light emitted from the light source can be polarized and separated so that light in one polarization direction is incident on the special modulation element, and light in the other polarization direction is inserted and removed at a position where the light is incident on the three modulation elements. Installed polarization separation means;
Polarization synthesis of the light modulated by the specific color modulation element and the light modulated by the three modulation elements, and the polarization synthesis installed so as to be inserted and removed at a position where the polarization synthesis light is incident on the projection lens The projector according to claim 1, further comprising: means.   10. The projector according to claim 1, further comprising a color filter that is installed in a replaceable or removable manner on an optical path of light incident on the specific color modulation element. 11. An xy color that receives light emitted from the light source, three modulation elements that modulate light of each of the three colors by receiving light emitted from the light source, and the light emitted from the light source that receives the light from the three colors A specific color modulation element for modulating the light of the fourth color represented by a point in the triangle on the degree diagram, light modulated by each of the three modulation elements and light modulated by the specific color modulation element A modulation control method for a projector comprising a projection lens for projecting these lights, and a control means for controlling the transmittance of the three modulation elements and the specific color modulation element,
A first step in which the control means determines whether or not a predetermined color range including the fourth color includes a color of a predetermined pixel of the input image signal;
When the control means determines in the first process that the color of the predetermined pixel is included, at least a second process of modulating the predetermined pixel with the specific color modulation element. A modulation control method comprising:

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