JP2002116749A - Image signal processor, image display device, multidisplay device and chromaticity regulating method for this multidisplay device - Google Patents

Abstract

(57) [Problem] A multi-display device capable of displaying an integrated image as a whole without causing color discontinuity between display screens displayed adjacent to each other by a plurality of image display devices. I will provide a. A multi-display device for distributing an image signal for one screen to a plurality of liquid crystal projectors 111 to 114 and displaying the image for one screen on the display screens, wherein Calculate the signal value, red to be displayed by the image display unit,
Each of the liquid crystal projectors 111 to 114 includes a chromaticity adjustment unit 61 to 64 for independently adjusting the chromaticity of each of the primary colors of green and blue. By properly setting the parameters in the chromaticity adjusting units 61 to 64, the liquid crystal projector 111
The chromaticity of the screen displayed by .about.114 can be matched, and an integrated image display as a whole is possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image signal processing device used as a pre-processing device of an image display device, an image display device equipped with such an image signal processing device, a multi-display device, and a multi-display device. The present invention relates to a chromaticity adjustment method.

[0002]

2. Description of the Related Art In recent years, in concerts and event venues, an image is often displayed on a huge screen aiming at a visual effect. In general, a multi-display device in which a large screen is formed by adjacent display screens of an image display device is used.

[0003] In a multi-display apparatus, continuity of each display screen is required in order not to give an observer an uncomfortable feeling. A normal image display device is provided with a function for adjusting the brightness, white balance, hue, and saturation of the display image. Conventionally, by appropriately adjusting one or more of these, each display image has An attempt has been made to make color reproducibility uniform to ensure continuity between adjacent screens (hereinafter referred to as “color continuity”).

[0004]

However, only the method of adjusting the luminance, white balance, hue, saturation, etc.,
It is not possible to obtain perfect screen continuity. That is,
Display devices and other optical elements in each image display device, especially liquid crystal display devices, color prisms, color filters, lamps, phosphors, etc., cause variations in color reproducibility, light emission characteristics, and transmission characteristics, which inevitably cause the A difference in chromaticity occurs, and the displayed image becomes discontinuous, giving an impression that the entire image is cut off.

Conventionally, in order to solve such inconveniences, there has been only a method of selecting an image display device having a similar chromaticity of a primary color to be displayed from a plurality of image display devices and arranging them next to each other. . However, there is no guarantee that there is an image display device having a similar chromaticity among a plurality of image display devices, and even if there is one, the colors do not completely match. There is a problem that a sense of unity is lost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has an image signal processing apparatus for realizing an image display with a sense of unity by matching chromaticities on a plurality of display screens. It is an object to provide an image display device and a multi-display device provided with such an image signal processing device, and a chromaticity adjustment method in the multi-display device.

[0007]

In order to achieve the above object, an image signal processing apparatus according to the present invention provides an image signal processing apparatus used as a preprocessing apparatus for an image display apparatus for displaying an image based on a color image signal. An image signal receiving unit that receives a color image signal, and calculates a signal value of the received color image signal, and independently sets chromaticity of each of red, green, and blue primary colors to be displayed by an image display device. And chromaticity adjusting means for adjusting the chromaticity.

As described above, by calculating the received color image signal and independently adjusting the chromaticities of red, green, and blue on the display screen, the image display device connected to this is used. The chromaticity of the displayed image can be freely adjusted. Here, the color image signal mainly means an RGB signal or a YUV signal, but any other type of image signal may be used as long as it can be finally converted to an RGB signal.

An image display device according to the present invention is an image display device comprising image signal preprocessing means for preprocessing a color image signal, and image display means for displaying an image based on the preprocessed image signal. The image signal pre-processing means includes an image signal receiving means for receiving a color image signal, a signal value of the received color image signal, and calculating each of the primary colors red, green, and blue to be displayed by the image display device. And a chromaticity adjusting means for independently adjusting the chromaticity of each color.

As described above, by independently adjusting the chromaticity of each of the primary colors of red, green and blue, the chromaticity of the image displayed by the image display means can be freely changed. Further, the multi-display device according to the present invention,
A multi-display apparatus in which a plurality of image display means are arranged such that their display screens are adjacent to each other, and an image for one screen is displayed by the plurality of display screens. Image distribution means for generating a color image signal to be displayed by the image display means, and a signal value of the color image signal provided for each image display means, which is input to the image display means, and displayed by the image display means And chromaticity adjusting means for independently adjusting the chromaticity of each of the primary colors of red, green, and blue to be performed.

According to this configuration, since the chromaticity of red, green and blue can be adjusted independently by each chromaticity adjusting means, it is possible to match the chromaticities of the images displayed by each image display means. As a result, color continuity can be obtained over the entire screen, and the observer does not feel uncomfortable.

Further, according to the chromaticity adjusting method for a multi-display device according to the present invention, each display in the multi-display device is provided such that a plurality of image display means are arranged so that their display images are displayed adjacent to each other. A method for adjusting chromaticity of a screen, wherein the multi-display device receives a parameter for each image display unit, calculates a signal value of a color image signal based on the parameter, and displays the signal value by the image display unit. Chromaticity adjusting means for independently adjusting the chromaticity of each of the primary colors red, green and blue to be performed, and inputting the image signals of the red, green and blue primary colors to each image display means, Display, for each image display means,
The first step of measuring the chromaticity and luminance of each primary color image and the respective chromaticities of red, green and blue displayed by each image display means substantially match based on the measured values of the chromaticity and luminance of each primary color image And a second step of setting the parameter for each chromaticity adjusting means.

By doing so, the chromaticity of red, green, and blue by each chromaticity adjusting means can be accurately adjusted within a range that can be displayed by each image display means, and the chromaticity of the display image by each image display means can be adjusted. Can be easily matched.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a multi-display device and the like according to the present invention will be described below with reference to the drawings.

First Embodiment (1) Overall Configuration of Multi-Display Device 1 FIG. 1 is a diagram showing the overall configuration of a multi-display device 1. In the present embodiment, the multi-display device 1 includes an image distribution device 100 and four liquid crystal projectors 111 to 114. The image distribution apparatus 100 divides an image signal for one screen transmitted from a VCR or a personal computer into four screens to be displayed by the liquid crystal projectors 111 to 114, and calculates an image signal corresponding to each screen. After executing the predetermined chromaticity adjustment, the liquid crystal projectors 111 to 1
14 is output.

The liquid crystal projectors 111 to 114 cause a transmission type liquid crystal display device to form an image based on an input image signal, irradiate the light with a light from a light source, and project the transmitted light on a screen by a projection lens. This is a known configuration, and is installed so that the respective display images 121 to 124 are projected adjacently to the horizontally elongated screen 120 at the same magnification.

Note that the notebook personal computer 130 is used for chromaticity adjustment performed when the multi-display device 1 is mounted or the like, and is input by inputting a predetermined numerical value from the input unit 131. The chromaticity adjustment parameters are determined so that the chromaticity reproducibility of each of the display images 121 to 124 projected by each of the liquid crystal projectors 111 to 114 is matched to form a screen with a sense of unity. The program is set to transfer to. The display unit 132 displays a message prompting the operator to input and a calculation result of the parameter. A specific method for obtaining the chromaticity adjustment parameter will be described later.

(2) Configuration of Image Distribution Apparatus 100 FIG. 2 is a block diagram showing the configuration of the image distribution apparatus 100. As shown in FIG.
The converter 41, the selector 42, the frame memory unit 43,
Image cutout unit 44, image enlargement units 51 to 54, chromaticity adjustment unit 6
1 to 64, an input port 71, a control unit 72, and the like. An image signal input from outside is a luminance / color difference signal (YU
V signal), the RGB converter 41
After being converted into a GB signal, it is sent to the selector 42. The RGB converter 41 is composed of a well-known matrix operation circuit, and executes an operation such as the following Expression 1 to convert the YUV signal into an RUV signal.
Convert to a GB signal.

[0019]

(Equation 1)

Here, C1 to C9 convert the YUV signal into RG
It is a known coefficient for converting to a B signal. The selector 42 is switched by manual operation of the operator,
Either a signal input or a YUV signal input is selected and sent to the subsequent frame memory unit 43. The selector 42 may be configured to detect an input terminal to which a signal has been input, instead of manual switching, and to automatically switch to the port. The frame memory unit 43 includes a frame memory for image signals of each color of RGB, and stores the value of each image signal for one screen. The image cutout unit 44 cuts out the image signal for one screen of each color stored in the frame memory unit 43 so as to be equally divided into four in the horizontal direction on the output screen while referring to the memory address. These are sent to the image enlargement units 51 to 54, respectively.

The image enlarging units 51 to 54 interpolate the signals between the respective pixels for the respective colors of RGB, thereby dividing the images cut and divided by the image cutting unit 44 for one screen in each of the liquid crystal projectors 112 to 114. The image is enlarged by increasing the number of pixels so that the image becomes a specific image. Specifically, a resize LSI is used. The image signals enlarged by the image enlarging units 51 to 54 are sent to chromaticity adjusting units 61 to 64, respectively, where chromaticity conversion processing is performed on the RGB image signals.

FIG. 3 is a block diagram showing the configuration of the chromaticity adjusting section 61 among the chromaticity adjusting sections 61 to 64. As shown in the figure, the chromaticity adjustment unit 61 includes a gamma correction unit 611, a chromaticity conversion unit 612, and an inverse gamma correction unit 613. The gamma correction is performed to correct the nonlinearity between the gradation in the input signal and the gradation in the display image. The gamma correction unit 611 includes a gamma correction unit for correcting such nonlinearity. A table indicating gradation conversion characteristics (hereinafter, referred to as a “gradation conversion table”) is provided for each of RGB, and gamma correction is performed for each color with reference to the table.

Usually, an image display device (in this embodiment,
The liquid crystal projector has a built-in gamma correction circuit, which performs the gamma correction. The reason why the gamma correction is performed in the image distribution device 100 is that the image display device This is because performing chromaticity correction on a signal value corresponding to the light to be projected can perform accurate chromaticity correction on a display image. Therefore, it is desired that the gradation conversion characteristic of the gamma correction unit 611 is substantially equal to the gradation conversion characteristic of the gamma correction circuit mounted on the actually connected image display device. The chromaticity converter 6 converts the image signal of each color subjected to the gamma correction
At 12, chromaticity conversion processing is performed on each primary color signal. The chromaticity conversion unit 612 is specifically composed of a matrix operation circuit, and as shown in the following (Equation 2), the input RGB signal values (RIN, GIN, BIN) are 3 × 3. The chromaticity of red, green, and blue is converted by multiplying a square matrix.

[0024]

(Equation 2)

The values of the parameters D1 to D9 in this square matrix can be changed under the control of the control unit 72.
Thereby, the chromaticities of red, green, and blue can be independently changed. Note that the matrix operation circuit itself is a known circuit including a plurality of multipliers and adders, and the operation of (Equation 2) is performed by controlling the multiplication coefficients (the above parameters D1 to D9) in each multiplier. You.

The RGB signal that has been subjected to the chromaticity conversion processing by the chromaticity conversion unit 612 is subjected to gamma correction opposite to that of the gamma correction unit 611 in the inverse gamma correction unit 613. If the inverse gamma correction is not performed in this way, the gamma correction circuit in the liquid crystal projector 111 will perform double gamma correction, and the color tone reproducibility will be deteriorated. The other chromaticity adjusting units 62 to 64 have the same configuration as the chromaticity adjusting unit 61, and only the parameters D1 to D9 in the internal matrix operation circuit are independently controlled by the control unit 72. At this time, the chromaticity of each screen finally displayed by the liquid crystal projectors 111 to 114 can be matched by appropriately determining the value of each parameter as described below.

(3) Method of Determining Parameters D1 to D9 Next, a method of determining the parameters D1 to D9 in the matrix operation circuits of the chromaticity adjusting units 61 to 64 will be described. FIG. 4 is a diagram in which, when two liquid crystal projectors are used, chromaticity xy on each of the red, green, and blue display screens projected on the screen is measured and plotted on chromaticity coordinates.
First, an image signal of only R is input from the personal computer 130 or the like to the image distribution apparatus 100 and projected on a screen by two projectors. Here, as the signal value of R, a value at which the luminance becomes the highest is input (if it is,
If the R image signal is represented by 256 gradations from 0 to 255, the signal value is 255. The same applies to signals of other colors. ).

The chromaticity and luminance of the red screen projected on the screen 120 by the liquid crystal projectors 111 and 112 are measured by a known chromaticity chromaticity meter, and the chromaticity xy and luminance values are obtained. The chromaticity xy obtained in this way is plotted on chromaticity coordinates to obtain points R1 and R2, respectively (subscripts “1” and “2” are measured values of the liquid crystal projector 111 and the liquid crystal projector 112, respectively). The same for other colors). Similarly, the G image signal and the B image signal are sequentially input to the image distribution device 100, and the chromaticity and luminance of the displayed images are measured.
Points G1, G2, B on the chromaticity coordinates from the chromaticity values
1 and B2 are plotted, respectively. In the following description, a point on the chromaticity coordinates plotted by the chromaticity xy is referred to as a “chromaticity coordinate point” for convenience of description.

Since all colors can be displayed by mixing the three primary colors, it can be said that $ R1G1B1 and $ R2G2B2 indicate the range of chromaticity that can be displayed by the liquid crystal projectors 111 and 112, respectively. Two liquid crystal projectors 11
In order to match the chromaticities of the images displayed by the first and the second 112, the parameters in at least one of the chromaticity adjustment units are changed to change the chromaticity range {R1G1B1 and △ R2G2B
What is necessary is just to make 2 coincide.

For this reason, first, in a portion where the chromaticity ranges that can be displayed by both liquid crystal projectors are common (hereinafter referred to as “common chromaticity range”), it should be a target for matching the chromaticity ranges. The chromaticity coordinate points Rs, Gs, and Bs of the three primary colors are set, and each of △ R1G1B1 and △ R2G2B2 is set to △ Rs
The chromaticity is adjusted by each chromaticity adjustment unit so as to match GsBs. At this time, the chromaticity coordinate points Rs,
It is desirable to set not to set Gs and Bs but to satisfy the following conditions.

In order to reproduce a hue close to that of the original image, the hue of the image displayed after the chromaticity conversion should be as small as possible from a standard one. In addition, the possible range of color reproduction should be as large as possible. Therefore, in the present embodiment, R,
The standard chromaticity coordinates of G and B are plotted (R0,
G0, B0), and points closest to the chromaticity coordinate points R0, G0, B0 on the boundary line of the common chromaticity range are respectively set as chromaticity coordinate points RsGsBs to be targeted for chromaticity conversion. The condition that is closest to the standard chromaticity coordinate points R0, G0, and B0 satisfies the condition, and the condition that it is on the boundary of the common chromaticity range is also satisfied.
When a point that satisfies the condition in the example of FIG. 4 is obtained, the intersection of the boundary lines of both the chromaticity ranges △ R1G1B1 and △ R2G2B2 becomes the chromaticity coordinate points Rs, Gs, and Bs.

The standard chromaticity coordinate points R0, G0, and B0 on the display screen of each of the three primary colors of red, green, and blue are empirically obtained. By the way, actually, the liquid crystal projector is 4
As shown in FIG. 5, first, the chromaticity range {RiGiB} which can be displayed by each of the four liquid crystal projectors, as shown in FIG.
i (i = 1, 2, 3, 4) is obtained, and a common chromaticity range of these chromaticity ranges is obtained (in the figure, the bold line indicates the boundary of the common chromaticity range). Then, as shown in the figure, points closest to the standard chromaticity coordinate points R0, G0, B0 on the boundary line are obtained, and these are set as target chromaticity coordinate points RsGsBs.

Incidentally, even when the number of liquid crystal projectors is five or more, the target chromaticity coordinate point can be obtained in the same manner. Next, the chromaticity of the three primary colors displayed by the liquid crystal projector 111 is calculated using the target chromaticity coordinate points Rs, G
A method of obtaining the parameters D1 to D9 to match the chromaticities of s and Bs will be described.

Here, the chromaticity coordinate x at the chromaticity coordinate point R1 of the liquid crystal projector 111 before the red chromaticity adjustment is represented by Xr
a, the chromaticity coordinate y is represented by Yra (hereinafter, “chromaticity coordinates (Xra,
Yra) ". The same applies to other colors. ), The luminance is set to Kra, the chromaticity coordinates of the chromaticity coordinate point G1 before the adjustment of the green color are (Xga, Yga), the luminance is Kga,
The chromaticity coordinates of the chromaticity coordinate point B1 before the adjustment of blue are represented by (Xba,
Yba), and the luminance is Kba.

The chromaticity coordinates of the chromaticity coordinate points Rs, Gs, and Bs, which are the target of the chromaticity adjustment of the three primary colors, are represented by (Xr
t, Yrt), (Xgt, Ygt), (Xbt, Yb
t), and the luminance of each primary color is Krt, Kgt, K
bt. Here, the luminance Krt, Kgt, Kb of each color
Since t must be a luminance that can be displayed by all the liquid crystal projectors 111 to 114, the lowest value among the luminances measured for each of the three primary colors of red, green, and blue for each projector is used. According to the principle of the additive color mixture, between the chromaticity and luminance of each color before adjustment of the liquid crystal projector 111 and the chromaticity and luminance of each color to be adjusted are expressed by the following (Equation 3) to (Equation 11). The relationship holds.

[0036]

(Equation 3)

[0037]

(Equation 4)

[0038]

(Equation 5)

Therefore, by solving this simultaneous equation, the chromaticity adjusting unit 6 corresponding to the liquid crystal projector 111 is solved.
Parameters D1 to D9 to be applied to the determinant inside 1
Can be obtained. Similarly, the chromaticity adjustment units 62 to 6 corresponding to the other liquid crystal projectors 112 to 114
4 to determine the values of the parameters to be set. In practice, the calculation for obtaining these parameters is executed by the personal computer 130 and transferred to the control unit 72 via the input port 71 of the image distribution device 100. The control unit 72 sequentially sets the received parameters in the matrix operation circuits of the corresponding chromaticity adjustment units 61 to 64.

By changing the parameters of the chromaticity adjusting units 61 to 64 in this way, the chromaticities of the three primary colors displayed by the liquid crystal projectors 111 to 114 are properly adjusted, and all the target chromaticity coordinates are set. Points Rs, G
Since the chromaticity of s and Bs can be made equal, the discontinuity of colors on the entire screen is eliminated, and the sense of unity of a plurality of display screens is enhanced. This makes it possible to project a powerful image without causing the observer to feel uncomfortable.

FIG. 6 is a flowchart summarizing the procedure for determining the chromaticity adjustment parameters. First, an R image signal is input to the image distribution apparatus 100, and a red image is projected on each of the liquid crystal projectors 111 to 114 (Step S1), and chromaticity and luminance are measured for each projection screen (Step S2). This operation is repeated for the G and B image signals (steps S3 to S6). The chromaticity and luminance values of each primary color on the projection screen for each liquid crystal projector obtained in this manner are input to the personal computer 130 via the input unit 131.

In the personal computer 130, R measured for each of the liquid crystal projectors 111 to 114,
Based on the chromaticity and luminance of the G and B projection screens, the values of the parameters D1 to D9 to be set in the chromaticity adjustment units 61 to 64 corresponding to the respective projectors are obtained (Step S).
7) Transfer this to the image distribution device 100. The parameters transferred to the control unit 72 of the image distribution device 100 are set in the chromaticity adjustment units 61 to 64 (step S8). FIG. 7 is a flowchart showing the processing content of step S7 executed by the personal computer 130.

First, when the parameter setting application installed in the personal computer 130 is started (Y in step S101), the variable i is set to 1
(Step S102). This application is stored in, for example, a flexible disk attached to the image distribution device 100 and is installed in the personal computer 130 in advance.

Next, R of the i-th liquid crystal projector,
Chromaticity coordinate points Ri, Gi, B for G, B projection screens
It waits for the input of the chromaticity / luminance of i (step S103), and if there is such an input, determines whether or not “i” is 4 or more (step S104). If “i” is less than 4 (N in step S104), “i” in step S105
Is incremented by 1 and the determination in step S103 is repeatedly executed. When “i” becomes 4 (step S104)
Since the input of chromaticity and luminance has been completed for all of Y), Ri, Gi, and Bi (i = 1, 2, 3, 4), the target chromaticity coordinates are determined based on the chromaticity values among them. The chromaticity xy of the points Rs, Gs, Bs is calculated.

As an example of such a calculation method, the following method can be considered. That is, four chromaticity ranges △ Ri
Based on the coordinates of each chromaticity coordinate point of GiBi (i = 1, 2, 3, 4: see FIG. 5), an equation of a boundary line in each chromaticity range is obtained. Next, the intersections between the boundaries of different chromaticity ranges are obtained, and from the obtained intersections, an intersection is selected such that when connecting them in order, none of the boundaries comes inside the boundary. Connect to obtain the boundary of the common chromaticity range.

If the coordinates of the two points are known, the equation of a straight line connecting the two points is specified.
The distance between the straight line and the fixed point is determined by a formula. Therefore, the distance between the boundary line composed of a plurality of straight lines in the common chromaticity range and each of the standard chromaticity coordinate points R0, G0, B0 can be easily calculated. Then, the points on the boundary line at which the respective distances become minimum are represented by R
What is necessary is just to set as s, Gs, and Bs.

On the other hand, each of the liquid crystal projectors 111 to 114
Since the luminance of the red, green, and blue projection screens obtained by measuring each of the primary colors is input, the same primary colors are compared, and the lowest luminance is searched for each primary color.
rt, Ygt, and Ybt (step S107).

Next, the variable n is set to 1 (step S10).
8) Solve the simultaneous equations of Equations 3 to 11 to obtain parameters D1 to D9 to be set in the chromaticity adjustment unit corresponding to the n-th liquid crystal projector. This is repeated until n = 4 to obtain the parameters to be set in all the chromaticity adjusting units 61 to 64 (step S110,
S111, S109), and transfer the values of those parameters to the image distribution apparatus 100. As described above, the parameters are automatically set by the personal computer 130 and transferred via the input port 71, so that the chromaticity of each of the liquid crystal projectors 111 to 114 can be adjusted extremely easily and quickly.

<Second Embodiment> In the multi-display device 1 according to the first embodiment, the chromaticity adjusting section 6
1 is built in the image distribution apparatus 100, but in the second embodiment, it is built in each liquid crystal projector. FIG. 8 is a diagram illustrating a configuration example of the liquid crystal projector 200 in such a case. The liquid crystal projector 200 converts the YUV signal into an RGB signal.
A converter 201, a selector 202 for selecting an input signal,
Gamma correction unit 203, chromaticity conversion unit 204 for adjusting chromaticity of three primary colors, display device driving unit 205, projection unit 2
06, a control unit 207, an input port 208, and the like.

The image signal selected by the selector 202 is gamma-corrected by a gamma correction unit 203 based on a preset gradation conversion characteristic in order to complement the non-linearity of gradation reproduction in the projection unit 206. The chromaticity conversion unit 204
It has the same configuration as the chromaticity adjustment unit 61 described above, and includes a matrix operation circuit inside. The parameter D is transmitted from the personal computer 130 to the control unit 207 via the input port 208.
The control unit 207 sets these parameters in a matrix operation circuit inside the chromaticity conversion unit 204.

The chromaticity converter 204 converts the chromaticities of the three primary colors based on the set parameters, and outputs the converted chromaticities to the display device driver 205. The projection unit 206 is a known type including a transmissive liquid crystal display, a light source, a projection lens, and the like. The display device driving unit 205 drives the liquid crystal display based on the chromaticity-converted RGB signals to project a projected image. Is formed.

By incorporating the chromaticity adjusting function in the liquid crystal projector in this way, a multi-display device can be formed using an existing product as an image distributor, which is economical. Further, if the LCD projector 200 is provided with an input section for manually setting chromaticity adjustment parameters, the user can set the chromaticity desired by the user and enjoy an image when using the LCD projector alone, which is very convenient. is there.

<Third Embodiment> In the multi-display device 1, the chromaticity adjustment section is not built in the image distribution device or the liquid crystal projector as in the first and second embodiments, but is used independently of these components. You may comprise as a chromaticity adjustment apparatus. FIG. 9 is a block diagram showing a configuration of the chromaticity adjusting device 300 according to the present embodiment. The chromaticity adjustment device 300 includes an RGB converter 301 for converting a YUV signal into an RGB signal, a selector 302 for selecting an input signal, a gamma correction unit 303, a chromaticity conversion unit 304 for adjusting the chromaticity of RGB, and an inverse chromaticity conversion unit 304. It comprises a gamma correction unit 305, a control unit 306, an operation unit 307, an input port 308, and the like.

The image signal selected by the selector 302 is input to a gamma correction unit 303. Like the gamma correction unit 611 in FIG. 3 and the gamma correction unit 203 in FIG. 8, the gamma correction unit 303 complements the non-linearity of gradation reproduction in an image display device connected at a subsequent stage prior to chromaticity conversion. However, in the present embodiment, a plurality of types of image display devices corresponding to a standard image display device are internally provided so that any type of image display device can be used at the subsequent stage. A gradation conversion table is stored, and when the type of an image display device to be actually connected is input from the operation unit 307, the gradation conversion table corresponding to the image display device is received in response to an instruction from the control unit 306. The gamma correction is selectively performed.

As a result, it is not necessary to prepare a chromaticity adjusting device for each type of image display device, which is economical and always provides an optimal chromaticity adjusting effect. On the other hand, the control unit 3 from the personal computer 130 via the input port 308
06 are given the values of the parameters D1 to D9, and the control unit 306 converts these parameters into the chromaticity conversion unit 304.
The chromaticity of the three primary colors is adjusted by setting an internal matrix operation circuit.

The inverse gamma correction unit 305 stores a plurality of inverse gradation conversion tables corresponding to the plurality of gradation conversion tables set in the gamma correction unit 303, and receives an instruction from the control unit 306. The inverse conversion table corresponding to the gradation conversion table selected by the gamma correction unit 303 is selected to execute the inverse gamma correction. The RGB signals subjected to the inverse gamma conversion are output to an image display device connected to the chromaticity adjustment device 300. By independently configuring the chromaticity adjusting device 300 as in the present embodiment, the user connects the chromaticity adjusting device 300 between the existing image display device and the image distribution device and sets their parameters. By simply doing so, the chromaticity of each display image can be made uniform, and continuity of the entire image can be ensured.

<Modifications> Although the present invention has been described based on the embodiments, it goes without saying that the contents of the present invention are not limited to the specific examples shown in the above embodiments.
For example, the following modifications can be considered.

(1) In the first embodiment, the calculations of the parameters D1 to D9 are performed by the personal computer 130. However, an operation unit for inputting chromaticity and luminance is provided on the image distribution apparatus 100 side. The control unit 72 may execute the flowchart of FIG. 7 based on the input values to obtain the above parameters. Similarly, in the second and third embodiments, the parameters may be calculated by the internal control unit. In these cases, the personal computer 130 is not required when setting the chromaticity adjustment parameters, which is very convenient.

(2) In the above embodiments, a liquid crystal projector has been mainly described as an image display device. However, the present invention is not limited to such a display device as long as an image can be displayed adjacently. For example, a reflection type projector using a light reflection type device or an electron beam in a CRT is intensified, and an image formed on a front panel thereof is
The present invention is also applicable to a CRT type projector that projects on a screen disposed in front of the front panel. In some cases, plasma displays
A flat display panel such as a panel may be used.

[0060]

As described above, according to the image signal processing device and the image display device of the present invention, the signal values of the received color image signals are calculated, and the red and green colors to be displayed by the image display device are calculated. , And the chromaticity of each of the blue primary colors can be independently adjusted, so that the chromaticity of a display image obtained by reproducing the adjusted color image signal can be freely adjusted.

Further, according to the multi-display device of the present invention, for each image display means, the signal value of the color image signal input to the image display means is calculated, and the red to be displayed by the image display means is calculated. , Chromaticity adjusting means for independently adjusting the chromaticity of each of the primary colors of green, blue, and blue, so that the chromaticity of the image displayed by each image display means can be matched. As a result, color continuity can be obtained over the entire screen, and the observer does not feel uncomfortable.

Further, according to the chromaticity adjusting method for the multi-display device according to the present invention, the multi-display device receives a parameter for each image display means, and, based on the parameter, a signal value of a color image signal. And red to be displayed by the image display means,
A chromaticity adjusting unit for independently adjusting the chromaticity of each of the primary colors of green and blue is provided, and an image signal of the primary colors of red, green and blue is input to each image display unit, and the image is displayed. The chromaticity and luminance of each primary color image are measured for each, and based on the measured values of the chromaticity and luminance of these primary color images, each chromaticity of red, green, and blue displayed by each image display means substantially matches. The above parameters are set for each chromaticity adjusting means, so that the chromaticities of red, green and blue are accurately matched within the range of chromaticity that can be displayed by each image display means. Color continuity can be secured, and a sense of unity of the entire screen can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of a multi-display device according to Embodiment 1 of the present invention.

FIG. 2 is a block diagram illustrating a configuration of an image distribution device.

FIG. 3 is a block diagram illustrating a configuration of a chromaticity adjustment unit in the image distribution device.

FIG. 4 is a diagram for explaining a method of obtaining a common chromaticity range that can be displayed for each of two liquid crystal projectors.

FIG. 5 is a diagram for explaining how to obtain a common chromaticity range that can be displayed for each of four liquid crystal projectors.

FIG. 6 is a flowchart showing a procedure for determining a parameter according to the first embodiment of the present invention.

FIG. 7 is a flowchart illustrating a parameter calculation process executed by the personal computer.

FIG. 8 is a block diagram showing a configuration of a liquid crystal projector according to Embodiment 2 of the present invention.

FIG. 9 is a block diagram showing a configuration of a chromaticity adjusting device according to Embodiment 3 of the present invention.

[Explanation of symbols]

 Reference Signs List 41 RGB converter 42 Selector 43 Frame memory unit 44 Image cutout unit 51-54 Image enlargement unit 61-64 Chromaticity adjustment unit 71 Input port 72, 207, 306 Control unit 100 Image distribution device 111-114 Liquid crystal projector 120 Screen 121- 124 display image 130 personal computer 131 input unit 132 display unit 200 liquid crystal projector 201 RGB converter 202, 302 selector 203, 303, 611 gamma correction unit 204 chromaticity conversion unit 205 display device drive unit 206 projection unit 208, 308 input port 300 Chromaticity adjustment device 301 RGB converter 304,612 Chromaticity conversion unit 305,613 Inverse gamma correction unit 307 Operation unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 9/64 H04N 9/64 FF term (Reference) 2H093 NA61 NC29 ND01 ND17 NG02 5C066 AA03 EC05 EE05 GA01 GA02 GA05 GB03 KE01 KE04 KE07 KP05 5C082 AA34 BA12 BA34 BA35 BB02 BB03 BD07 CA12 CB01 DA51 MM01 MM10

Claims (10)

[Claims] 1. An image signal processing device used as a pre-processing device of an image display device for displaying an image based on a color image signal, comprising: an image signal receiving unit for receiving a color image signal; And a chromaticity adjusting unit that independently calculates the chromaticity of each of the primary colors red, green, and blue to be displayed by the image display device. 2. The chromaticity adjusting means comprises: a matrix calculating means for multiplying a signal value of a color image signal by a determinant; and a determinant changing means for changing a determinant based on the received parameter. 2. The apparatus according to claim 1, wherein the adjusting unit adjusts the chromaticity of each primary color by performing an operation using the changed determinant.
5. The image signal processing device according to claim 1. 3. The image processing apparatus according to claim 1, wherein the chromaticity adjusting unit includes a gamma correction unit that performs gamma correction on the color image signal, and performs an operation on the signal value of the gamma-corrected color image signal. The image signal processing device according to any one of the preceding claims. 4. The gradation conversion characteristic of said gamma correction means is substantially equal to a gradation conversion characteristic required for correcting a gradation reproduction characteristic of a display device of said image display device. The image signal processing device according to any one of the preceding claims. 5. The image signal processing apparatus according to claim 3, further comprising an inverse gamma correction unit that performs an inverse gamma correction on the color image signal output from the chromaticity adjustment unit. 6. The image signal processing device according to claim 1, wherein the color image signal is a luminance / color difference signal, and the image signal receiving unit converts the received luminance / color difference signal into an RGB signal. 6. The chromaticity adjustment unit according to claim 1, further comprising a conversion unit, wherein the chromaticity adjustment unit performs an operation on each signal value of the converted RGB signal to adjust the chromaticity of each of the primary colors. The image signal processing device according to any one of the above. 7. An image display device comprising: image signal preprocessing means for preprocessing a color image signal; and image display means for displaying an image based on the preprocessed image signal. Calculates the signal value of the received color image signal, and independently adjusts the chromaticity of each of the red, green, and blue primary colors to be displayed by the image display device. An image display device comprising: chromaticity adjusting means. 8. A multi-display apparatus in which a plurality of image display means are arranged such that their display screens are adjacent to each other, and an image for one screen is displayed by said plurality of display screens. Image distribution means for generating a color image signal to be displayed on each image display means from the image signal; and a signal value of the color image signal provided to each image display means and inputted to the image display means. A multi-display apparatus comprising: chromaticity adjusting means for independently adjusting the chromaticity of each of the primary colors red, green, and blue to be displayed by the image display means. 9. A method for adjusting the chromaticity of each display screen in a multi-display apparatus in which a plurality of image display means are arranged so that those display images are displayed adjacent to each other, wherein: The display device receives a parameter for each image display unit, calculates a signal value of a color image signal based on the parameter, and calculates the chromaticity of each of the primary colors red, green, and blue to be displayed by the image display unit. Chromaticity adjusting means for independently adjusting the color of each primary color image by inputting image signals of red, green, and blue primary colors to each image display means and displaying the image. A first step of measuring the chromaticity and luminance, and based on the measured values of the chromaticity and luminance of each primary color image, each chromaticity of each of the red, green, and blue displayed by each image display means so as to substantially match each other. Adjustment means A second step of setting the parameter for each color. 10. The second step includes: a first sub-step for obtaining a chromaticity range that can be displayed in each image forming unit from chromaticity values of each primary color; and a display in each of the obtained image forming units. A second sub-step of obtaining a common range of chromaticity ranges to be obtained and setting red, green, and blue chromaticities to be references within the common chromaticity range; , Green and blue chromaticity,
10. The chromaticity adjustment method according to claim 9, further comprising: a third sub-step of determining the parameter so as to substantially match the chromaticities of red, green, and blue as the reference.