JP3187787B2 - Image control 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 control apparatus and a method for performing correction of the image.

[0002]

2. Description of the Related Art In an image display device such as a television receiver or a monitor device for a computer, a cathode ray tube (C) is used.
RT) 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 a cathode ray tube having a plurality of electron guns, see, for example,
No. 9-25641, Japanese Patent Publication No. 42-4928, and Japanese Patent Application Laid-Open No. 50-17167. According to such a cathode ray tube having a plurality of electron guns, there is an advantage that a larger screen can be achieved while shortening the depth than a cathode ray tube using a single electron gun.

[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. Furthermore, in the cathode ray tube, the influence of geomagnetism etc. differs depending on the use environment,
Since image distortion and the like occur, the display of the above-mentioned joint portion is also adversely affected. However, in the conventional double electron gun type cathode ray tube, display control of the joint portion in consideration of this use environment is not sufficiently performed. . In the case of a cathode ray tube, the display performance of an image is also deteriorated due to the aging of a processing circuit such as a deflection circuit. Display control is not sufficient. As described above, in the related art, the technology of how to display and control the plurality of divided screens and appropriately join them in consideration of the usage environment and the aging variation is insufficient. There is no guarantee that it will not be seen enough to withstand viewing.

Further, in order to correct image distortion and misconvergence during use of the cathode ray tube and to appropriately connect a plurality of divided screens, the amount of image distortion and misconvergence is measured during use of the cathode ray tube. It is necessary to
Conventionally, measurement of data for correcting such image distortion or the like is generally performed at the time of manufacturing, and measurement is not performed much while a cathode ray tube is used.

The present invention has been made in view of such a problem, and a first object of the present invention is to appropriately connect a plurality of divided screens and display images satisfactorily over the entire screen.
It is to provide an image control device and method, and an image display device capable of the data necessary for earthenware pots get across the screen throughout.

[0012] A second object of the present invention, Rukoto alignment connecting a plurality of split screens so inconspicuous joint portion
It is an object of the present invention to provide an image control device and method and an image display device which can perform image display satisfactorily and can display images satisfactorily over the entire screen .

[0013]

An image control apparatus according to the present invention obtains data relating to a pixel position at a joint portion of each divided screen based on a light or electric signal output from a position detecting means. A position estimating means for estimating data relating to a pixel position in an area other than a joint portion of each divided screen based on the obtained data relating to the pixel position ;
Multiple split screens can be applied based on
It will be connected properly and the whole screen will be displayed properly
Control to correct the image data corresponding to the video signal.
Control means .

Further, the image display device according to the present invention is provided at a position corresponding to a joint portion between adjacent divided screens, and includes a position detecting means for outputting a light or electric signal according to a display state of an image. Based on the light or electric signal output from the position detecting means, data on the pixel position of the joint portion of each divided screen is obtained, and based on the data on the obtained pixel position, A plurality of divided screens are properly connected based on the position estimating means for estimating and estimating the data on the pixel position of the other region other than the joint portion based on the data on each pixel position obtained by the position estimating means , and Whole screen
Control means for controlling image data corresponding to a video signal so that the body is properly displayed, and image display means for displaying an image based on the image data corrected by the control means It is.

Further, according to the image control method of the present invention, based on the light or electric signal output from the position detecting means, data relating to the pixel position of the joint portion of each divided screen is obtained, and the obtained data is obtained. based on the data relating to the pixel position, determined Me guessing data relating the pixel positions of the regions other than the joint portion of each divided screen was determined
Multiple split screens based on data on each pixel location
Are properly connected and the entire screen is displayed properly.
Control to correct the image data corresponding to the video signal
Is performed .

In the image control device and method and the image display device according to the present invention, based on the light or electric signal output from the position detecting means provided at the position corresponding to the joint between adjacent divided screens, Data on the pixel position of the joint portion of each divided screen is obtained, and based on the data on the obtained pixel position, data on the pixel position of the area other than the joint portion of each divided screen is estimated. Desired.

Further, in the image control apparatus and method and the image display apparatus according to the present invention, a plurality of divided screens are properly connected and the entire screen is properly displayed on the basis of the obtained data on each pixel position. Thus, control for correcting the image data is performed.

[0018]

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

[First Embodiment] FIG. 1 is a block 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 selection mechanism 12 made of a thin metal plate arranged so as to face the phosphor screen 11. The color selection mechanism 12 is also called an aperture grill or a shadow mask or the like depending on the type of the color selection mechanism. The outer periphery of the color selection mechanism 12 is supported by a frame 13 and attached to the inner surface of the panel section 10 via a support spring 14. I have. Funnel 2
At 0, an anode unit (not shown) for applying the anode voltage HV is provided. Each of the electron beams e irradiated from the electron guns 31L and 31R is provided on an outer peripheral portion from the funnel portion 20 to each of the neck portions 30L and 30R.
Deflection yokes 21L, 2 for deflecting BL, eBR
1R 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 disposed 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 the tube of the 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). , A rectangular flat plate-like index electrode 70 is provided at a position facing the fluorescent screen 11. Further, in the cathode ray tube, between the index electrode 70 and the phosphor screen 11,
Electron beams eBL and eBR overscanning overscanning region OS
A V-shaped beam shield 27 serving as a shielding member for the electron beams eBL and eBR is arranged so that the light beams reach the phosphor screen 11 and do not emit light carelessly. The beam shield 27 is installed, for example, on the basis of the frame 13 that supports the color selection mechanism 12. The beam shield 27 is
The anode voltage HV is obtained by being electrically connected to the internal conductive film 22 via the frame 13.

As shown in FIG.
As shown in the figure, a notch 7 having an inverted triangular shape in the longitudinal direction.
A plurality of 1s are provided at equal intervals. The index electrode 70 outputs an electrical detection signal according to the incidence of each of the electron beams eBL and eBR. The detection signal output from the index electrode 70 is input to a processing circuit for image correction outside the cathode ray tube (hereinafter, also simply referred to as “outside the tube”), and mainly the electron beams eBL, e.
It is used for controlling image data corresponding to a joint portion of BR. The operation of detecting the scanning positions of the electron beams eBL and eBR using the index electrode 70 and the control of the image data will be described later in detail with reference to FIG.

Here, the index electrode 70 corresponds to a specific example of "position detecting means" and "electron beam detecting means" in the present invention.

In this embodiment, the overscanning area is an area outside each scanning area of the electron beams eBL and eBR forming an effective screen in each scanning area 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.

The index electrode 70 is made of a conductive material such as a metal, and is provided, for example, on a frame 13 via an insulator (not shown). Also,
The index electrode 70 is electrically connected to a resistor R1 connected to the inner surface of the funnel 20, and is supplied with the anode voltage HV via the internal conductive film 22, the resistor R1, and the like. Also, the index electrode 7
Numeral 0 is electrically connected via a lead wire 26 to an electrode 42 inside the tube of a capacitor Cf formed using a part of the funnel section 20. The capacitor Cf is provided in the funnel portion 20 with a region that partially (eg, in a circular shape) that does not cover the internal conductive film 22 and the external conductive film 23, and further includes, for example, a circular electrode 41 in the internal region. , 42 are formed so as to face each other with the funnel portion 20 interposed therebetween.

FIG. 2 is a circuit diagram showing an equivalent circuit of a circuit formed by circuit elements around the index electrode 70. The electrode 41 outside the tube of the capacitor Cf is connected to an amplifier AMP1 for signal amplification. Capacitor C
f between the electrode 41 and the amplifier AMP1.
The input resistance Ri and the input capacitance Ci of MP1 are connected. One ends of the input resistance Ri and the input capacitance Ci are grounded. In the tube, the index electrode 7
A stray capacitance Cs is generated between 0 and the beam shield 27 and the internal conductive film 22 maintained at the anode voltage HV. In this circuit diagram, the index electrode 7
The electron beams eBL, eBR incident on zero are represented as complete current sources IB. In the equivalent circuit shown in this figure, the current source IB, the resistance R1, the stray capacitance Cs, and the input resistance R
i and the input capacitance Ci are connected in parallel in this order, and the capacitor C is connected between the stray capacitance Cs and the input resistance Ri.
f is connected. The positive electrode of the capacitor Cf is connected to the current source IB, the resistor R1, and the positive electrode of the stray capacitance Cs. The negative electrode of the capacitor Cf is connected to the input resistance Ri and the input capacitance Ci.
And the amplifier AMP1.

When the overscanned electron beams eBL and eBR collide (incident and collide) on the index electrode 70, the potential thereof changes from the anode voltage HV (V) to Ib ×
The voltage drops by R (V). In the present embodiment, the signal whose voltage has dropped is guided outside the tube as a detection signal via the capacitor Cf. Note that Ib
Is a current value generated by the flow of the electron beams eBL and eBR. By the way, the cathode ray tube has an electron beam eB
The L and eBR are made to function by scanning, and in the present embodiment, a signal generated by colliding with the index electrode 70 provided at a specific portion in the tube is an intermittent signal. Therefore, the detection signal from the index electrode 70 does not need to be transmitted by DC coupling, but is derived by a transmission path by AC coupling via the capacitor Cf and supplied to a processing circuit for image correction outside the tube. can do.

Here, the capacitance of the capacitor Cf will be examined. The capacitor Cf uses, as its dielectric, a glass material forming a funnel portion 20 which is one of the envelopes forming a cathode ray tube. The relative dielectric constant ガ ラ ス of the glass material used for the funnel portion 20 is generally around 6. Assuming that the thickness of the glass serving as the dielectric constituting the capacitor Cf is 5 mm and the area of each of the electrodes 41 and 42 is 4 cm ² , the dielectric constant ε _{0 of the} vacuum is 8.85 × 1
Since 0 ^-12 [C / Vm], from C = χε ₀ S / d,
The capacitance C of the capacitor Cf becomes 4.25 pF. As will be described later, such a small capacity is sufficient for processing by a processing circuit for image correction outside the tube.

Next, the characteristics of the circuit in the signal path of the detection signal from the index electrode 70 will be described with reference to FIG. FIG. 3 is a characteristic diagram showing frequency characteristics of the equivalent circuit shown in FIG. In this figure, the vertical axis indicates gain (dB), and the horizontal axis indicates frequency (Hz). In this characteristic diagram, in each circuit element in the equivalent circuit shown in FIG. This is obtained when the resistance value of the input resistor Ri is 10 MΩ and the capacitance value of the input capacitor Ci is 1 pF. The following is clear from this characteristic diagram. First, the signal voltage VIN generated at the index electrode 70 starts to attenuate in a high frequency band of several MHz or more, which is due to a shunt effect due to the capacitance Cs. Next, the low-frequency characteristic of the output voltage VOUT input to the amplifier AMP1 is represented by the capacitor Cf and the input resistance Ri.
Is controlled by the cutoff frequency of the high-pass filter composed of In the middle range (10 kHz) or higher, the output voltage V
OUT and the signal voltage VI generated at the index electrode 70
The ratio of N is governed by the voltage division ratio of the capacitor Cf and the input capacitance Ci. In this specific example, several kHz to 10
It can be said that signals can be detected with a substantially flat frequency characteristic up to about MHz. Since the scanning frequency of a normal cathode ray tube is in the range of several kHz to several hundred kHz, this frequency characteristic is sufficient for a signal detection circuit.

FIG. 4 is a block diagram showing a signal processing circuit of the cathode ray tube according to the present embodiment. In this figure, NTSC (National Television System) is used as the image signal D _IN.
2 shows an example of a circuit for inputting an analog composite signal of a (Committee) system and displaying a moving image according to the signal. Here, the signal processing circuit shown in the figure corresponds to a specific example of “image control device” in 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 has a
(Video signal) A composite / RGB converter 51 that converts an analog composite signal that is input one-dimensionally as D _IN into signals for each of R, G, and B and outputs the converted signal, and an output from the composite / RGB converter 51 An analog / digital signal (hereinafter, referred to as “A / D”) converter 5 that converts the analog signals for each color into digital signals and outputs the digital signals.
2 (52r, 52g, 52b) and the A / D converter 5
The frame memory 53 (53r, 5) that stores the digital signal output from the second unit two-dimensionally for each color in frame units.
3g, 53b) and a memory controller 54 for generating a write address and a read address of image data for the frame memory 53. As the frame memory 53, 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 image data for the left divided screen among the image data for each color stored in the frame memory 53.
SP (Digital Signal Processor) circuit 50L, DS
P circuit 55L1, frame memory 56L (56Lr, 5
6Lg, 56Lb), a DSP circuit 55L2, a digital / analog signal (hereinafter referred to as "D / A") converter 57L (57Lr, 57Lg, 57Lb), and image data of each color stored in the frame memory 53. The DSP circuit 50R, the DSP circuit 55R1, and the frame memory 56R that control the image data for the right divided screen.
(56Rr, 56Rg, 56Rb), DSP circuit 55R
2 and D / A converter 57R (57Rr, 57Rg, 5
7Rb). The DSP circuits 50L, 5L
0R is a luminance correction circuit provided mainly for luminance correction. On the other hand, the other DSP circuits 55L1, 55L1,
55L2, 55R1, 55R2 (hereinafter, these four D
The SP circuits are also simply referred to as “DSP circuits 55”. ) Is a circuit for position correction provided mainly for position correction. Details of the functions of these DSP circuits will be described later.

[0035]

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 the display state of an image, and an amplifier AM.
An index signal processing circuit 61 that receives the index signal S2 output from P1 and analyzes the scanning position of the electron beams eBL and eBR from the input index signal S2 and outputs data S3 indicating the analysis result; , The data S3 indicating the analysis result from the index signal processing circuit 61 and the correction data from the correction data memory 60 are input, and the DS for luminance correction is input.
P circuits 50L, 50R and DSP circuit 5 for position correction
Control unit 62 for instructing an arithmetic method and the like to the control unit 5
And a memory controller 63 for generating a write address and a read address of image data for the frame memories 56L and 56R.

In this embodiment, mainly
A / D converter 52, frame memories 53 and 56L,
56R, memory controllers 54 and 63, DSP circuits 50L and 50R for luminance correction, DSP circuit 5 for position correction
5L1, 55L2, 55R1, 55R2, D / A converter
57L and 57R, the index signal processing circuit 61 and the control unit 62 correspond to a specific example of “control means” in the present invention. The index signal processing circuit 61 and the control unit 62 correspond to a specific example of “position estimating means” in the present invention. Further, the correction data memory 60 corresponds to a specific example of “correction data storage unit” in the present invention .

The index signal S2 is a signal corresponding to a detection signal from the index electrode 70. A method of analyzing the scanning positions of the electron beams eBL and eBR using the index signal S2 will be described later in detail.

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 created, for example, at the time of manufacturing a cathode ray tube to correct image distortion and the like in an initial state of the cathode ray tube. The correction data is created by measuring an image distortion amount, a misconvergence amount, and the like of an 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 device (not shown) that creates correction data based on the image captured by the imaging device 64. Data creation means. The imaging device 64 includes, for example, an imaging device such as a CCD (Charge Coupled Device), and images a display screen displayed on the surface of the cathode ray tube for each of R, G, and B colors, and the imaging screen Is output for each color as image data. The correction data creating means is constituted by a microcomputer or the like, and
4, data relating to the amount of movement of each pixel from an appropriate display position in the discretized two-dimensional image data representing the image captured by 4 is created as correction data. The apparatus 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. 11-17 / 1999).
572) can be used. The calculation processing for correcting an image using the correction data will be described later in detail.

The luminance correction DSP circuits 50L and 50R and the position correction DSP circuits 55 (55L1 and 55L)
2, 55R1, 55R2) are each configured by, for example, a one-chip general-purpose LSI (large-scale integrated circuit). DSP circuits 50L, 50R and D
The SP circuit 55 performs various types of arithmetic processing on the input image data in accordance with an instruction from the control unit 62 in order to correct luminance in the overlapping area OL and correct image distortion and misconvergence of the cathode ray tube. It has become.

The control section 62 converts the correction data (first correction data) stored in the correction data memory 60 and the correction data obtained by analyzing the detection signal from the index electrode 70. Based on the DSP circuit 5
The instruction of the operation method is given to each of the 0L, 50R and the DSP circuit 55. The analysis of the detection signal from the index electrode 70 is first performed in the index signal processing circuit 61. Data S3 indicating the analysis result by the index signal processing circuit 61
Is output to the control unit 62. The control unit 62 obtains the above-described correction data based on the data S3 indicating the analysis result output from the index signal processing circuit 61.
Index signal processing circuit 61 and control unit 6
The data for correction obtained by 2 includes data on the pixel position of the joint portion of each divided screen. Further, the control unit 62 estimates and obtains data on the pixel position of the area other than the joint part of each divided screen based on the data on the pixel position of the joint part of each divided screen. . The data relating to these pixel positions is, for example, data indicating a fine movement amount for correcting the correction data stored in the correction data memory 60 in advance. The details of the correction data obtained by analyzing the detection signal from the index electrode 70 will be described later.

The DSP circuit 50L includes a frame memory 53
Of the image data for each color stored in the DSP circuit 55. The image data for the left divided screen is mainly subjected to the luminance correction processing, and the corrected image data is stored in the DSP circuit 55 for each color.
L1. Also, the DSP circuit 55L1
Is a device that performs a positional correction process mainly in the horizontal direction (first direction) on image data for each color output from the DSP circuit 50L and outputs the correction result to the frame memory 56L for each color. It is. DSP circuit 55L2
Performs a positional correction process mainly in the vertical direction (second direction) on the image data for each color stored in the frame memory 56L, and outputs the correction result to the D / A converter 57L for each color. Output.

The DSP circuit 50R includes a frame memory 53
Of the image data for each color stored in the image data for the right divided screen is mainly subjected to the luminance correction processing, and the corrected image data is stored in the DSP circuit 55 for each color.
Output to R1. Also, the DSP circuit 55R1
Is a device that performs a positional correction process mainly in the horizontal direction (first direction) on the image data for each color output from the DSP circuit 50R, and outputs the correction result to the frame memory 56R for each color. It is. DSP circuit 55R2
Performs positional correction processing mainly in the vertical direction (second direction) on the 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. Output.

Each of the D / A converters 57L and 57R converts the calculated image data output from each of the DSP circuits 55L2 and 55R2 into an analog signal, and converts each of the electron guns 31 into an analog signal.
Output to the L, 31R side. Note that each D
A more specific example of the arithmetic processing performed in the SP circuits 55L1, 55L2, 55R1, 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 can generate image data write addresses for the frame memories 56L and 56R, and can generate read addresses for image data stored in the frame memories 56L and 56R in a different order from the write address order. It has become.
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, the DSP
The image data output from the circuits 55L1 and 55R1 is set to an image state suitable for performing the vertical correction operation performed by the DSP circuits 55L2 and 55R2.
Image conversion can be appropriately performed.

Next, the operation of the cathode ray tube configured as described above will be described. The following description also serves as the description of the image control 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. 4, 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 out according to a control signal Sa2 indicating a read address generated by the memory controller 54, and is output to the brightness correction DSP circuits 50L and 50R.

Of the image data for each color stored in the frame memory 53, the image data for the left divided screen is
In the DSP circuit 50L, the DSP circuit 55L1, the frame memory 56L, and the DSP circuit 55L2, the correction data stored in the correction data memory 60 and the correction data obtained by analyzing the detection signal from the index electrode 70 , An arithmetic process for correcting the image is performed. 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
In the DSP circuit 50R, the DSP circuit 55R1, the frame memory 56R, and the DSP circuit 55R2, the correction data stored in the correction data memory 60 and the correction data obtained by analyzing the detection signal from the index electrode 70 , An arithmetic process for correcting the image is performed. The image data for the right divided screen after the arithmetic processing is converted into an analog signal via a D / A converter 57R, and a 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.

When the electron beams eBL and eBR scan the overscanning area OS and strike the index electrode 70, a voltage drop occurs at the index electrode 70, and a signal corresponding to this voltage drop is used as a detection signal as a detection signal in the funnel section 20.
Is guided out of the tube via the capacitor Cf provided in the
An index signal S2 is output from the amplifier AMP1. The index signal processing circuit 61 analyzes the scanning position of the electron beams eBL and eBR based on the index signal S2, and outputs data S3 indicating the analysis result to the control unit 62. Based on the correction data stored in the correction data memory 60 and the data S3 indicating the analysis result from the index signal processing circuit 61, the control unit 62 controls the brightness correction DSP circuits 50L, 50L.
The operation method is instructed to the 50R and the DSP circuit 55 for position correction. The index signal processing circuit 6
The data S3 indicating the analysis result from No. 1 is mainly used for controlling such that the left and right divided screens are appropriately connected and displayed.

FIG. 5 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 50L. As shown in FIG. 3A, image data of, for example, 640 pixels horizontally × 480 pixels vertically is input to the DSP circuit 50L. Of the image data of 640 pixels in width × 480 pixels in height, for example, 62 pixels in the center part (32 pixels on the left side + 32 pixels on the right side) × 4 pixels in the center
The area of 80 pixels is an overlapping area OL of the left and right divided screens. Therefore, of the image data input to the DSP circuit 50L, data of 352 horizontal pixels × 480 vertical pixels indicated by the shaded area in the figure is data for the left divided screen.

FIG. 9B shows the DSP circuits 50L and 50L.
It shows image data written into the frame memory 56L after the image correction processing is performed by the SP circuit 55L1. The DSP circuit 50L includes a DSP circuit 55L1
Before performing the correction processing according to, the luminance of the overlap area OL is corrected for the data of 352 horizontal pixels × 480 vertical pixels indicated by the hatched area in FIG. Calculation processing for 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. The details of the luminance correction process will be described later with reference to FIGS.

On the other hand, after the luminance correction processing by the DSP circuit 50L is performed, the DSP circuit 55L1 applies the horizontal 352 pixels × vertical 480 pixels data indicated by the hatched area in FIG. A calculation process involving (first direction) correction 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. The DSP circuit 55L1 is
When this image is enlarged, at the same time, based on the correction data stored in the correction data memory 60 and the correction data obtained by analyzing the detection signal from the index electrode 70, the horizontal direction The arithmetic processing for correcting the image distortion or 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. The method of converting the number of pixels will be described later in detail with reference to FIGS. I do.

It should be noted that the DSP circuit 50L is omitted from the components, and the luminance correction processing in the DSP circuit 50L is performed by the DS circuit 50L.
The P circuit 55L1 may be performed at the same time as the arithmetic processing for correcting image enlargement and image distortion.

The DSP circuit 5 is stored in the frame memory 56L.
The 0L and the image data processed by the DSP circuit 55L1 are stored for each color in accordance with 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. The image data stored in the frame memory 56L is
In accordance with a control signal Sa4L indicating a read address generated in the memory controller 63, data is read for each color and input to the DSP circuit 55L2. Here, in the present embodiment, 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. In the example of FIG. 3B, the order of the read address is opposite to the write address, and the image data is
The 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
5L2, based on the correction data stored in the correction data memory 60 and the correction data obtained by analyzing the detection signal from the index electrode 70 at the same time when the image is enlarged. , An arithmetic process for correcting vertical image distortion and the like is performed.

The scanning of the electron beam eBL is performed from right to left on the basis of the image data ((D) in the figure) obtained through the above arithmetic processing, so that the left 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 left image displayed on the phosphor screen 11 is an appropriate image without image distortion and the like. The display is made.

FIG. 6 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 50R. Similarly to the DSP circuit 50L, for example, image data of 640 horizontal pixels × 480 vertical pixels is input to the DSP circuit 50R. Of the image data of 640 pixels in width × 480 pixels in height, for example, 62 pixels in the center part (32 pixels on the left side + 32 pixels on the right side) × 4 pixels in the center
The area of 80 pixels is an overlapping area OL of the left and right divided screens. Therefore, of the image data input to the DSP circuit 50R, data of 352 horizontal pixels × 480 vertical pixels shown on the right in the shaded area in the drawing becomes data for the right divided screen.

FIG. 11B shows the DSP circuits 50R and 50D.
This shows image data written to the frame memory 56R after the image correction processing is performed by the SP circuit 55R1. The DSP circuit 50R includes a DSP circuit 55R1.
Before performing the correction processing according to, the luminance of the overlap area OL is corrected for the data of 352 horizontal pixels × 480 vertical pixels indicated by the hatched area in FIG. Calculation processing for 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.

On the other hand, after the luminance correction processing by the DSP circuit 50R is performed, the DSP circuit 55R1 applies the data of 352 horizontal pixels × 480 vertical pixels shown by the hatched area in FIG. A calculation process involving (first direction) correction 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. The DSP circuit 55R1
When this image is enlarged, at the same time, based on the correction data stored in the correction data memory 60 and the correction data obtained by analyzing the detection signal from the index electrode 70, the horizontal direction The arithmetic processing for correcting the image distortion or the like is performed.

It should be noted that the DSP circuit 50R is omitted from the components, and the brightness correction processing in the DSP circuit 50R is performed by the DS circuit 50R.
The P circuit 55R1 may perform the arithmetic processing for correcting the enlargement of the image and the image distortion at the same time.

The DSP circuit 5 is stored in the frame memory 56R.
The image data processed by the 0R and the DSP circuit 55R1 is stored for each color in accordance with the control signal Sa3R indicating the write address generated by the memory controller 63. In the example of FIG. 3B, image data is sequentially written rightward starting from the upper left corner. The image data stored in the frame memory 56R is
In accordance with a control signal Sa4R indicating a read address generated in the memory controller 63, data is read for each color and input to the DSP circuit 55R2. Here, in the processing of the left divided screen shown in FIG. 5, the order of the write address and the order of the read address to 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. 11C 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 includes the 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
5R2 simultaneously performs the enlargement of the image based on the correction data stored in the correction data memory 60 and the correction data obtained by analyzing the detection signal from the index electrode 70. , An arithmetic process for correcting vertical image distortion and the like is performed.

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 fluorescent 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. 5 (E),
Since the left and right divided screens shown in FIG. 6E have been corrected for image distortion and the like, when the left and right screens are joined, it is possible to perform an appropriate image display in which the joint portion is inconspicuous. .

Next, with reference to FIGS. 7 to 19, the arithmetic processing for correcting an image using the correction data will be described in detail. In the following description with reference to FIGS. 7 to 19, an arithmetic process for mainly performing positional correction on image data will be described.

First, the outline of the correction data stored in the correction data memory 60 (FIG. 4) 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 calculation process 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 at the same time, but as described above, the signal processing circuit illustrated in FIG. Is performed separately in the vertical and horizontal directions.

FIGS. 10 and 11 show how the 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 left or right divided screen on the frame memory 53. (B) shows that the input image is the DSP circuit 55L1 or D
Via the SP circuit 55R1, the DSP circuit 55L2 or D
It shows an image output from the SP circuit 55R2.
(C) shows an image of the left or right split screen actually displayed on the phosphor screen 11.

FIG. 10 shows how an input image is deformed when a correction operation using correction data is not performed in the processing circuit shown in FIG.
If the correction calculation is not performed, the image 160 (FIG. (A)) on the frame memory 53 and the image 161 (FIG. (B)) output from the DSP circuit 55L2 or 55R2 are the same as the input image. It has the same shape. 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. 11 shows a change in an input image when a correction operation is performed in the processing circuit shown in FIG. 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 images stored in the frame memory 53 correspond to the DSP circuits 55L1, 55L2, 55R1, 55
Based on the correction data, the input image is deformed in the cathode ray tube by R2 (deformation due to the characteristics of the cathode ray tube; see FIG. 10C). Correction calculation is performed. FIG. 7B shows the image 163 after this calculation. In FIG. 7B, the image indicated by the dotted line is the image 160 in the frame memory 53, and corresponds to the image before the correction operation 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. Thus, an ideal image 164 (FIG. 10C) is displayed on the phosphor screen 11. In addition, FIG.
, The image shown by the dotted line corresponds to the image 163 shown in FIG.

Next, the DSP circuit 55 (DSP circuit 55L)
1, 55L2, 55R1, 55R2) will be described in more detail. FIG. 12 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). Here, the pixel value described above
The relationship of movement is associated with screen scanning in a cathode ray tube.
explain. Usually, in the cathode ray tube, in the horizontal direction,
Electrons from left to right (X direction in FIG. 12) on the screen
The beam is scanned, and in the vertical direction,
Scanning is performed from top to bottom (in the −Y direction in FIG. 12).
U. Therefore, even if the pixel arrangement is as shown in FIG.
For example, when scanning based on the original video signal,
The scanning of the pixel at (1,1) is the scanning of the pixel at coordinates (3,4).
It will be done “after” the inspection. However,
Correction calculation processing is performed by the DSP circuit 55 of the present embodiment.
When scanning based on the video signal after
The scanning of the pixel at the coordinates (1, 1) in the video signal is
Rather than scanning the pixel at coordinates (3, 4) in the video signal
It will be done "first." Thus, the form of this embodiment
In the state, the arrangement state of the pixels in the two-dimensional image data
Are rearranged based on the correction data and the like.
Transforms a one-dimensional video signal temporally and spatially in pixel units.
A correction calculation process is performed to make the correction calculation.

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. 13 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. 13, the portions indicated by the dotted lines indicate 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 described.
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.

By the way, 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 operation, a method of performing the correction operation 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. 7 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. 8 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. 7 by the processing circuit shown in FIG.
In this figure, the divided screen on the left corresponds to the screen shown in FIG. 5 (E), and has 640 horizontal pixels × 480 vertical pixels, and is divided into 11 horizontal blocks × 16 vertical blocks. 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. 14 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.

Here, assuming that the image area on the DSP circuit 55 is composed of “horizontal 640” and “vertical 480” 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 always 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. 15 and FIG. 16, when the control points are set in a grid pattern as shown in FIG. 14, a method of obtaining the movement amount at an arbitrary pixel in each divided area Will be described. FIG. 15 is a diagram for explaining a method of obtaining the movement amount by interpolation, and FIG. 16 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. It should be noted that it is possible to obtain all pixels by extrapolation, but extrapolation can be used only when obtaining pixels in an area around the screen (dotted hatched area shown in FIG. 14). 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)

The operations shown in these equations (5) and (6) are also estimation methods based on linear interpolation. However, the estimation method is not limited to linear interpolation, and may use other operation methods. 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 in the initial state of the correction data (first data).
(Correction data). Control section 6
0 is the fine movement amount ΔFr (i, i,
j), ΔGr (i, j), ΔFg (i, j), ΔGg
(I, j), ΔFb (i, j), ΔGb (i, j) are calculated and added to the correction data in the initial state, whereby each of the DSP circuits 55L1, 55L2, 55R1, 55
The correction data to be given to R2 is created.

Here, the amount of fine movement (variation) with respect to the correction data in the initial state obtained based on the data S3 indicating the analysis result of the index signal S2 corresponds to the "second correction data" in the present invention. .

The final correction data created by the control unit 60 is represented by the following equations (A) to (F). In these equations, Fr (i, j) ′ is the amount of movement in the X direction (lateral direction) with respect to the R color, and Gr (i, j).
j) 'is the amount of movement in the Y direction (vertical direction) with respect to the R color. Fg (i, j) 'is the amount of movement in the X direction for the G color, and Gg (i, j)' is the amount of movement in the Y direction for the G color. Fb (i, j) 'is the amount of movement in the X direction with respect to B color, and Gb (i, j)' is the amount of movement with respect to B color.
The amount of movement in the direction.

Fr (i, j) ′ = Fr (i, j) + ΔFr (i, j) (A) Gr (i, j) ′ = Gr (i, j) + ΔGr (i, j) (B ) Fg (i, j) '= Fg (i, j) + ΔFg (i, j) ... (C) Gg (i, j)' = Gg (i, j) + ΔGg (i, j) ... (D) Fb (I, j) '= Fb (i, j) +. DELTA.Fb (i, j) ... (E) Gb (i, j)' = Gb (i, j) +. DELTA.Gb (i, j) ... (F)

Next, referring to FIGS. 17 to 19, the amount of fine movement (ΔFr
(I, j), ΔGr (i, j),...) Will be described.

In this embodiment, as described above, first, the image data is controlled based on the correction data stored in the correction data memory 60. For example, the image distortion in the initial state of the cathode ray tube at the time of manufacturing is controlled. Are corrected. Thereafter, image distortion or the like caused by the installation location of the cathode ray tube or a change with time is corrected by controlling the image data based on the fine movement amount of the correction data obtained by analyzing the detection signal from the index electrode 70. You. By the way, the fine movement amount of the correction data that can be directly derived by the detection signal from the index electrode 70 is a portion corresponding to the position where the index electrode 70 is provided (in the example of FIG. 1, the center portion of the screen). However, it is difficult to directly derive the other regions by the detection signal from the index electrode 70. On the other hand, the influence of the geomagnetism on the image display of the cathode ray tube, that is, how the image is deformed by the geomagnetism can be estimated in advance over the entire screen. Therefore, in the present embodiment, the fine movement amount of the correction data at a position (for example, the periphery of the screen) where it is difficult to directly derive the detection signal from the index electrode 70 depends on the display state of the image due to the influence of terrestrial magnetism. In consideration of the change of the index data, it is inferred from the fine movement amount of the correction data in the portion corresponding to the position where the index electrode 70 is provided.

Next, before describing a specific method of calculating the fine movement amount, an example of a change in the display state of an image due to the influence of geomagnetism will be described with reference to FIG. The example shown in the figure shows an example of a change in image distortion due to geomagnetism in Japan. In the same figure, a portion indicated by a reference sign SL indicates a left divided screen before being deformed by geomagnetism, and a portion indicated by a reference sign SL ′ indicates a left divided screen after being deformed by geomagnetism. Show. The part indicated by reference numeral SR indicates a right divided screen before being subjected to deformation by geomagnetism, and the part indicated by reference numeral SR 'indicates a right divided screen after being subjected to deformation by geomagnetism. Points indicated by symbols LO and RO are the center points of the left and right split screens SL and SR.

In Japan, when the magnetic field due to the terrestrial magnetism is eastward, the left and right split screens SL and SR spread outward on the lower side and on the upper side as shown in FIG. It undergoes a trapezoidal deformation that shrinks inward. On the other hand, if the geomagnetic field is westward,
As shown in FIG. 7B, the left and right split screens SL and SR
However, contrary to the eastward magnetic field, it undergoes a trapezoidal deformation that expands outward on the upper side and contracts inward on the lower side. When the magnetic field due to the terrestrial magnetism is directed south, the left and right divided screens SL and SR rotate clockwise with the center points LO and RO of each screen as the rotation axis, as shown in FIG. Subject to rotating deformation. On the other hand, when the magnetic field due to the terrestrial magnetism is in the north direction, the left and right split screens SL and SR are located at the center point of each screen, as shown in FIG. It is deformed to rotate counterclockwise around LO and RO.
As described above, the left and right split screens SL and SR undergo deformation in accordance with the direction of the terrestrial magnetism, but the amount of deformation received by each split screen is substantially the same for the left and right screens. Therefore, the shapes of the left and right divided screens SL ′ and SR ′ after deformation due to terrestrial magnetism are similar.

Next, with reference to FIG. 18, a method of calculating the fine movement amount with respect to the correction data in the initial state will be described more specifically. Here, a case where the magnetic field due to the geomagnetism is directed north as shown in FIG. 18 will be described as an example. However, even when the direction of the magnetic field is different, the method of obtaining the amount of fine movement is the same. FIG. 18 shows an example of a grid-like image obtained by dividing each of the left and right divided screens into 5 horizontal blocks × 4 vertical blocks.

First, the amount of fine movement at the pixel position at the joint portion of each divided screen can be directly obtained based on the detection signal from the index electrode 70.
Here, the left divided screen SL 'directly obtained is
The amount of fine movement at the pixel position k at the seam portion is denoted by ｋk (FIG. 1).
In the example of FIG. 8, 微 k (○ 0 to △ 4), and the fine movement amount at the pixel position k at the joint portion of the right divided screen SR ′ is と す る k (（0 to △ 4 in the example of FIG. 18). The fine movement amount ｋk and the fine movement amount △ k (k = 0 to 4 in the example of FIG. 18) correspond to the fine movement amounts ΔFr (i, j), ΔGr (i, j), ΔFg (i, j), respectively. ), ΔGg
(i, j), ΔFb (i, j), ΔGb (i, j) (in the example of FIG. 18, i =
0, 5, j = 0 to 4) as elements.

Next, with respect to the amount of fine movement at the pixel position in a region other than the joint portion of each divided screen, as described above, the left and right divided screens S after deformation by geomagnetism are described.
Since the shapes of L ′ and SR ′ are similar, for example, the fine movement amount k at the pixel position k at the joint portion of the left divided screen SL ′ (the right end position of the left divided screen SL ′) is Can be associated with the fine movement amount ｋk '(in the example of FIG. 18 ０0 ′ to ４4 ′) at the rightmost pixel position k ′ of the divided screen SR ′ (that is, ｋk = ○ k ′). Similarly,
The fine movement amount に お け る k at the pixel position k of the joint portion of the right divided screen SR '(the left end position of the right divided screen SR')
Can be associated with the fine movement amount △ k '(△ 0' to △ 4 'in the example of FIG. 18) at the leftmost pixel position k' of the left divided screen SL '(that is, △ k = △ k'). ).
As described above, even at the pixel positions in the area other than the joint portion of each divided screen, the fine movement amounts ｋk 'and △ k' at the other pixel positions corresponding to the joint portion are determined by the pixels of the joint portion. The position can be obtained in association with the fine movement amounts ｋk and △ k.

Further, in areas other than the joint portions of the divided screens, correction operations such as linear interpolation are performed on the fine movement amounts of still other pixel positions not corresponding to the joint portions of the divided screens. By doing so, the index electrode 70
Of each fine movement obtained based on the detection signal from
Can be inferred. For example, an arithmetic expression using linear interpolation is represented by the following expressions (i) to (vi).
In Equations (i) to (vi), L is the horizontal length of each divided screen, and x is the horizontal length of one divided block in each divided screen. In the example of FIG.
imax = 5 and imin = 0. Also, the following formulas (i) to (vi)
In, for example, ΔFr (imax, j) corresponds to one element of fine movement amount ○ k, and ΔFr (imin, j) corresponds to one element of fine movement amount Δk.

ΔFr (i, j) = [x (i + 1) × ΔFr (imax, j) + {Lx (i + 1)} × ΔFr (imin, j)] / L (i) ΔGr (i , j) = [x (i + 1) × ΔGr (imax, j) + ｛Lx (i + 1)｝ × ΔGr (imin, j)] / L ... (ii) ΔFg (i, j) = [x (i + 1) × ΔFg (imax, j) + ｛Lx (i + 1)｝ × ΔFg (imin, j)] / L… (iii) ΔGg (i, j) = [x (i + 1) × ΔGg (imax, j) + ｛Lx (i + 1)｝ × ΔGg (imin, j)] / L… (iv) ΔFb (i, j) = [x (i + 1) × ΔGb (imax, j) + ｛Lx (i + 1)｝ × ΔGb (imin, j)] / L… (V) ΔGb (i, j) = [x (i + 1) × ΔGb (imax, j) + ｛Lx (i + 1)｝ × ΔGb (imin, j)] / L… (vi)

Next, the overall flow of how to determine the amount of fine movement as described above will be described with reference to the flowchart of FIG. First,
Index signal processing circuit 61 and control unit 6
2 is a fine movement amount of a pixel position at a joint portion of each divided screen based on a detection signal from the index electrode 70 (FIG. 1).
In the example of No. 8, ○ 0 to △ 4, △ 0 to △ 4) are obtained (step S101). Next, based on the amount of fine movement of the pixel position of the joint portion, the amount of fine movement of another pixel position corresponding to the joint portion in the area other than the joint portion of each divided screen (FIG. 1)
In the example of No. 8, ○ 0 'to ４4', △ 0 'to △ 4') are obtained (step S102). Next, in another area other than the joint portion of each divided screen, another pixel position (i = 1 in the example of FIG. 18) that does not correspond to the joint portion of each divided screen.
微 5, j = 0 to 4) (step S103). In this way, a plurality of divided screens are properly connected , and a good image is displayed over the entire screen.
Passed to the entire screen of the fine movement amount of data required to perform the
It is possible to find me.

In the above description, since the screen is arranged on the left and right, the fine movement amount is predicted from the left and right ends. For example, when the screen is arranged vertically,
The index electrodes 70 may be arranged in the horizontal direction, and the amount of fine movement may be predicted from the upper and lower ends.

Next, with reference to FIGS. 20 to 24, the conversion process 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 will be described in detail.

Conversion of image enlargement and sampling frequency (number of pixels) of an image (conversion between image standards having 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. 20 is an explanatory diagram showing an example of an original image before the image is enlarged or the like. 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. 21 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 to about 1.4292 times. For example, in the original image shown in FIG. 20, the number of pixels in each pixel row in the horizontal direction is 8, but in the enlarged image shown in FIG. 21, 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. 22 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. Note that FIG. 22 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 the enlargement depends on the correspondence between 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, referring to FIG. 23, a case where the sampling frequency is increased by, for example, (10/7) without changing the size of the image will be considered. 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. 23, the image is converted into an image having one-dimensionally about 1.429 times the number of pixels, that is, 1.4292 times the area density.

The correspondence between each pixel in FIG. 20 and each pixel in FIG. 21 and the correspondence between each pixel in FIG. 20 and each pixel in FIG. 23 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, an operation 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 ideal “interpolation” is performed, a sinc function 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. 24B, the data of one pixel after interpolation is calculated from the data of one pixel of the original image. Note that the variable x in Equation (8) and FIG. 24B 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.

[0123]

(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. . Note that the variable x in Expression (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.

[0125]

(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. 24D 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.

[0127]

(Equation 3)

The convolution operation using these functions is as follows:
This can be performed using a so-called FIR (Finite Impulse Response) digital filter. In that 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 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 operation, since the phase P with the pixel of the original image is different for each interpolation point for calculating 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, data obtained by analyzing the detection signal from the index electrode 70 will be described with reference to FIG.

FIG. 25 is a diagram showing an example of the structure of the index electrode 70 in the cathode ray tube according to the present embodiment and a waveform of a detection signal output from the index electrode 70. In the present embodiment, by providing the cutout hole 71 in the conductive index electrode 70, it is possible to detect the scanning positions of the electron beams eBL and eBR in the horizontal direction (line scanning direction) and the vertical direction (field scanning direction). I have to. In this figure, only the right electron beam eBR will be described, but the same applies to the left electron beam eBL. As described above, in the present embodiment, for the electron beam eBR, line scanning is performed from left to right at the center of the screen, and field scanning is performed from top to bottom (Y direction in the drawing).

In FIG. 17A, a trajectory BY is a trajectory of a horizontal scanning start point of the electron beam eBR before image correction. In the example of this figure, the electron beam eB before image correction is used.
The trajectory BY of R is a pincushion type (pin cushion type) in which the center in the horizontal direction is reduced and the upper and lower parts in the horizontal direction are elongated. Also, locus B
Y0 is the trajectory of the horizontal scanning start point of the electron beam eBR when appropriate image correction has been performed. In the present embodiment, in order to detect the position of the electron beam eBR, the overscan area OS provided with the index electrode 70 is provided.
, A plurality of electron beams B for position detection in the horizontal direction.
1 to B5 are passed at least by the number corresponding to the number of the cutout holes 71. Hereinafter, when an appropriate image correction is performed, for example, as shown in the illustrated electron beams B10 to B50, a plurality of notches 7
The description will be made on the assumption that the electron beam passes through almost the center of the reference numeral 1. Note that the number of electron beams passing through the index electrode 70 for position detection is not limited to the same number as the number of the cutout holes 71.

When the electron beams B1 to B5 for position detection pass through the index electrode 70, a detection signal having two pulse signals is output as shown in FIG. The two pulse signals are signals output when the electron beams B1 to B5 pass through the electrode portions at both ends of the cutout hole 71. The time (th1 to th5) from the scanning start point (time t = 0) of the electron beams B1 to B5 to the edge portion of the first pulse signal indicates the amplitude of horizontal deflection and the state of image distortion. When all the times reach the fixed time th0, the horizontal deflection is completely corrected.

FIG. 17C shows a detection signal output after the horizontal deflection has been corrected. As described above, when the electron beams B1 to B5 pass through the portion of the index electrode 70 where the cutout holes 71 are provided, two pulse signals are output. tv1 to tv5) are cutout holes 71
Corresponding to the vertical direction (vertical direction). Therefore, when the pulse intervals (tv1 to tv5) all reach the fixed time tv0, the vertical amplitude and the linearity are adjusted, and the vertical deflection is completely corrected. When both the horizontal deflection and the vertical deflection are corrected, the time from the scanning start point (t = 0) to the edge portion of the first pulse signal is a fixed time th0 as shown in FIG. A detection signal whose two pulse intervals are the predetermined time tv0 is output. At this time, as shown in (E), in the index electrode 70, the electron beams B1 'to B5' in the ideal state pass through almost the center of the plurality of cutout holes 71.

In the analysis of the pulse interval of the detection signal output from the index electrode 70, the index signal processing circuit 61 (FIG. 4) actually detects the detection signal from the index electrode 70 obtained through the amplifier AMP1. Is performed by analyzing the index signal S2 corresponding to. Index signal processing circuit 61, based on the analysis of the index signal S2, data is required to create the fine movement amount of the correction data in the control unit 6 2 S
3 is output. Control unit 6 2 is based on the data S3 from the index signal processing circuit 61, to create a fine movement amount for correction data in the initial state stored in advance in the correction data memory 60, the DSP circuits 55R1,5
Create correction data to be given to 5R2. DSP circuit 55R1,55R2 corrects the image data based on the correction data supplied from the control section 6 2. Thereby, control of image data is performed, and image correction is performed so that image distortion and the like are corrected. The same applies to the left DSP circuits 55L1 and 55L2.

The cathode ray tube of the present embodiment is capable of displaying a color image, and has an electron beam eBR to be adjusted.
Are for each of R, G, and B colors. However, if image data is controlled for each of R, G, and B colors, convergence correction can be automated. By performing such automatic control, for example, the pincushion-type image distortion such as the locus BY shown in FIG. 25A can be automatically corrected.

The above description is for the right electron beam eBR, so that about the right half screen of the entire screen area is corrected. Similarly, the left electron beam eBL is also corrected. By doing so, the screen on the left is corrected. By correcting the left and right split screens in this manner, the left and right split screens are displayed in a state of being appropriately joined together. The index electrode 70
Has only one electron beam eB
The scanning positions of L and eBR cannot be detected completely simultaneously. Therefore, the left and right divided screens cannot be simultaneously corrected. However, for example, the scanning positions of the electron beams eBL and eBR are alternately detected for each line operation or field scan, and the image data for the left and right divided screens is alternately detected. By performing the correction, the left and right split screens can be corrected.

The shape of the cutout hole 71 provided in the index electrode 70 is not limited to the above-described inverted triangular shape, and various shapes of cutout holes can be used as shown in FIG. It is. In the example shown in FIG. 9A, a cutout hole 91 having a substantially right triangular shape whose horizontal shape becomes smaller as it goes downward. Electron beam eB when the electrode of the example shown in FIG.
The detection of the L and eBR scanning positions is basically the same as when the index electrode 70 shown in FIG. 25 is used.
FIGS. 7B, 7C, and 7D are examples of electrodes provided with diamond-shaped, circular, and elliptical cutout holes 92, 93, and 94, respectively. In the examples of FIGS. 3B, 3C, and 3D, since the shape of each cutout hole is vertically symmetrical, it is necessary to obtain one position information in the vertical direction.
A plurality of holes (for example, 3
Book) electron beam. The same figure (E)
Is an example in which a notch hole 95 for position detection is provided, and a notch hole 96 for reducing capacitance for reducing stray capacitance generated in the pipe is provided. In the example of (E), a region not used for position detection on the electrode is formed by a cutout hole 9.
6, the internal conductive film 22 and the beam shield 27 whose electrodes are maintained at the anode voltage HV.
It has the advantage of reducing the stray capacitance of the detection signal and improving the high frequency characteristics of the detection signal.

Although FIGS. 25 and 26 show an example in which five notches are provided in one index electrode, the number of notches provided in the index electrode is limited to five. Instead, more or less configurations may be used. However, when the distortion of the image is more complicated and includes higher-order components, it is considered that it is necessary to increase the number of cutout holes to increase the detection accuracy. Further, the intervals between the plurality of cutout holes do not necessarily have to be equal.

Further, in the above description, the scanning position of each of the electron beams eBL and eBR is detected by one index electrode 70. However, by providing a plurality of index electrodes 70, the electron beams eBL and eBR can be detected. It is also possible to independently detect the scanning positions.

FIG. 27 shows left and right electron beams eBL and eB.
FIG. 3 is a configuration diagram showing a structure of an index electrode that can independently detect each scanning position of R, together with a configuration of a peripheral portion thereof. In FIG. 3A, the index electrodes 70L,
Only the main components of the 70R peripheral circuit are shown.
In the example shown in this figure, an index electrode 70L is provided in the overscanning region of the electron beam eBL and an index electrode 70R is provided in the overscanning region of the electron beam eBR on the joint side of the left and right divided screens. The basic structure of the index electrodes 70L, 70R is the same as that of the index electrode 70 shown in FIG. 25, and a plurality of inverted triangular cutout holes 71 are provided at equal intervals in the longitudinal direction.

The configuration of the peripheral circuit for deriving the detection signals of the index electrodes 70L and 70R is basically the same as that of the index electrode 70. That is, as shown in FIG. 2A, the resistor R11 to which the anode voltage HV is supplied and the positive electrode of the capacitor Cf1 are connected to the index electrode 70R. The negative electrode of the capacitor Cf1 is connected to the amplifier AMP1-R. The resistor R12 to which the anode voltage HV is supplied and the positive electrode of the capacitor Cf2 are connected to the index electrode 70L. The negative electrode of the capacitor Cf2 is connected to the amplifier AMP1-L. The capacitors Cf1 and Cf2 are formed using a part of the funnel unit 20, similarly to the capacitor Cf shown in FIG. Index electrodes 70R, 70L
Then, when the electron beams eBR and eBL respectively strike,
A voltage drop occurs independently at each electrode, and a signal corresponding to the voltage drop is guided outside the tube as an independent detection signal via the capacitors Cf1 and Cf2. The detection signal from each electrode guided outside the tube is
These are output as independent index signals S2R and S2L via the amplifiers AMP1-R and AMP1-L, respectively. These independent index signals S2R, S2L
Are separately processed by a processing circuit outside the tube, whereby the scanning positions of the electron beams eBL and eBR can be detected independently and simultaneously, and the left and right divided screens can be simultaneously corrected. .

It is to be noted that between the index electrodes 70L and 70R and the phosphor screen 11 (not shown in FIG. 27), for example, a mountain-shaped beam shield 27 'is arranged as shown in FIG. You. At the center of the beam shield 27 ', a shielding plate 72 for shielding each of the electron beams eBL and eBR is provided. Index electrode 70
L and 70R are provided on the left and right of a shielding plate 72 provided at the center of the beam shield 27 '. FIG. 2B shows an example in which the index electrodes 70L and 70R are arranged obliquely with respect to the phosphor screen 11.
The index electrodes 70L and 70R may be arranged so as to face the phosphor screen 11 instead of obliquely.

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

In the above-described arithmetic processing of image correction in the DSP circuit 55, by controlling image data,
The positional correction of the image is performed so that the left and right divided screens are properly joined. In the present embodiment, however, the overlapping area OL is further adjusted in order to adjust the luminance in the overlapping area OL of the left and right divided screens. A special luminance modulation process is performed on pixels corresponding to OL. In the present embodiment, the luminance modulation processing is performed by correcting values relating to the luminance of the image data in the luminance correction DSP circuits 50L and 50R.

FIG. 28 is an explanatory diagram showing the outline of the modulation for this image data, and shows the relationship between the position of each divided screen and the modulation waveform in three dimensions. In the figure, the portion indicated by reference numeral 81 corresponds to the left divided screen,
The portion indicated by is equivalent to the right split screen. As described above, in the overscanning area OS on the joint side between the divided screens 81 and 82, the respective electron beams eBL and eBR scan the index electrode 70 to output a detection signal. In the drawing, the waveforms of index drive signals S1L and S1R, which are drive signals for scanning in the overscanning region OS of the electron beams eBL and eBR, are shown at the same time.

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.

[0152]

(Equation 4)

FIG. 29 shows a cathode current I corresponding to luminance.
FIG. 5 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 overlap region OL of the modulated 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.

[0154]

(Equation 5)

[0155]

(Equation 6)

FIG. 30 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. 29, the luminance gradient is linear in each of the divided screens 81 and 82, but a function in which the derivative (derivative) of the change in luminance (cathode current Ik) at both ends of the overlap region OL becomes zero. (Eg, a cosine function) is also possible. In the example of FIG. 30, 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 (14). 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.

[0157]

(Equation 7)

A function in which the derivative (derivative) of the luminance change is zero as shown in FIG. 30 is considered innumerable. For example, a function obtained by synthesizing a parabola (quadratic) curve may be used. Good.

In the above-described brightness control, for example, the index signal processing circuit 61 (FIG. 4) starts the start points P1L and P1 of the overlapping area OL for the left and right divided screens based on the index signal S2 from the index electrode 70.
By performing the determination of R and transmitting the determination result to the control unit 62, the modulation of the luminance can be performed from the start points P1L and P1R of the overlapping area OL. The DSP circuits 50L and 50R for luminance correction perform luminance modulation control on the left and right image data based on an 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, e based on the image data modulated in luminance from the electron guns 31L, 31R.
BR is fired.

FIG. 31 is a diagram showing the relationship between the scanning position of the electron beam and the timing of the luminance modulation control. Although the right electron beam eBR is shown in this drawing, the same applies to the left electron beam eBL. In the present embodiment, as described with reference to FIG. 25, in the overscanning region OS, the plurality of electron beams B1, B2 for position detection scan on the index electrode 70. In the same figure, a period Ti corresponds to FIG.
8 is a period during which a plurality of electron beams B1, B2,... For position detection are output based on the index drive signal S1R shown in FIG. Note that, in the same drawing, a return line B0 of the electron beams B1, B2,... Is also shown. When the electron beam moves from the overscan area OS to the overlap area OL,
From the starting point P1R, scanning based on the video signal SV is performed.
In the figure, a modulation waveform S3R representing the correction of the luminance is shown corresponding to the video signal SV.

The timing for correcting the image data based on the above-mentioned index signal S2 can be set arbitrarily. For example, the timing can be set when the cathode ray tube is activated, or after a period of time. It is possible to select intermittently or further always. Further, the control of the image data may be alternately performed on the left and right divided screens. Furthermore, if a so-called feedback loop is configured to reflect the correction result of the image data at the time of the next field scan of each electron beam eBL, eBR, the position and orientation of the cathode ray tube can be changed during the operation of the cathode ray tube. Even if such is the case, it is possible to automatically correct image distortion and the like due to changes in the external environment such as terrestrial magnetism. Further, even when the scanning screen fluctuates due to the aging of each processing circuit, it is possible to automatically absorb the fluctuation and display an appropriate image. If the operation of each processing circuit is stable and the installation position is unchanged, it is sufficient to perform the correction only at the time of starting the cathode ray tube. As described above, in the present embodiment, the influence of the change of the external environment such as the terrestrial magnetism or the temporal change of each processing circuit on the display image is automatically corrected in terms of position and luminance, and the left and right divided screens are displayed. Displayed properly connected.

As described above, according to this embodiment, the overscan area OS of the electron beams eBL and eBR at the joint side of the adjacent left and right divided screens in the tube.
Is provided with an index electrode 70 for outputting an electrical detection signal in accordance with the incidence of the electron beams eBL and eBR, so that the scanning position of the electron beams eBL and eBR can be easily adjusted with a simple structure and configuration. Can be detected. In addition, since the image data is controlled based on the detection signal output from the index electrode 70, based on the scanning position detected by the index electrode 70, the screen scanning amplitude, image distortion, misconvergence, etc. It is possible to automatically correct the image display. Further, according to the present embodiment, the notch 71 is provided in the index electrode 70, so that the scanning position of the electron beam eB can be detected in both the horizontal and vertical directions, and the image correction in the vertical direction as well as the horizontal direction Can be performed.

According to the present embodiment, based on the detection signal output from the index electrode 70, data (for example,
The amount of fine movement with respect to the correction data stored in the correction data memory 60) is obtained, and based on the obtained data regarding the pixel positions, the data regarding the pixel positions in the areas other than the joint portions of the divided screens is obtained. Since it is determined by guessing, it is possible to obtain data necessary for properly joining the left and right divided screens over the entire screen as needed.

Therefore, according to the present embodiment, it is possible to control the display of an image based on the detection signal output from the index electrode 70 so that the left and right divided screens are appropriately connected in position. . Further, according to the present embodiment, based on the detection signal output from the index electrode 70, the modulation of the luminance of the joint portion is performed on the input image data. Image display control can be performed so that a change in luminance is not noticeable. As described above, according to the present embodiment, the left and right divided screens can be connected to each other such that the joint portions are not conspicuous in terms of position and luminance, and an excellent image display can be performed. Further, the cathode ray tube of the present embodiment
Since image display is performed using the two electron guns 31L and 31R, the distance from the electron gun to the phosphor screen can be made shorter than in a cathode ray tube using a single electron gun, and the depth can be reduced. it can. Therefore, it is possible to perform image display with good focus characteristics (small image magnification). Further, since the two electron guns 31L and 31R are provided, it is possible to easily increase the brightness and to reduce the size of the display despite the large screen.

Further, according to the present embodiment, correction data for correcting the display state of an image obtained from an image displayed on the screen and a detection signal from index electrode 70 are analyzed. Based on the correction data obtained,
An operation for correcting the image data is performed so that the image is properly displayed, and the corrected image data is output as image data for display. , Image distortion and misconvergence can be reduced. 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. Further, once all the correction data has been created, the correction data is stored, so that correction of image distortion and the like can be performed automatically thereafter.

Further, according to the present embodiment, it is not necessary 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 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. 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 from the center of the screen to the outside in the horizontal direction ( (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. 36 is a diagram showing an example of the structure of an index electrode used in the cathode ray tube of the present embodiment and a waveform of a detection signal output from the index electrode. Note that, in the figure, the left side of the paper corresponds to the upper side of the screen, and the right side of the paper corresponds to the lower side of the screen. The longitudinal direction of the index electrode 70A in the present embodiment is such that the electron beams eBL and eBR are in the line scanning direction (Y direction).
A rectangular cutout hole 131 provided so as to be perpendicular to the substrate, and an elongated slit provided so as to be oblique to the field scanning direction (X1, X2 directions in FIG. 32) of the electron beams eBL, eBR. And a notch hole 132 having a shape. A plurality of notch holes 131 and notch holes 132 are arranged alternately. In the example shown in this figure, the arrangement is such that both ends of the index electrode 70A are cut-out holes 131 as a result. Adjacent cut holes 131 are arranged at equal intervals. As for the cutout holes 132, adjacent ones are arranged at equal intervals.

Assuming that two electron beams eB1 and eB2 for position detection pass through the index electrode 70A in the line scanning direction as shown in FIG.
Detection signals are output as shown in FIGS. 6B and 6C, the amplitude and position of the line scanning of the electron beams eB1 and eB2 can be detected from the periods T _T and T _B shown at both ends. Further, the electron beams eB1 and eB2 pass through the adjacent notches 131.
The irregularity of the periods T ₁₃ , T ₃₅ , T ₅₇ , and T ₇₉ during the passage indicates whether the linearity of the line scanning is good or not. Also,
The electron beams eB1 and eB2 form oblique notch holes 132
The position of the pulse signal (pulses P1 to P4 in (C)) generated when the signal passes through represents the information of the amplitude of the field scan.

FIG. 18E shows a detection signal output from the index electrode 70A when the electron beam eB3 having the pincushion type image distortion passes as shown in FIG. FIG. 9F shows a detection signal output from the index electrode 70A when the electron beam eB4 having a barrel-shaped image distortion passes as shown in FIG. FIG. 7G shows a detection signal output when there is an electron beam eB5 passing through a substantially central portion in the longitudinal direction of the index electrode 70A as shown in FIG. As you can see from these figures,
From the index electrode 70A, the passing electron beam e
Detection signals having different waveforms are output according to the difference between the scanning position and the scanning timing of BL and eBR. Therefore, for example, the electron beams eBL and eBR are
By observing and analyzing the phase of the pulse signal train when passing through 1, 132, the trajectories of the electron beams eBL and eBR on the index electrode 70A can be estimated.

The analysis of the phase of the pulse signal train is actually performed by
The index signal processing circuit 61 (FIG. 4)
This is performed by analyzing the index signal S2 corresponding to the detection signal from the index electrode 70A acquired via P1. The index signal processing circuit 61 outputs, based on the analysis of the index signal S2, the data S3 required for the control unit 61 to generate the fine movement amount of the correction data. The control unit 61 creates a fine movement amount for the correction data in the initial state previously stored in the correction data memory 60 based on the data S3 from the index signal processing circuit 61, and gives the amount to the DSP circuits 55R1 and 55R2. Create correction data. The DSP circuits 55R1 and 55R2 correct image data based on the correction data provided from the control unit 61. Thereby, control of image data is performed, and image correction is performed so that image distortion and the like are corrected.
The same applies to the left DSP circuits 55L1 and 55L2.

In the present embodiment, such image correction is performed on both the left and right divided screens, so that the left and right divided screens are properly connected and displayed.
Since only one index electrode 70A is provided, the scanning positions of the electron beams eBL and eBR cannot be detected completely simultaneously. Therefore, although the left and right split screens cannot be corrected simultaneously, for example, the electron beam eB
The left and right divided screens can be corrected by alternately detecting the L and eBR scanning positions and correcting the image data for the left and right divided screens alternately.

In FIG. 36, the index electrode 70
Although an example in which nine cutout holes are provided in each of A is shown, the number of cutout holes to be provided is not limited to nine, and may be larger or smaller. However, when the distortion of the image is more complicated and includes higher-order components, it is considered that it is necessary to increase the number of cutout holes to increase the detection accuracy. Also, in the above,
Although the example in which the notches 131 and 132 are provided at equal intervals has been described, the interval between the notches 131 and 132 is
The intervals need not always be equal.

In the above description, the scanning position of each of the electron beams eBL and eBR is detected by one index electrode 70A. However, by providing a plurality of index electrodes 70A, the electron beams eBL and eB are detected.
It is also possible to independently detect the scanning positions of R.
In the case where a plurality of index electrodes 70A are provided, the structure of the electrodes and the configuration of the periphery thereof are the same as those described with reference to FIG. 27 in the first embodiment. By providing a plurality of index electrodes 70A, the scanning positions of the electron beams eBL and eBR can be independently and simultaneously detected, and the left and right divided screens can be simultaneously corrected.

FIG. 33 is an explanatory diagram showing a specific example of the arithmetic processing performed on the 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. 33A shows image data read from the frame memory 53 and input to the DSP circuit 50L in the present embodiment. DSP
The image data input to the circuit 50L is the same as that described with reference to FIG. 5A in the first embodiment. For example, image data of 640 horizontal pixels × 480 vertical pixels is input. .

[0178] FIG. 17B is a diagram showing the structure of the present embodiment.
It shows image data written to the frame memory 56L after the image correction processing is performed by the SP circuit 50L and the DSP circuit 55L1. DSP circuit 50L
In the same manner as described with reference to FIG. 5B in the first embodiment, before performing the correction processing by the DSP circuit 55L1, the horizontal 35 indicated by the hatched area in FIG.
The arithmetic processing for correcting the luminance in the overlapping area OL is performed on the data of 2 pixels × 480 pixels vertically, independently of the positional correction. 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. The details of the luminance correction processing are the same as those described in the first embodiment.

On the other hand, the DSP circuit 55L1 performs the luminance correction processing by the DSP circuit 50L in the same manner as that described in the first embodiment with reference to FIG. The arithmetic processing including the correction in the horizontal direction (first direction) is performed on the data of 352 horizontal pixels × 480 vertical pixels indicated by the hatched area in A). 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 circuit 55L1 enlarges the image, the circuit 55L1 simultaneously performs the correction based on the correction data stored in the correction data memory 60 and the correction data obtained by analyzing the detection signal from the index electrode 70A. , An arithmetic process for correcting horizontal image distortion and the like is performed.

The frame memory 56L has a DSP circuit 5
The 0L and the image data processed by the DSP circuit 55L1 are stored for each color in accordance with 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. The image data stored in the frame memory 56L is
In accordance with a control signal Sa4L indicating a read address generated in the memory controller 63, data is read for each color and input to the DSP circuit 55L2. Here, in the present embodiment, 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. 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
5L2, based on the correction data stored in the correction data memory 60 and the correction data obtained by analyzing the detection signal from the index electrode 70A at the same time when the image is enlarged. , An arithmetic process for correcting vertical image distortion and the like is performed.

The scanning of the electron beam eBL is performed from top to bottom based on the image data (FIG. (D)) 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 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. 34 is an explanatory diagram showing a specific example of arithmetic processing performed on 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 that of the processing circuit shown in FIG. FIG. 34A shows image data read from the frame memory 53 and input to the DSP circuit 50R in the present embodiment. DSP
The image data input to the circuit 50R is the same as that described with reference to FIG. 6A in the first embodiment. For example, image data of 640 horizontal pixels × 480 vertical pixels is input. .

FIG. (B) shows that D in this embodiment.
The figure shows image data written to the frame memory 56R after the image correction processing is performed by the SP circuit 50R and the DSP circuit 55R1. DSP circuit 50R
In the same manner as described with reference to FIG. 6B in the first embodiment, before performing the correction processing by the DSP circuit 55R1, the horizontal 35 indicated by the hatched area in FIG.
The arithmetic processing for correcting the luminance in the overlapping area OL is performed on the data of 2 pixels × 480 pixels vertically, independently of the positional correction. FIG. 7B shows a modulated waveform 80L representing the correction of the luminance in the right divided screen in association with the image data.

On the other hand, the DSP circuit 55R1 performs the luminance correction processing by the DSP circuit 50R in the same manner as in the first embodiment described with reference to FIG. The arithmetic processing with horizontal correction is performed on the data of 352 horizontal pixels × 480 vertical pixels indicated by the hatched area in A). 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.

The DSP circuit 5 is stored in the frame memory 56R.
The image data processed by the 0R and the DSP circuit 55R1 is stored for each color in accordance with the control signal Sa3R indicating the write address generated by the memory controller 63. In the example of FIG. 3B, image data is sequentially written rightward starting from the upper left corner. The image data stored in the frame memory 56R is
In accordance with a control signal Sa4R indicating a read address generated in the memory controller 63, data is read for each color and input to the DSP circuit 55R2. Here, in the present embodiment, the order of the write address and the order of the read address for the frame memory 56R generated by the memory controller 63 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. 23C 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 the correction data stored in the correction data memory 60 with the index electrode 7.
Calculation processing for correcting vertical image distortion and the like is performed based on the correction data obtained by analyzing the detection signal from 0.

By scanning the electron beam eBR from top to bottom on the basis of the image data (FIG. 14D) obtained through the above-described arithmetic processing, the right side on the phosphor screen 11 is scanned. 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. 33 (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. 35 is a table showing an image displayed on the phosphor screen 11 after correcting the image of the grid-like reference image shown in FIG. 7 by the processing circuit shown in FIG. An example is shown. In this figure, the divided screen on the left corresponds to the screen shown in FIG. 33 (E), and the number of pixels is 480 pixels in width × 640 pixels in height, and 11 blocks in width.
It is divided into 16 vertical blocks. In this figure, the right divided screen corresponds to the screen shown in FIG. 34 (E), and the number of blocks is the same as that on the left.

In this embodiment, as described with reference to FIGS. 8, 14 and the like in the first embodiment, 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 (first correction data). The control unit 62 determines the fine movement amount ΔFr (i, j), ΔG of the correction data in the initial state based on the data S3 indicating the analysis result of the index signal S2 output from the index signal processing circuit 61.
r (i, j), ΔFg (i, j), ΔGg (i, j),
ΔFb (i, j) and ΔGb (i, j) are calculated and added to the correction data in the initial state.
Correction data to be given to the circuits 55L1, 55L2, 55R1, 55R2 is created. In the present embodiment,
The final correction data created by the control unit 62 is expressed in the same manner as the above-described equations (A) to (F).

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 well.

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

[Third Embodiment] Next, a third embodiment of the present invention will be described.
An embodiment will be described. In the following description, the same components as those in the first and second embodiments are denoted by the same reference numerals, and description thereof will not be repeated.

In the first and second embodiments, the overscan area OS on the joint side of the adjacent divided screens is
Although a conductive electrode for generating an electric detection signal according to the incidence of each of the electron beams eBL and eBR is provided, in the present embodiment, a member that emits light according to the incidence of the electron beam is provided. It was made.

FIG. 37 is a configuration diagram schematically showing a cathode ray tube according to the third embodiment of the present invention. In the cathode ray tube according to the present embodiment, an index plate 110 that emits light in response to the incidence of each of the electron beams eBL and eBR is disposed at a position corresponding to the index electrode 70 shown in FIG. Further, the cathode ray tube according to the present embodiment has a region 1 corresponding to the index plate 110 in the funnel portion 20.
12, an optically transparent detection window for detecting light emitted from the index plate 110 is provided. Outside the funnel section 20 (outside the tube), a photodetector 111 is provided at a position corresponding to the detection window. The photodetector 111 is connected to the amplifier AMP2. Note that the photodetector 111 is a “photodetector” in the present invention.
Corresponds to one specific example.

The photodetector 111 includes an index plate 110
In addition to detecting the light emitted from, the detected light is converted into an electric signal and output. The amplifier AMP2 amplifies the signal output from the photodetector 111 and outputs it as an index signal S2 '. The index signal S2 'output from the amplifier AMP2 is output to the index signal processing circuit 61 in the same manner as in the first and second embodiments.
(FIG. 4), and the signal is analyzed. The index signal processing circuit 61 outputs, based on the analysis of the index signal S2 ', the data S3 necessary for the control unit 62 to generate the fine movement amount of the correction data. The process of analyzing the detection signal in the index signal processing circuit 61 and the method of correcting the image data using the data S3 output after the analysis are the same as those in the first and second embodiments.

FIG. 38 is a configuration diagram showing an example of the index plate. Index plate 110A shown in FIG.
Can be used, for example, in 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 top to bottom, similarly to the index electrode 70 shown in FIG.

The index plate 110A is made of a rectangular plate-like member as shown in FIG. The index plate 110A is provided with a phosphor 120 that emits light in response to the incidence of the electron beams eBL and eBR. The phosphor 120 preferably has, for example, a short afterglow characteristic. For example, P37 (ZnS: A
g, Ni), P46 (Y 3 Al 5 O 12: Ce), P47
(Y ₂ SiO ₅ : Ce) or the like can be used. This phosphor 120 has an index plate 110 such that an inverted triangular pattern similar to the cutout hole 71 provided in the index electrode 70 shown in FIG.
A is provided over the entire central portion in the longitudinal direction of A. In FIG. 5A, a plurality of inverted triangular regions indicated by reference numeral 121 are regions where the phosphors 120 are not provided. The pattern formed by the phosphor 120 is
It is not limited to what is shown, for example, FIG.
Various patterns can be applied in the same manner as the cutout hole pattern in each index electrode shown in FIG. Since the phosphors 120 are provided in a predetermined pattern as described above, the index plate 110 is provided.
When each of the electron beams eBL and eBR passes over A, the portion where the phosphor 120 is provided intermittently emits light. This light emission pattern can correspond to a pattern of an electrical detection signal detected at the index electrode 70.

As shown in FIG. 20B, by bending the side portions of the index plate 110A into a mountain shape, the electron beams eBL and eBR can be transmitted to the index plate 110A.
When scanning A, it is possible to prevent the fluorescent screen 11 from inadvertently emitting light by detaching from the index plate 110A. That is, the beam shield 2 shown in FIG.
7 can have the same effect.

FIG. 39 is a configuration diagram showing another example of the configuration of the index plate. Index plate 11 shown in FIG.
0B is the index electrode 70A shown in FIG.
Similarly to the above, for example, it can be used when performing line scanning by the electron beams eBL and eBR from top to bottom and performing field scanning in the horizontal direction. The configuration of the index plate 110B is the same as that of the index plate 110A shown in FIG. 38 except that the shape of the pattern formed by the phosphor 120 is different. In the index plate 110B, a pattern having the same shape as each of the cutout holes 131 and 132 provided in the index electrode 70A shown in FIG. It is formed in each of the regions 122 and 123. Since the phosphors 120 are provided in a predetermined pattern as described above, when the electron beams eBL and eBR pass on the index plate 110B, a portion where the phosphors 120 are provided emits light intermittently. Will be. This light emission pattern corresponds to the index electrode 7
It can correspond to the pattern of the electrical detection signal detected at 0A.

In the index plates 110A and 110B shown in FIGS. 38 and 39, the area where the phosphor 120 is provided may be inverted with respect to the state shown. For example, the index plate 11 shown in FIG.
At 0A, the phosphor 120 may be provided only in a plurality of inverted triangular regions indicated by reference numeral 121.

As described above, according to this embodiment, the overscan area OS of the electron beams eBL and eBR at the joint side of the adjacent left and right divided screens in the tube.
An index plate 110 that emits light in response to the incidence of the electron beams eBL and eBR is provided, and light emitted from the index plate 110 is detected by a photodetector 111 and output as an index signal S2 'via an amplifier AMP2. Thus, similarly to the first and second embodiments, it is possible to control the image data based on the index signal S2 ', and to make the joint part inconspicuous in terms of position and luminance. Image display can be performed well by joining the left and right split screens. Further, according to the present embodiment, the electron beams eBL and eBR are optically
Is detected in response to the incident light, the index signal S is compared with the method of deriving the electric detection signal using the conductive electrode as in the first and second embodiments.
There is an advantage that the high frequency characteristic 2 'is excellent.

The other structure, operation, and effects of the present embodiment are the same as those of the first and second embodiments.

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. 32, 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. 4). 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. 4). Regardless of which image signal is used, in the circuit example shown in FIG.
Subsequent circuits may have substantially the same circuit configuration.

Also, in the circuit shown in FIG. 4, 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 projection 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.

[0211]

As described above, claims 1 to 6
According to the image control device according to any one of the claims, the image control method according to the claim 15 or 16, or the image display device according to any one of the claims 7 to 14 ,
Based on the light or electric signal output from the position detecting means, data on the pixel position at the joint portion of each divided screen is obtained, and on the basis of the data on the obtained pixel position, the connection of each divided screen is performed. since the seek guessing data relating the pixel positions of the regions other than the eye portion, align properly connecting a plurality of split screens when co
To an effect that the data required in order to perform satisfactorily image display over the entire screen can be obtained over the screen throughout.

[0212] The method according to any one of claims 1 to 6
An image control device, the image according to claim 15 or claim 16.
An image control method or any one of claims 7 to 14
According to the image display device described above, further, control for correcting image data such that a plurality of divided screens are properly connected based on the obtained data on each pixel position and the entire screen is properly displayed. So that
With joint portions can if <br/> Align Rukoto connecting a plurality of split screens unobtrusively, an effect that it is possible to perform good image display over the entire screen.

[0213]

[0214]

In particular, according to the image control device described in claim 5 or the image display device described in claim 11 , in the image control device described in claim 3 or the image display device described in claim 9 , 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 estimated from the correction data for the representative pixel. As well as a possible reduction in the 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 circuit diagram showing an equivalent circuit of a circuit formed by circuit elements around an index electrode in the cathode ray tube shown in FIG.

FIG. 3 is a characteristic diagram illustrating frequency characteristics of the circuit illustrated in FIG. 2;

FIG. 4 is a block diagram showing a configuration of a signal processing circuit in the cathode ray tube shown in FIG.

5 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. 4;

6 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. 4;

FIG. 7 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. 8 is an explanatory diagram showing a display example when the reference image shown in FIG. 7 is displayed on the cathode ray tube shown in FIG. 1;

FIG. 9 is an explanatory diagram schematically showing correction data used in the processing circuit shown in FIG. 4;

FIG. 10 is an explanatory diagram illustrating a state of deformation of an input image when a correction operation using correction data is not performed in the processing circuit illustrated in FIG. 4;

11 is an explanatory diagram illustrating a state of deformation of an input image when a correction operation using correction data is performed in the processing circuit illustrated in FIG. 4;

FIG. 12 is an explanatory diagram illustrating a first method of the correction operation processing in the processing circuit illustrated in FIG. 4;

FIG. 13 is an explanatory diagram illustrating a second method of the correction operation processing in the processing circuit illustrated in FIG. 4;

FIG. 14 is an explanatory diagram illustrating control points used in a third method of the correction operation processing in the processing circuit illustrated in FIG. 4;

FIG. 15 is an explanatory diagram showing interpolation used in a third method of the correction operation processing in the processing circuit shown in FIG. 4;

FIG. 16 is an explanatory diagram illustrating extrapolation used in a third method of the correction operation processing in the processing circuit illustrated in FIG. 4;

FIG. 17 is an explanatory diagram illustrating an example of a change in an image due to the influence of terrestrial magnetism.

FIG. 18 is an explanatory diagram showing an example of a method of calculating a fine movement amount of correction data.

FIG. 19 is a flowchart illustrating a method of calculating a fine movement amount of correction data.

20 is a diagram for describing conversion of the number of pixels performed in the processing circuit illustrated in FIG. 4, and is an explanatory diagram illustrating an example of an original image before performing image enlargement and the like.

FIG. 21 is an explanatory diagram showing an example of an image obtained by enlarging the size of the original image shown in FIG. 20;

22 is a diagram illustrating a relationship between a pixel position in the original image illustrated in FIG. 20 and a pixel position in the enlarged image illustrated in FIG. 21;

FIG. 23 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. 20;

24 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. 4;

FIG. 25 is an explanatory diagram for explaining a structure of an index electrode in the cathode ray tube shown in FIG. 1 and a position detecting operation using the index electrode.

26 is an external view showing another configuration example of the index electrode shown in FIG. 25.

FIG. 27 is an external view showing still another configuration example of the index electrode shown in FIG. 25.

28 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;

29 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.

FIG. 30 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. 1;

FIG. 31 is an explanatory diagram showing a relationship between a scanning position of an electron beam and timing of luminance modulation control in the cathode ray tube shown in FIG. 1;

FIG. 32 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. 33 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. 34 is an explanatory diagram showing a specific example of arithmetic processing performed on image data for the right divided screen in the second embodiment of the present invention.

FIG. 35 is an explanatory diagram showing a display example when an image is displayed based on the reference image shown in FIG. 7 in the second embodiment of the present invention.

FIG. 36 is an explanatory diagram for explaining a structure of an index electrode in a cathode ray tube according to a second embodiment of the present invention and a position detecting operation using the index electrode.

FIG. 37 is a configuration diagram schematically showing a cathode ray tube which is an example of an image display device according to a third embodiment of the present invention.

38 is a configuration diagram showing an example of an index plate in the cathode ray tube shown in FIG.

39 is a configuration diagram showing another example of the index plate in the cathode ray tube shown in FIG. 37.

[Explanation of symbols]

eBL, eBR: electron beam, OS: overscanning area, S2
... index signal, 10 ... panel part, 11 ... fluorescent screen,
12 ... color selection mechanism, 13 ... frame, 14 ... support spring,
20: funnel part, 21L, 21R: deflection yoke, 2
2: Internal conductive film, 23: External conductive film, 70, 70A: Index electrode, 26: Lead wire, 30L, 30R: Neck, 31L, 31R: Electron gun, 32L, 32R: Convergence yoke, 50L, 50R, 55L1 , 55
L2, 55R1, 55R2: DSP circuit, 51: Composite / RGB converter, 52: A / D converter, 53, 5
6L, 56R: frame memory, 54, 63: memory controller, 57L, 57R: D / A converter, 60: correction data memory, 61: index signal processing circuit,
62: control unit, 64: imaging device, 110, 11
0A, 110B ... index plate, 111 ... photodetector,
120 ... Phosphor.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-11-338400 (JP, A) JP-A-11-122562 (JP, A) JP-A-10-283947 (JP, A) JP-A-8-108 186832 (JP, A) JP-A-62-51383 (JP, A) JP-A-2000-138946 (JP, A) JP-A-2000-333102 (JP, A) JP-A 2001-42848 (JP, A) 3-34716 (JP, B2) Patent 3057230 (JP, B1) Patent 3068115 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) G09G 1/00 G09G 5/00 H04N 5/68

Claims (16)

(57) [Claims] 1. A single screen is formed by joining a plurality of divided screens, an image is displayed based on an input video signal , and each divided screen is positioned at a position corresponding to a joint between adjacent divided screens. provided the position detection means for detecting the joint position of the screen, the control of the image displayed on the image display apparatus which can output an optical or electrical signal from the position detecting means in accordance with the display state of the image An image control device for performing, based on the light or electrical signal output from the position detection means, to obtain data on the pixel position of the joint portion of each divided screen, and the obtained pixel position based on the data relating to the position estimating means for obtaining guessing data relating the pixel positions of the regions other than the joint portion of each divided screen, obtained by said position estimating means About the pixel position
Based on the data, the plurality of divided screens are properly connected.
So that the entire screen is properly displayed
A system that performs control to correct image data corresponding to video signals
Image control apparatus being characterized in that a control means. 2. The method according to claim 1, wherein the position estimating means includes a portion other than a joint portion.
First, map pixels in other areas to the joints
Data for the other pixel locations to be
Data on other pixel positions that do not correspond to the eye
2. The image control device according to claim 1, wherein the value is obtained. 3. A correction data storage unit for storing first correction data for correcting a display state of an image obtained from an image displayed on a screen, wherein the position estimating unit includes: As the data relating to the pixel position, second correction data for correcting the first correction data over the entire screen is obtained, and the control unit determines the first correction data stored in the correction data storage unit. And the plurality of divided screens are properly connected , and the entire screen is properly displayed , based on the correction data of (i) and the second correction data as data relating to the pixel position obtained by the position estimating means. so that, the performs calculation for correcting the image data, image control apparatus according to claim 1, wherein the output is converted into a video signal for displaying the image data after the correction. 4. The first and second correction data include:
The data on the amount of movement of each pixel from an appropriate display position in the discretized two-dimensional image data representing the image displayed on the screen. Each pixel value of the image data after correction is an image before correction. 4. The image control device according to claim 3 , wherein the data is calculated using a pixel value at a position shifted by the movement amount. 5. The first and second correction data include:
It is data relating to the amount of movement of each of a plurality of representative pixels in the discretized two-dimensional image data representing the image displayed on the screen from the appropriate display position, and is representative of the corrected image data. The pixel value of each of the plurality of pixels is calculated using the pixel value at a position shifted by the moving amount with respect to the representative pixel in the image data before correction, and the representative pixel value in the image data after correction is calculated. The pixel values of the pixels other than the plurality of pixels are shifted in the image data before correction by a shift amount from the appropriate display position estimated and calculated from the shift amount of the representative pixel. 4. The image control device according to claim 3, wherein the calculation is performed using a certain pixel value. 6. An image display device comprising: a plurality of electron guns that emit a plurality of electron beams for scanning an effective screen and an overscan area outside the effective screen; Provided in the overscanning region of the electron beam, and a cathode ray tube including electron beam detection means corresponding to the position detection means such as outputting a light or an electrical signal in response to the incidence of the electron beam, The position estimating means is configured to detect a position of a joint based on a light or an electric signal output from the electron beam detecting means .
After obtaining the data on the pixel position,
Based on the data on the elementary position,
2. The image control device according to claim 1, wherein the data relating to the pixel position of the region is estimated and obtained . 7. An image display apparatus which forms a single screen by connecting a plurality of divided screens and performs image display based on an input video signal , wherein a joint between adjacent divided screens is provided. A position detecting unit that is provided at a position corresponding to the part and outputs a light or electric signal in accordance with the display state of the image, based on the light or electric signal output from the position detecting unit, A position for obtaining data relating to a pixel position of a joint portion of a divided screen, and estimating data relating to a pixel position of a region other than the joint portion of each divided screen based on the obtained data relating to the pixel position. and estimating means, on the basis of the data for each pixel position obtained by the position estimating means, the plurality of divided screens are combined properly connect, and the entire screen is properly As shown in the above,
An image display device comprising: a control unit that performs control for correcting image data corresponding to a video signal; and an image display unit that displays an image based on the image data corrected by the control unit. 8. The position estimating means includes:
First, map pixels in other areas to the joints
Data for the other pixel locations to be
Data on other pixel positions that do not correspond to the eye
The image display device according to claim 7, wherein the value is obtained. 9. A correction data storage unit for storing first correction data for correcting a display state of an image obtained from an image displayed on a screen, wherein the position estimating unit includes: As the data relating to the pixel position, second correction data for correcting the first correction data over the entire screen is obtained, and the control unit determines the first correction data stored in the correction data storage unit. And the plurality of divided screens are properly connected , and the entire screen is properly displayed , based on the correction data of (i) and the second correction data as data relating to the pixel position obtained by the position estimating means. 8. The image display device according to claim 7 , wherein an operation for correcting the image data is performed, and the corrected image data is converted into a video signal for display and output. 10. The first and second correction data are data relating to an amount of movement of each pixel from an appropriate display position in discretized two-dimensional image data representing an image displayed on a screen. 10. The image display according to claim 9 , wherein each pixel value of the corrected image data is calculated using a pixel value at a position shifted by the moving amount in the image data before correction. apparatus. 11. The first and second correction data are obtained from an appropriate 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 is a pixel at a position shifted by the amount of movement with respect to the representative pixel in the image data before correction. The pixel values of pixels other than the representative plurality of pixels in the corrected image data are estimated from the movement amount of the representative pixel in the image data before correction. 10. The image display device according to claim 9, wherein the calculation is performed using a pixel value at a position shifted by an amount of movement from the obtained proper display position. 12. A plurality of electron guns for emitting a plurality of electron beams for scanning an effective screen and an overscan area outside the effective screen, and an electron beam at a joint side between adjacent divided screens. An electron beam detection unit provided in a scanning area and corresponding to the position detection unit that outputs a light or an electric signal in accordance with the incidence of the electron beam; and the position estimation unit includes the electron beam detection unit. Based on the light or electrical signal output from the
After obtaining the data on the pixel position,
Based on the data on the elementary position,
8. The image display device according to claim 7, wherein data relating to the pixel position of the area is estimated and obtained . 13. A member provided with light detecting means for detecting light output from the electron beam detecting means, wherein the electron beam detecting means is provided with a phosphor which emits light in response to the incidence of the electron beam. 13. The image display device according to claim 12, comprising: 14. The image display device according to claim 12, wherein a scanning direction of the plurality of electron beams is a vertical direction or a horizontal direction. 15. A single screen is formed by connecting a plurality of divided screens, an image is displayed based on input image data, and each divided screen is positioned at a position corresponding to a joint between adjacent divided screens. provided the position detection means for detecting the joint position of the screen, the control of the image displayed on the image display apparatus which can output an optical or electrical signal from the position detecting means in accordance with the display state of the image An image control method for performing, based on a light or electric signal output from the position detecting means, data on a pixel position of a joint portion of each divided screen is obtained, and the obtained pixel position is obtained. about on the basis of the data, we determined Me guessing data relating the pixel positions of the regions other than the joint portion of each divided screen, based on the data for each pixel position obtained, Serial
Multiple split screens are properly connected and the whole screen is
The image data corresponding to the video signal is displayed so that it is displayed properly.
An image control method comprising performing control for correcting data. 16. Pixels in an area other than the joint portion
First, the other pixel positions associated with the joint portion
Ask for data about, then do not correspond to the joint
It is characterized by obtaining data on other pixel positions.
16. The image control method according to claim 15, wherein: