JPH066816A - Convergence adjustment device and method therefor - Google Patents

Abstract

PURPOSE:To realize the convergence adjustment device able to easily correct color slurring even at picture projection based on a usual input signal without use of a test signal. CONSTITUTION:This device is provided with a projector 2 projecting a picture based on an input signal is onto a screen 1, a camera 3 picking up the projected picture onto the screen 1, and a control section 7 comparing the picture data inputted to the projector 2 with the picture data picked up by the camera 3, detecting a color slurring error of the projected picture data with respect to input picture information and correcting color slurring of the projector 2 based on the detected color slurring error and convergence is adjusted even in the input of a usual video signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a convergence adjusting apparatus and method for correcting color misregistration of an image projected on a screen from a projector or the like or an image on a display.

[0002]

2. Description of the Related Art For example, when a color image is projected on a screen using a projector, first, input signals are three primary colors of R (Red; red), G (Green; green) and B (Blue; blue). The signals are separated into signals, and these primary color signals R, G, and B are input to different cathode ray tubes (CRTs), and three images corresponding to the respective colors are projected so as to be superimposed on the screen.

In this case, since an image is projected in the shape of a trapezoid in OHP or the like, the image distortion is corrected by making it a quadrangle. Further, at the time of image projection, as described above, the three CRTs are used to project the three images corresponding to the respective colors so as to be superimposed on the screen.
Since the colors are not completely overlapped with each other and a color shift that causes a color blur occurs, so-called convergence adjustment, which is a correction of the color shift, is performed.

The color shift is unlikely to shift after being adjusted once on the monitor, but with a projector or the like,
Since the deviation easily occurs due to the movement of the installation location or the change of the ambient temperature, it is necessary to adjust the convergence regarding the color misregistration according to the movement of the installation location or the change of the ambient temperature.

As a convergence adjustment method, a method of inputting a test signal into a projector, outputting a test pattern such as a crosshatch, a cursor, a dot, etc., and then manually adjusting it has been adopted as a convergence adjustment method. The image above is picked up by an image pickup means such as a CCD camera, the amount of color shift is detected from the image data at that time, and the amplitude of the CRT deflection waveform is changed in accordance with the amount of shift to automatically correct the color shift. The method of adjusting to is proposed and put to practical use.

FIG. 5 is a diagram showing an example of the configuration of a conventional convergence adjustment device that employs the automatic color shift adjustment method in a projector. In FIG. 5, 1 is a screen, 2 is a decoder 21, amplifiers 22R, 22G, 22B, and CRT2.
A projector having 3R, 23G and 23B and a deflection waveform generating circuit 24, 3 is a CCD camera (hereinafter, simply referred to as a camera), 4 is an RGB decoder 41, analog / digital (A / D) converters 42R, 42G and 42B, and a frame Photographed image processing units 5 having memories 43R, 43G, 43B and image processing circuits 44R, 44G, 44B represent control units, respectively.

Convergence adjustment in the configuration of FIG. 5 is performed as follows. That is, at the time of automatic adjustment, in order to recognize which position on the screen 1 the position of the beam projected from the projector 2 is, the test signal TS for a special pattern such as a circular figure or a rhombus figure is recognized.
T is input to the decoder 21 of the projector 2. In the decoder 21, the primary color signals R, G, B are extracted from the input test signal TST, and the horizontal synchronizing signal H _sync is also extracted.
And the vertical sync signal V _sync is separated. Decoder 21
The primary color signals R, G, B extracted in
The signals are input to G and 22B, respectively, and subjected to an amplifying effect, and are input to CRTs 23R, 23G and 23B corresponding to the respective colors. On the other hand, the horizontal synchronizing signal H separated by the decoder 21
_{The sync} and the vertical sync signal V _sync are generated by the deflection waveform generation circuit 24.
To the deflection yoke of each of the CRTs 23R, 23G, and 23B, and a deflection waveform corresponding to the input synchronizing signal is generated. As a result, each CRT 23R, 23G, 23
A predetermined beam is emitted from B, and a special test pattern is projected at a predetermined position on the screen 1.

A screen 1 on which a test pattern is projected
The entire pattern projection plane of is photographed by the camera 3.
The projection image on the screen 1 taken by the camera 3 is input to the RGB decoder 41. RGB decoder 41
Then, the three primary color signals R, G, B are extracted from the input image data, and the primary color signals R, G, B which are analog signals thereof are extracted.
Is converted into a digital signal by the A / D converters 42R, 42G, 42B, and the frame memories 43R, 43
It is stored in G and 43B respectively. Next, the respective primary color signals R, stored in the frame memories 43R, 43G, 43B,
The image processing circuit 44 for the image data corresponding to G and B.
Processing such as edge detection is performed by R, 43G, and 43B, and the result is output to the control unit 5.

The control unit 5 compares the input processing result with preset reference data to calculate a color misregistration amount, and the projector 2 corrects the misregistration amount.
A control signal CTL for changing the amplitude of the deflection waveform is generated and output to the deflection waveform generation circuit 24. As a result, a deflection waveform whose amplitude is controlled according to the amount of color misregistration is applied to the deflection yoke of each CRT 23R, 23G, 23B, and the color misregistration is corrected.

[0010]

However, in the above-mentioned conventional convergence adjusting device, the test signal T
Convergence adjustment cannot be performed unless ST is input to the decoder 21 of the projector 2. Therefore, in a device such as a rear projector in which color misregistration occurs only by deflecting the setting direction under the influence of the earth's magnetism, it is necessary to input the test signal TST each time to perform convergence adjustment. It was complicated. Also, for example, in a show or video theater, when color deviation occurs due to temperature drift during demonstration of the projector, normal video signals cannot be switched to test signals, so convergence adjustment is extremely difficult. There was a problem that it was not possible to provide a satisfactory image.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to easily perform color misregistration correction even when an image is projected based on a normal input signal without using a test signal. An object is to provide a convergence adjusting device and its method.

[0012]

In order to achieve the above object, the convergence adjusting apparatus of the present invention separates a plurality of basic color signals based on an input signal, and superimposes the images of these basic color signals on a screen. To project the image projected on the screen, to compare the image data input to the projecting unit with the image data captured by the image capturing unit, and to project the input image data. A means for detecting a color shift error of data and a means for correcting the color shift of the projection means based on the color shift error detected by the color shift error detecting means are provided.

In the convergence adjusting device of the present invention,
A cathode ray tube corresponding to a plurality of color signals, separating into a plurality of basic color signals based on the input signal, a means for projecting images of these basic color signals so as to be superimposed on a screen, and the projection means A means for detecting a luminance change of the input image data, comparing the input image data having the luminance change with the image data imaged by the image pickup means, and detecting a color shift error of the projection image data with respect to the input image data. ,
And a means for correcting the color shift by adjusting the deflection of the cathode ray tube in the projection means based on the color shift error detected by the color shift error detecting means.

In the convergence adjusting method of the present invention,
An image formed by projecting images of a plurality of basic color signals separated based on the input signal so as to be superimposed on the screen is captured, and the image data based on the input signal and the captured image data are compared, The color shift error of the projection image data with respect to the input image data is detected, and the color shift correction is performed based on the detected color shift error.

In the convergence adjusting method of the present invention,
By a projection means having a cathode ray tube corresponding to a plurality of color signals, an image obtained by projecting images of a plurality of basic color signals separated based on the input signals so as to be superimposed on a screen is captured, The image data based on the image data is compared with the captured image data to detect a color misregistration error of the projection image data with respect to the input image data, and the deflection of the cathode ray tube in the projection means is adjusted based on the detected color misregistration error. To correct the color misregistration.

[0016]

According to the convergence adjusting device of the present invention,
Images of a plurality of basic color signals separated based on the input signal by the projection means are projected so as to be superimposed on the screen, and one image is displayed. The image projected on the screen is captured by the image capturing means. The projection image data obtained by the image pickup is compared with the input image data to the projection unit, and the color shift error detection unit detects the color shift of the projection image with respect to the input image. The detection result is input to the color misregistration correction unit, and the color misregistration correction is performed on the projection unit.

Further, according to the convergence adjusting device of the present invention, the color misregistration correction is performed by adjusting the deflection of the cathode ray tube of the projection means.

According to the convergence adjusting method of the present invention, the images of the plurality of basic color signals separated based on the input signals projected so as to be superimposed on the screen are picked up. The projection image data obtained by the image pickup is compared with the input image data based on the input signal, the color shift error detecting means detects the color shift with respect to the input image, and the color shift correction is performed based on the detection result.

Further, according to the convergence adjustment method of the present invention, the color misregistration correction is performed by adjusting the deflection of the cathode ray tube of the projection means.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing an embodiment of the convergence adjusting apparatus according to the present invention, and the same components as those in FIG. That is,
1 is a screen, 2 is a decoder 21, and amplifiers 22R, 2
A projector having 2G, 22B, CRTs 23R, 23G, 23B and a deflection waveform generation circuit 24, 3 is a camera (CCD camera), 4 is an RGB decoder 41, A / D converters 42R, 42G, 42B, a frame memory 43R,
43G, 43B and image processing circuits 44R, 44G, 4
4B is a captured image processing unit, 6 is an input image processing unit, and 7 is an input image processing unit.
Indicates the control units, respectively.

The input image processing section 6 includes an A / D converter 61.
R, 61G, 61B, frame memories 62R, 62G,
62B and image processing circuits 63R, 63G, 63B. A / D converters 61R, 61G, 61
B is the input video signal I in the decoder 21 of the projector 2.
The primary color signals R, G, which are analog signals extracted from S
B is quantized and converted into a digital signal. The frame memories 62R, 62G, and 62B are the A / D converters 61.
The video signals converted into digital signals by R, 61G, and 61B are stored. Image processing circuits 63R, 63G, 63B
Is the edge detection for the image data stored in the frame memories 62R, 62G, and 62B, and the frame memories 62R, 62G, and 6 of the points at which the most changing points appear significantly.
The coordinates on 2B are detected.

The control section 7 is composed of a pattern discriminating circuit 71, comparators 72R, 72G and 72B, an arithmetic circuit 73 and a control signal generating circuit 74. The pattern discriminating circuit 71 includes image processing circuits 63R and 6R of the input image processing unit 6.
By inputting the processing results of 3G and 63B, for example, it is determined whether the image pattern has no brightness change and cannot be adjusted, such as the entire white color, or the image pattern has brightness change and is adjustable. Image processing circuit 63R,
Outputs of 63G and 63B are output to comparators 72 corresponding to respective colors.
Output to R, 72G, 72B.

The comparators 72R, 72G and 72B are provided with the image processing circuit 63R, which is input through the pattern discriminating circuit 71.
The image data as the processing result of 63G, 63B and the image data as the processing result of the image processing circuits 44R, 44G, 44B of the photographed image processing unit 4 are compared, and the image data based on the input video and the image are projected on the screen 1. Image of camera 3
The deviation amount from the projection image data captured by is detected.

The arithmetic circuit 73 includes comparators 72R, 72G,
The correction amount of the projector deflection waveform is calculated from the shift amount between the input image data and the projection image data detected by 72B. Specifically, for example, a process such as obtaining a bit movement amount with respect to a shift based on preset adjustment data is performed. The control signal generation circuit 74 generates a control signal CTL for instructing to change the amplitude of the deflection waveform based on the correction amount calculated by the arithmetic circuit 73, and outputs it to the deflection waveform generation circuit 24 of the projector 2. .

Next, the convergence adjustment operation with the above configuration will be described with reference to the flow chart of FIG. 2 and FIGS. First, when performing the adjustment, the frame memories 62R, 6R of the input image processing unit 6 for the input signal IS
2G, 62B and the frame memory 43 of the captured image processing unit 4
The position of the camera 3 is calibrated by correlating the coordinates of R, 43G, and 43B and recognizing the position of the camera 3.

Specifically, as shown in FIG. 3A, for example, a test signal for displaying a cross cursor at the center is used as the input signal IS as the decoder 21 of the projector 2.
Is input to (S1). In the decoder 21, the primary color signals R, G, B are extracted from the input test signal, and the horizontal sync signal H _sync and the vertical sync signal V _sync are separated. The primary color signals R, G, B extracted by the decoder 21 are input to the amplifiers 22R, 22G, 22B, respectively, and subjected to an amplifying action to the CRTs 23R, 23G, 23B corresponding to the respective colors.
A of the input image processing unit 6
The analog signals are input to the D / D converters 61R, 61G, 61B, and the analog signals are converted into digital signals, and the frame memory 6
It is stored in 2R, 62G, and 62B.

The horizontal synchronizing signal H separated by the decoder 21
_{The sync} and the vertical sync signal V _sync are generated by the deflection waveform generation circuit 24.
To the deflection yoke of each of the CRTs 23R, 23G, and 23B, and a deflection waveform corresponding to the input synchronizing signal is generated. As a result, each CRT 23R, 23G, 23
A predetermined beam is emitted from B, and a cross-shaped cursor pattern is projected onto a predetermined position on the screen 1 at a substantially central portion.

The frame memory 62 of the input image processing unit 6
The input image data stored in R, 62G, and 62B are extracted by the image processing circuits 63R, 63G, and 63B, respectively, and the figure extraction processing of the cross character cursor is performed.
As shown in (b) of, the center coordinates (x _s ,
y _s ) and the inclination θ _{s of the} vertical and horizontal lines are detected (S2). The detection result is input to the control unit 7, and is input to the comparators 72R, 72G, 72B via the pattern determination circuit 71, respectively.

On the other hand, the entire pattern projection surface of the screen 1 on which the cross-shaped cursor pattern is projected is photographed by the camera 3. Screen 1 taken by camera 3
The projected image above is input to the RGB decoder 41. RG
The B decoder 41 extracts the three primary color signals R, G, B from the input image data, and the primary color signals R, G, B, which are analog signals of these, are converted into A / D converters 42R, 42G, 42.
It is converted into a digital signal by B and stored in the frame memories 43R, 43G and 43B, respectively.

The projection image data stored in each of the frame memories 43R, 43G and 43B is stored in the image processing circuit 4.
4R, 44G, taken out by 44B, as with respect to the input image data described above, shapes extraction process of the photographed cross cursor is performed, as shown in (c) of FIG. 3, the center coordinates of the cursor (x _c , y _c ) and the inclination θ _{c of the} vertical and horizontal lines are detected (S3). The detection results are input to the comparators 72R, 72G, 72B of the control unit 7, respectively.

In each of the comparators 72R, 72G and 72B, frame memories 62R and 62 for storing input image data.
G, 62B and the frame memory 43R, 43G, 43B for storing the projection image data, the shift of the coordinate position (x _c −x
_s , y _c −y _s ) and the difference in inclination (θ _c −θ _s ). The above operation is similarly performed for all the positions to be adjusted, and the position calibration value of the camera 3 is obtained.

When actually projecting a normal image, V
Video signal of TR or computer screen is input signal IS
Is input to the decoder 21 of the projector 2 (S5). As in the case of the test signal input described above, in the decoder 21, the primary color signals R, G, B are input from the input video signal.
Is extracted, and the horizontal sync signal H _sync and the vertical sync signal V _sync are separated. The primary color signals R, G, B extracted by the decoder 21 are amplifiers 22R, 22G, 22B.
Each color is input to and is amplified and CR for each color
T23R, 23G, and 23B are respectively input, and the A / D conversion units 61R, 61G, and
The signal is input to 61B, the analog signal is converted into a digital signal, and the digital signal is stored in the frame memories 62R, 62G, and 62B.

The horizontal synchronizing signal H separated by the decoder 21
_{The sync} and the vertical sync signal V _sync are generated by the deflection waveform generation circuit 24.
To the deflection yoke of each of the CRTs 23R, 23G, and 23B, and a deflection waveform corresponding to the input synchronizing signal is generated. As a result, each CRT 23R, 23G, 23
A predetermined beam is emitted from B, and an image is projected at a predetermined position on the screen 1.

The frame memory 62 of the input image processing unit 6
The data stored in R, 62G, and 62B, for example, in FIG.
The input image data as shown in (3) is taken out by the image processing circuits 63R, 63G, 63B, respectively, and the input image data has a brightness change and a convergence adjustable pattern. It is detected whether or not there is no pattern and convergence adjustment is not possible (S6, S7). Specifically, for example, when the color misregistration of the central portion is corrected, the image of the central region of the frame memories 62R, 62G, and 62B is processed, and there is a portion where a luminance difference appears in the horizontal or vertical direction. Whether or not it is searched. As the image processing at this time, edge extraction filtering or the like is performed. Further, as shown in (b) of FIG. 4, the coordinates (X _s ,
Y _s ) is detected (S8). The above detection result is input to the comparators 72R, 72G, and 72B via the pattern determination circuit 71 if the pattern is a convergence adjustable pattern. Note that the above processing does not necessarily have to be performed at the same time for the three colors of R, G, and B, and may be for a single color or for only one direction.

On the other hand, the entire projection surface of the screen 1 on which the image as shown in FIG. 4A is projected is photographed by the camera 3. The projection image on the screen 1 taken by the camera 3 is input to the RGB decoder 41. In the RGB decoder 41, the three primary color signals R,
G, B are extracted, and primary color signals R, G, B which are analog signals are converted into digital signals by the A / D converters 42R, 42G, 42B, and the frame memory 43.
It is stored in each of R, 43G, and 43B.

The projection image data stored in each of the frame memories 43R, 43G, 43B is stored in the image processing circuit 4.
4R, 44G, and 44B, as in the case of the input image data described above, as shown in FIG. 4C, the coordinates (X _c , _Yc ) is detected (S9). The detection result is input to the comparators 72R, 72G, 72B.

Here, frame memories 62R and 62G for storing the input image data obtained based on the test signal,
62B and a frame memory 43 for storing projection image data
Deviation of coordinate position from R, 43G, 43B (x _c −x _s ,
y _c −y _s ) from the image processing circuits 63R, 63G, 63
The frame memories 43R, 43G, 4 corresponding to the coordinate positions on the frame memories 62R, 62G, 62B obtained in B.
The coordinate position on 3B is calculated. Edge extraction and pattern matching processing are performed again from the brightness difference data of that color in that portion, and the coordinate position is detected. The coordinates on the frame memories 43R, 43G, and 43B corresponding to the coordinates (X _s , Y _s ) obtained by the above processing are (X _s +
x _c −x _s , Y _s + y _c −y _s ) and the shift amount is (X
_{s -X c + x c -x s} , the _{Y s -Y c + y c -y} s).

The above results are input to the arithmetic circuit 73.
In the arithmetic circuit 73, since the coordinate shift amount corresponds to the color shift amount, the input process result is compared with preset reference data to calculate the color shift correction amount (S
10) The control signal generation circuit 74 generates the control signal CTL for changing the amplitude of the deflection waveform of the projector 2 so as to correct the deviation amount so as to be small, and outputs the control signal CTL to the deflection waveform generation circuit 24. As a result, the deflection waveform whose amplitude is controlled according to the amount of color misregistration becomes
It is applied to the deflection yokes of 23G and 23B to correct the color misregistration (S11).

As described above, according to this embodiment,
Color shift adjustment can be performed in parallel with image projection when a normal video signal is input, without using a special test signal or the like. Therefore, even in a device such as a rear projector in which color misregistration occurs only by deflecting the setting direction due to the influence of the earth's magnetism, it is necessary to input a test signal each time and perform a complicated adjustment such as convergence adjustment. No need for labor. Further, in a show, a video theater, or the like, even if a color shift occurs due to a temperature drift or the like during a demonstration of the projector, the color shift adjustment can be performed without being noticed by the audience and giving a sense of discomfort.

In the present embodiment, the convergence adjustment is performed based on the absolute coordinates on the frame memory so that the R, G, B single colors or one direction can be adjusted, but the present invention is not limited to this. However, it is also possible to correct only the relative deviation of R, G, and B, for example. In this case as well, the same system configuration as in FIG. 1 can be used, and an image in which the change in the brightness of the input signal occurs simultaneously with three or two colors is an adjustable image. The frame memory 43 in which the captured image data at this time is stored
If the coordinates of changing the two colors or the three colors are different in the data of R, 43G, and 43B, the deflection waveform of the projector 2 is corrected so that they are the same. According to this method, calculation for calibrating the camera position is almost unnecessary.

Further, since the color misregistration usually occurs not in a short cycle of a few seconds but in a cycle of minutes such as 5 minutes, for example, when a normal video signal is input, a test signal for adjustment is supplied to the projector every predetermined time. It is also possible to input 2 and make automatic adjustment based on this.

[0042]

As described above, according to the convergence adjusting apparatus of the present invention, color misregistration adjustment can be performed by any signal source, not limited to a predetermined test signal. Therefore, in a show, a video theater, or the like, even if a color shift occurs during a demonstration of the projector, for example, the color shift adjustment can be performed without being noticed by the audience and giving a sense of discomfort.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a convergence adjusting device according to the present invention.

FIG. 2 is a flowchart for explaining a convergence adjustment operation according to the present invention.

FIG. 3 is a diagram for explaining an operation during camera position calibration.

FIG. 4 is a diagram for explaining an operation during normal color misregistration correction.

FIG. 5 is a configuration diagram of a conventional convergence adjustment device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Screen 2 ... Projector 21 ... Decoder 22R, 22G, 22B ... Amplifier 23R, 23G, 23B ... CRT 24 ... Deflection waveform generating circuit 3 ... Camera 4 ... Shooting image processing part 41 ... RGB decoder 42R, 42G, 42B ... A / D converter 43R, 43G, 43B ... Frame memory 44R, 44G, 44B ... Image processing circuit 6 ... Input image processing unit 61R, 61G, 61B ... A / D converter 62R, 62G, 62B ... Frame memory 63R, 63G, 63B Image processing circuit 7 Control unit 71 Pattern determination circuit 72R, 72G, 72B Comparator 73 Operation circuit 74 Control signal generation circuit

Claims (4)

[Claims] 1. A means for separating into a plurality of basic color signals based on an input signal and projecting the images of these basic color signals so as to be superimposed on a screen, and a means for picking up the image projected on the screen. The means for comparing the image data input to the projection means with the image data captured by the imaging means to detect a color shift error of the projection image data with respect to the input image data, and the means for detecting the color shift error detection means. And a means for correcting the color shift of the projection means based on the color shift error. 2. A means having a cathode ray tube corresponding to a plurality of color signals, separating into a plurality of basic color signals based on an input signal, and projecting images of these basic color signals so as to be superimposed on a screen. , Means for picking up an image projected on the screen and a change in brightness of the image data input to the projection means are detected, and the input image data having a change in brightness and the image data picked up by the image pickup means are compared. Then, based on the color shift error detected by the color shift error detection unit and the color shift error of the projection image data with respect to the input image data, the deflection of the cathode ray tube in the projection unit is adjusted to correct the color shift. And a means for performing the convergence adjustment device. 3. A convergence adjustment method for an image, which comprises projecting a plurality of images of basic color signals separated based on an input signal so as to be superimposed on a screen, and capturing the image projected on the screen. Then, the image data based on the input signal is compared with the captured image data to detect the color misregistration error of the projection image data with respect to the input image data, and the color misregistration correction is performed based on the detected color misregistration error. Convergence adjustment method characterized by. 4. Convergence of images formed by projecting images of a plurality of basic color signals separated based on input signals so as to be superimposed on a screen by a projection means having a cathode ray tube corresponding to a plurality of color signals. An adjusting method, in which an image projected on a screen is captured, image data based on an input signal is compared with the captured image data, and a color shift error of the projected image data with respect to the input image data is detected, A convergence adjustment method characterized in that the deviation of the cathode ray tube in the projection means is adjusted to correct the color deviation based on the detected color deviation error.