JPH05344543A - Instrument for measuring vertical landing deviation - Google Patents

Abstract

PURPOSE:To find out an accurate vertical landing deviation by setting up the brightness of a beam spot equally to that obtained at the time of normal operation of an image display element and displaying two spots in one vertical section. CONSTITUTION:A display element driving circuit 59 displays an image in an image display element 54 and a horizontally deflected voltage adjusting device adjusts the horizontally deflected voltage of the element 54 and a phosphor is accurately irradiate with electron beams. A camera controller 57 controls a television(TV) camera, executes the A/D conversion of an image output and transfers the converted digital data to a computer 58. A robot is moved up to the position of a raster for measuring the TV camera, processes the transferred data and finds out the vertical landing deviation of the beam radiated from the element 54. When the brightness of the beam spot is set up almost equally to that obtained at the normal operation of the element 54, the shape of the beam spot obtained at the time of measurement becomes the same as that of normal operation. Thereby a deviation equal to that obtained at the normal operation of the element 54 can be found out, so that the vertical landing deviation of the image display device can be always accurately found out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generates an electron beam for each division when a screen on a screen is divided into a plurality of divisions in the vertical and horizontal directions. The present invention relates to a beam vertical landing deviation measuring device for an image display device that displays a plurality of lines by deflecting in a horizontal direction and a horizontal direction and displays an image as a whole.

[0002]

2. Description of the Related Art The basic structure of an image display device will be described with reference to FIG.

This display element has a back electrode 1, a line cathode 2 as a beam source, a beam extraction electrode 3, a beam flow control electrode 4, a focusing electrode 5 in this order from the rear to the anode side.
A horizontal deflection electrode 6, a vertical deflection electrode 7, a screen plate 8, etc. are arranged and configured, and these are housed inside a vacuum container.

A line cathode 2 as a beam source is stretched in the horizontal direction so as to generate an electron beam which is linearly distributed in the horizontal direction. (Only 7 of 2 a to 2 are shown)
It is provided. In this configuration, the line cathode spacing is 4.4 mm,
Assuming that 19 pieces are provided, the number of the line cathodes is 2 to 2 pieces. The space between the line cathodes cannot be set freely, and is regulated by the space between the vertical deflection electrode 7 and the screen plate 8 described later. As a configuration of these wire cathodes 2, an oxide cathode material is applied to the surface of a tungsten rod having a diameter of 10 to 30 μm. As will be described later, the above-mentioned line cathode is controlled so as to sequentially emit an electron beam from the upper line cathode 2a to the lower two line cathodes at regular intervals.
The back electrode 1 not only prevents the generation of electron beams from other line cathodes but also pushes out the electron beam only toward the anode. Although a vacuum container is not shown in FIG. 8, it is possible to use the back electrode 1 to form a structure integrated with the vacuum container.

The beam extraction electrode 3 is a conductive plate 11 having a plurality of through-holes 10 which are arranged in a row in the horizontal direction facing each of the line cathodes 2a to 2 and are arranged at regular intervals, and are emitted from the line cathode 2. The electron beam is taken out through the through hole 10.

Next, the beam flow control electrode 4 is connected to the linear cathodes 2a-2.
A plurality of vertically extending conductive plates 15 each having a through hole 14 at a position facing each other are arranged side by side in the horizontal direction at a predetermined interval. 11 in this configuration
Four beam flow control electrode conductive plates 15a to 15n are provided. (In FIG. 8, only eight are shown). The beam flow control electrode 4 controls the passing amount of each of the electron beams horizontally divided by the beam extraction electrode 3 in accordance with the picture element of the video signal and in synchronization with the horizontal deflection timing described later. ing.

The focusing electrode 5 is a conductive plate 17 having a through hole 16 at a position facing each through hole 14 provided in the beam flow control electrode 4, and focuses the electron beam.

The horizontal deflection electrode 6 is composed of a plurality of conductive plates 18 and 18 'vertically arranged along both sides of the through hole 16 in the horizontal direction. A horizontal deflection voltage is applied to ′. The electron beam for each picture element is deflected in the horizontal direction, and the R, G, and B phosphors are sequentially irradiated on the screen 8 to emit light. In this configuration, each electron beam is deflected by 2 trio.

The vertical deflection electrode 7 is composed of a plurality of conductive plates 19 and 19 'arranged in the horizontal direction at the respective intermediate positions in the vertical direction of the through hole 16, and a vertical deflection voltage is applied to the vertical deflection electrode 7. The electron beam is vertically deflected.
In this structure, the electron beam generated from one line cathode is deflected by 12 lines in the vertical direction by the pair of electrodes 19 and 19 '. And a vertical deflection electrode 7 composed of 20 pieces
Thus, 19 pairs of vertical deflection conductor pairs corresponding to 19 line cathodes are formed, and 228 horizontal scanning lines are drawn in the vertical direction on the screen 8.

As described above, in this structure, a plurality of horizontal deflection electrodes 6 and vertical deflection electrodes 7 are arranged in a comb shape. Further, by setting the distance to the screen 8 longer than the distance between the horizontal and vertical deflection electrodes, it becomes possible to irradiate the screen 8 with an electron beam with a small deflection amount. As a result, horizontal and vertical co-deflection distortion can be reduced.

As shown in FIG. 8, the screen 8 is formed by coating the back surface of the glass plate 21 with the phosphor 20 in a stripe shape. Although not shown, metal back and carbon are also applied. The phosphor 20 horizontally deflects the electron beam passing through one of the through holes 14 of the beam flow control electrode 4 to form two phosphor pairs of three colors of R, G, and B.
It is provided to irradiate the amount of trio, and is applied in stripes in the vertical direction.

In FIG. 8, broken lines drawn on the screen 8 indicate vertical divisions displayed corresponding to the plurality of line cathodes 2, and two-dot chain lines indicate each of the plurality of beam flow control electrodes 4. Shows the horizontal divisions displayed in correspondence with. FIG. 9 shows an enlarged view of one section partitioned by a broken line and a two-dot chain line. As shown in FIG. 9, two trio R, G, and B phosphors have a width in the horizontal direction and a width of 12 lines in the vertical direction. In this example, the size of one section is 1 mm in the horizontal direction and 4.4 mm in the vertical direction. In FIG. 9, R, G,
Although the phosphors of three colors of B are illustrated in a stripe shape, they may be arranged in a delta shape. However, when they are arranged in a delta shape, it is necessary to apply horizontal deflection and vertical deflection waveforms suitable for them. Note that, in FIG. 8, the vertical and horizontal dimensional ratios are different from those actually displayed on the screen for convenience of explanation. Further, in this configuration, R, G, and B phosphors for two trios are provided for one through hole 14 of the beam flow control electrode 4, but one trio or three trios or more is used. Is also good. However, 1 for the beam flow control electrode 4
Trio, or R, G, B video signals of 3 or more trios are sequentially added, and horizontal deflection must be performed in synchronization with them.

Next, the operation of the display element drive circuit of this image display element will be described with reference to FIG. First, the drive portion that irradiates the screen 8 with the electron beam and displays the electron beam will be described. The power supply circuit 22 is a circuit for applying a predetermined bias voltage to each electrode of the display device. The power supply circuit 22 has V1 for the back electrode 1, V3 for the beam extraction electrode 3, V5 for the focusing electrode 5, and V8 for the screen 8. Apply DC voltage respectively.

The line cathode drive circuit 26 uses the vertical synchronizing signal V and the horizontal synchronizing signal H to create line cathode drive pulses (a to t). FIG. 11 shows the timing chart. As shown in FIG. 11 (a to c), each of the line cathodes 2a to 2c is heated by the current flowing while the drive pulse is at a high potential, and the drive pulse (a to c) is at a low potential period. The heating state is maintained so as to emit electrons. As a result, electrons are emitted from the 19 line cathodes 2a to 2t only during the 12 horizontal scanning periods in which low potential drive pulses (a to t) are applied. During the period when the high potential is applied, the linear cathode 2 is higher than the potential around the linear cathode 2 determined by the bias voltage applied to the back electrode 1 and the beam extraction electrode 3.
Since the potential applied to a to two is higher,
No electrons are emitted from the line cathode. To compose one screen, the upper line cathode 2 a to the lower line cathode 2 a are sequentially
It suffices to switch the potential every two scanning periods.

Next, the deflecting portion will be described. The deflection voltage generation circuit 40 includes a direct memory access controller (hereinafter referred to as a DMA controller) 41, a deflection voltage waveform storage memory (hereinafter referred to as a deflection memory) 42, a horizontal deflection signal generator 43h, a vertical deflection signal generator 43v, and the like. It is configured to generate vertical deflection signals v, v'and horizontal deflection signals h, h '. In this configuration, the vertical deflection signal is displayed in 228 horizontal scanning periods in one field in consideration of overscan. In addition, the memory address area storing the vertical deflection position information corresponding to each line is divided into a first field and a second field, and each has a set of memory capacity. When displaying, data is read from the corresponding deflection memory 42, converted into an analog signal by the vertical deflection signal generator 43v, and added to the vertical deflection electrode 7. The vertical deflection position information stored in the deflection memory 42 is composed of regular data for every 12 horizontal scanning periods, and the waveform converted into the vertical deflection signal is also a 12-step vertical deflection signal. As described above, the memory capacity for two fields is provided so that the position can be finely adjusted for each horizontal scanning line. Regarding the horizontal deflection signal, it is necessary to horizontally deflect the electron beam in six steps in one horizontal scanning period, and a memory is provided so that the deflection position can be finely adjusted for each horizontal scanning. Therefore, assuming that 456 horizontal scanning periods are displayed during one frame, 456
A memory of × 6 = 2736 bytes is required, but since the data of the first field and the second field are shared, the memory of 1368 bytes is actually used.
When displaying, the deflection information corresponding to each horizontal scanning line is read from the deflection memory 42, and the horizontal deflection signal generator 4 is read.
It is converted into an analog signal in 3 h and added to the horizontal deflection electrode 6. In summary, during the display period of the vertical cycle excluding the vertical blanking period, the electron beam emitted from the linear cathode of the linear cathodes 2a to 2c to which the low-potential drive pulse is applied is the beam. 1 by the extraction electrode 3 in the horizontal direction
It is divided into 14 sections to form 114 electron beam trains. As will be described later, the beam flow control electrode 4 controls the beam passage amount of each electron beam, the electron beam is focused by the focusing electrode 5, and then the electron beam changes in approximately six stages as shown in FIG. Horizontal deflection signals h, h '
Are added to the horizontal deflection electrodes 18, 18 'and the like, R1, G1, B1 and R of the screen 8 are displayed in each horizontal display period.
Phosphors such as 2, G2, B2, etc. are sequentially irradiated in horizontal display periods / 6 each. Thus, each horizontal line has 11 rasters
A color image can be displayed on the screen 8 by modulating the electron beam for each of the four sections with the video signals corresponding to R1, G1, B1 and R2, G2, B2.

Next, the electron beam modulation control portion will be described. First, in FIG. 10, the signal input terminals 23R, 2
The R, G, and B video signals added to 3G and 23B are
It is added to 114 sets of sample and hold circuit groups 31a to 31n. The sample-hold groups 31a to 31n are respectively for R1, G1, B1, and R2, G2,
It is composed of six sample and hold circuits for B2. The sampling pulse generating circuit 34 has a horizontal period (63.
During the horizontal display period (about 50 μsec) out of 5 μsec),
Each of 14 sets of sample hold circuits 31a to 31n R
684 (114 ×) corresponding to the sample-hold circuits for 1, G1, B1, and R2, G2, B2
6) Sampling pulses Ra1 to Rn2 are sequentially generated. Each of the 684 sampling pulses is 11
Six samples are added to each of the four sample-hold circuit groups 31a to 31n, so that each sample-hold circuit group has two lines when one line is divided into 114 lines.
The image signals R1, G1, B1, R2, G2, and B2 of the picture elements are individually sampled and held. 114 sets of sample-held R1, G1, B1, R2,
The video signals of G2 and B2 are transferred all at once to the 114 sets of memories 32a to 32n by the transfer pulse t after the completion of the sample hold for one line, and are held there for the next one horizontal scanning period. The held signal is applied to 114 switching circuits 35a to 35n. Switching circuit 3
5a to 35n are R1, G1, B1, R2, and G, respectively.
2 and B2, and a common output terminal for sequentially switching and outputting them, and switching pulses r1, g1, b1, r2, g2, b2 applied from the switching pulse generating circuit 36.
Are simultaneously controlled by the switch. The switching pulses r1, g1, b1, r2, g2, and b2 divide each horizontal display period into six, and switch the switching circuits 35a to 35n by the horizontal display period / 6 every R1, G1, B1 ,.
R2, G2, and B2 video signals are time-divided and sequentially output, and pulse width modulation (hereinafter referred to as PWM) circuits 37a to 3a.
It is being supplied to 7n. Each switching circuit 35a-35
The output of n is applied to 114 sets of PWM circuits 37a to 37n, pulse-width modulated according to the magnitude of each video signal of R1, G1, B1, R2, G2, and B2, and output. The outputs of the PWM circuits 37a to 37n serve as control signals for modulating the electron beam, and are output to the control electrode 4 of the display element 11.
Each of the four conductive plates 15a to 15n is individually added.

Next, the timing of horizontal deflection and display will be described. R in the switching circuits 35a to 35n
Switching of video signals of 1, G1, B1, R2, G2, and B2, and electron beams R1 and G by the horizontal deflection drive circuit 41
The synchronous control is performed so that the switching timing and the order of the horizontal deflection of the phosphors of 1, B1, R2, G2, and B2 to the phosphors completely match. As a result, when the R1 phosphor is irradiated with the electron beam, the irradiation amount of the electron beam is controlled by the R1 control signal, and G1, B1, R2, G2,
The same applies to B2, and R1 and G of each picture element are controlled.
The emission of each of the phosphors of 1, B1, R2, G2, and B2 is controlled by the video signals of R1, G1, B1, R2, G2, and B2 of the picture element, and the picture image of each picture element is input. The light is displayed according to the signal. This control is simultaneously executed for 114 sets (two picture elements each) for one line, an image of 228 picture elements for one line is displayed, and 228 lines for one field are sequentially performed from the upper line, The image is displayed on the screen 8. Further, the above-described operations are repeated for each field of the input video signal so that a television signal or the like is displayed on the screen 8.
Displayed in.

The basic clock required for this configuration is shown in FIG.
Is supplied from the pulse generating circuit 39 shown in FIG. 1 and the timing is controlled by the horizontal synchronizing signal H and the vertical synchronizing signal V.

By the way, the image display device as described above is
Since it has a structure in which a plurality of image display units each having a single line cathode are connected in the vertical direction, a mechanical assembly error occurs for each image display unit. The relationship of the beam deflection amount differs for each image display unit.

For the above reasons, in order to obtain a raster with good uniformity (a raster in which the joints of each image display unit are not visible as a peculiar pattern) using the image display device as described above, the vertical direction of each electron beam is used. The deflection voltage needs to be adjusted accurately.

However, the adjustable range of the deviation of the vertical beam landing position (hereinafter abbreviated as V landing) caused by the assembly error is the dynamic range of the adjustment, the variation range of the beam spot diameter due to the deflection distortion, and the power consumption increased by the adjustment. Because it is limited by
If the mechanical assembly error is too large, the adjustment becomes impossible. Therefore, it is necessary to measure whether the V landing deviation amount of the assembled image display element is within the adjustable range. Therefore, the V landing deviation amount is measured using the V landing measuring device described below.

FIG. 3 is a block diagram of a V landing measuring device for an image display device, FIG. 4 is a block diagram of an image display device driving circuit for a V landing deviation amount measuring device, and FIG. 12 is a display line switching type line shown in FIG. FIG. 5 is a block diagram of a cathode driving circuit, and FIG. 5 is a block diagram of a horizontal deflection voltage adjusting device for an image display element.

First, the operation of the V landing measuring apparatus for the image display device will be described. In FIG. 3, 54 is an image display element to be measured, 55 is a CCD camera, and 56 is a CCD.
A robot for moving the camera to a predetermined position, 57
Is a camera controller, 58 is a computer, 59 is an image display element drive circuit for driving the image display element,
Reference numeral 60 denotes a horizontal deflection voltage adjusting device for an image display element. First, the image display element 54 displays white (single color is also acceptable) by the signal output from the image display element drive circuit 59.
In this state, a horizontal deflection voltage adjusting device 60 for an image display device, which will be described later, is used to adjust the horizontal deflection voltage for each scanning line so that each electron beam accurately irradiates the phosphor over all the scanning lines. Next, the amount of V landing deviation is measured.
Here, the image display element 54 is the image display element drive circuit 59.
A raster display suitable for measuring the amount of V landing deviation as shown in FIG. First 19
The measurement of the amount of V landing shift between B and 19 'will be described. The CCD camera 55 is set by a robot 56 in an area centered between two beam spots (here, 19a and 19'a) where the V landing displacement amount of the image display element 54 is to be measured. The magnification of the CCD camera 55 is set so that at least two beam spots to be measured enter the area detected by the CCD camera 55. The camera controller 57 is CC
The computer 58 controls the D camera 55 and A / D converts the video output output from the CCD camera 55.
Transfer to. The transferred data is processed by the computer 58 to obtain the vertical diameters of the two beam spots, and the vertical distance between the center points of the vertical diameters of the two beam spots is measured to measure the V landing deviation amount at the measurement point. Can be asked. The data measured here is stored in the data storage area of the computer 58 in a predetermined format. Horizontal processing 1
By performing this for 14 units, the V landing deviation amount between 19a and 19'b can be measured. Next, by moving the CCD camera 55 to the horizontal position a between 19 'and 19' and performing the above processing, the V landing deviation amount between 19 'and 19' can be measured. By repeating the above-described processing up to 19 and 19 ′, the V landing deviation amount of the entire image display element 54 can be measured.

Next, a horizontal deflection voltage adjusting device for an image display device for adjusting the horizontal irradiation position of the beam will be described. In FIG. 5, 54 is an image display element to be adjusted,
59 is an image display element drive circuit, 63 is a light receiving element with R, G and B filters, 64 is an amplifier, 65 is an A / D converter,
66 is a memory, 67 is a controller, 68 is a CPU, 6
Reference numeral 9 is a deflection data storage memory. For the sake of explanation, it is assumed that the horizontal deflection voltage output from the image display element drive circuit 59 can be 256 kinds of voltages V0 to V255. First, the controller 67 fixes the horizontal deflection voltage of the image display element drive circuit 59 to V0. In this state, a raster is drawn on the image display element 54, the light receiving element 63 with R, G, and B filters is attached to the portion to be adjusted on the screen, and the output of the light receiving element 63 of each color for each scanning line is input to the amplifier 64. .. The amplifier 64 adjusts the amplitude and offset of the waveform so as to match the input level of the A / D converter 65. The A / D converter 65 receives the input from the amplifier 64 as A / D.
The data is D converted and stored in the memory 66. If the number of scanning lines = 228, the data amount becomes 228 × 3, and the required time is 1 /
60 seconds. Next, the horizontal deflection voltage is fixed at V1 and the same operation is repeated. The above operation is repeated until the horizontal deflection voltage becomes V255. The total data volume is 228 x 3 x 256, and the required time is (1/60) x 256 (approximately 4.3
Seconds). Next, a method of creating horizontal deflection data based on 228 × 3 × 256 data will be described with reference to FIG. When one scanning line is fixed and the horizontal deflection voltage is used as a variable, the output of each of the light receiving elements 63 with R, G, and B filters is plotted as fR, fG, and fB in FIG. The horizontal h deflection voltage that gives a maximum to each of fR, fG, and fB is connected to the stairs in the order of R1, G1, B1, R2, G2, and B2, and the horizontal h is necessary to draw the scanning line specified above. It becomes a deflection voltage waveform. The adjustment for horizontal deflection is completed by obtaining the horizontal deflection voltage waveform in the same manner for all the scanning lines. The above data manipulation is CP
The horizontal deflection data stored in the deflection data storage memory 69 (the vertical deflection data and the horizontal deflection data are stored in advance in the deflection data storage memory 69) can be performed by using U68. The area is overwritten.

Next, the operation of the image display element drive circuit 59 will be described with reference to FIG. 4 separately for the horizontal deflection voltage adjustment and the V landing deviation amount measurement. In FIG. 4, a power supply circuit 61 is a circuit for applying a predetermined bias voltage to each electrode of the image display element 54. The back electrode 1 is V1, the beam extraction electrode 3 is V3, and the beam flow control electrode 4 is. Is applied to the focusing electrode 5, and a DC voltage of V8 is applied to the screen 8. The pulse generating circuit 39 generates a basic clock (the timing is controlled by the horizontal synchronizing signal H and the vertical synchronizing signal V) and various control signals necessary for this configuration and supplies them to each block of this configuration.

First, the operation during white display before adjusting the horizontal deflection voltage will be described. First, the drive portion that irradiates the screen 8 with the electron beam and displays the electron beam will be described. The display line switching type line cathode drive circuit 62 uses the horizontal synchronizing signal H and the control signal output from the pulse generation circuit 39 to create line cathode drive pulses (a to t). At this point,
The line cathode drive pulse changeover switch 53 (a to t) in FIG.
Is switched to the a side, the linear cathode drive pulse (a ~
Is output from the display line switching type line cathode drive circuit 62 at the timing shown in FIG. As shown in FIG. 11 (a to c), each of the linear cathodes 2a to 2c is heated by a current flowing while the drive pulse is at a high potential.
The heating state is maintained so that (c) emits electrons during a low potential period. As a result, electrons are emitted from the 19 line cathodes 2a to 2t only during the 12 horizontal scanning periods in which low potential drive pulses (a to t) are applied. During the period in which the high potential is applied, the potential is applied to the line cathodes 2a to 2t higher than the potential around the line cathode 2 determined by the bias voltage applied to the back electrode 1 and the beam extraction electrode 3. Since the potential is higher, no electrons are emitted from the line cathode. In order to form one screen, the line cathode drive pulse may be sequentially applied every 12 horizontal scanning periods from the upper line cathode 2a to the lower line cathodes 2.

Next, the deflection portion will be described. The deflection voltage generation circuit 40 includes a DMA controller 41, a horizontal deflection signal generator 43h, a vertical deflection signal generator 43v, etc., and generates vertical deflection signals v, v ′ and horizontal deflection signals h, h ′. In this configuration, the vertical deflection signal is displayed in 228 horizontal scanning periods in one field in consideration of overscan. The memory address area storing the vertical deflection position information corresponding to each line has a memory capacity for one field, and the same data is used in both the first field and the second field. When displaying, the vertical deflection data is read from the deflection data storage memory 69 of the horizontal deflection voltage adjusting device 60 and converted into an analog signal by the vertical deflection signal generator 43v,
It is added to the vertical deflection electrode 7. The vertical deflection position information stored in the deflection data storage memory 69 is composed of completely regular data every 12 horizontal scanning periods.
The waveform converted into the vertical deflection signal is also a 12-stage vertical deflection signal. Regarding the horizontal deflection signal, it is necessary to horizontally deflect the electron beam in six steps in one horizontal scanning period, and a memory is provided so that the deflection position can be finely adjusted for each horizontal scanning. Therefore, in order to display 456 horizontal scanning periods in one frame, a memory of 456 × 6 = 2736 bytes is required, but since the data of the first field and the second field are shared, it is actually 1368 bytes. You are using memory. Before the horizontal deflection voltage adjustment, the same horizontal deflection data (six stages of completely regular data in one horizontal scanning period) is stored in advance in the deflection data storage memory 69 for all horizontal scanning lines. The waveform converted into a signal is also a horizontal deflection signal of 6 stages. After the horizontal deflection voltage adjustment, the horizontal deflection data for each horizontal scanning line obtained by the horizontal deflection voltage adjusting device 60 is stored in the deflection data storage memory 69. At the time of display, deflection information corresponding to each horizontal scanning line is read from the deflection data storage memory 69, converted into an analog signal by the horizontal deflection signal generator 43h, and added to the horizontal deflection electrode 6.

In summary, during the display period of the vertical cycle excluding the vertical blanking period, the electron beam emitted from the linear cathode of the linear cathodes 2A to 2C to which the low-potential drive pulse is applied. Are divided into 114 sections in the horizontal direction by the beam extraction electrode 3 to form 114 electron beam trains. As will be described later, the electron beam is controlled by the beam flow control electrode 4 for each section so that the beam passage amount is controlled, and the electron beam is focused by the focusing electrode 5, and then the electron beam is changed into approximately six stages as shown in FIG. Horizontal deflection signal h of
With the horizontal deflection electrodes 18, 18 ', etc. to which h'is added,
In each horizontal display period, the phosphors such as R1, G1, B1 and R2, G2, B2 of the screen 8 are sequentially displayed in the horizontal display period / 6.
It is irradiated one by one. In the case of this image display element drive circuit for the V-landing measuring apparatus, since the constant voltage V4 is applied to the beam flow control electrode 4 instead of the signal pulse width modulated by the video signal, the beam extraction is performed. The electron beams extracted by the electrode 3 are all controlled by the control electrode 4.
After passing through, the screen 8 is illuminated and white color is displayed on the screen 8.

Next, the measurement of the V landing deviation amount will be described. First, the drive portion that irradiates the screen 8 with the electron beam and displays the electron beam will be described. The display line switching type line cathode drive circuit 62 uses the horizontal synchronizing signal H and the control signal output from the pulse generation circuit 39 to create line cathode drive pulses (a to t). At this point in time, since the line cathode drive pulse changeover switch 53 (a to t) in FIG. 12 is switched to the b side, the line cathode drive pulse (a to t) processed by the 1 & 12 line selection unit 51 is changed to that in FIG. It is output from the display line switching type line cathode drive circuit 62 at the timing shown in FIG. As shown in FIGS. 13A to 13C, each of the linear cathodes 2A to 2C is heated by the current flowing while the drive pulse is at a high potential, and the drive pulse (A to C) is at a low potential period. The heating state is maintained so as to emit electrons. As a result, only the two horizontal scanning periods (corresponding to line 1 and line 12 in FIG. 9) in which low-potential drive pulses (a to t) are respectively applied from the 19 line cathodes 2a to 2 Is released. During the period when the high potential is applied, the linear cathode 2 is higher than the potential around the linear cathode 2 determined by the bias voltage applied to the back electrode 1 and the beam extraction electrode 3.
Since the potential applied to a to two is higher,
No electrons are emitted from the line cathode. To compose one screen, the upper line cathode 2 a to the lower line cathode 2 a are sequentially
The line cathode drive pulse may be applied every two horizontal scanning periods.

Next, the deflection portion will be described. The vertical deflection waveform is the same as in the above horizontal voltage adjustment, and therefore its description is omitted. The horizontal deflection signal will be described. Immediately after the horizontal deflection voltage adjustment, the area corresponding to each horizontal scanning line of the deflection data storage memory 69 of the horizontal deflection voltage adjustment device 60 is set in FIG.
R1, G1, B1, R2, G of each scan line as shown in
All horizontal scanning line segments are stored with horizontal deflection data capable of generating a horizontal deflection signal as shown in FIG. 11 for accurately irradiating the phosphors of No. 2 and B2 with an electron beam. Here, for example, if the beam spot diameter is measured with the fluorescent substance of G1 in FIG. 9 in the line 1 in one section in the vertical direction and with the fluorescent substance of G2 in the line 12, before measuring the V landing deviation amount, R1 and B of the horizontal deflection waveform of line 1 shown in FIG.
The horizontal deflection data for generating the voltage of G1 of line 1 is stored in the memory area for storing the horizontal deflection data for generating the voltages of R1, R2, G2, B2, and R1 of the horizontal deflection waveform of line 12 shown in FIG. The horizontal deflection data for generating the voltage of G2 on the line 12 is written in the memory area for storing the horizontal deflection data for generating the voltages of B1, G1, R2 and B2. This operation is performed by the horizontal deflection voltage adjusting device 6
0 CPU 68. At the time of display, the deflection data corresponding to each horizontal scanning line is read from the deflection data storage memory 69, converted into an analog signal by the horizontal deflection signal generator 43h, and added to the horizontal deflection electrode 6 for each scanning. During the line display period, the electron beam is exactly on the G1 phosphor on line 1 and G2 on line 12 of each unit.
The phosphor is irradiated. The horizontal deflection signal at this time is shown in FIG.
The waveform is as shown in. When measuring the V landing shift amount using a fluorescent substance other than G1 and G2, the beam may be irradiated only to the selected fluorescent substance by performing the same process as above.

In summary, the electron beam emitted from the line cathodes of the line cathodes 2A to 2C to which the low-potential drive pulse is applied during the display period excluding the vertical blanking period of the vertical cycle. Are divided into 114 sections in the horizontal direction by the beam extraction electrode 3 to form 114 electron beam trains. The passing amount of the electron beam is controlled by the beam flow control electrode 4 for each section, and the focusing electrode 5
After being focused by the horizontal deflection signals h and h'as shown in FIG. 13, the horizontal deflection electrodes 18 and 18 ', etc., cause G1 in the line 1 of each vertical unit of the screen 8 during each horizontal display period. In the line 12, the G2 phosphor is irradiated. In the case of this image display element drive circuit for the V-landing measuring device, since the constant voltage V4 is applied to the beam flow control electrode 4 instead of the signal pulse width modulated by the video signal, the beam extraction electrode 3
All the electron beams extracted by the beam pass through the control electrode 4 and are applied to the screen 8. Therefore, the screen 8
Shows a measurement pattern as shown in FIG. The brightness of the beam spot in this case is about 6 times as high as when the image display element 54 is normally operated.

The quality of the image display element can be determined by measuring the V landing deviation amount of the image display element with the V landing measuring device for the image display element as described above.

[0033]

However, in the V landing measuring apparatus for an image display device having the above-mentioned structure, the brightness of the beam spot at the time of measuring the V landing deviation amount is about 6 times that of the normal operation of the image display device. Therefore, the shape of the beam spot during measurement is different from the shape of the beam spot during normal operation, and therefore the vertical diameter of the beam spot to be measured is different from that during normal operation. There is a problem in that the distance between the center points of the vertical diameters of the spots may be different from that during normal operation, and it may not be possible to obtain an accurate V landing deviation amount of the image display element.

In view of the above-mentioned problems, the present invention uses the conventional line cathode drive pulse in which the first line and the 12th line in one vertical section are used.
At the time of measuring the V landing deviation amount, the low potential period of the line had the same pulse width as that of one horizontal scanning period, but the pulse width of the low potential period was changed to about 1/6 the width of one horizontal scanning period. Since the brightness of the beam spot becomes almost equal to that when the image display element is normally operated, and the distance between the center points of the vertical diameters of the two beam spots can be measured under almost the same conditions as in the normal operation. The present invention provides a V landing measuring device for an image display device, which can always obtain an accurate V landing deviation amount of the image display device.

[0035]

In order to solve the above problems, a beam vertical landing deviation amount measuring apparatus for an image display device of the present invention is one component of the beam vertical landing deviation amount measuring apparatus. Display line switching type line cathode drive pulse for generating a pulse for driving the line cathode of the image display element of the image display element drive circuit for displaying the raster for measuring the vertical landing shift amount of the beam on the display element In the generation circuit, set the pulse width of the low potential period when measuring the V landing deviation amount to about 1 of the horizontal scanning period.
A pulse width shortening circuit for changing the period to / 6 is added, and the pulse width of the low potential period of the line cathode drive pulse at the time of measuring the V landing deviation amount is set to about ⅙ of one horizontal scanning period. ..

[0036]

According to the present invention, by setting the pulse width of the low potential period of the line cathode drive pulse at the time of measuring the V landing displacement amount to about 1/6 of one horizontal scanning period, the beam at the time of measuring the V landing displacement amount can be obtained. The spot brightness is almost the same as when the image display element is operating normally, and the distance between the center points of the vertical diameters of the two beam spots can be measured under almost the same conditions as during normal operation, so it is always accurate. It is possible to realize a V landing measuring device for an image display element, which can obtain a V landing deviation amount of a different image display element.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A V-landing measuring apparatus for an image display device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a block diagram of a V landing measuring device for the image display device, FIG. 4 is a block diagram of an image display device driving circuit for the V landing deviation amount measuring device, and FIG. 1 is FIG.
A block diagram of the display line switching type line cathode drive circuit shown in FIG.
FIG. 5 is a block diagram of a horizontal deflection voltage adjusting device for an image display device.

First, the operation of the V landing measuring apparatus for the image display device will be described. In FIG. 3, 54 is an image display element to be measured, 55 is a CCD camera, and 56 is a CCD.
A robot for moving the camera to a predetermined position, 57
Is a camera controller, 58 is a computer, 59 is an image display element drive circuit for driving the image display element,
Reference numeral 60 denotes a horizontal deflection voltage adjusting device for an image display element. First, the image display element 54 displays white (single color is also acceptable) by the signal output from the image display element drive circuit 59.
In this state, a horizontal deflection voltage adjusting device 60 for an image display device, which will be described later, is used to adjust the horizontal deflection voltage for each scanning line so that each electron beam accurately irradiates the phosphor over all the scanning lines. Next, the amount of V landing deviation is measured.
Here, the image display element 54 is the image display element drive circuit 59.
A raster display suitable for measuring the amount of V landing deviation as shown in FIG. First 19
The measurement of the amount of V landing shift between B and 19 'will be described. The CCD camera 55 is set by a robot 56 in an area centered between two beam spots (here, 19a and 19'a) where the V landing displacement amount of the image display element 54 is to be measured. The magnification of the CCD camera 55 is set so that at least two beam spots to be measured enter the area detected by the CCD camera 55. The camera controller 57 is CC
The computer 58 controls the D camera 55 and A / D converts the video output output from the CCD camera 55.
Transfer to. The transferred data is processed by the computer 58 to obtain the vertical diameters of the two beam spots, and the vertical distance between the center points of the vertical diameters of the two beam spots is measured to measure the V landing deviation amount at the measurement point. Can be asked. The data measured here is stored in the data storage area of the computer 58 in a predetermined format. Horizontal processing 1
By performing this for 14 units, the V landing deviation amount between 19a and 19'b can be measured. Next, by moving the CCD camera 55 to the horizontal position a between 19 'and 19' and performing the above processing, the V landing deviation amount between 19 'and 19' can be measured. By repeating the above-described processing up to 19 and 19 ′, the V landing deviation amount of the entire image display element 54 can be measured.

The horizontal deflection voltage adjusting device for an image display element for adjusting the horizontal irradiation position of the beam is the same as the conventional one, and therefore its explanation is omitted.

Next, the operation of the image display element drive circuit 59 will be described separately with reference to FIG. 4 for the horizontal deflection voltage adjustment and the V landing deviation amount measurement. In FIG. 4, a power supply circuit 61 is a circuit for applying a predetermined bias voltage to each electrode of the image display element 54. The back electrode 1 is V1, the beam extraction electrode 3 is V3, and the beam flow control electrode 4 is. Is applied to the focusing electrode 5, and a DC voltage of V8 is applied to the screen 8. The pulse generating circuit 39 generates a basic clock (the timing is controlled by the horizontal synchronizing signal H and the vertical synchronizing signal V) and various control signals necessary for this configuration and supplies them to each block of this configuration.

First, the operation at the time of white display before adjusting the horizontal deflection voltage is performed, but since this operation is the same as the conventional one, its explanation is omitted. Next, the measurement of the V landing deviation amount will be described.

First, the drive portion for irradiating the screen 8 with the electron beam to display the image will be described. The display line switching type line cathode drive circuit 62 uses the horizontal synchronizing signal H and the control signal output from the pulse generation circuit 39 to create line cathode drive pulses (a to t). At this point in time, since the line cathode drive pulse changeover switch 53 (a to t) in FIG. 1 is switched to the b side, the line cathode drive pulse (a to t) processed by the 1 & 12 line selection unit 51 is further pulsed. The width shortening circuit 52 shortens the pulse width of the low potential period to about ⅙ of one horizontal scanning period, and it is output from the display line switching type line cathode driving circuit 62 at the timing shown in FIG. As shown in FIG. 2 (a to c), each of the linear cathodes 2a to 2c is heated by a current flowing while the drive pulse is at a high potential, and the drive pulse (a to c) is at a low potential period. The heating state is maintained so as to emit electrons. This gives 19 line cathodes 2
Drive pulse of low potential from a to two (a to t)
The electrons are emitted only for about 1/6 of one horizontal scanning period (corresponding to line 1 and line 12 in FIG. 9). During the period in which the high potential is applied, the potential is applied to the line cathodes 2a to 2t higher than the potential around the line cathode 2 determined by the bias voltage applied to the back electrode 1 and the beam extraction electrode 3. Since the potential is higher, no electrons are emitted from the line cathode. In order to form one screen, the line cathode drive pulse may be sequentially applied every 12 horizontal scanning periods from the upper line cathode 2a to the lower line cathodes 2.

Next, a description will be given of the deflecting portion, but since it is the same as the conventional V landing deviation amount measuring device, it will be omitted.

In summary, the electron beams emitted from the line cathodes of the line cathodes 2a to 2c to which the drive pulse of the low potential is applied during the display period excluding the vertical blanking period of the vertical cycle. Are divided into 114 sections in the horizontal direction by the beam extraction electrode 3 to form 114 electron beam trains. The passing amount of the electron beam is controlled by the beam flow control electrode 4 for each section, and the focusing electrode 5
After being focused by the horizontal deflection electrodes 18 and 18 ', to which horizontal deflection signals h and h'are added as shown in FIG. 2, G1 is applied to the line 1 of each vertical unit of the screen 8 during each horizontal display period. In the line 12, the G2 phosphor is irradiated. In the case of this image display element drive circuit for the V-landing measuring device, since the constant voltage V4 is applied to the beam flow control electrode 4 instead of the signal pulse width modulated by the video signal, the beam extraction electrode 3
All the electron beams extracted by the beam pass through the control electrode 4 and are applied to the screen 8. Therefore, when the low potential period of the line cathode drive pulse is the same length as one horizontal scanning period as in the conventional case, the brightness of the beam spot at the time of measuring the V landing deviation amount is about 6 times that of the normal operation of the image display element. Therefore, the shape of the beam spot during measurement was different from the shape of the beam spot during normal operation, but the low potential period of the line cathode drive pulse was approximately 1/1 of one horizontal scanning period.
By changing the width to 6, the brightness of the beam spot at the time of measuring the V landing deviation amount becomes almost the same as that when the image display element normally operates, and the shape of the beam spot at the time of measuring the V landing deviation amount is the shape at the normal operation. Is almost equal to.

As described above, according to this embodiment, the pulse width in the low potential period is changed to the linear cathode drive pulse whose width is about ⅙ of one horizontal scanning period, so that the beam spot at the time of measuring the V landing displacement amount is measured. Since the luminance of the image display element is almost equal to that when the image display element is normally operated, and the distance between the center points of the vertical diameters of the two beam spots can be measured under almost the same conditions as in the normal operation, it is always accurate. It is possible to obtain the V landing deviation amount of the image display element.

[0047]

As described above, according to the present invention, it is one component of the apparatus for measuring the amount of vertical landing deviation of a beam.
Display line switching type line cathode drive for generating a pulse for driving the line cathode of the image display element of the image display element drive circuit for displaying the raster for measuring the vertical landing shift amount of the beam on the image display element By adding a pulse width shortening circuit to the pulse generation circuit, which reduces the pulse width of the low potential period during measurement of the V landing deviation amount to about 1/6 of one horizontal scanning period, The pulse width of the potential period is about 1/6 of one horizontal scanning period
By changing to the width of the line cathode drive pulse, the brightness of the beam spot at the time of measuring the amount of V landing deviation becomes almost equal to that when the image display element is normally operated, and the two beam spots are dropped under the same conditions as in the normal operation. Since it is possible to measure the distance between the center points of the diameter, it is possible to always obtain an accurate V landing deviation amount of the image display element.

[Brief description of drawings]

FIG. 1 is a block diagram of a display line switching type line cathode drive circuit according to an embodiment of the present invention.

FIG. 2 is a waveform diagram for explaining the operation of the image display element drive circuit of the present invention.

FIG. 3 is a block diagram of a V landing measuring device for an image display device.

FIG. 4 is a block diagram of an image display element driving circuit for a V landing deviation amount measuring device.

FIG. 5 is a block diagram of a horizontal deflection voltage adjusting device for an image display device.

FIG. 6 is an explanatory diagram of a method of creating horizontal deflection data.

FIG. 7 is a part of a raster pattern for measuring the amount of V landing deviation displayed on the image display device.

FIG. 8 is an exploded perspective view of an image display device used in the present invention.

FIG. 9 is an enlarged view of a phosphor screen of the image display device.

FIG. 10 is a block diagram of an image display device using the image display device.

FIG. 11 is a waveform diagram for explaining the operation of the image display device.

FIG. 12 is a block diagram of a conventional display line switching type line cathode drive circuit.

FIG. 13 is a waveform diagram for explaining the operation of a conventional image display element drive circuit.

[Explanation of symbols]

50 line cathode drive pulse generation unit 51 1 & 12 line selection unit 52 pulse width shortening circuit 53 line cathode drive pulse changeover switch 54 image display device to be fixed 55 CCD camera 56 robot for moving CD camera to predetermined position 57 camera controller 58 computer 59 image display element drive circuit for driving image display element 60 horizontal deflection voltage adjusting device for image display element 61 power supply circuit 62 display line switching type line cathode drive circuit 63 light receiving element with R, G, B filter 64 amplifier 65 A / D converter 66 Memory 67 Controller 68 CPU 69 Deflection data storage memory

Claims (1)

[Claims] 1. A screen on a screen is vertically divided into a plurality of sections, and an electron beam generated from a line cathode provided for each vertical section is deflected in the vertical and horizontal directions. A beam for an image display element which forms a color image by many beam spots formed on the screen by irradiating phosphors of three colors of R, G, B which are vertically stripe-coated on the screen. As a vertical landing deviation amount measuring device, a display element drive circuit for displaying an image on the image display element, and a horizontal deflection for adjusting a horizontal deflection voltage of the image display element for accurately irradiating the phosphor with an electron beam. The voltage regulator, the TV camera that captures a part of the raster displayed on the image display device, and the TV camera are controlled and output from the TV camera. The camera controller that A / D converts the video output to be transferred to the computer, the robot that moves the TV camera to the raster position for measurement, and the vertical landing of the beam of the image display device by processing the data transferred from the camera controller. For each scanning line which is provided with a camera controller and a computer for controlling the robot for determining the deviation amount, and which is obtained by the horizontal deflection voltage adjusting device after the horizontal deflection voltage adjustment and is stored in the adjustment data storage memory of the horizontal deflection voltage adjusting device. Line 1 and line 12 in the vertical section, which are created by using the horizontal deflection data of 2 different fluorescent substances (for example, G1 in line 1 is defined as G1 in line 1). Of phosphor,
In line 12, a horizontal deflection signal for accurately irradiating the G2 phosphor) with an electron beam is input over all scanning lines, and in the line cathode, 1 line and 1 line in one vertical section are input.
A line cathode drive pulse that emits an electron beam during about 1/6 of one horizontal scanning period is input only during the period of two lines so that the brightness of the beam spot becomes substantially equal to that during normal operation of the image display device. And by displaying two beam spots (for example, G1 of line 1 and G2 of line 12) in one vertical section, the spot shape of each beam of the image displayed on the image display device during measurement is Since the shape is almost the same as the normal operating state of the display element,
The vertical landing deviation amount of the beam for the image display element enables the accurate vertical landing deviation amount to be obtained because the vertical landing deviation amount that is almost equal to that appearing in the normal operation state of the image display element is displayed on the image display element. Quantity measuring device.