JPH04188992A - Automatic adjusting device for screen position - Google Patents

Abstract

PURPOSE:To automatically adjust the horizontal and vertical positions by changing horizontal and vertical screen positions so that the luminance distribution on the whole screen may be the same as the reference pattern. CONSTITUTION:The above device is composed of a television camera 54 capable of measuring luminance on the whole screen in a picture display device 50, an A/D converter 53 performing an A/D conversion for a video signal, a controller 51 controlling the screen position data in the picture display device 50 and a personal computer 52 performing the data processing for a video signal and controlling the controller 51. The horizontal or vertical screen position is changed so that the luminance distribution on the whole screen may be the same as the reference pattern, by measuring the luminance distribution on the whole screen in the picture display device 50 with the camera 54 and by comparing the luminance distribution on the whole screen with the preliminarily prepared reference pattern. Thus, the horizontal and vertical screen position in the picture display device 50 can be automatically adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention displays a plurality of scanning lines by vertically deflecting each electron beam when a screen is vertically divided into a plurality of sections. , generally relates to a device for automatically adjusting the horizontal and vertical screen position of a device for displaying television images.

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

This display element has a back electrode 1. Line cathode as a beam source 2° beam extraction electrode 3. Beam flow control electrode 4. Focusing electrode5. Horizontal deflection electrode 6. Vertical deflection electrode7. A screen plate 8, etc. are arranged, and these are housed inside the vacuum container.

A line cathode 2 serving as a beam source is stretched horizontally so as to generate an electron beam distributed linearly in the horizontal direction.
A plurality of line cathodes 2 are further provided at intervals in the vertical direction (in this description, only seven line cathodes 2A to 2G are shown). In this configuration, the spacing between the line cathodes is 3 m, and the number of line cathodes is 30, and the number of line cathodes is 2 to 27. The spacing between the linear cathodes cannot be freely increased;
This is regulated by the distance between the vertical deflection electrode 7 and the screen 8, which will be described later. The configuration of these line cathodes 2 is 10 to 3.
An oxide cathode material is applied to the surface of a 0 μmφ tungsten rod. As will be described later, the line cathodes are controlled to sequentially emit electron beams from the upper line cathode 2a to the lower line cathode 27 for a fixed period of time. The back electrode 1 has the function of suppressing the generation of electron beams from line cathodes other than the corresponding line cathode, and also has the function of pushing the electron beams only toward the anode. Although the vacuum container is not shown in FIG. 4, it is also possible to adopt a structure in which the back electrode 1 is used to integrate the back electrode 1 with the vacuum container. The beam extraction electrode 3 is the line cathode 2~
The conductive plate 11 has a large number of through holes 10 arranged at regular intervals in the horizontal direction facing each of the wire cathodes 2 and 27.
Take it out through. Next, the control electrode 4 is connected to the line cathodes 2-2.
It is composed of a vertically long conductive plate 15 having a through hole 14 at a position facing each of the conductive plates 7, and a plurality of conductive plates 15 are arranged in parallel in the horizontal direction at a predetermined interval.

In this configuration, there are 120 conductive plates 15a to 15n for control electrodes.
are provided (only 8 are shown in Figure 4)
. The control electrode 4 controls the amount of passage of each of the electron beams divided horizontally by the beam extraction electrode 3 in accordance with the picture elements of the video signal and in synchronization with the timing of horizontal deflection, which will be described later. . 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 control electrode 4, and focuses the electron beam.

The horizontal deflection electrode 6 is composed of a plurality of conductive plates 18 and 18' arranged vertically along both horizontal sides of the through hole 16, and each conductive plate has a horizontal deflection plate. voltage is applied. The electron beam for each picture element is deflected in the horizontal direction, and sequentially irradiates the R, G, and H phosphors on the screen 8 to emit light. In this configuration, each electron beam is deflected by two trios.

The vertical deflection electrodes 7 include a plurality of conductive plates 19 arranged horizontally at vertically intermediate positions of the through holes 16.
．． 19', and a vertical deflection voltage is applied to deflect the electron beam in the vertical direction. In this configuration,
A pair of electrodes 19 and 19' deflects the electron beam generated from one line cathode by eight lines in the vertical direction. Then, by the vertical deflection electrode 7 composed of 31 pieces, 30
Thirty vertical deflection conductor pairs corresponding to each of the line cathodes of the book are constructed to draw 240 horizontal scanning lines in the vertical direction on the screen 8.

As explained above, in this configuration, the horizontal deflection electrode 6. A plurality of vertical deflection electrodes 7 are arranged in a 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 the electron beam with a small deflection amount. This allows horizontal and vertical deflection of the electrode.

As shown in FIG. 4, the screen 8 is constructed by coating the back surface of a glass plate 21 with phosphor 20 in stripes. Although not shown, a metal back and carbon are also coated. The phosphor 20 is located in one through hole 1 of the control electrode 4.
It is designed to irradiate two trios of R, G, and B phosphor pairs by horizontally deflecting the electron beam passing through the phosphor 4, which is applied vertically in stripes. .

In FIG. 4, the broken lines drawn on the screen 8 indicate the vertical divisions displayed corresponding to each of the plurality of line cathodes 2, and the two-dot chain lines indicate the sections corresponding to each of the plurality of control electrodes 4. Indicates the horizontal division that will be displayed. FIG. 5 shows an enlarged view of one section partitioned by broken lines and two-dot chain lines. As shown in Figure 5, in the horizontal direction, R, G for two trios,
The B phosphor has a width of 8 lines in the vertical direction.

In this example, the size of one section is 1 spindle in the horizontal direction and 3M in the vertical direction.
It is.

Although the phosphors of each of the three colors R, G, and B are shown in stripes in FIG. 5, they may be arranged in a delta pattern. However, when arranged in a delta shape, it is necessary to apply horizontal and vertical deflection waveforms that are compatible with the arrangement.

In FIG. 5, for convenience of explanation, the vertical and horizontal dimension ratios are different from the image displayed on the actual screen.

Further, in this configuration, two trios of R, G, and H phosphors are provided for one through hole 14 of the control electrode 4, but the phosphors may be composed of one trio or more than three trios. good. However, one trio or three or more trios of R, G, and B video signals are sequentially arranged on the control electrode 4, and it is necessary to perform horizontal deflection in synchronization with the R, G, and B video signals.

Next, the operation of the drive circuit for driving this display element will be explained with reference to FIG. First, a driving portion that irradiates the screen 8 with an electron beam to display an image will be explained.

The power supply circuit 22 is a circuit for applying a predetermined bias voltage to each electrode of the display element; Vl is applied to the back electrode 1, V3 is applied to the beam extraction electrode 3, V5 is applied to the convergence electrode 5, and ■8 is applied to the screen 8. Apply a DC voltage of The line cathode drive circuit 26 uses the vertical synchronization signal V and the horizontal synchronization signal H to create line cathode drive pulses (I-MA). FIG. 7 shows the timing diagram. As shown in FIG. 6 (I-MA), each line cathode 2A-27 is heated by a current flowing during the period when the drive pulse is at a high potential, and during the period when the drive pulse (I-MA) is at a low potential. The heated state is maintained so as to emit electrons. As a result, electrons are emitted from the 30 line cathodes 2a to 27 only during eight horizontal scanning periods to which low-potential drive pulses (i to ma) are applied, respectively. During the period when a high potential is applied, the potential applied to the line cathodes 2-27 is lower 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. is higher, so no electrons are emitted from the line cathode.

To construct one screen, it is sufficient to sequentially switch from the upper line cathode 2a to the lower line cathode 27 every 8 scanning periods.

Next, the deflection portion will be explained. The deflection voltage generation circuit 40 is connected to a direct memory access controller 41 (hereinafter referred to as D).
MA controller), deflection voltage waveform storage memory 42 (hereinafter referred to as deflection memory), digital-to-analog converters 43h and 43v (hereinafter referred to as D/A converter), etc., and vertical deflection signals v, v. ' and a horizontal deflection signal, h'.

In this configuration, 240 horizontal scanning periods are displayed in one field in consideration of overscanning regarding the vertical deflection signal. Further, the memory address area storing vertical deflection position information corresponding to each line is divided into a first field and a second field, each having one set of memory capacity. When displaying, select the corresponding deflection memory 4
Data is read out from 2, converted into an analog signal by a D/A converter 43v, and applied to the vertical deflection electrode 7. The vertical deflection position information stored in the deflection memory 42 is composed of almost regular data for every 8 horizontal scanning periods, and the D/A converted waveform also becomes a vertical deflection signal of approximately 8 stages. However, it has a memory capacity for two fields as described above, so that the position can be finely adjusted for each horizontal scanning line.

Further, regarding the horizontal deflection signal, it is necessary to horizontally deflect the electron beam in six stages during 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 480 horizontal scanning periods are displayed between one frame, 480x6 = 2880 bytes of memory are required, but since the data of the first field and the second field are shared, the memory is actually 1440 bytes. using memory.

During display, deflection information corresponding to each horizontal scanning line is read out from the deflection memory 42, converted into an analog signal by a D/A converter 43v, and applied to the horizontal deflection electrode 6. To summarize, during the display period excluding the vertical retrace period of the vertical period, the electron beam emitted from the line cathode to which a low-potential drive pulse is applied among the line cathodes 2A to 27 is beam extracted. It is horizontally divided into 120 sections by the electrodes 3, forming 120 electron beam rows.

As will be described later, the amount of beam passing through each section is controlled by a control electrode 4, and after being focused by a focusing electrode 5, the electron beam is passed through a pair of horizontal beams that change in approximately six steps as shown in FIG. The horizontal deflection electrodes 18, 18', etc., to which the deflection signals h' are applied, cause the R1°G1. Bl and R2, G2. B2
The phosphors are sequentially irradiated for each horizontal display period/6.

Thus, each horizontal line raster directs the electron beam to R1, G1 . Bl and R2°G2.
By modulating with the video signal corresponding to B2,
Color images can be displayed on the screen 8.

Next, the modulation control portion of the electron beam will be explained.

First, in FIG. 6, the signal input terminal 23R123G,
Each R, G, and B video signal added to 23B is 120
sample and hold circuits MA318-31n. Each sample hold a31a to 31n is for R1, Gl, Bl, and R2, G2, B2.
It consists of six sample and hold circuits. The sampling pulse generation circuit 34 has a horizontal period (63, 5
During the horizontal display period (approximately 501 US) of .mu.s), the 120 sets of sample and hold circuits 31a to 31n are used for R1 and Gl, respectively.

720 (120×6) sampling pulses Ral to Rn2 corresponding to the sample and hold circuits for B1, R2, G2, and B2 are sequentially generated. Said 720
Six sampling pulses are applied to each of the 120 sample-and-hold circuit sets 31a to 31n, and as a result, each sample-and-hold circuit set receives data for each of two picture elements when one line is divided into 120 pieces. R1,
Gl.

Bl, R2, G2. Each B2 video signal is individually sampled and held. sample held 12
0 set of R1, Gl, B1. After the video signals R2, G2°B2 are sampled and held for one line, they are transferred all at once to 120 sets of memories 32a to 32n by a transfer pulse t, where they are held for the next one horizontal scanning period. The held signals are applied to 120 switching circuits 35a-35n. The switching circuits 35a to 35n each have R1, Gl, Bl, R2, G2 . This circuit is composed of a circuit having individual input terminals of B2 and a common output terminal that sequentially switches and outputs them, and the switching pulse rl applied from the switching pulse generation circuit 36.
, gl, bL r2. Switching is controlled simultaneously by g2 and b2.

The switching pulses rl, gl, bl, r2°g2
．． b2 divides each horizontal display period into 6 and switches the switching circuits 35a to 35n for each horizontal display period/6.
1, G1. B1. R2, G2. The B2 video signals are time-divided and sequentially output, and supplied to the pulse width modulation circuits 37a to 37n.

The output of each switching circuit 35a to 35n is connected to 120 sets of pulse width modulation (hereinafter referred to as PWM) circuits 37a to 3.
7n, R1, G1 . Bl.

R2, G2. The pulse width is modulated according to the magnitude of each B2 video signal and output. This pulse width modulation circuit 37a~
The output of 37n is used as a control signal for modulating the electron beam to the 120 conductive plates 15a to 15a of the control electrode 4 of the display element.
15n each separately.

Next, horizontal deflection and display timing will be explained.

R1. in the switching circuits 35a to 35n. Gl,
Bl, R2, G2. B2 video signal switching and electron beam R1, G1 . Bl,
R2, G2. The timing and order of switching the horizontal deflection to the B2 phosphor are synchronously controlled so that they completely match. As a result, when the electron beam is irradiating the R1 phosphor, the irradiation amount of the electron beam is controlled by the R1 control signal, and the following G1. B1. R2°G2. B2 is similarly controlled, and R1, G1 . B1
．． R2, G2. B2 The light emission of each phosphor is the R1 of that picture element,
G1. Each picture element is controlled by the video signals of B1, R, 2, G2 and B2, and each picture element is displayed by emitting light according to the input video signal. Such control?1
120 sets of lines (2 picture elements each) are executed at a time to display an image of 240 picture elements per line, and then 24.0 lines per field are executed sequentially from the upper line to screen 8. The image is displayed above.

Furthermore, the above-mentioned operations are repeated for each field of the input video signal, and a television signal or the like is displayed on the screen 8.

The basic clock necessary for this configuration is supplied from the pulse generation circuit 39 shown in FIG. 6, and the horizontal synchronization signal H1
The timing is controlled by a vertical synchronization signal V.

Problems to be Solved by the Invention However, in the above-mentioned image display devices, the screen position is determined based on screen position data, but due to variations in circuit elements, the screen position differs from one image display device to another. .

Therefore, it is necessary to adjust the screen position for each image display device, and conventionally, the screen position was checked visually.
Adjustments were made by changing the screen position take, and the work efficiency was very poor.

The present invention solves the above problems by measuring the brightness distribution of the entire screen using a camera and comparing the brightness distribution of the entire screen with a reference pattern. The present invention aims to provide a method for automatically adjusting the horizontal and vertical screen positions by changing the horizontal and vertical screen positions so that the horizontal and vertical screen positions become more accurate.

Means for Solving the Problems In order to solve the above problems, the present invention provides a television camera that can measure the brightness of the entire screen of an image display device;
It consists of an A/D converter that A/D converts a video signal, a controller that controls screen position data of an image display device, and a personal computer that processes data of the video signal and controls the controller.

Effect: With this configuration, the screen position can be automatically adjusted by the following procedure.

By measuring the brightness distribution of the entire screen of the image display device using a camera and comparing the brightness distribution of the entire screen with a reference pattern prepared in advance, the brightness distribution of the entire screen becomes similar to the standard pattern. Change the horizontal and vertical screen position and automatically adjust the horizontal and vertical screen position.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1, 2, and 3.

First, in FIG. 1, 50 is an image display device whose screen position is to be adjusted, 54 is a television camera that can measure the brightness of the entire screen of the image display device, and 53 is a video signal.
An A/D converter performs A/D conversion, 51 is a controller that controls screen position data of the image display device, and 52 is a personal computer that processes video signal data and controls the controller.

FIG. 2 is an example of a flow chart of the operation.

FIG. 3 is a diagrammatic example of the operation.

The operation will be explained below.

For the sake of explanation, the variable width of the horizontal screen position data N of the image display device is 1 to 5, and the variable width of the vertical screen position data M is 1 to 5.
Set it to 7. First, the image display device controller 51 is controlled by the personal computer 52, and the screen position data of the image display device 50 is set to N=1. Let M=1. In that state,
The brightness distribution of the entire screen of the image display device 50 is measured using the television camera 54. At this time, a signal that displays a rectangle with higher brightness than the surrounding area at the center of the screen is input as a video signal to the image display device, as shown in FIG.

The video signal output from the television camera 54 is subjected to A/DL processing by the A/D converter 53 and then input to the personal computer 52 . The total luminance Ls of the obtained video signal data is calculated by the personal computer 52. In order to compare the results with the luminance sum LH of the reference pattern shown in Fig. 3,
The absolute value of the difference ILK Lsl is determined and the result is stored in memory.

As shown in the flowchart of FIG. 2, the above operation is performed by first keeping the horizontal screen position N constant and changing the vertical screen position data M from 1 to 7.

Next, the above operation is repeated by changing the horizontal screen position data N one step at a time until it reaches 5. In that case, IL):
The change in Lsl is as shown in FIG.

Horizontal screen position data N when ILK Lsl is minimum
The vertical screen position data M is the same as the screen position of the reference pattern. Therefore, if horizontal screen position data N and vertical screen position data M are calculated from the above results, N=3. M=5. If the screen position data is transferred to the image display device, the horizontal and vertical screen positions can be automatically adjusted.

Effects of the Invention As described above, according to the present invention, the horizontal and vertical screen positions of an image display device can be automatically adjusted.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram showing an embodiment of the present invention, Fig. 2 is a flowchart showing the flow of its operation, Fig. 3 is a schematic diagram for explaining the operation, and Fig. 4 provides the present invention. An exploded perspective view showing the basic structure of the image display device, FIG. 5 is an enlarged view of its fluorescent screen, and FIG. 6 is a block diagram showing the drive circuit of the device.
FIG. 7 is a waveform diagram for explaining the operation. 50... Image display device, 51... Image display device controller, 52... Personal computer, 53... A/DI! device, 54.
...TV camera. Name of agent Patent attorney Haruaki Ogata and 2 others @5 Figure 2θ Approximately 3θ

Claims (1)

[Scope of Claims] A screen coated with a phosphor that emits light when irradiated with an electron beam; a line cathode that generates an electron beam in each vertical division of the screen above the screen; separation means for separating the electron beam generated by the line cathode into each horizontal section and irradiating the screen; a deflection electrode that deflects the electron beam in multiple stages, and a beam flow control back surface that controls the amount of light emitted from each pixel on the screen by controlling the amount of electron beams separated into the horizontal sections irradiated onto the screen. An image display device comprising an electrode and an accelerating electrode for accelerating electron beam irradiation to the screen, comprising: means for changing the horizontal and vertical screen positions; and means for measuring the luminance distribution of the entire screen using a camera; means for comparing the luminance distribution of the entire screen with a reference pattern, and changing the horizontal and vertical screen positions so that the luminance distribution of the entire screen becomes similar to the reference pattern, and automatically adjusting the horizontal and vertical screen positions. An automatic screen position adjustment device characterized by being able to adjust the screen position.