JP3178526B2 - Image correction apparatus and method, and image display apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display apparatus which forms a single screen by joining a plurality of divided screens to display an image, and an image displayed on the image display apparatus. The present invention relates to an image correction apparatus and a method for performing correction.

[0002]

2. Description of the Related Art In an image display device such as a television receiver or a monitor device for a computer, for example, a cathode ray tube (CRT) is widely used. The cathode ray tube irradiates an electron beam from an electron gun provided inside the cathode ray tube (hereinafter, also simply referred to as the inside of the tube) toward a fluorescent screen to form a scanning screen according to the scanning of the electron beam. A cathode ray tube generally has a single electron gun, but in recent years, a double electron gun system having a plurality of electron guns has been developed. In such a cathode ray tube, a plurality of divided screens are formed by a plurality of electron beams emitted from a plurality of electron guns, and a single screen is formed by connecting the plurality of divided screens to form an image. Display is performed. Regarding the technology related to the cathode ray tube having the plurality of electron guns, for example,
JP-B-39-25641, JP-B-42-4928
And Japanese Patent Application Laid-Open No. Sho 50-17167. According to such a cathode ray tube having a plurality of electron guns, a cathode ray tube using a single electron gun is
There are advantages such as being able to increase the screen size while reducing the depth.

[0003]

In the above-described cathode ray tube of the double electron gun type, when a plurality of divided screens are connected to display a single screen, the joints between the divided screens are as conspicuous as possible. It is desirable not to do so. However, in the related art, the technology for making the joints of the plurality of divided screens inconspicuous is insufficient, and there has been a problem that a good image cannot always be obtained on the entire screen.

In a cathode ray tube for displaying a color image, electron beams for a plurality of colors, which are the basics of color display, are used. The trajectory of the electron beam for each color is affected by different magnetic fields for each color. May not match. However, in order to accurately reproduce the input signal on the screen, the electron beams for each color must match on the screen. Such a phenomenon that the position of the electron beam for each color is shifted on the tube surface is called misconvergence. In general, since the screen of a cathode ray tube is rectangular, the flight distance of the electron beam reaching the tube surface is the longest at the four corners of the screen. Therefore, the image displayed on the tube usually looks distorted like a pincushion. This image distortion is usually called “image distortion”.

Conventionally, the occurrence of the above-described image distortion has been minimized by optimizing the deflection magnetic field generated by the deflection yoke. However, in recent years, with the wide angle of the image display device, the flattening of the tube surface, and the change in the allowable level of image distortion required from the market, etc., the image quality is not sufficient with the deflection magnetic field generated by the deflection yoke alone. The distortion cannot be corrected. As a method of correcting the remaining image distortion, for example, a method of modulating and correcting a deflection current supplied to a deflection yoke or the like is used. However,
In the method of modulating the deflection current, a circuit for performing a new modulation must be added, and there is a problem that the cost is increased. At this time, an inexpensive circuit can be used to reduce the cost, but there is a problem that it is difficult to perform accurate correction with an inexpensive circuit.

[0006] Further, with respect to the correction of misconvergence, basically, similarly to the image distortion, the design is performed such that the electron beams for the respective colors coincide over the entire screen by the deflection magnetic field distribution generated by the deflection yoke itself. However,
Like image distortion, it is difficult to completely correct misconvergence only by the magnetic field distribution of the deflection yoke. Conventionally, in order to correct the remainder of this misconvergence correction, a sub-yoke for correction independent of the original deflection yoke is added, and the electron beams for each color are individually moved, and the electron beams are correctly matched. A method has also been adopted. However, according to this method, in addition to the sub-yoke, a circuit for driving the sub-yoke is newly required, which causes an increase in manufacturing cost.

As described above, conventionally, a method of correcting image distortion and misconvergence by a deflection magnetic field is generally used. However, since the adjustment work of the correction by the deflection magnetic field needs to be repeatedly performed while being spread over the entire screen in the horizontal and vertical directions, the workability is poor and at the same time, there is variation due to the adjuster, and the optimum image distortion is always obtained. Is difficult to adjust. Further, since it is necessary to add a complicated deflection coil and an adjusting mechanism, the cost of the apparatus is increased.

In order to eliminate image distortion and misconvergence with the deflection yoke, it is necessary to forcibly distort the deflection magnetic field and the deflection yoke is not a uniform magnetic field. Conventionally, the distorted magnetic field causes a problem that the focus characteristics (spot size and the like) of the electron beam are deteriorated and the resolution is deteriorated. Further, in order to correct image distortion and misconvergence with the deflection yoke, a development and design period of the deflection yoke is required, which causes a problem that the cost is increased.

The above-described problems relating to correction of image distortion and misconvergence further affect the accuracy of joining a plurality of divided screens in the above-described double electron gun type cathode ray tube. Therefore, in the above-described double electron gun type cathode ray tube, image distortion and misconvergence are appropriately corrected, and a plurality of divided screens are appropriately connected so that a joint between the divided screens is not conspicuous. It is desirable.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to provide an image correcting apparatus and an image correcting apparatus which can display an image satisfactorily by joining a plurality of divided screens so that joints are not noticeable. A method and an image display device are provided.

[0011]

An image correction apparatus according to the present invention performs an operation of correcting image data in a first direction so that a plurality of divided screens are appropriately connected and displayed in a first direction. A first operation unit and an image conversion unit that performs an image conversion on the image data output from the first operation unit in a state suitable for performing an operation of correcting the image data in a second direction different from the first direction. Conversion means for performing the operation of correcting the image data output from the conversion means in the second direction so that the plurality of divided screens are appropriately connected and displayed in the second direction. It is provided.

An image display device according to the present invention includes a first arithmetic unit for performing an arithmetic operation for correcting image data in a first direction so that a plurality of divided screens are appropriately connected and displayed in a first direction. Converting means for performing image conversion so that image data output from the first calculating means is in a state suitable for performing a calculation for correcting the image data in a second direction different from the first direction; Calculating means for correcting image data output from the converting means in the second direction so that the divided screens are properly connected and displayed in the second direction, and the second calculating means And an image display means for displaying an image based on the image data output from.

[0013] Further, the image correction method according to the present invention comprises the following steps:
Calculation means for correcting the image data in the first direction so that the plurality of divided screens are properly connected and displayed in the first direction by the calculation means, and the image data output from the first calculation means Image conversion is performed so as to be in a state suitable for performing a calculation for correcting in a second direction different from the first direction, and a plurality of divided screens are shifted by the second calculation means in the first direction. In order to display the image data properly connected and displayed in a second direction different from the above, an operation for correcting the image-converted image data in the second direction is performed.

In the image correction device and method and the image display device according to the present invention, the first arithmetic means converts the image data into the first image so that the plurality of divided screens are properly connected and displayed in the first direction. An operation for correcting in the direction is performed, and the image data output from the first operation unit is in a state suitable for performing an operation for correcting in the second direction different from the first direction. Image conversion is performed. Further, the image data subjected to the image conversion is corrected in the second direction by the second calculation means so that the plurality of divided screens are appropriately connected and displayed in the second direction different from the first direction. You.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[First Embodiment] FIG. 1 is a configuration diagram schematically showing a cathode ray tube which is an example of an image display device according to a first embodiment of the present invention. In this figure, (B)
1 is a front view of a cathode ray tube, and FIG. 1A is a cross-sectional view taken along line AA ′ in FIG. 1B. As shown in this figure, the cathode ray tube according to the present embodiment includes a panel section 10 having a fluorescent screen 11 formed inside, and a funnel section 20 integrated with the panel section 10. Funnel 20
On the left and right sides of the rear end, there are formed two elongated neck portions 30L, 30R each containing an electron gun 31L, 31R. In this cathode ray tube, a panel portion 10, a funnel portion 20, and neck portions 30L and 30R form an overall appearance of two funnels. Hereinafter, the overall shape of the cathode ray tube is also referred to as an “enclosure”. The panel unit 10 and the funnel unit 20 have their respective openings fused to each other so that a high vacuum state can be maintained inside. On the phosphor screen 11, a striped pattern (not shown) made of a phosphor is formed. The fluorescent screen 11 corresponds to a specific example of “image display means” in the present invention.

Inside the cathode ray tube, there is arranged a color selecting mechanism 12 made of a thin metal plate arranged so as to face the fluorescent screen 11. The color selection mechanism 12 is also called an aperture grill or a shadow mask or the like depending on the type thereof, and its outer periphery is supported by a frame 13 and attached to the inner surface of the panel unit 10 via a support spring 14. . The funnel unit 20 is provided with an anode unit (not shown) for applying the anode voltage HV. The electron beam eB emitted from the electron guns 31L and 31R is provided on the outer peripheral portion from the funnel portion 20 to the neck portions 30L and 30R.
Deflection yokes 21L and 21 for deflecting L and eBR
R and convergence yokes 32L, 32R for convergence (concentration) of the electron beams for each color emitted from the electron guns 31L, 31R are attached. The inner peripheral surface from the neck portion 30 to the phosphor screen 11 of the panel portion 10 is covered with a conductive internal conductive film 22. The internal conductive film 22 is electrically connected to an anode (not shown) and is maintained at the anode voltage HV.
Further, the outer peripheral surface of the funnel portion 20 is covered with a conductive external conductive film 23.

The electron guns 31L and 31R are not shown,
Red (Red = R), green (Green = G) and blue (Bl
ue = B), in which a plurality of electrodes (grids) are arranged in front of a hot cathode structure provided with three cathodes (hot cathodes), and an electron beam eBL emitted from the cathode at each electrode. , EBR control, acceleration and the like. The electron beams for each color emitted from the electron guns 31L and 31R pass through the color selection mechanism 12 and the like, and irradiate the phosphor of the corresponding color on the phosphor screen 11.

In the cathode ray tube of the present embodiment, the electron beam e from the electron gun 31L arranged on the left side is used.
Approximately the left half of the screen is drawn by BL, and approximately the right half of the screen is drawn by the electron beam eBR from the electron gun 31R arranged on the right side, and the ends of the left and right split screens formed by this are drawn. By partially overlapping and joining, a single screen SA is formed as a whole and an image is displayed. Therefore, the central portion of the screen SA formed as a whole is an area OL where the left and right divided screens overlap (overlap). Overlapping area OL
Is shared by the electron beams eBL and eBR. Here, in the present embodiment, the line scanning of the electron beam eBL from the electron gun 31L is performed from right to left in the horizontal deflection direction (X2 direction in the drawing), and the field scan is performed from top to bottom in the vertical deflection direction. It should be done toward. Further, the line scanning of the electron beam eBR from the electron gun 31R is performed in the horizontal deflection direction from left to right (X in the drawing).
1) and the field scanning is performed from top to bottom in the vertical deflection direction. Therefore, in the present embodiment, as a whole, line scanning by each of the electron beams eBL and eBR is performed in the opposite direction from the center of the screen to the outside in the horizontal direction, and the field scanning is performed.
It is performed from top to bottom like a general cathode ray tube.

In this cathode ray tube, an overscan area OS of the electron beams eBL and eBR at the joint side of the adjacent left and right divided screens (in the present embodiment, the center of the entire screen). The electron beams eBL and eBR overscanning the overscanning region OS are
1 so that the electron beam e
A V-shaped beam shield 27 serving as a shielding member for BL and eBR is arranged. The beam shield 27 is
For example, it is installed on a frame 13 that supports the color selection mechanism 12 as a base. The beam shield 27 is mounted on the frame 1
3, the anode voltage HV is obtained by being electrically connected to the internal conductive film 22.

In this embodiment, the overscanning region is a region outside each scanning region of the electron beams eBL and eBR forming an effective screen in each scanning region of the electron beams eBL and eBR. Say. In FIG. 1, the area SW1 is an effective screen on the phosphor screen 11 in the horizontal direction of the electron beam eBR, and the area SW2 is an effective screen on the phosphor screen 11 in the horizontal direction of the electron beam eBL.

FIG. 2 is a block diagram showing a signal processing circuit of the cathode ray tube according to the present embodiment. In this figure, as the image signal D _IN NTSC (National Television Syst
1 shows an example of a circuit for inputting an analog composite signal of an em committee) type and displaying a moving image according to the signal. Here, the signal processing circuit shown in the figure corresponds to a specific example of the “image correction device” of the present invention.
In this figure, only the circuit part relating to the present invention is shown, and other processing circuits are not shown.

The cathode ray tube according to the present embodiment converts the analog composite signal input as the image signal D _IN to R,
Composite / convert to G / B color signals and output
An RGB converter 51 and an analog / digital signal (hereinafter, referred to as an analog / digital signal) which converts an analog signal for each color output from the composite / RGB converter 51 into a digital signal and outputs the digital signal.
It is described as “A / D”. ) Converter 52 (52r, 52g, 5)
2b), a frame memory 53 (53r, 53g, 53b) for storing the digital signal output from the A / D converter 52 in frame units for each color, and a write address and a read address of image data to and from the frame memory 53. And a memory controller 54 that generates The frame memory 53 is, for example, an SDRAM
(Synchronous dynamic random access memory) or the like is used.

The cathode ray tube according to the present embodiment further controls the left divided screen image data of the image data for each color stored in the frame memory 53.
SP (digital signal processor) circuit 55L1, frame memory 56L (56Lr, 56Lg, 56L)
b), a DSP circuit 55L2 and a digital / analog signal (hereinafter referred to as “D / A”) converter 57L (57L)
r, 57Lg, 57Lb), the DSP circuit 55R1 for controlling the image data for the right divided screen among the image data for each color stored in the frame memory 53, and the frame memory 56R (56Rr, 56Rg, 56R).
b), DSP circuit 55R2 and D / A converter 57R
(57Rr, 57Rg, 57Rb).

Note that the DSP circuits 55L1 and 5
5R1 corresponds to a specific example of “first operation means” in the present invention, and the DSP circuits 55L2 and 55R2
Corresponds to a specific example of the “second calculation means” in the present invention. Further, the frame memories 56L and 56R correspond to a specific example of "image data storage means" in the present invention.

The cathode ray tube according to the present embodiment further includes a correction data memory 60 for storing correction data for each color for correcting an image display state, and a correction data from the correction data memory 60. Data is entered,
Each DSP circuit 55L1, 55L2, 55R1, 55R2
(Hereinafter, these four DSP circuits are collectively referred to simply as “DS
Also referred to as “P circuit 55”. ), A control unit 62 for instructing an arithmetic method and the like, and frame memories 56L, 56L
A memory controller 63 for generating a write address and a read address of image data for the 6R.

The memory controller 63 corresponds to a specific example of "address generation means" in the present invention.
Further, the frame memories 56L and 56R and the memory controller 63 correspond to a specific example of “conversion unit” in the present invention.

The correction data memory 60 has a memory area for each color, and stores correction data for each color in each memory area. The correction data stored in the correction data memory 60 is, for example, created at the time of manufacturing the cathode ray tube. This correction data is
It is created by measuring the amount of image distortion and the amount of misconvergence of the image displayed on the cathode ray tube. The device for creating the correction data includes, for example, an imaging device 64 that captures an image displayed on a cathode ray tube,
And a correction data generating unit (not shown) for generating correction data based on the image captured by the control unit 4. The imaging device 64 includes, for example, an imaging device such as a CCD (Charge Coupled Device), and captures a display screen displayed on the surface of the cathode ray tube for each of R, G, and B colors.
The imaging screen is output as image data for each color. The correction data creation means is constituted by a microcomputer or the like, and moves each pixel from an appropriate display position in the discretized two-dimensional image data representing an image captured by the imaging device 64. Data relating to the amount is created as correction data. The device for creating the correction data and the image correction processing using the correction data are described in the invention filed earlier by the present applicant (Japanese Patent Application No. 11-1).
No. 7572) can be used. The calculation processing for correcting an image using the correction data will be described later in detail.

Each DSP circuit 55L1, 55L2, 55R
1,55R2 is, for example, a one-chip general-purpose LS
I (large scale integrated circuit) and the like. Each D
The SP circuits 55L1, 55L2, 55R1, 55R2
In order to correct image distortion, misconvergence, and the like of the cathode ray tube, various arithmetic processing is performed on the input image data in accordance with an instruction from the control unit 62. The control unit 62 is configured to instruct each DSP circuit 55L1, 55L2, 55R1, 55R2 of a calculation method based on the correction data stored in the correction data memory 60.

Here, the DSP circuit 55L1 mainly performs a horizontal (first direction) correction process on the image data for the left divided screen among the image data for each color stored in the frame memory 53. The correction result is output to the frame memory 56L for each color. DS
The P circuit 55L2 performs mainly vertical (second direction) correction processing on the image data for each color stored in the frame memory 56L, and outputs the correction result to the D / D converter for each color.
This is output to the A converter 57L. DSP circuit 55
R1 corresponds to the image data for the right divided screen among the image data for each color stored in the frame memory 53,
The correction process is mainly performed in the horizontal direction, and the correction result is output to the frame memory 56R for each color. The DSP circuit 55R2 mainly performs vertical correction processing on image data for each color stored in the frame memory 56R, and outputs the correction result to the D / A converter 57R for each color. is there. Each D / A converter 57
L and 57R are the DSP circuits 55L2 and 55R, respectively.
2 is converted into an analog signal and output to each of the electron guns 31L and 31R. Note that each of the DSP circuits 55L1, 55L2, 5
More specific examples of the arithmetic processing in 5R1 and 55R2 will be described later in detail with reference to the drawings.

Each of the frame memories 56L and 56R stores the calculated image data output from each of the DSP circuits 55L1 and 55R1 on a frame basis for each color, and outputs the stored image data for each color. Has become. The frame memories 56L and 56R are memories that can be randomly accessed at high speed.
M (static RAM) or the like is used. If the frame memories 56L and 56R are constituted by a single memory that can be randomly accessed at a high speed, a frame overtaking operation occurs at the time of writing and reading operation of image data, causing image disturbance. Therefore, as the configuration of the frame memories 56L and 56R, two memories (double buffers) are used respectively. Note that the frame memories 56L and 56R perform the writing operation of the image data according to the order of the write addresses generated by the memory controller 63, and perform the reading operation of the image data according to the order of the read addresses generated by the memory controller 63. It has become.

The memory controller 63 generates write addresses of image data for the frame memories 56L and 56R, and generates read addresses of the image data stored in the frame memories 56L and 56R in the same or different order as the write addresses. It is possible. In the present embodiment, since the order of the read address and the write address can be separately generated as described above, for example, rotation or inversion of an image is performed on image data at the time of writing to the frame memories 56L and 56R. The image data can be read out accordingly. Thereby, in the present embodiment,
It is possible to appropriately perform image conversion on the image data output from the DSP circuits 55L1 and 55R1 so that the image data is suitable for performing the vertical correction operation performed by the DSP circuits 55L2 and 55R2. .

Next, the operation of the cathode ray tube configured as described above will be described. The following description also serves as a description of the image correction method according to the present embodiment.

The analog composite signal input as the image signal D _IN is converted into a composite / RGB converter 51
As shown in FIG. 2, the image signal is converted into an image signal for each of the colors R, G, and B, and the A / D converter 52 converts the image signal into a digital image signal for each color. At this time, I
When P (interlaced / progressive) conversion is performed,
This is preferable because the subsequent processing becomes easy. A / D converter 52
Are stored in the frame memory 53 for each color in frame units according to the control signal Sa1 indicating the write address generated in the memory controller 54. The frame-based image data stored in the frame memory 53 is read in accordance with a control signal Sa2 indicating a read address generated in the memory controller 54, and each DSP circuit 55L
1, 55R1.

Of the image data for each color stored in the frame memory 53, the image data for the left divided screen is
DSP circuit 55L1, frame memory 56L and DS
In the P circuit 55L2, an arithmetic process for correcting an image is performed based on the correction data stored in the correction data memory 60. The image data for the left divided screen after the arithmetic processing is converted into an analog signal via a D / A converter 57L, and a cathode drive voltage is applied to a cathode (not shown) arranged inside the left electron gun 31L. Given as

Of the image data for each color stored in the frame memory 53, the image data for the right divided screen is
DSP circuit 55R1, frame memory 56R and DS
In the P circuit 55R2, arithmetic processing for correcting an image is performed based on the correction data stored in the correction data memory 60. The image data for the right split screen after the arithmetic processing is converted into an analog signal via the D / A converter 57R, and the cathode drive voltage is applied to a cathode (not shown) arranged inside the right electron gun 31R. Given as

Each of the electron guns 31L and 31R emits each of the electron beams eBL and eBR according to the applied cathode drive voltage. The cathode ray tube according to the present embodiment is capable of displaying a color image.
The L and 31R are provided with cathodes for each of the colors R, G and B, and the electron guns 31L and 31R emit electron beams for each color.

The electron beams eBL and eBR for each color emitted from the electron guns 31L and 31R undergo convergence by the electromagnetic action of the convergence yokes 32L and 32R, respectively, and the deflection yokes 21L and 21R.
Of the fluorescent screen 1 by being deflected by the electromagnetic action of
1 is scanned, and the screen SA is
A desired image is displayed in (FIG. 1). At this time, about the left half of the screen is drawn by the electron beam eBL, and about the right half of the screen is drawn by the electron beam eBR, and the ends of the left and right divided screens formed thereby partially overlap. Thus, a single screen SA is formed as a whole.

FIG. 3 shows the processing circuit shown in FIG.
FIG. 9 is an explanatory diagram showing a specific example of an arithmetic process performed on image data for the left divided screen. FIG. 7A shows image data read from the frame memory 53 and input to the DSP circuit 55L1. DSP circuit 55L1
As shown in FIG. 2A, image data of, for example, 640 pixels in width × 480 pixels in height is input. 640 horizontal
In the image data of pixels × 480 pixels vertically, for example, an area of 62 pixels horizontally (32 pixels left + 32 pixels right) × 480 pixels vertically in the center portion is an overlap area OL of the left and right divided screens. Therefore, out of the image data input to the DSP circuit 55L1, 352 horizontal pixels 352 pixels on the left side indicated by the hatched area in FIG.
The data of 480 vertical pixels is the data for the left divided screen.

FIG. 7B shows image data output from the DSP circuit 55L1 and written into the frame memory 56L. The DSP circuit 55L1 performs an arithmetic process including a correction in the horizontal direction (first direction) on the data of 352 horizontal pixels × 480 vertical pixels indicated by the hatched area in FIG. By this arithmetic processing, as shown in FIG. 7B, for example, the horizontal direction of the image is enlarged from 352 pixels to 480 pixels, and image data of 480 pixels × 480 pixels is created. When the DSP circuit 55L1 enlarges the image, the DSP circuit 55L1
Based on the correction data stored in, an arithmetic process for correcting horizontal image distortion and the like is performed. In order to increase the number of pixels, it is necessary to interpolate data relating to pixels that do not exist in the original image. A method for converting the number of pixels will be described later in detail with reference to the drawings.

Further, the DSP circuit 55L1 has an overlapping area O
Calculation processing for luminance modulation correction in L is also performed. In FIG. 7B, a modulation waveform 80L representing the correction of the luminance in the left divided screen is shown corresponding to the image data. Note that the luminance correction processing may be performed before performing arithmetic processing for correcting enlargement of an image, image distortion, or the like, or may be performed after performing these arithmetic processing.

The DSP circuit 5 is stored in the frame memory 56L.
The image data processed in 5L1 is stored for each color according to the control signal Sa3L indicating the write address generated in the memory controller 63.
In the example of FIG. 3B, image data is sequentially written rightward starting from the upper left corner. Frame memory 56L
Is a control signal Sa indicating a read address generated by the memory controller 63.
4L, each color is read out, and the DSP circuit 55L
2 is input. Here, in the present embodiment, the frame memory 56 generated by the memory controller 63 is used.
The order of the write address and the order of the read address for L are different. In the example of FIG. 3B, the order of the read addresses is opposite to the write address, and the image data is sequentially read leftward starting from the upper right.

FIG. 9C shows image data read from the frame memory 56L and input to the DSP circuit 55L2. As described above, in the present embodiment, the order of the read addresses for the frame memory 56L is opposite to the order of the write addresses.
The image input to the SP circuit 55L2 has a form in which the image is converted so that the image is mirror-inverted with respect to the state of the image shown in FIG.

The DSP circuit 55L2 includes a frame memory 5
The arithmetic processing including the correction in the vertical direction (second direction) is performed on the data (480 pixels in the horizontal direction × 480 pixels in the vertical direction) read from 6L ((C) in the same figure). By this arithmetic processing, for example, as shown in FIG.
It is enlarged from 0 pixels to 640 pixels, and 640 pixels wide x
Image data of 480 vertical pixels is created. DSP circuit 5
The 5L2 performs an arithmetic process for correcting vertical image distortion or the like based on the correction data stored in the correction data memory 60 at the same time when the image is enlarged.

The scanning of the electron beam eBL is performed from right to left based on the image data (FIG. 2D) obtained through the above-described arithmetic processing. The screen is displayed as shown in the hatched area in FIG. In the present embodiment, as described above, since the image data is subjected to correction processing in consideration of image distortion and the like, the left image displayed on the phosphor screen 11 is an appropriate image without image distortion and the like. The display is made.

FIG. 4 shows the processing circuit shown in FIG.
FIG. 9 is an explanatory diagram showing a specific example of a calculation process performed on image data for the right divided screen. FIG. 7A shows image data read from the frame memory 53 and input to the DSP circuit 55R1. DSP circuit 55R1
In the same manner as the DSP circuit 55L1, for example,
Image data of 480 pixels × pixels is input. Width 64
Of the image data of 0 pixels × 480 pixels vertically, for example, 62 pixels horizontally (32 pixels left + 32 pixels right) at the center portion ×
An area of 480 pixels vertically is an overlapping area OL of the left and right divided screens. Accordingly, of the image data input to the DSP circuit 55R1, data of 352 horizontal pixels × 480 vertical pixels shown by the shaded area in the figure becomes the data for the right divided screen.

FIG. 9B shows image data output from the DSP circuit 55R1 and written into the frame memory 56R. Similarly to the DSP circuit 55L1, the DSP circuit 55R1 applies the horizontal (first) data to the data of 352 horizontal pixels × 480 vertical pixels indicated by the hatched area in FIG.
) Is performed. By this calculation processing, for example, the horizontal direction of the image is enlarged from 352 pixels to 480 pixels as shown in FIG.
Image data of 80 × 480 pixels is created. D
When the image is enlarged, the SP circuit 55R1 simultaneously performs an arithmetic process for correcting image distortion in the horizontal direction based on the correction data stored in the correction data memory 60.

The DSP circuit 55R1 has an overlapping area O
Calculation processing for luminance modulation correction in L is also performed. In FIG. 7B, a modulation waveform 80R representing the correction of the luminance in the right divided screen is shown corresponding to the image data. Note that the luminance correction processing may be performed before performing arithmetic processing for correcting enlargement of an image, image distortion, or the like, or may be performed after performing these arithmetic processing.

The DSP circuit 5 is stored in the frame memory 56R.
The image data processed in 5R1 is stored for each color according to the control signal Sa3R indicating the write address generated in the memory controller 63.
In the example of FIG. 3B, image data is sequentially written rightward starting from the upper left corner. Frame memory 56R
Is a control signal Sa indicating a read address generated by the memory controller 63.
4R, each color is read out, and the DSP circuit 55R
2 is input. Here, in the processing of the left divided screen shown in FIG. 3, the order of the write address and the order of the read address for the frame memory 56L generated by the memory controller 63 are different, but in the processing of the right divided screen. , The order of the write address and the order of the read address for the frame memory 56R are the same. That is, in the example of FIG. 3B, the image data is sequentially read rightward starting from the upper right.

FIG. 7C shows image data read from the frame memory 56R and input to the DSP circuit 55R2. As described above, in the present embodiment, the order of the read addresses for the frame memory 56R is in the same direction as the write addresses.
The image input to the SP circuit 55R2 has the same shape as the state of the image shown in FIG.

The DSP circuit 55R2 has a frame memory 5
The arithmetic processing including the correction in the vertical direction (second direction) is performed on the data of 480 pixels horizontally × 480 pixels vertically read from 6R ((C) in the same figure). By this arithmetic processing, for example, as shown in FIG.
It is enlarged from 0 pixels to 640 pixels, and 640 pixels wide x
Image data of 480 vertical pixels is created. DSP circuit 5
When the image is enlarged, the 5R2 simultaneously performs a calculation process for correcting vertical image distortion and the like based on the correction data stored in the correction data memory 60.

The scanning of the electron beam eBR is performed from left to right on the basis of the image data (FIG. 3D) obtained through the above-described arithmetic processing, so that the right side on the phosphor screen 11 is The screen is displayed as shown in the hatched area in FIG. In the present embodiment, as described above, since the image data is subjected to correction processing in consideration of image distortion and the like, the right image displayed on the phosphor screen 11 is an appropriate image without image distortion and the like. The display is made. FIG. 3 (E),
Since the left and right divided screens shown in FIG. 4E have their respective image distortions corrected, it is possible to perform an appropriate image display in which the joint portions are not noticeable when the left and right screens are joined. .

Next, with reference to FIG. 5 to FIG. 14, the calculation processing for correcting the image using the correction data will be described in detail.

First, the outline of the correction data stored in the correction data memory 60 (FIG. 2) will be described with reference to FIG. The correction data is represented by, for example, a movement amount with respect to a reference point arranged in a grid. Here, for example, using the grid point (i, j) shown in FIG. 7A as a reference point, the amount of movement in the X direction with respect to the R color is Fr (i, j), Y
The amount of movement in the direction of Gr (i, j), the amount of movement in the X direction for the G color is Fg (i, j), and the amount of movement in the Y direction is Gg (i, j).
j), the amount of movement in the X direction for the B color is Fb (i, j),
Assuming that the moving amount in the Y direction is Gb (i, j), the pixels of each color at the grid point (i, j) are moved by these moving amounts, respectively, as shown in FIG. Become like By combining the images shown in FIG. 3B, an image as shown in FIG. 3C is obtained. When the image obtained in this manner is displayed on the phosphor screen 11, misconvergence and the like are eventually corrected due to the influence of image distortion characteristics of the cathode ray tube itself and geomagnetism. , G, and B pixels are displayed on the same point. In the processing circuit shown in FIG.
In 5L1 and 55R1, correction based on the movement amount in the X direction is performed, and in the DSP circuits 55L2 and 55R2, correction based on the movement amount in the Y direction, for example.

Next, the arithmetic processing using the correction data will be described. Note that the correction calculation is performed for each of the colors R, G, and B, but the calculation method is the same for each color except for the correction data used for the calculation. Accordingly, in the following, the correction calculation of the R color will be described as a representative, and the description of the G color and the B color will be omitted unless otherwise specified. In addition, in the following, in order to facilitate the description, the image correction may be simultaneously described in the vertical direction and the horizontal direction, but as described above, the signal processing circuit illustrated in FIG. Is performed separately in the vertical and horizontal directions.

FIGS. 8 and 9 show how an input image is deformed in the processing circuit shown in FIG. Here, an example in which a lattice image is input as an input image is shown. In these figures, (A) shows the frame memory 5
3 shows a split screen on the left or right side of FIG. Also,
(B) indicates that the input image is a DSP circuit 55L1 or DSP
Via the circuit 55R1, the DSP circuit 55L2 or the DSP
It shows an image output from the circuit 55R2. (C)
Indicates an image of the left or right split screen actually displayed on the phosphor screen 11.

FIG. 8 shows the processing circuit shown in FIG.
The state of deformation of the input image when the correction operation using the correction data is not performed is shown. When the correction calculation is not performed, the image 160 (FIG. 10A) on the frame memory 53 is stored in the DSP circuit 55L2 or D.
The image 161 (FIG. 13B) output from the SP circuit 55R2 has the same shape as the input image. Thereafter, the image is distorted due to the characteristics of the cathode ray tube itself. For example, the image 162 which has been deformed as shown in FIG.
Is displayed on the phosphor screen 11. Note that, in FIG. 3C, the image indicated by the dotted line corresponds to the image to be displayed originally. In the process of displaying an image like this,
A phenomenon in which an image of each color of R, G, and B undergoes exactly the same deformation is image distortion. If different deformation occurs in each color, misconvergence occurs. Here, in order to correct the image distortion as shown in FIG. 3C, it is sufficient to apply a deformation in the direction opposite to the characteristics possessed by the cathode ray tube at a stage before inputting the image signal to the cathode ray tube. .

FIG. 9 shows the processing circuit shown in FIG.
9 illustrates a change in an input image when a correction operation is performed. Even when the correction calculation is performed, the image 160 on the frame memory 53 (FIG. 10A) has the same shape as the input image. The image stored in the frame memory 53 is
Each DSP circuit 55L1, 55L2, 55R1, 55R2
In this case, based on the correction data, the input image is deformed by the cathode ray tube (deformation due to the characteristics of the cathode ray tube. See FIG. 8C). An operation is performed. FIG. 7B shows the image 163 after this calculation. In FIG. 8B, the image shown by the dotted line is the image 160
, Which corresponds to an image before the correction calculation is performed. As described above, the signal of the image 163 deformed in the opposite direction to the characteristics of the cathode ray tube is further distorted by the characteristics of the cathode ray tube, resulting in the same shape as the input image. And ideal image 164 (FIG. (C))
Is displayed on the phosphor screen 11. Note that in FIG. 9C, the image indicated by the dotted line is the image 16 shown in FIG.
Equivalent to 3.

Next, the DSP circuit 55 (DSP circuit 55L)
1, 55L2, 55R1, 55R2) will be described in more detail. FIG. 10 is an explanatory diagram showing a first method of the correction calculation processing performed by the DSP circuit 55. In this figure, pixels 170 are arranged in a grid on integer positions of XY coordinates. This figure shows 1
This is an example of calculation when attention is paid only to pixels, and DS
The value of the R signal (hereinafter, referred to as “R value”) Hd, which is the pixel value of the pixel at the coordinates (1, 1) before the correction calculation by the P circuit 55, is added to the coordinates (3, 4) after the calculation. This shows a moving state. In the drawing, the portion indicated by the dotted line indicates the R value (pixel value) before the correction calculation. Here, assuming that the moving amount of the R value is represented by a vector (Fd, Gd), (Fd, Gd) = (2, 3). When this is viewed from the pixel after the calculation, when the pixel has the coordinates (Xd, Yd), the coordinates (Xd−Fd, Yd)
-It can be interpreted that the R value Hd of (Gd) is copied.
If such an operation of copying is performed for each pixel after calculation, an image to be output as a display image is completed. Therefore, the correction data stored in the correction data memory 60 includes the movement amount (Fd,
Gd).

In the case where the value of the movement amount (Fd, Gd) as the correction data used in the above-described correction calculation is limited to an integer value, the simple operation of moving the pixel value as described above is performed by the correction calculation. It only needs to be applied as. However, the image corrected by performing the calculation based on the limitation of the integer value may have a so-called jagged shape in which a straight line image is jagged, or may appear unnatural because the thickness of the character image becomes uneven. Trouble often occurs. In order to solve this problem, a method of extending the value of the movement amount (Fd, Gd) to a real number, estimating the R value of the imaginary pixel, and using the same is conceivable.

Next, with reference to FIG.
The method will be described. This is because the movement amount (Fd, G
This is a correction calculation method when d) is a real number.
FIG. 11 shows correction data at coordinates (Xd, Yd),
That is, when the movement amounts (Fd, Gd) are each given as a real number, the manner in which the R value Hd of the pixel after calculation is obtained is shown. The coordinates (Ud,
Vd) is represented by the following equation (1).

(Ud, Vd) = (Xd−Fd, Yd−Gd) (1)

Here, (Fd, Gd) = (1.5, 2..
In the case of 2), since the pixel is located only at an integer coordinate position, there is no pixel at the coordinates (Ud, Vd).
Therefore, in the second method, an operation of estimating the R value of the pixel at the coordinates (Ud, Vd) from four pixels near the coordinates (Ud, Vd) by linear interpolation is performed. In FIG. 11, a portion shown by a dotted line shows these four pixels. Here, integers obtained by rounding down the respective decimal parts of the coordinate values Ud and Vd are referred to as values U0 and V0, respectively.
If U1 = U0 + 1 and V1 = V0 + 1, the coordinates (U
0, V0), (U1, V0), (U0, V1), (U
The pixels at (1, V1) are four pixels near the coordinates (Ud, Vd). Here, the coordinates (U0, V
0), (U1, V0), (U0, V1), (U1, V1)
The R value of each pixel in 1) is sequentially determined as H00, H
10, H01, H11, the coordinates (U
d, Vd) is represented by the following equation (2).

Hd = (U1−Ud) × (V1−Vd) × H00 + (Ud−U0) × (V1−Vd) × H10 + (U1−Ud) × (Vd−V0) × H01 + (Ud−U0) × (Vd−V0) × H11 (2)

Here, when the above-described correction method is considered in detail, the amount of movement (Fd, Gd) as correction data is considered.
The pixel values (H00, H10, H01, H11) to be used for estimating the R value are selected and determined by the integer part (first component) of each value of. The coefficient applied to each pixel value in (2) (for example, H00
(U1−Ud) × (V1−Vd)).

In the above example, the R value of the pixel at the coordinates (Ud, Vd) was estimated from the pixel values at the four neighboring points by a method called linear interpolation.
The present invention is not limited to this, and the calculation may be performed using other calculation methods. In the above description, the correction data is interpreted as a relative coordinate difference for referring to the pixel value before the calculation, the pixel value Hd at the imaginary coordinates (Ud, Vd) is estimated, and then the corrected coordinates ( (Xd, Yd). However, conversely, the correction data is interpreted as the amount by which the pixel value Hd before the calculation is moved, and the pixel value Hd after the calculation after the movement based on the movement amount (Fd, Gd) is calculated. A calculation method in which pixel values at four neighboring points at the coordinate position are assigned is also conceivable. In this method, a program for executing the operation is slightly complicated, but such a method may be used.

Incidentally, the movement amounts (Fd, Gd) as the correction data are separately defined for the three colors RGB for each pixel. Therefore, when the correction data is set for all pixels, the total data amount becomes so large that it cannot be ignored, and a large-capacity memory for storing the correction data is required, which increases the cost of the apparatus. Becomes
Further, the correction data creation device (not shown) including the imaging device 64 measures the image distortion amount and the misconvergence amount of the cathode ray tube for all the pixels, calculates the correction data, and gives the correction data to the cathode ray tube side. Work time will also be considerably long. On the other hand, the amount of image distortion and the amount of misconvergence of the cathode ray tube do not vary so much between pixels in pixels located at a short distance from each other. Therefore, utilizing this fact, the entire screen area is divided into several areas, correction data is given only to representative pixels in each divided area, and correction data in other pixels is representative pixel data. A method of inferring from the correction data of (1) is conceivable. This method is effective for reducing the total amount of correction data and shortening the operation time.

Next, as a third method of the correction calculation, a method of performing the correction calculation by giving correction data to only the representative pixels will be described. Note that the movement of pixels in the divided area is determined by the amount of movement of the representative pixels, and hereinafter, the location where the representative pixels are located will be referred to as a “control point”.

FIG. 5 is a diagram showing an example of a reference image for correction used in the third method of the correction calculation. The figure shows an example of a grid-like image obtained by dividing 640 horizontal pixels × 480 vertical pixels into 20 horizontal blocks and 16 vertical blocks. One block is composed of 32 horizontal pixels × 30 vertical pixels. In the figure, the shaded area is the overlap area OL where the left and right divided screens are joined. The control points described above are set, for example, at each grid point of such an image.

FIG. 6 shows a display example of an image displayed on the phosphor screen 11 after correcting the image of the grid-like reference image shown in FIG. 5 by the processing circuit shown in FIG.
In this figure, the divided screen on the left corresponds to the screen shown in FIG. 3 (E), and the number of pixels is 640 horizontal pixels × 480 vertical pixels, and is divided into 11 horizontal blocks × 16 vertical blocks. Also, in this figure, the right split screen is shown in FIG.
This corresponds to the screen shown in (E), and the number of blocks is the same as that on the left.

FIG. 12 shows an example in which the entire screen area on the DSP circuit 55 is divided into a plurality of rectangular areas, and the control points are set in a two-dimensional grid. In the case of a television image or the like, image information having a size larger than the screen size actually displayed on the screen of the cathode ray tube is supplied, and there is an area called overscan. For this reason, as shown in FIG.
0 is set larger than the effective screen area 191 of the cathode ray tube in consideration of the overscan area. On the DSP circuit 55, a large number of control points 192 are set so as to also serve as control points of adjacent divided areas. In the example of this figure, the total number of control points 192 is 11 × 15 × 2 = 3.
There are only 30.

If it is assumed that the image area on the DSP circuit 55 is composed of “640 horizontal pixels and 480 vertical pixels” in each of the left and right divided screens, all the pixels are 640 × 480 × 2 = 61.
It will be 4,400. Considering this, it can be said that the total number of correction data is considerably reduced when the representative control point 192 is provided as the correction data, compared with the case where the correction data is provided to all the pixels. For example, if it is assumed that correction data of 8 bits is provided in each of the X direction and the Y direction for all three colors of RGB in all pixels, the capacity of the correction data memory 60 is at least represented by the following equation (3). Such an amount is necessary. However, if the control points are set as shown in the figure, the capacity shown by the following equation (4) is sufficient. Further, not only the capacity but also the work time required for image correction is greatly reduced.

(8 × 2 × 3) × (640 × 480) × 2/8 = 3,686,400 (bytes) (3) (8 × 2 × 3) × (11 × 15) × 2 / 8 = 1980 (bytes) ... (4)

The control points need not necessarily be set in a grid pattern as shown in the figure, but may be set at any other position other than the grid pattern.

Next, referring to FIG. 13 and FIG. 14, when the control points are set in a grid pattern as shown in FIG. 12, a method of obtaining the movement amount at an arbitrary pixel in each divided area Will be described. FIG. 13 is a diagram for explaining a method of obtaining the movement amount by interpolation, and FIG. 14 is a diagram for explaining a method of obtaining the movement amount by extrapolation. Here, the interpolation refers to a method of interpolating a movement amount of an arbitrary pixel located inside a plurality of control points, and the extrapolation refers to an arbitrary position located outside a plurality of control points. It refers to a method of interpolating the movement amount in a pixel. Note that it is possible to obtain all the pixels by extrapolation, but extrapolation can be used only when obtaining the pixels in the area around the screen (the hatched area shown by the dotted line in FIG. 12). desirable. As described above, in general, extrapolation is used in the divided area around the screen including the outer frame of the entire image area, and interpolation is used in other cases. It can be represented by an arithmetic method. In these figures, the coordinates of the four control points are (X0, Y0), (X1, Y0), (X0, Y
1), (X1, Y1), and the movement amounts corresponding to the respective correction data are (F00, G00), (F10, G1).
0), (F01, G01), (F11, G11). At this time, the movement amount (Fd, Gd) at a pixel at an arbitrary coordinate (Xd, Yd) is calculated by the following equation (5).
(6). These expressions are
It can be used commonly for interpolation and extrapolation.

Fd = ｛(X1−Xd) × (Y1−Yd) × F00 + (Xd−X0) × (Y1−Yd) × F10 + (X1−Xd) × (Yd−Y0) × F01 + (Xd−X0) × (Yd−Y0) × F11｝ / {(X1−X0) × (Y1−Y0)} (5) Gd = {(X1−Xd) × (Y1−Yd) × G00 + (Xd−X0) × (Y1−Yd) × G10 + (X1−Xd) × (Yd−Y0) × G01 + (Xd−X0) × (Yd−Y0) × G11｝ / {(X1−X0) × (Y1−Y0)} (6)

Note that the operations shown in these equations (5) and (6) are also estimation methods based on linear interpolation, but the estimation method is not limited to linear interpolation, and other operation methods may be used. You can go there.

When each grid point is set as a control point as described above, correction data is given to each grid point.
For example, if only the left divided image is considered, the initial state movement amount Fr (i, j) for each grid point (i, j) (i = 1 to 11, j = 1 to 15), Gr (i,
j), Fg (i, j), Gg (i, j), Fb (i, j)
j) and Gb (i, j). This movement amount is stored in the correction data memory 60 as correction data in an initial state.

Next, with reference to FIGS. 15 to 19, a description will be given in detail of the conversion processing of the number of pixels accompanying the enlargement of the image performed by the DSP circuit 55 together with the correction of the image data.

Conversion of image enlargement and image sampling frequency (number of pixels) (conversion between image standards with different resolutions)
Both are realized by performing, for each pixel position of the original image, an operation for obtaining data of a pixel that did not exist in the original image. This calculation can be performed using an “interpolation filter” described later.

FIG. 15 is an explanatory diagram showing an example of an original image before the image is enlarged. The circles in the figure represent the positions of the pixels. This original image includes eight pixels in the horizontal direction and six pixels in the vertical direction. It should be noted that the number of pixels is set to a small number in the figure for ease of explanation. Next, this original image is, for example, 10/7 (approximately 1.4) in the vertical and horizontal directions.
29) A case where the magnification is doubled will be described. The magnification here indicates not the area but the length ratio.

FIG. 16 is an explanatory diagram showing an example of an enlarged image of the original image shown in FIG. The image shown in this figure was obtained by enlarging without changing the display standard of the original image, and the pixel arrangement (the interval between adjacent pixels, etc.)
It is kept the same as the original image (the interval between adjacent pixels is 1 in the figure). However, here, the magnification of the image is (1
0/7), the length of one side of the image is about 1.42.
9 times, and the number of pixels increases by about 1.429 ² times. For example, in the original image shown in FIG. 15, the number of pixels in each pixel row in the horizontal direction is 8, but in the enlarged image shown in FIG. 16, the number of pixels is 11 or 12 (8 × 10/7).
= An integer close to 11.429). Therefore, the positional relationship between each pixel position in the original image and the positional relationship between each pixel corresponding to the same portion of the original image in the enlarged similar image are different from each other. The value is different from the original image.

FIG. 17 shows the relationship between each pixel position in the horizontal direction (horizontal direction) in the original image and each pixel position in the enlarged image. In the figure, the upper Ri (i =
..) Represent pixel data of the original image, and the lower Qi (i = 1, 2,...) Represents pixel data of the enlarged image. . The pixels corresponding to Ri are arranged at an interval (10/7) times the interval between the pixels corresponding to Qi. FIG. 17 shows only the state of enlargement in the horizontal direction, but the same applies to the vertical direction (vertical direction), and a description thereof will be omitted. As will be described later, the value of the data of each pixel after enlargement depends on the correspondence relationship with the position of each pixel of the original image as shown in FIG. From the value,
It can be calculated by performing an operation using an “interpolation filter”, that is, a convolution operation of an interpolation function.

Next, a case where the sampling frequency is increased by, for example, (10/7) without changing the size of the image with reference to FIG. This conversion of the sampling frequency is equivalent to conversion to an image standard whose resolution is (10/7) times higher. That is, the number of pixels in the horizontal direction is (10/7)
Changed to double. In this case, the original image shown in FIG.
As shown in FIG. 18, the image is one-dimensionally converted into an image having about 1.429 times the number of pixels, that is, an area density of 1.429 ² times.

The correspondence between each pixel in FIG. 15 and each pixel in FIG. 16 and the correspondence between each pixel in FIG. 15 and each pixel in FIG. 18 are as shown in FIG. Therefore, the operation for converting to an image standard having a large number of pixels can be performed in the same manner as the above-described image operation.

As described above, when the image is enlarged and the sampling frequency (the number of pixels) of the image is converted, an interpolation filter for calculating the data of the pixel at a position not existing in the original image is used. Required.

Next, a calculation method using an interpolation filter will be described with reference to FIG.

The sampling interval (the interval between adjacent pixels) of the original image is S, and the distance (phase) from the position of the pixel R of the original image is S.
Assuming that the position separated by P is the position (interpolation point) of the pixel Qi generated by interpolation, the value of the pixel Qi can be calculated by a convolution operation on the pixel value R of the original image around the pixel Qi. . Here, according to the “sampling theorem”, when performing ideal “interpolation”, the sinc function as represented by the following equation (7) and FIG. ), A convolution operation is performed from a pixel in the past in the infinite time to a pixel in the future in the infinite time. In the equation (7), π indicates the pi.

F (x) = sinc (π × x) = sinc (π × x) / (π × x) (7)

However, in an actual operation, it is necessary to calculate an interpolated value within a finite time. Therefore, an interpolation function that approximates a sinc function within a finite range is used. As an approximation method, a “nearest neighbor approximation method”, a “bilinear approximation method”, a “Cubic approximation method”, and the like are generally known.

In the nearest neighbor approximation method, the following equation (8) is used.
Using the interpolation function as shown in FIG. 19B, data of one pixel after interpolation is calculated from data of one pixel of the original image. The variable x in the equation (8) and FIG. 19B is a horizontal displacement from the pixel position of the original image.
It represents the amount normalized by the sample interval of the original image.

[0092]

(Equation 1)

In the bilinear approximation method, data of one pixel after interpolation is calculated from data of two pixels of the original image by using an interpolation function as shown in Equation (9) and FIG. 19C. . Note that the variable x in Equation (9) and FIG.
It is assumed that the displacement in the horizontal direction from the pixel position of the original image represents an amount normalized by the sample interval of the original image. The bilinear approximation method is well known as "linear interpolation", and a weighted average is calculated.

[0094]

(Equation 2)

In the Cubic approximation method, equation (10)
And an interpolation function as shown in FIG.
The data of one pixel after interpolation is calculated from the data of four pixels of the original image. Note that the variable x in Expression (10) and FIG. 19D represents an amount obtained by normalizing the horizontal displacement from the pixel position of the original image by the sampling interval of the original image.

[0096]

(Equation 3)

A convolution operation using these functions is as follows:
This can be performed using a so-called FIR (Finite Impulse Respons) digital filter. In this case, the center of the interpolation function is set to the interpolation point, and a value obtained by sampling the interpolation function at the sampling points of the original image nearby by a predetermined number of pixels is used as an interpolation filter coefficient set.

For example, in the case where the interpolation operation is performed by the bilinear approximation method, when the phase P is 0.0, the two weights (filter coefficients) constituting the filter coefficient set are 1.0 and 0.0. , A coefficient set that outputs the data value of the pixel of the original image at the same position as it is. When the phase P is 0.5, the two filter coefficients are set to 0.
5 and 0.5, and when the phase P is 0.3, the two filter coefficients are 0.7 and 0.3.

When the interpolation operation is performed by the cubic approximation method, when the phase P is 0.0, the four weights (filter coefficients) constituting the filter coefficient set are 0.0,
The coefficient set is 1.0, 0.0, and 0.0, and is a coefficient set that directly outputs the data value of the pixel of the original image whose position matches. When the phase P is 0.5, the four filter coefficients are -0.125, 0.625, 0.62
5 and -0.125, and when the phase P is 0.3, the four filter coefficients are -0.063, 0.84
7, 0.363 and -0.147.

In the actual calculation, since the phase P with the pixel of the original image is different for each interpolation point for calculating the data, a plurality of sets of filter coefficients corresponding to different phases are required. Such arithmetic processing is what the DSP circuit 55 is good at.

In the present embodiment, the DSP circuit 5
The image enlargement process performed in step 5 is to increase the number of pixels without changing the size of the image.

Next, the luminance correction processing will be described with reference to FIGS.

In the above-described image correction, the positional correction of the image is performed by controlling the image data so that the left and right divided screens are properly joined. In the present embodiment, the left and right divided screens are further corrected. In order to adjust the luminance in the overlapping area OL of the divided screen, the luminance modulation processing is performed on the pixels corresponding to the overlapping area OL. FIG. 20 is an explanatory diagram showing an outline of the modulation for the image data, and three-dimensionally shows the relationship between the position of each divided screen and the modulation waveform. In the figure, the portion indicated by reference numeral 81 corresponds to the left divided screen, and the portion indicated by reference numeral 82 corresponds to the right divided screen.

In this embodiment, the modulation waveform 80 shown in FIG.
As shown by L and 80R, in each of the divided screens 81 and 82, image output is started from the start points P1L and P1R of the overlap area OL, the output amplitude is gradually increased, and the end points P2L and P2R.
Then, the modulation correction of the luminance of the image data is performed so that the image output amount becomes the maximum, and thereafter, the modulation amount is maintained up to the screen edge in the area other than the overlapping area OL. Such modulation is simultaneously performed on each of the divided screens 81 and 82, and the overlapping area OL is obtained.
Then, by controlling the sum of the luminances of the two screens to be constant everywhere, the joint between the two screens can be made inconspicuous.

The modulation control of the luminance in the overlapping area OL will be considered in more detail. Generally, the brightness of a cathode ray tube is proportional to the cathode current Ik of the electron guns 31L and 31R (FIG. 1). The relationship between the cathode current Ik and the cathode drive voltage Vk applied to the cathodes of the electron guns 31L and 31R is expressed by the following equation (11). In equation (11), γ
(Gamma) is a constant peculiar to a cathode ray tube.
The value is around 6. As described above, since the cathode drive voltage Vk and the cathode current Ik have a non-linear relationship, when the luminance of the input image data is modulated, the modulation amount is determined in consideration of the gamma characteristic. Must have done it.

[0106]

(Equation 4)

FIG. 21 shows a cathode current I corresponding to luminance.
FIG. 6 is a diagram illustrating an example of a relationship between k and a waveform of a luminance modulation amount. The horizontal axis in the figure indicates the position in the overlapping area OL, where the starting points P1L and P1R of the overlapping area OL are set as the origin, and the end points P2L and P2R are normalized to 1.0. The vertical axis in the figure indicates the modulation amount. As shown in the figure, for example, in order to make the slope of the luminance (cathode current Ik) linear in each of the divided screens 81 and 82, the modulation waveform 80 has an upwardly convex curve. Here, the modulation waveform 80
Corresponds to the waveform in the overlapping area OL of the modulation waveforms 80L and 80R shown in FIG.
This is obtained from the following equation (12) based on 1). The equation (12) is a function using the cathode current Ik as a variable. In the equation (12), the following equation (13) is obtained when Ik = x. Modulated waveform 80 in FIG.
Is represented by the equation (13). By performing such modulation simultaneously on the image data for each of the divided screens 81 and 82, the sum of the luminance in the overlapping area OL can be made constant as a result.

[0108]

(Equation 5)

[0109]

(Equation 6)

FIG. 22 shows a cathode current I corresponding to luminance.
FIG. 9 is a diagram illustrating another example of the relationship between k and the waveform of the modulation amount of luminance. In FIG. 21, the brightness gradient is linear in each of the divided screens 81 and 82, but a function in which the derivative (derivative) of the change in the brightness (cathode current Ik) at both ends of the overlapping area OL becomes zero. Modulation that becomes (for example, a cosine function) is also possible. In the example of FIG. 22, the cathode current Ik corresponding to the luminance is a function represented by {1/2 (1-cosπx)}. Therefore, the modulation waveform 8 shown in FIG.
0 'is represented by the following equation (4). By performing such luminance modulation, the apparent luminance change in the overlapping area OL becomes more natural, and the margin for the positional error of the superposition of the left and right divided screens is larger.

[0111]

(Equation 7)

A function in which the derivative (derivative) of the luminance change becomes zero as shown in FIG. 22 can be considered innumerable. Good.

In the brightness control described above, the DSP circuit 55 actually controls the brightness modulation of the left and right image data based on the instruction from the control unit 62. The luminance-modulated left and right image data are reflected in a cathode drive voltage applied to a cathode (not shown) disposed inside each of the electron guns 31L and 31R. Thereby, the electron beams eBL and eBR based on the image data modulated in luminance are emitted from the electron guns 31L and 31R.

As described above, according to the present embodiment, the image data is displayed by the DSP circuits 55L1 and 55R1 such that the left and right divided screens are appropriately joined and displayed in the horizontal direction (first direction). Is performed in the horizontal direction, and the image data output from the DSP circuits 55L1 and 55R1 is changed in the vertical direction (second direction) by appropriately changing the order of the write address and the read address for the frame memories 56L and 56R. The image is appropriately converted so as to be in a state suitable for performing the correction operation, and then the frame memories 56L and 55R2 are displayed by the DSP circuits 55L2 and 55R2 so that the left and right divided screens are properly joined and displayed in the vertical direction. Since the calculation for correcting the image data read from the 56R in the vertical direction is performed, the With correction calculation which is easily, it is possible to perform good image display by connecting the left and right divided screens so inconspicuous seam portion. Also,
The cathode ray tube of the present embodiment has two electron guns 31L, 31L.
Since image display is performed using R, the distance from the electron gun to the phosphor screen can be shorter than that of a cathode ray tube using a single electron gun, and the depth can be reduced. Therefore, it is possible to perform image display with good focus characteristics (small image magnification). Further, two electron guns 31L, 31
Since R is provided, it is possible to easily increase the brightness and to reduce the size despite the large screen.

Further, according to the present embodiment, based on the correction data for correcting the display state of the image obtained from the image displayed on the screen, the image is displayed so as to be properly displayed. Since data correction is performed and the corrected image data is output as display image data, image distortion and misconvergence are reduced as compared with a method of adjusting an image using a deflection yoke or the like. Can be done. For example, in order to eliminate image distortion or the like using a deflection yoke or the like, it is necessary to deflect the deflection magnetic field, and there is a problem that the magnetic field is not a uniform magnetic field. In the present embodiment, it is not necessary to adjust the image distortion or the like with the magnetic field of the deflection yoke, and the deflection magnetic field can be a uniform magnetic field, so that the focus characteristics can be improved. Also, once you have created all the correction data,
By storing the correction data, correction of image distortion and the like can be automatically performed thereafter.

Further, according to the present embodiment, there is no need to develop and design a special deflection yoke used for correcting image distortion and the like, and the development time and cost of the deflection yoke can be reduced. Further, in the conventional method of adjusting with a deflection yoke or the like, since the correction amount of image distortion or the like is not so large, the cathode ray tube is adjusted so that image distortion or the like caused by manufacturing variation of the deflection yoke or the like is suppressed to some extent. Although it is necessary to suppress variations in assembly, in the present embodiment, a large amount of correction for image distortion and the like can be obtained, so that the assembly accuracy can be reduced and manufacturing costs can be reduced. If the influence of an external magnetic field such as terrestrial magnetism is known in advance, the information can be used as correction data, and an image with more excellent characteristics can be displayed.

As described above, according to the present embodiment, high-quality image display can be performed at a low cost by correcting a display state defect such as image distortion. Therefore, it is possible to optimally perform correction of image distortion and the like for a cathode ray tube having a wide angle and a flat surface. Further, according to the present embodiment, since the image processing relating to the joint between the left and right divided screens is performed on the memory, the image display state may change every moment as time passes. Accordingly, appropriate image display can be performed so that the joint between the left and right split screens is not noticeable.

[Second Embodiment] Next, a second embodiment of the present invention will be described.
An embodiment will be described. In the following description, the same portions as the components in the first embodiment are denoted by the same reference numerals, and the description will be appropriately omitted.

In the first embodiment, the case where the line scanning by the electron beams eBL and eBR is performed in the horizontal direction, and the field scanning is performed from the top to the bottom, is described in the present embodiment. As shown in (1), line scanning by each of the electron beams eBL and eBR is performed from top to bottom (Y direction in the figure), and field scanning is performed in a direction opposite to each other in a horizontal direction from the center of the screen to the outside ( (X1 and X2 directions in the figure). As described above, in the present embodiment, the line scanning and the field scanning by the electron beams eBL and eBR are exactly reversed from the first embodiment.

FIG. 24 is an explanatory diagram showing a specific example of arithmetic processing performed on image data for the left divided screen in the cathode ray tube of the present embodiment. In this embodiment, the configuration of the processing circuit for performing the arithmetic processing on the image data for the left divided screen is the same as that of the processing circuit shown in FIG. FIG. 24A shows image data read from the frame memory 53 and input to the DSP circuit 55L1 in the present embodiment. DS
The image data input to the P circuit 55L1 is the same as that described with reference to FIG. 3A in the first embodiment. For example, image data of 640 horizontal pixels × 480 vertical pixels is input. .

FIG. 17B shows the case where D
The output from the SP circuit 55L1, the frame memory 56L
2 shows image data to be written. DSP circuit 5
5L1 is the same as that described with reference to FIG. 3B in the first embodiment, except that the horizontal 352 pixels × vertical 480 pixels data indicated by the hatched area in FIG. An arithmetic process involving correction of the direction (first direction) is performed. By this arithmetic processing, as shown in FIG. 7B, for example, the horizontal direction of the image is enlarged from 352 pixels to 480 pixels, and image data of 480 pixels × 480 pixels is created. This calculation process is the same as that of the first embodiment. When the DSP circuit 55L1 enlarges an image, the DSP circuit 55L1 simultaneously performs a horizontal process based on the correction data stored in the correction data memory 60. An arithmetic process for correcting image distortion and the like is performed.

The DSP circuit 55L1 has the overlapping area O
Calculation processing for luminance modulation correction in L is also performed. In FIG. 7B, a modulation waveform 80L representing the correction of the luminance in the left divided screen is shown corresponding to the image data. Note that the luminance correction processing may be performed before performing arithmetic processing for correcting enlargement of an image, image distortion, or the like, or may be performed after performing these arithmetic processing.

The frame memory 56L has a DSP circuit 5
The image data processed in 5L1 is stored for each color according to the control signal Sa3L indicating the write address generated in the memory controller 63.
In the example of FIG. 3B, image data is sequentially written rightward starting from the upper left corner. Frame memory 56L
Is a control signal Sa indicating a read address generated by the memory controller 63.
4L, each color is read out, and the DSP circuit 55L
2 is input. Here, in the present embodiment, the frame memory 56 generated by the memory controller 63 is used.
The order of the write address and the order of the read address for L are different. In the example of FIG. 3B, the read address is such that the image data is sequentially read downward starting from the upper right.

FIG. 17C shows image data read from the frame memory 56L and input to the DSP circuit 55L2. As described above, in the present embodiment, since the order of the read addresses for the frame memory 56L is downward starting from the upper right, the image input to the DSP circuit 55L2 is shown in FIG. 90 ° counterclockwise with respect to the state of the image indicated by
The image is transformed so as to rotate.

The DSP circuit 55L2 has a frame memory 5
The arithmetic processing including the correction in the vertical direction (second direction) is performed on the data (480 pixels in the horizontal direction × 480 pixels in the vertical direction) read from 6L ((C) in the same figure). By this arithmetic processing, for example, as shown in FIG.
It is enlarged from 0 pixels to 640 pixels, and 640 pixels wide x
Image data of 480 vertical pixels is created. DSP circuit 5
The 5L2 performs an arithmetic process for correcting vertical image distortion or the like based on the correction data stored in the correction data memory 60 at the same time when the image is enlarged.

By scanning the electron beam eBL from top to bottom on the basis of the image data (FIG. 14D) obtained through the above-described arithmetic processing, the left side of the fluorescent screen 11 The screen is displayed as shown in the hatched area in FIG. In the present embodiment, as described above, since the correction processing is performed on the input image data in consideration of the image distortion and the like, the left image displayed on the phosphor screen 11 has no image distortion or the like. Appropriate image display is performed.

FIG. 25 is an explanatory diagram showing a specific example of the arithmetic processing performed on the image data for the right divided screen in the cathode ray tube of the present embodiment. In this embodiment, the configuration of the processing circuit for performing the arithmetic processing on the image data for the right divided screen is the same as the processing circuit shown in FIG. FIG. 25A shows image data read from the frame memory 53 and input to the DSP circuit 55R1 in the present embodiment. DS
The image data input to the P circuit 55R1 is the same as that described with reference to FIG. 4A in the first embodiment. For example, image data of 640 (horizontal) × 480 (vertical) pixels is input. .

FIG. 17B shows the case where D
Output from the SP circuit 55R1, the frame memory 56R
2 shows image data to be written. DSP circuit 5
5R1 is the same as that described with reference to FIG. 4B in the first embodiment, except that the horizontal 352 pixels × vertical 480 pixels data indicated by the hatched area in FIG. Performs arithmetic processing with direction correction. By this calculation processing, for example, the horizontal direction of the image is enlarged from 352 pixels to 480 pixels as shown in FIG.
Image data of pixels × 480 pixels vertically is created. This calculation process is the same as that of the first embodiment. When the DSP circuit 55R1 enlarges an image, the DSP circuit 55R1 simultaneously performs a horizontal operation based on the correction data stored in the correction data memory 60. An arithmetic process for correcting image distortion and the like is performed.

The DSP circuit 55R1 has the overlapping area O
Calculation processing for luminance modulation correction in L is also performed. In FIG. 7B, a modulation waveform 80R representing the correction of the luminance in the right divided screen is shown corresponding to the image data. Note that the luminance correction processing may be performed before performing arithmetic processing for correcting enlargement of an image, image distortion, or the like, or may be performed after performing these arithmetic processing.

The frame memory 56R contains the DSP circuit 5
The image data processed in 5R1 is stored for each color according to the control signal Sa3R indicating the write address generated in the memory controller 63.
In the example of FIG. 3B, image data is sequentially written rightward starting from the upper left corner. Frame memory 56R
Is a control signal Sa indicating a read address generated by the memory controller 63.
4R, each color is read out, and the DSP circuit 55R
2 is input. Here, in the present embodiment, the frame memory 56 generated by the memory controller 63 is used.
The order of the write address and the order of the read address for R are different. In the example of FIG. 3B, the read address is such that the image data is sequentially read downward starting from the upper left corner.

FIG. 17C shows image data read from the frame memory 56R and input to the DSP circuit 55R2. As described above, in the present embodiment, the order of the read addresses for the frame memory 56R is downward starting from the upper left as a starting point. Therefore, the image input to the DSP circuit 55R2 is shown in FIG. The image is mirror-inverted with respect to the state of the image indicated by, and the image is converted so that the inverted image is rotated counterclockwise by 90 °.

The DSP circuit 55R2 has a frame memory 5
The arithmetic processing including the vertical correction is performed on the data of 480 pixels horizontally × 480 pixels vertically read from 6R (FIG. 10C). As a result of this calculation processing, for example, as shown in FIG.
The image data is enlarged to 0 pixels, and image data of 640 horizontal pixels × 480 vertical pixels is created. When the image is enlarged, the DSP circuit 55R2 simultaneously performs an arithmetic process for correcting vertical image distortion and the like based on the correction data stored in the correction data memory 60.

The scanning of the electron beam eBR is performed from top to bottom based on the image data ((D) in the figure) obtained through the above-described arithmetic processing, so that the right side on the phosphor screen 11 is The screen is displayed as shown in the hatched area in FIG. In the present embodiment, as described above, since the input image data is subjected to the correction processing in consideration of image distortion and the like, the right image displayed on the phosphor screen 11 has no image distortion or the like. Appropriate image display is performed. The left and right split screens shown in FIG. 24 (E) and FIG.
Since each image distortion or the like has been corrected, it is possible to perform an appropriate image display in which the joint portion is inconspicuous when the left and right screens are joined.

FIG. 26 is a table showing an image displayed on the phosphor screen 11 after the grid-like reference image shown in FIG. 5 is corrected by the processing circuit shown in FIG. 2 in the present embodiment. An example is shown. In this figure, the divided screen on the left side corresponds to the screen shown in FIG. 24 (E), and has 480 horizontal pixels × 640 vertical pixels, and 11 horizontal blocks ×
It is divided into 16 vertical blocks. In this figure, the right divided screen corresponds to the screen shown in FIG. 25 (E), and the number of blocks is the same as that on the left.

In this embodiment, as described in the first embodiment with reference to FIGS. 6, 12 and the like, when each grid point shown in FIG. Since correction data is given to a point, for example, if only the left divided image is considered, for each grid point (i, j) (i = 1 to 11, j = 1 to 15), The movement amounts Fr (i, j), Gr (i, j) in the initial state,
Fg (i, j), Gg (i, j), Fb (i, j), G
b (i, j) is given. This movement amount is stored in the correction data memory 60 as correction data in an initial state.

As described above, according to the present embodiment, for example, line scanning by each of the electron beams eBL and eBR is performed from top to bottom, and field scanning is performed horizontally from the center of the screen to the outside. In a case where the images are directed in opposite directions, the left and right divided screens can be connected to each other so that the joint portion is not conspicuous, and an image can be displayed satisfactorily.

The other configurations, operations, and effects of this embodiment are the same as those of the first embodiment.

The present invention is not limited to the above embodiments, and various modifications can be made. For example, in each of the above embodiments, a cathode ray tube capable of color display has been described. However, the present invention can also be applied to a cathode ray tube that performs monochrome display. Further, in each of the above-described embodiments, the case where two electron guns are provided and two scanning screens are connected to form a single screen has been described. Equipped with a gun,
The present invention can be applied to a screen in which one screen is formed by combining three or more scanning screens. In each of the above embodiments, the divided screens are partially overlapped with one another.
Although one screen is obtained, one screen may be obtained by simply connecting the ends of the divided screens linearly without providing the overlapping area.

In the first embodiment, as shown in FIG. 1, the line scanning by the electron beams eBL and eBR is performed in opposite directions from the center of the screen toward the outside, and the field scanning is performed. Although the example in which the scanning is performed from top to bottom as in a general cathode ray tube has been described, the scanning direction of each of the electron beams eBL and eBR is not limited to this. It is also possible to do so. In the second embodiment, as shown in FIG. 23, each electron beam e
The field scanning by BL and eBR is performed in the opposite directions from the center of the screen to the outside. In this field scanning, for example, the field scanning is performed from the outside of the screen to the center of the screen. It is also possible. Further, the scanning directions of the electron beams eBL and eBR can be aligned in the same direction.

In each of the above embodiments, the image signal D
An example has been described to use the analog NTSC composite signal as _IN, an image signal D _IN is not limited thereto. For example, an RGB analog signal may be used as the image signal D _IN . In this case, RGB signals can be obtained without passing through the composite / RGB converter 51 (FIG. 2). Further, a digital signal such as used in digital television may be input as the image signal D _IN . In this case, a digital signal can be directly obtained without using the A / D converter 52 (FIG. 2). Regardless of which image signal is used, in the circuit example shown in FIG.
Subsequent circuits may have substantially the same circuit configuration.

In the circuit shown in FIG. 2, the frame memories 56L and 56R are omitted from the configuration, and the DSP circuit 5
Image data output from 5L1 and 55R1 is directly converted to DS
Electron guns 31L, 31 via P circuits 55L2, 55R2
It may be supplied to R. Furthermore, in each of the above embodiments, the input image data is corrected in the horizontal direction and then the vertical correction is performed. Conversely, after the correction in the vertical direction is performed, the Correction may be performed. Further, in each of the above embodiments, the image is enlarged together with the correction of the input image data. However, the image data may be corrected without enlarging the image.

Further, the present invention is not limited to the cathode ray tube, but may be any of various types of image display devices such as a projection type image display device in which an image displayed on a cathode ray tube or the like is enlarged and projected on a screen via a projection optical system. It can be applied to an image display device.

[0143]

As described above, claims 1 to 8 can be used.
19. The image correction apparatus according to claim 1, wherein
According to the image correction method described above or the image display device according to any one of claims 9 to 17, the plurality of divided screens are appropriately connected and displayed in the first direction by the first calculation means. As described above, it is necessary to perform an operation of correcting image data in a first direction and perform an operation of correcting image data output from the first operation unit in a second direction different from the first direction. Image conversion is performed so as to be in a suitable state, and the image is converted by the second arithmetic unit so that the plurality of divided screens are appropriately connected and displayed in a second direction different from the first direction. Since the calculation for correcting the data in the second direction is performed, the correction calculation for the image data becomes easy, and the image is displayed well by connecting a plurality of divided screens so that the joint portion is not conspicuous. There is an effect that it is possible.

According to the image correction device of the seventh aspect or the image display device of the fifteenth aspect, in the image correction device of the fifth aspect or the image display device of the thirteenth aspect, the corrected image data Is calculated using the pixel value at a position shifted by the amount of movement with respect to the representative pixel in the image data before correction in the image data before correction, and the other pixel values in the image data after correction. The pixel value of the pixel is calculated using the pixel value at a position shifted by the amount of movement from the appropriate display position obtained by estimating from the amount of movement of the representative pixel in the image data before correction. Thus, the correction data is given only to the representative pixel, and the correction data for the other pixels can be inferred from the correction data for the representative pixel. As well as a possible reduction of the total amount, an effect that it becomes possible to shorten the working time required for the correction.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing a cathode ray tube which is an example of an image display device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a signal processing circuit in the cathode ray tube shown in FIG.

FIG. 3 is an explanatory diagram showing a specific example of arithmetic processing performed on image data for a left divided screen in the processing circuit shown in FIG. 2;

FIG. 4 is an explanatory diagram showing a specific example of arithmetic processing performed on image data for a right divided screen in the processing circuit shown in FIG. 2;

FIG. 5 is an explanatory diagram showing an example of a reference image used for correcting image data in the cathode ray tube shown in FIG.

FIG. 6 is an explanatory diagram showing a display example when the reference image shown in FIG. 5 is displayed on the cathode ray tube shown in FIG. 1;

FIG. 7 is an explanatory diagram schematically showing correction data used in the processing circuit shown in FIG. 2;

FIG. 8 is an explanatory diagram showing a state of deformation of an input image when a correction operation using correction data is not performed in the processing circuit shown in FIG. 2;

FIG. 9 is an explanatory diagram showing a state of deformation of an input image when a correction operation using correction data is performed in the processing circuit shown in FIG. 2;

FIG. 10 is an explanatory diagram illustrating a first method of the correction operation processing in the processing circuit illustrated in FIG. 2;

FIG. 11 is an explanatory diagram showing a second method of the correction operation processing in the processing circuit shown in FIG. 2;

FIG. 12 is an explanatory diagram illustrating control points used in a third method of the correction calculation processing in the processing circuit illustrated in FIG. 2;

13 is an explanatory diagram illustrating interpolation used in a third method of the correction calculation processing in the processing circuit illustrated in FIG. 2;

FIG. 14 is an explanatory diagram illustrating extrapolation used in a third method of the correction calculation processing in the processing circuit illustrated in FIG. 2;

15 is a diagram for describing conversion of the number of pixels performed in the processing circuit illustrated in FIG. 2, and is an explanatory diagram illustrating an example of an original image before image enlargement and the like are performed.

FIG. 16 is an explanatory diagram showing an example of an image obtained by enlarging the size of the original image shown in FIG.

17 is a diagram showing a relationship between a pixel position in the original image shown in FIG. 15 and a pixel position in the enlarged image shown in FIG. 16;

FIG. 18 is an explanatory diagram showing an example of an image obtained by enlarging the number of pixels with respect to the original image shown in FIG.

19 is an explanatory diagram illustrating an example of a function used for an interpolation filter for converting the number of pixels performed in the processing circuit illustrated in FIG. 2;

20 is an explanatory diagram three-dimensionally showing a relationship between a position of each divided screen and a modulation waveform of luminance in the cathode ray tube shown in FIG. 1;

21 is an explanatory diagram showing an example of a relationship between a cathode current corresponding to luminance and a modulation waveform in the cathode ray tube shown in FIG.

22 is an explanatory diagram showing another example of a relationship between a cathode current corresponding to luminance and a waveform of a modulation voltage in the cathode ray tube shown in FIG.

FIG. 23 is an explanatory diagram showing a scanning direction of an electron beam of a cathode ray tube which is an example of an image display device according to a second embodiment of the present invention.

FIG. 24 is an explanatory diagram showing a specific example of arithmetic processing performed on image data for the left divided screen in the second embodiment of the present invention.

FIG. 25 is an explanatory diagram showing a specific example of arithmetic processing performed on image data for a right divided screen in the second embodiment of the present invention.

FIG. 26 is an explanatory diagram showing a display example when displaying an image based on the reference image shown in FIG. 7 in the second embodiment of the present invention.

[Explanation of symbols]

eBL, eBR: electron beam, OS: overscanning area, 10
... panel part, 11 ... phosphor screen, 12 ... color selection mechanism, 13 ...
Frame, 14: support spring, 20: funnel, 21
L, 21R: deflection yoke, 22: internal conductive film, 23: external conductive film, 30L, 30R: neck portion, 31L, 31R
... Electron gun, 32L, 32R ... Convergence yoke, 5
1: Composite / RGB converter, 52: A / D converter, 53, 56L, 56R: Frame memory, 54, 6
3. Memory controller, 55L1, 55L2, 55R
1, 55R2: DSP circuit, 57L, 57R: D / A converter, 60: correction data memory, 62: control unit, 64: imaging device.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 5/68

Claims (18)

(57) [Claims] 1. A method for correcting an image displayed on an image display device which forms a single screen by joining a plurality of divided screens and displays an image based on input image data. An image correction device, comprising: a first calculation unit that performs a calculation to correct the image data in the first direction so that the plurality of divided screens are appropriately connected and displayed in a first direction; Conversion means for performing image conversion on the image data output from the first calculation means so as to be in a state suitable for performing a calculation for correcting the image data in a second direction different from the first direction; A second calculating means for performing a calculation for correcting the image data output from the converting means in the second direction so that the plurality of divided screens are properly connected and displayed in the second direction. Equipped An image correction device characterized by the following. 2. The image processing apparatus according to claim 1, wherein the converting unit stores the image data output from the first arithmetic unit in an order according to a write address, and stores the stored image data in an address in the same or different order from the write address. Image data storage means readable according to the following, and a write address of image data to the image data storage means is generated, and a read address of the image data stored in the image data storage means is the same as or different from the order of the write addresses. 2. An address generating means capable of generating addresses in order.
The image correction device according to the above. 3. The first arithmetic means performs an arithmetic operation for correcting the image data in the first direction and an arithmetic operation for enlarging an image in the first direction. 2. The image correction apparatus according to claim 1, wherein a calculation is performed to correct the image data in the second direction, and a calculation is performed to enlarge the image in the second direction. 4. The image correction apparatus according to claim 1, wherein a plurality of said first calculation means and a plurality of said second calculation means are provided corresponding to each of said plurality of divided screens. 5. The image processing apparatus according to claim 1, wherein the first calculating unit and the second calculating unit are configured to correct the image data based on correction data for correcting a display state of an image obtained from an image displayed on a screen. 2. The image correction apparatus according to claim 1, wherein an operation for correcting is performed. 6. The correction data is data relating to a movement amount of each pixel from an appropriate display position in discretized two-dimensional image data representing an image displayed on a screen, and wherein the first calculation is performed. Means that each pixel value of the corrected image data corrected by the means and the second calculation means is calculated using the pixel value at a position shifted by the movement amount in the image data before correction. Claim 5
The image correction device according to the above. 7. The correction data is data relating to an amount of movement from a proper display position for each of a plurality of representative pixels in discretized two-dimensional image data representing an image displayed on a screen. The pixel value of each of a plurality of representative pixels in the corrected image data corrected by the first calculation unit and the second calculation unit is:
The pixel values of pixels other than the representative plurality of pixels in the corrected image data are calculated using a pixel value at a position shifted by the moving amount with respect to the representative pixel. 6. The image data is calculated by using a pixel value at a position shifted by an amount of movement from an appropriate display position estimated from the amount of movement of the representative pixel. The image correction device according to the above. 8. The image display device is a cathode ray tube including a plurality of electron guns for emitting a plurality of electron beams, and the plurality of divided screens are scanned by scanning a plurality of electron beams emitted from the electron gun. The image correction apparatus according to claim 1, wherein the image is formed and the image is displayed. 9. An image display apparatus which forms a single screen by joining a plurality of divided screens and performs image display based on input image data, wherein the plurality of divided screens are A first operation unit for performing an operation of correcting the image data in the first direction so that the image data is appropriately connected and displayed in a first direction; and an image data output from the first operation unit. Converting means for performing image conversion so as to be in a state suitable for performing a calculation for correcting in a second direction different from the first direction; and A second calculating unit for performing a calculation for correcting the image data output from the converting unit in the second direction so that the image data is connected and displayed, and based on the image data output from the second calculating unit. Was Image display apparatus comprising the image display means an image is displayed. 10. The conversion means stores image data output from the first arithmetic means in an order according to a write address, and stores the stored image data in an address in the same or different order from the write address. Image data storage means readable according to the following, and a write address of image data to the image data storage means is generated, and a read address of the image data stored in the image data storage means is the same as or different from the order of the write addresses. 10. An address generating means capable of generating addresses in order.
The image display device as described in the above. 11. The first arithmetic means performs an arithmetic operation for correcting the image data in the first direction and an arithmetic operation for enlarging an image in the first direction. 10. The image display device according to claim 9, wherein the computer performs an operation of correcting the image data in the second direction, and performs an operation of enlarging an image in the second direction. 12. The image display device according to claim 9, wherein a plurality of said first calculation means and a plurality of said second calculation means are provided corresponding to each of said plurality of divided screens. 13. The image processing apparatus according to claim 1, wherein the first arithmetic unit and the second arithmetic unit are based on correction data for correcting a display state of the image obtained from the image displayed on the screen.
The image display device according to claim 9, wherein an operation for correcting the image data is performed. 14. The correction data is data relating to the amount of movement of each pixel from an appropriate display position in discretized two-dimensional image data representing an image displayed on a screen, and the first operation Means that each pixel value of the corrected image data corrected by the means and the second calculation means is calculated using the pixel value at a position shifted by the movement amount in the image data before correction. Claim 1.
3. The image display device according to 3. 15. The correction data is data relating to an amount of movement of each of a plurality of representative pixels in a discretized two-dimensional image data representing an image displayed on a screen from an appropriate display position. The pixel value of each of a plurality of representative pixels in the corrected image data corrected by the first calculation unit and the second calculation unit is:
The pixel values of pixels other than the representative plurality of pixels in the corrected image data are calculated using a pixel value at a position shifted by the moving amount with respect to the representative pixel. The image data is calculated using a pixel value at a position deviated by an amount corresponding to the amount of movement from an appropriate display position estimated from the amount of movement of the representative pixel.
The image display device as described in the above. 16. A method according to claim 16, further comprising: a plurality of electron guns for emitting a plurality of electron beams, wherein the plurality of divided screens are formed by scanning the plurality of electron beams emitted from the electron gun, and the image display is performed. The image display device according to claim 9, wherein: 17. The image display device according to claim 16, wherein a scanning direction of the plurality of electron beams is a vertical direction. 18. A method for correcting an image displayed on an image display device that forms a single screen by joining a plurality of divided screens and performs image display based on input image data. An image correction method, wherein a first calculation unit performs a calculation for correcting the image data in the first direction so that the plurality of divided screens are appropriately connected and displayed in a first direction. Performing image conversion on the image data output from the first arithmetic unit so as to be in a state suitable for performing an arithmetic operation for correcting the image data in a second direction different from the first direction; Calculating means for correcting the image-converted image data in the second direction so that the plurality of divided screens are properly connected and displayed in a second direction different from the first direction. An image correction method comprising performing an operation.