JP5812674B2 - Projection type image display apparatus and control method thereof - Google Patents

Description

The present invention relates to a projection type image display apparatus capable of performing multi-screen display together with another projection type image display apparatus, and a control method thereof .

  Conventionally, when a multi-screen is configured using a plurality of projection type image display devices, an overlapping region of an image is provided for each adjacent projection type image display device, and brightness correction is performed on the image signal of the overlapping region. The seam is inconspicuous. In addition, by setting the overlapping region to a predetermined width, even if characteristics such as luminance and color are slightly different for each projection type image display device, it is difficult to visually recognize.

  Here, the projection-type image display device cannot completely block the transmitted light in the transmissive type and the reflected light in the reflective type, and thus has a minute brightness even in black display. Accordingly, in the black display in the multi-screen configuration, the luminance of the overlapping area of the effective image becomes higher than the luminance outside the overlapping area of the effective image, and the joint is visually recognized.

  Patent Document 1 discloses a technique for independently adjusting the overlapping area of the effective image and the outside of the overlapping area of the effective image for each adjacent projection type image display device. Patent Document 2 discloses a technique for adding an offset value to an image signal in accordance with a luminance distribution when a multi-screen is configured.

JP 2002-268625 A JP 2003-274319 A

  By the way, for example, a reflection type display device has an element drive circuit outside the effective image area in structure, and has a dummy pixel that has the same reflection as black display in order to eliminate unnecessary reflected light from the drive circuit. Further, a light shielding mask is provided to block illumination light outside the effective image area. Ideally, the light-shielding mask shields all light outside the effective image area including the dummy pixels, but in reality, the dummy pixel portion cannot completely shield light. The dummy pixels that cannot be shielded from light have a predetermined width on the outer periphery of the effective image area, and become reflected light (peripheral reflected light) that is comparable to the black display of the effective image area. In addition, there is a small amount of reflected light (mask reflected light) even in the light shielding mask. Accordingly, when a multi-screen is configured using a plurality of reflection type projection image display devices, these reflected lights are superimposed on the effective image area.

  Further, for example, when keystone correction is used together, a black display area is generated outside the corrected effective image area, and this black display area is overlapped with the effective image area of the adjacent projection type image display apparatus.

  However, in the technique disclosed in Patent Document 1, a region is determined based on an image overlapping region and an outside of the image overlapping region for each adjacent projection type image display device. For this reason, when a reflective projection display device is used, it is not possible to determine the region for the peripheral reflected light and the mask reflected light outside the image overlap region. Similarly, when the keystone correction is used together, it is impossible to determine the area for the black display area after the keystone correction. Therefore, there is a problem that correction for luminance change due to overlapping of these regions cannot be performed.

  On the other hand, the technique disclosed in Patent Document 2 includes a peripheral display light and a mask reflection light when using a reflective projection type image display device, or a black display region when using a keystone correction together. Correction is possible as a luminance distribution in the screen configuration. However, since the projection-type image display apparatus does not have a means for determining these areas, there is a problem that correction cannot be performed easily.

The present invention, in cooperation with other projection-type image display device, to provide a projection type image display device capable of constituting a multi-screen display which is not visible luminance change in black display. The present invention also makes it possible to determine a black display area even when, for example, peripheral reflection light, mask reflection light, or keystone correction outside the overlapping area of effective images is used.

According to one aspect of the present invention, there is provided a projection-type image display device capable of performing multi-screen display together with another projection-type image display device, the projection unit projecting an image, and the first projection of an image by the projection unit. A dividing unit that divides a peripheral overlapping region that overlaps a peripheral region of the second projection region into a plurality of divided regions without overlapping a second projection region of an image by another projection type image display device among the regions; The first offset added to the image corresponding to the first divided area divided by the dividing unit is determined, and the image corresponding to the second divided area farther from the second projection area than the first divided area And a determining unit that determines a second offset to be added so that a correction amount for increasing the luminance is larger than that of the first offset. It is.

According to the present invention, on a multi-screen screen configured in cooperation with another projection type image display device, the black light in consideration of the peripheral reflection light, the mask reflection light, or the black display area outside the overlapping area of the effective image. Display correction can be easily performed. Therefore, there is provided a projection type image display device capable of constructing a multi-screen screen without impairing the sense of unity of the screen even in black display.

1 is a schematic block diagram of a projection type image display device in an embodiment. Explanatory drawing at the time of arranging two projection type image display apparatuses horizontally. Explanatory drawing at the time of arranging two projection type image display apparatuses horizontally and applying keystone correction. Explanatory drawing at the time of arranging two projection type image display apparatuses vertically and horizontally. The block diagram which shows the structure of the projection type image display apparatus in embodiment. The flowchart which shows the control procedure of the projection type image display apparatus in embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment, It shows only the specific example advantageous for implementation of this invention. Moreover, not all combinations of features described in the following embodiments are indispensable for solving the problems of the present invention.

  The projection type image display system in the present embodiment includes a plurality of projection type image display devices, and constitutes a multi-screen screen using these projection type image display devices. FIG. 1 shows an example of a schematic block for one of the plurality of projection-type image display devices. The projection type image display device includes an image overlap portion correction circuit 100, a black display correction circuit 200, a light valve driving unit 300, and a light valve 400.

  When a multi-screen screen is configured using a plurality of projection type image display devices, an overlapping image region is provided for each adjacent projection type image display device. The image overlap portion correction circuit 100 makes the joint inconspicuous by performing luminance correction on the image signal in the overlap region. The image overlap portion correction circuit 100 includes a correction timing generation circuit 110, a correction coefficient generation circuit 120, and a multiplier 130.

  The correction timing generation circuit 110 generates a pixel position in the image overlap area from the synchronization signal. The correction coefficient generation circuit 120 generates a correction coefficient in the image overlap area based on the pixel position generated by the correction timing generation circuit 110. The multiplier 130 multiplies the input image signal by the correction coefficient generated by the correction coefficient generation circuit 120, and outputs an image signal whose luminance has been corrected thereby.

  The black display correction circuit 200 includes a coordinate designation unit 210, an offset addition timing generation circuit 220, an offset value generation circuit 230, and an adder 240. The coordinate designating unit 210 designates coordinate values representing the boundary of the area when the image is divided into areas. The designation of the boundary is performed by designating at least two coordinates, for example. The area is divided by a straight line connecting the designated coordinates. The offset addition timing generation circuit 220 generates a timing for adding a luminance value offset from the coordinates specified by the coordinate specification unit 210 and the synchronization signal. The offset value generation circuit 230 generates a luminance offset value for each divided region in accordance with the offset addition timing generated by the offset addition timing generation circuit 220. The adder 240 adds the offset value generated by the offset value generation circuit 230 to the image signal whose luminance has been corrected by the image overlap portion correction circuit 100. In this way, the black display correction circuit 200 corrects the luminance in black display to be uniform.

  The image signal that has been subjected to the luminance correction of the image overlap area by the image overlap correction circuit 100 and the black display correction by the black display correction circuit 200 is projected through the light valve driving unit 300 and the light valve 400. The

Next, the operation of the black display correction circuit 200 will be specifically described.
FIG. 2A shows a projected image when two reflective projection-type image display devices are arranged side by side. The left projected image is indicated by a broken line. In FIG. 2A, 1000 is an effective image area. Reference numeral 1100 denotes an overlapping area (peripheral reflection overlapping area) of reflected light existing on the outer periphery of the effective image area in the reflective display device. Reference numeral 1200 denotes an overlapping region (mask reflection overlapping region) of reflected light in a light shielding mask for blocking illumination light to the display device. Also in the left projected image indicated by the broken line, a similar reflected light region exists outside the effective image region, and is projected onto the effective image region in the right projected image. These regions are indicated by (1) to (4). (1) is a first area where valid images overlap. On the other hand, (2) to (4) are second regions other than the first region where the effective images overlap. Specifically, the second region can be divided into a peripheral reflection overlapping region (2), a mask reflection overlapping region (3), and a non-overlapping region (4).

  FIG. 2B is a diagram showing an example of a luminance cross section in the black display of the projection image of FIG. As shown in the drawing, the luminance is highest in the region (1), and then the luminance decreases from (2) → (3) → (4). In the correction for black display, it is necessary to specify and correct these areas independently.

  FIG. 2C shows an example of coordinate designation in the coordinate designation unit 210. In the example of FIG. 2, there are four luminance areas in the effective image area as described above. Therefore, in the coordinate designating unit 210, 6 of P10 (x1, 0) -P11 (x1, ymax), P20 (x2, 0) -P21 (x2, ymax), P30 (x3, 0-P31 (x3, ymax)). Each coordinate value is specified as a pair, so that the image is divided at the boundary defined by the specified coordinate value, although the specification method is not particularly limited, for example, a marker is displayed and the marker is displayed. In this example, the x-coordinates of the straight lines connecting the coordinates specified in pairs are the same, and therefore x <x1, x1 ≦ x with the upper left corner of the screen as the origin of the coordinates. The timing of <x2, x2 ≦ x <x3, x3 ≦ x is generated by the offset addition timing generation circuit 220.

  Then, the offset value generation circuit 230 generates an offset value suitable for the luminance of the area (1), for example, as shown in FIG. It adds to the image signal of the divided area. By the way, since the brightness | luminance of area | region (1)-(4) does not change abruptly, when it is set as a uniform offset value for every area | region, the boundary of an area | region may be visually recognized. Therefore, for example, as shown in FIG. 2E, an offset value that gradually increases with distance from the region (1) may be generated. Specifically, for example, the offset value generation circuit 230 may generate a correction value that gradually becomes equal to the offset value of the adjacent region as the distance from the segment dividing the region is increased.

  FIG. 3 shows a projected image when two reflective projection-type image display devices are arranged side by side and keystone correction is applied. In FIG. 3A, 1000 is an effective image area, 1001 is a black display area by applying keystone correction, and 1100 is a reflected light (peripheral reflected light) area existing around the effective image area in the reflective display device. Here, in order to simplify the description, it is assumed that there is no mask reflection overlapping region shown in FIG. Further, (1) is an overlapping area of effective images, (1) 'is an overlapping area of black display by applying keystone correction, (2) is a peripheral reflection overlapping area, and (3) is a non-overlapping area. Here, since both the region (1) and the region (1) 'are regions where the black display of the left image is overlapped, they have the same luminance.

FIG. 3B shows an example of coordinate designation by the coordinate designation unit 210, and four coordinates of P10 (x10, 0) -P11 (x11, ymax) and P20 (x20, 0) -P21 (x21, ymax). Are specified in pairs. In this example, the division is only in the horizontal direction (x coordinate). When the upper left corner of the screen is the origin of coordinates and the horizontal position is x1, x2 and the vertical position is y, the area can be divided into the following formulas.
x1 = x10 + {(x11−x10) / ymax} × y,
x2 = x20 + {(x21−x20) / ymax} × y
Therefore, the offset added timing generation circuit 220 generates the timings x <x1, x1 ≦ x <x2, and x2 ≦ x. Then, an individual offset value is generated by the offset value generation circuit 230 for the area divided by the respective coordinates, and is added to the image signal by the adder 240.

  FIG. 4A shows a projected image when two reflection type projection image display devices are arranged in the vertical and horizontal directions. In addition, it shows with a broken line except an attention projection image. Here, it is assumed that each projected image has a peripheral reflected light region. In this case, regions (1) to (9) are generated in the target projected image. (1) is a four-sided overlapping region of the effective image, (2) is a two-sided overlapping region of the effective image + peripheral reflection overlapping region, (3) is a two-sided overlapping region of the effective image, and (4) is two sides of the effective image. It is an overlapping area + two-surface peripheral reflection overlapping area. Furthermore, (5) is a two-surface peripheral reflection overlapping region, (6) is a peripheral reflection overlapping region, (7) is a two-surface overlapping region of an effective image, (8) is a peripheral reflection overlapping region, and (9) is non-overlapping. It is an area.

  FIG. 4B shows an example of coordinate designation in the coordinate designation unit 210. In the example of FIG. 4, there are nine luminance areas as described above in the effective image area. The coordinate designating unit 210 designates four coordinates of Px10 (x1,0) -Px11 (x1, ymax) and Px20 (x2,0) -Px21 (x2, ymax) as a pair as the horizontal region division. . Further, as the vertical region division, four coordinates of Py10 (0, y1) −Py11 (xmax, y1) and Py20 (0, y2) −Px21 (xmax, y2) are specified in pairs.

  In this example, the x-coordinate and y-coordinate of the straight line connecting the coordinates specified in pairs are the same. Therefore, with the coordinate origin at the upper left of the screen, x <x1, x1 ≦ x <x2, x2 ≦ x <x3, x3 ≦ x, and y <y1, y1 ≦ y <y2, y2 ≦ y <y3, y3 ≦ Each region can be specified by nine combinations of y. These nine timings are generated by the offset addition timing generation circuit 220. Then, an individual offset value is generated by the offset value generation circuit 230 for the region divided by the respective coordinates, and is added to the image signal by the adder 240.

  According to the present embodiment, it is possible to specify individual areas in consideration of the peripheral reflected light and mask reflected light that are overlapped outside the overlapping area of the effective image, or the black display area when keystone correction is used together. In addition, it is possible to add an offset independently for each individually designated area. As a result, it is possible to provide a multi-screen screen in which the joint is not conspicuous even in black display and does not impair the sense of unity.

  In the embodiment described above, each function of the projection type image display apparatus may be configured by a dedicated circuit, or may be configured to be controlled by a computer as shown in FIG. In the example of FIG. 5, the image overlap portion correction circuit 100, the black display correction circuit 200, and the light valve driving unit 300 are each controlled by the CPU 500. The CPU 500 is also connected to a RAM 600 that functions as a main storage device and a ROM 700 that stores fixed data and programs. The ROM 700 includes a control program 710, and the control processing as described above is realized by the CPU 500 executing the control program 710. That is, as shown in the flowchart of FIG. 6, the CPU 500 divides the area based on the coordinate value designated by the coordinate designation unit 210 (S10), and adds the offset value to the image signal for each divided area. In step S20, the image signal is corrected.

(Other embodiments)
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed. In this case, the program and the storage medium storing the program constitute the present invention.

Claims (9)

A projection-type image display device capable of performing multi-screen display together with other projection-type image display devices,
Projection means for projecting an image;
Among the first projection areas of the image by the projection means, a plurality of peripheral overlapping areas that do not overlap with the second projection area of the image by another projection type image display device and overlap with the peripheral area of the second projection area Dividing means for dividing into areas,
A first offset to be added to an image corresponding to the first divided area divided by the dividing unit is determined, and a second divided area farther from the second projection area than the first divided area is handled. Determining means for determining a second offset to be added to the image so that a correction amount for increasing the luminance is larger than the first offset;
A projection-type image display device.   The projection type image display device according to claim 1, further comprising designation means for designating a boundary for dividing the peripheral overlap region. A moving means for moving the display position of the marker projected together with the image by the projecting means;
The projection type image display device according to claim 2, wherein the designation unit designates the boundary based on a position after the marker is moved by the moving unit. The first offset added to the image corresponding to the first divided area is constant regardless of the position in the first divided area, and is added to the image corresponding to the second divided area. 4. The projection type image display device according to claim 1, wherein the second offset is constant regardless of a position in the second divided region. 5.   The determining means includes a second farther from the second projection area than the first area of the peripheral overlap area than an offset added to an image corresponding to the first area of the first divided area. Determining the first offset to be added to the image corresponding to the first divided region so that the offset added to the image corresponding to the region has a larger correction amount for increasing the luminance; The projection type image display device according to claim 1, wherein the projection type image display device is a projection type image display device.   The determining means includes a second farther distance from the peripheral overlap area than the first area of the second divided area than an offset added to an image corresponding to the first area of the second divided area. Determining the second offset to be added to the image corresponding to the second divided region so that the offset added to the image corresponding to the region has a larger correction amount for increasing the luminance. The projection type image display device according to claim 1, wherein the projection type image display device is a projection type image display device. A control method for a projection type image display device capable of performing multi-screen display together with other projection type image display devices,
A control step of projecting an image onto the projection means;
Among the first projection areas of the image by the projection means, a plurality of peripheral overlapping areas that do not overlap with the second projection area of the image by another projection type image display device and overlap with the peripheral area of the second projection area A dividing step of dividing into regions,
A first offset to be added to an image corresponding to the first divided area divided by the dividing step is determined, and a second divided area farther from the second projection area than the first divided area is determined. A determining step of determining a second offset to be added to the image so that a correction amount for increasing the luminance is larger than the first offset;
A control method characterized by comprising: The control method according to claim 7 , further comprising a designation step of designating a boundary for dividing the peripheral overlap region. A moving step of moving the display position of the marker projected together with the image by the projecting means;
The control method according to claim 8 , wherein the specifying step specifies the boundary based on a position after the movement of the marker by the moving step.