JPS60244176A - Picture display device - Google Patents

Abstract

PURPOSE:To correct automatically the shift of the beam landing position and to prevent the deterioration of quality of displayed pictures, by providing an electrode within a display device to detect the beam deflection degree and using the detection output of the beam deflection degree to control the deflection degree of each section via a deflection control circuit. CONSTITUTION:An electron beam is produced for each section and deflected vertically and horizontally to display pictures on a screen. This display device contains an odd H1 anode 50a, an even H2 anode 50b, a V1 anode 51a and a V2 anode 51b. The anodes 50b is connected to the anode 51a to detect the beam deflection degree together with anodes 50a, 50b and 51b. The detected beam deflection degree is applied to a current/voltage converter 55 of a control circuit. Then the beam deflection degree of each section is processed by an A/D converter 57 and a microcomputer 58. Then the values of memories 27 and 29 are updated. Thus the shift of the beam landing position is corrected automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a flat image display device, and more particularly to a means for correcting changes over time, temperature changes, AC input voltage fluctuations, etc.゛ - Conventional structure and its problems Traditionally, cathode ray tubes have been mainly used as display elements for displaying color television images, but conventional cathode ray tubes have a very large depth compared to the screen size. It was impossible to create a long, thin television receiver. In addition, although EL display elements, plasma display devices, liquid crystal display elements, etc. have recently been developed as flat display elements, all of them are insufficient in terms of performance such as brightness, contrast, and color display, and have not been put into practical use. This has not yet been achieved.

Therefore, in order to achieve a flat display device using electron beams, the present applicant filed Japanese Patent Application No. 66-20618 (
A new display device was proposed in Japanese Patent Application Laid-Open No. 67-13E5590.

This method generates an electron beam for each section when the screen is vertically divided into multiple sections, and displays multiple lines by deflecting each electron beam vertically for each section. However, it displays the television image as a whole.

First, a basic configuration example of the image display element used here will be explained with reference to FIG.

This display element includes, in order from the back to the front, a back electrode 1, a line cathode 2 as a beam source, and vertical focusing electrodes 3, 3'.
, vertical deflection electrode 4, beam flow control electrode 5, horizontal focusing type!
f1.6, a horizontal deflection electrode 7, a beam accelerating electrode 8, and a screen plate 9 are arranged, and these are housed in the evacuated interior of a flat glass bulb (not shown).

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, and a plurality of line cathodes 2 (here, (Only four wires, 2i to 22 are shown) are provided. In this embodiment, it is assumed that 15 pieces are provided. Let these be 2i to 2yo. These wire cathodes 2 are constructed by coating the surface of a tungsten wire with a diameter of 10 to 2 .mu..phi. with an oxide cathode material for thermionic emission.

These wire cathodes 2A to 2Y are heated so as to generate a thermionic electron beam by passing an electric current through them, and as described later, the electron beams are emitted for a certain period of time in order from the green cathode 2I. controlled to emit. The back electrode 1 suppresses generation of electron beams from line cathodes 2 other than the line cathode 2 controlled to emit electron beams for a certain period of time, and directs the generated electron beams only in the forward direction. It has the effect of pushing it towards. This back electrode 1 may be formed by a coating of electrically conductive material applied to the inner surface of the rear wall of the glass bulb. In addition, these back electrodes 1
Instead of the linear cathode 2, a planar electron beam emitting cathode may be used.

The vertical focusing electrode 3 is a conductive plate 11 having a horizontally long slit 1o facing each of the line cathodes 2a to 2yo, and collects the electron beam emitted from the line cathode 2 through the slit 10, and , vertically focused.

Electron beams for one horizontal line (360 pixels) are taken out at the same time.

In the figure, only one section in the horizontal direction is shown. The slits 10 may be provided with crosspieces at appropriate intervals in the middle, or may be substantially a row of through holes arranged horizontally at small intervals (nearly touching intervals). It may also be configured as a slit. The vertical focusing electrode 3' is also similar.

A plurality of vertical deflection electrodes 4 are arranged horizontally at intermediate positions of the slits 10, and conductors 13, 13' are provided on the upper and lower surfaces of the insulating substrate 12, respectively.
It consists of a set of Then, the conductors 13, 13. A vertical deflection voltage is applied between ' and deflects the electron beam in the vertical direction. In this embodiment, the pair of conductors 13.13 deflects the electron beam from the one-line cathode 2 to positions corresponding to 16 lines in the vertical direction.

The 16 vertical deflection electrodes 4 constitute 15 pairs of conductors corresponding to each of the 15 wire cathodes 2, and in the end, electrons are transmitted to form 240 horizontal lines on the screen 9. Deflect the beam.

Next, the control electrodes 5 are composed of conductive plates 15 each having a long slit 14 in the vertical direction, and a plurality of control electrodes 15 are arranged in parallel in the horizontal direction at appropriate intervals. In this example, there are 180 control electrode conductors.

Electric plates 15a to 15n are provided (only nine are shown in the figure). Each of the control electrodes 6 divides the electron beam into two picture elements in the horizontal direction, and controls the amount of electron beam passing therethrough in accordance with the video signal for displaying each picture element.

Therefore, the conductive plates 16a to 15n for the control electrode 5 are
If 0 lines are provided, 360 picture elements can be displayed per horizontal line/minute. In addition, in order to display images in color, each picture element is displayed with phosphors of three colors R, a, and B, and each control electrode 6 has two picture elements of R, G, and B. Each video signal is applied sequentially.

In addition, 180 control electric fi, 5 conductive plates 15a to 15
180 pairs for one line (2 per pair for each n)
The video signals of the pixels (picture elements) are applied simultaneously, and one line of video is displayed at one time.

The horizontal focusing electrode 6 is composed of a conductive plate 17 having a plurality of vertically long slits 16 (180 mm) opposite to the slits 14 of the control electrode 5, and collects electrons for each pixel divided in the horizontal direction. Each beam is focused horizontally into a narrow electron beam.

The horizontal deflection electrodes 7 include a plurality of conductive plates 18 arranged vertically on both sides of the slits 16.
, 19', each electrode 18.18
Six levels of horizontal deflection voltage are applied to the electron beam for each picture element, and the deflection range thereof is a width of two picture elements for each electron beam in this embodiment.

The acceleration electrode 8 is composed of a plurality of conductive plates 19 provided horizontally at the same position as the vertical deflection electrode 4.
The electron beam is accelerated to collide with the screen 9 with sufficient energy.

The screen 9 is constructed by applying a phosphor 2o that emits light when irradiated with an electron beam to the back surface of a terrace board 21, and adding a metal barrier layer (not shown).

The phosphors 2o are provided with two pairs of phosphors of three colors, R2G and B, for each slit 14 of the control electrode 5, that is, for each horizontally divided electron beam. It is applied in vertical stripes.

In FIG. 11, the broken lines drawn on the screen 9 indicate divisions in the vertical direction that are displayed corresponding to each of the plurality of line cathodes 2, and the two-dot chain lines correspond to each of the plurality of control electrodes 5. Indicates the horizontal division that will be displayed. As shown in an enlarged view in FIG. 2, one section partitioned by these two pixels has two picture elements of R, G2, etc. in the horizontal direction. There is a B phosphor 20, which has a width of 16 lines in the vertical direction. The size of one section is, for example, 1 block in the horizontal direction and 9 blocks in the vertical direction.

Note that in FIG. 1, the length in the horizontal direction is greatly expanded relative to the length in the vertical direction for the sake of clarity.

In this embodiment, only one pair of R, G, and B phosphors 20 for two picture elements are provided for one tree of 1lilJ control electrodes 5, that is, for one tree of electron beams. A picture element or three or more picture elements may be provided, and in that case, R, G, and B video signals for one picture element or three or more picture elements are sequentially provided to the control electrode 5, and synchronously horizontal deflection.

Next, the basic configuration of a drive circuit for displaying television images on this display element will be explained with reference to FIG. First, a driving portion for irradiating the screen 9 with an electron beam to emit raster light will be explained.

The power supply circuit 22 is a circuit for applying a predetermined bias voltage (operating voltage) to each electrode of the display element. 6 is v6, accelerating electrode 8 is ■8° screen 9
A DC voltage of v9 is applied to.

Next, a composite video signal of a television signal is applied to the input terminal 23, and a synchronization separation circuit 24 outputs a vertical synchronization signal V and a horizontal synchronization signal H.

The vertical deflection drive circuit 40 includes a vertical deflection counter 25.
Memory 27 for vertical deflection signal storage. It is constituted by a digital-to-analog converter 39 (hereinafter referred to as a DA converter). The input pulse of the vertical deflection drive circuit 40 is as follows:
A vertical synchronizing signal (2) and a horizontal synchronizing signal (H) shown in FIG. 4 are used. The vertical deflection counter 25 (8 bits) is reset by the vertical synchronizing signal v and counts the horizontal synchronizing signal H. This vertical deflection counter 25 is counted during an effective scanning period (in this case, 2
This count output is supplied to the address of the memory 27. The memory 27 outputs vertical deflection signal data (1Q bit in this case) corresponding to each address, and the data (1Q bit in this case) is outputted by the DA converter 39 as shown in FIG.

V' is converted into a vertical deflection signal. In this circuit 240
There is a memory address for storing a vertical deflection signal corresponding to each line of H minutes, and by storing regular data in the memory every 16H minutes, a 16-step vertical deflection signal can be obtained.

On the other hand, the line cathode drive circuit 26 uses the vertical synchronization signal V and the output of the vertical deflection counter 25 to create line cathode drive pulses [I to YO]. FIG. 6(a) shows the vertical synchronizing signal ■, the horizontal synchronizing signal H, and the lower position of the vertical deflection counter 25.
It shows the relationship between 5 bits. FIG. 5(b) shows a method of creating line cathode drive pulses [A' to Y'] every 16H using these signals. In FIG. 5, LSB indicates the lowest bit, and (LSB +1) means the bit one higher than the LSB.

The first line cathode drive pulse [A'] can be created using an R-S flip-flop or the like using the vertical synchronization signal V and the output (LSB+4) of the vertical deflection counter 25.
The line cathode drive pulses [d to y'] can be obtained by using a shift register to transfer the line cathode drive pulse [a'] using the inverted version of the output (LSB+3) of the vertical deflection counter 26 as a clock. can. This drive pulse [A' to Yo'] is inverted and converted into a line cathode drive pulse [I to Yo], which has a low potential only during each pulse period, and a high potential of about 20 volts during other periods. , are added to each line cathode 2i to 2yo.

Each of the line cathodes 2i to 2yo is heated by passing a current through it during the high potential of the driving pulse [i to yo].
The heated state is maintained so that electrons can be emitted during the low potential period (I to Y). With this, 15 wooden wire cathodes 2~
From 2yo onwards, electrons are emitted only during the 16H period in which low-potential drive pulses [I to YO] are applied to each of them. During the period when a high potential is applied, the potential applied to the line cathodes 2 is lower than the potential at the position of the line cathode 2 determined by the bias voltage applied to the back electrode 1 and the vertical focusing electrode 3. Since the higher potential of
Electrons are emitted every 6H period.

The emitted electrons are pushed forward by the back electrode 1, pass through the opposing slits 10 of the vertical focusing electrode 3, and are vertically focused to form a flat electron beam.

Next, the line cathode drive pulses [I to Y] and the vertical deflection signal v
, v' will be explained using FIG.

The vertical deflection signals v and v' change by 1H during the 16H period of each line cathode/Z line [I to Y], and change in 16 steps. The center voltage of both the vertical deflection signal ■ and V' is v
4, the values change in opposite directions such that ■ increases sequentially and V' decreases sequentially. These vertical deflection signals V and V' are applied to the electrodes 13 and 13' of the vertical deflection electrode 4, respectively, and as a result, the electron beams generated from the respective line cathodes 2I to 2Y are vertically divided into 16 steps. As described above, on the screen 9, one electron beam is deflected so that a raster of 16 lines is sequentially drawn one line at a time from the top.

As a result of the above, an electron beam 75 is emitted from the top of the 15 line cathodes 2A to 2Y in order of 16H brightness. By sequentially deflecting one line at a time, on the screen 9, from the first line at the top to the 240th line at the bottom.
L up to the line! The electron beam is vertically deflected one line at a time, and a raster of 1 (-24°) lines is drawn.

The electron beam vertically deflected in this way moves forward [j both electrodes 5
It is divided into 180 sections in the horizontal direction by the horizontal focusing electrode 6 and the horizontal focusing electrode 6. Figure 1 shows one of these categories. This electron beam is controlled by the control electrode 6 for each section, and horizontally focused by the horizontal focusing electrode 6 to become a single thin electron beam. The light is deflected by the light beam and is sequentially irradiated onto each of the R, G, and B phosphors χ corresponding to two picture elements on the screen 9. FIG. 2 shows the vertical and horizontal divisions. Each of the control electrodes 5 15a to 1
The phosphor corresponding to 6n is R1G, B for two picture elements, but for convenience of explanation, one picture element is R1, G1°B1, and the other is R.
2, G2. Let's call it B2.

Next, the horizontal deflection drive circuit 41 is composed of a horizontal deflection counter (11 bits), a memory 29 storing horizontal deflection signals, and a DA converter 38. As shown in FIG. 7, the input pulses of the horizontal deflection drive circuit 41 are synchronized with the vertical synchronizing signal V and the horizontal synchronizing signal H, and a pulse 6H having a repetition frequency six times that of the horizontal synchronizing signal H is used.

The horizontal deflection counter 28 is reset by the vertical synchronizing signal V and counts the horizontal six-fold pulse 6H. This horizontal deflection counter 28 is 1H (7) fffiK6
240HX6/) (=1440 times) between IV(7) and this count output is supplied to the address of the memory 29. From the memory 29, horizontal deflection signal data (8 bits in this case) according to the address is sent. is output and '
The DA converter 38 converts it into horizontal deflection signals such as h and h' shown in FIG.

In this circuit, there is a memory address for storing horizontal deflection signals for each of 6 x 240 lines, and by storing 6 pieces of regular data for each line in the memory, 6 step waves are generated in 1H period. A horizontal deflection signal can be obtained.

This horizontal deflection signal is a pair of horizontal deflection signals b' and b' that change in six steps as shown in FIG. As they progress, they change in opposite directions. These horizontal deflection signals h and h' are applied to the electrode 1 of the horizontal deflection electrode 7, respectively.
8 and 18'. As a result, each horizontally segmented electron beam is applied to the R, G, B, R of the screen 9 during each horizontal period.

G, B (R1, Q, , B1.R2, G2.B2
) is horizontally deflected so that the phosphors are sequentially irradiated with H/6. Thus, in the raster of each line, the electron beams are divided into R1, G1, . B
1R2, G2. Each phosphor 20 of B2 is sequentially irradiated with light.

Therefore, the electron beam is set to R1, G for each horizontal section of each line.
1. B1. R2, G2. By modulating with the B2 video signal, a color television' image can be displayed on the screen 9.

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

First, the composite video signal applied to the television signal input terminal 23 is applied to the color demodulation circuit 30, where the R-Y
and B-Y color difference signals are demodulated, the G-Y color difference signals are matrix-synthesized, and further, they are combined with the luminance signal Y to generate R, G, and H primary color signals (hereinafter R, G, and B 75g (referred to as a video signal) is output. Furthermore, the R, G, B
6 video signals are processed by 180 sample and hold circuit sets 318
~Added to 31H. Each sample and hold circuit group 31
a to 31n are for R1, G1, B1, R2, and G2, respectively.

The six sample-hold outputs for B are applied to respective holding memory sets 32a-32n.

On the other hand, the reference clock oscillator 33 is constituted by a PLL (phase-locked loop) circuit or the like, and in this embodiment, the reference clock oscillator 33 has a reference clock frequency six times as large as the color subcarrier fBC.
,. and a double reference clock 2fs0 is generated. The reference clock is controlled to always have a constant phase with respect to the horizontal synchronizing signal H. The reference clock 21Bo is applied to the deflection Noculus generation circuit 42, and a signal 6H which is six times the horizontal synchronization signal H and a signal switching pulse y. r,
, gl, bl, r2.

I am getting G2 and B2 pulses. On the other hand, reference clock 6f
BC is added to the sampling pulse generation circuit 34,
Here, the clock is delayed by one clock period by the shift register, so that the clock is delayed by one period during the effective horizontal scanning period (approximately 50 μsC) of the horizontal period (63, rsttSeC).
080 sampling pulses Ra1 to Bn2 are sequentially generated, and then one transfer pulse t is generated. These sampling pulses Ra1 to Bn2 correspond to each picture element when one line of the video to be displayed is divided into 360 picture elements in the horizontal direction, and their positions are always constant with respect to the horizontal synchronizing signal H. controlled so that

These 1080 sampling pulses Ra1 to B n
2 are each 180 sample and hold circuit sets 3
18 to 31H, and one line is added to each sample and hold circuit set 318 to 31n.
R1, G for 2 pixels each when divided into 80 pieces
1. B1. R2, G2. Each video signal of B2 is individually sampled and held. The sampled and held 180 pairs of R1, G1. B1. R2, G2.
After completing the sampling and holding of one line, the Bρ video signal is transferred all at once to 180 sets of memories 32a to 32H by a transfer pulse t, where it is held for the next horizontal period.

This retained R1. G,, B1. R2, G2. It is added to the Bρ multiplied signal switching circuits 35a to 36n.

The switching circuits 356 to 35n each have R1 and G.
1. B1. R2, G2. It is composed of a tri-state or analog gate having individual input terminals of B2 and a common output terminal that sequentially switches and outputs them.

The output of each switching circuit 35a-35H is applied to 180 sets of vanosys width modulation (PWM) circuits 378-37H, where sampled and held R1. G1. B1
．． R2, G2. The reference pulse signal is pulse width modulated according to the magnitude of the B2 video signal and output. The repetition period of the reference pulse signal is the above signal switching bar)L/S r1
．． gl, b1', r2. It is desirable that the pulse width of g2°B2 is sufficiently smaller, for example, 1:
A ratio of about 10 to 1:100 is used.

The outputs of the pulse width modulation circuits 3a to 37n are individually applied to the 180 conductive plates 15a to 15n of the control electrode 5 of the display element as control signals for modulating the electron beam. Each switching circuit 358 to 36n receives a switching pulse r1191 +"1 + r2+92+b2 applied from the switching pulse generating circuit 36.
Switching is controlled at the same time by The switching pulse generation circuit 36 receives signals switching P/L/S r1. from the aforementioned deflection pulse generation circuit 42. g1. b1. r2. g2. B2
Each horizontal period is divided into 6 and H
Switch the switching circuits 35a to 35n by /e,
R1°G1. B1. R2, G2. Each video signal of B2 is time-divided and sequentially outputted to the pulse width modulation circuits 37a to 37.
switching signal r1 +q1 +b1 so as to be supplied to n;
Generate r2+(J2 z B2.

What should be noted here is that the switching circuit 36 a
R1.-35n. G1. B1. R2, G2゜B2
Switching the supply of video signals, and electron beam R1101'B1' R2, G2'B by the horizontal deflection drive circuit 41.
The horizontal deflection for switching the irradiation onto the phosphor in step 2 is synchronously controlled so that it completely matches both the timing and the order. This causes the electron beam to R1
When the phosphor is irradiated with the electron beam, the irradiation amount of the electron beam is controlled by the R1 video signal, and the R1, G1 . B
1. R2, G2. B2 is controlled in the same way, and each picture element's R, , G1°B1 . R2, G2. B2 The light emission from each phosphor corresponds to the R1, G, , B1 . R,,G
2. Each picture element is controlled by the video signal of B2, and each picture element is displayed by emitting light according to the input video signal. Such control is performed simultaneously for 180 sets (2 picture elements each) for 1 line to display an image of 12 in 360 picture elements, and then sequentially for 240 minutes from the upper line to display the screen. One image will be displayed on 9.

The above operations are performed on one input television signal.
The combs are returned field by field, and as a result, a moving television image is displayed on the screen 9 in the same way as in a normal television receiver.

However, in the above-mentioned image display device, each beam lading position within each vertical section is strictly determined.
Beam deviation in the horizontal direction impairs color reproducibility.
Although it is a matter of course that this should not occur, if the beams shift in the vertical direction, that is, if the beam intervals in the vertical direction are no longer equally spaced, a difference in brightness will appear and significantly deteriorate the image quality.

In particular, in order to maintain equal vertical beam spacing near the boundaries of each vertical section on the screen, the accuracy of each electrode voltage and deflection waveform becomes more demanding. If the voltage applied to each electrode is stabilized and a highly accurate amplifier is used to amplify the deflection waveform, the power consumption and cost will increase, which is impractical.

OBJECT OF THE INVENTION The present invention solves the above-mentioned problems of the prior art. An object of the present invention is to provide an image display device that can detect a shift and automatically correct a landing position.

Structure of the Invention The image display device according to the present invention includes a beam deflection amount detection electrode and a control circuit that controls the beam deflection amount using the detection output, so that even if the beam landing position deviates, it is automatically corrected to the correct position. This is what I did.

In order to achieve the second object, the present invention uses an anode (metal bank) on the back surface of the phosphor as a beam deflection detection electrode in a vertical stripe shape (hereinafter referred to as an H anode) and in a horizontal stripe shape (hereinafter referred to as a V anode). ), the H anode and the V anode are separated by an insulating layer, and the beam spot is arranged between each stripe.

The control circuit that controls the amount of beam deflection includes: (i) an amplifier circuit that converts and amplifies the deflection amount detection output current as described above; an A/D converter that converts the output of the amplifier circuit into digital data; and an A/D converter that converts the output of the amplifier circuit into digital data. It consists of a microcomputer that calculates increases and decreases in the amount of deflection and uses the results to rewrite data in the memory 27.

Alternatively, (11) it is composed of an amplifier circuit that converts and amplifies the deflection amount detection output current into a voltage, and a control circuit that uses the output of the amplifier circuit to control the electrode voltage that affects horizontal and vertical deflection sensitivity.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 8 shows the configuration of a horizontal anode ai (H anode) and a vertical anode (V anode) of an image display device in an embodiment of the present invention.

In Fig. 8, there is 60a, and sob is the H anode.

s; 1a and slb are V anodes, 52 is an insulating layer, 63 is a phosphor, and 54 is each beam spot. ■Anode s1a, s
1b, H anodes 60a and 50b are made by ram evaporation at 7/l/mm, and ■ anode 61a.

The number of stripes for 51b is the number of beam spots in the vertical direction on the screen (the number of two-scanning lines 480) + 1, and the number of stripes for 50a and 50b is the number of beam spots in the horizontal direction on the screen. (=e,oo)+1
It's a tree.

In order to independently detect positional deviations in the vertical and horizontal directions, the sum of the currents flowing through each anode requires at least three anodes at the spot position, and in this example, the odd-numbered H anode ( H1 anode (hereinafter referred to as H1 anode) 50a, even numbered H anode (hereinafter referred to as H2 anode) 5ob.

Of the odd-numbered V anodes (hereinafter referred to as v1 anodes) 51a and the even-numbered v anodes ai (hereinafter referred to as v2 anodes) 61b, the H1 anode, v
1 anode, H2 anode and ■2 anode connected (hereinafter referred to as HV
The three anodes (anode) are used as the -2 beam deflection detection electrodes.

In FIG. 9, 55 is a current-voltage converter, 56 is an amplifier, and 57
~ A microcomputer that calculates the increase/decrease in the deflection amount of the A/DgA/D converter and uses the results to rewrite the deflection data in the memory 27.29＼ Regarding the image display device configured as above, the following is Let's explain its operation. The total current of the above three anodes changes depending on the image signal, but when the beam spot shifts upward from the position of ■ shown in Figure 8, ■1 the anode current increases, and when it shifts downward, v
1 Anode current decreases.

Also, when the position shifts to the left or right, the H1 anode current and force j increase or decrease in the same way. However, a deviation of more than one spot interval cannot be detected.

The current of the three anodes is converted into a voltage by a current-voltage converter 65 using a photointerrupter, etc.
6 outputs the amount of positional deviation of the beam spot based on the ratio of the current of the H1 anode and H2 anode to the total beam current, which is converted into a digital signal by the A/D converter 57, and is output by the microcomputer 58. , memory 27
．． 29 is rewritten to correct the spot position to the correct position.

According to this embodiment, in order to correct the electron beam spot to the correct position by adjusting the electron beam spot position due to aging, temperature change, AC voltage fluctuation, etc.
Deterioration of image quality can be suppressed.

FIG. 10 shows a three-way configuration for detecting the amount of beam deflection in an image display device according to another embodiment of the present invention.

In this embodiment, a phosphor is used as an insulating layer separating the H anodes 60a, 50b and the V anodes 61a, 61b. As the three anodes, a v1 anode, a v2 anode, and an H1 anode in which the H1 and H2 anodes are tangential are used.

Effects of the Invention As described above, according to the present invention, changes over time, temperature increase, and A
By automatically correcting beam landing position deviations due to C voltage fluctuations and returning to the correct landing position, it is possible to prevent image quality deterioration. ′

[Brief explanation of drawings]

Fig. 1 is a block diagram of an image display device to which the present invention is applied, Fig. 2 is a block diagram of a unit pixel on a phosphor surface of the device, and Fig. 3 is a block diagram of a drive circuit in the device. figure,
Figure 4 is a waveform diagram of the vertical deflection signal, Figures 6a and b are timing charts for explanation of operation, Figure 6 is a waveform correlation diagram of each signal, Figure 7 is a waveform diagram of the horizontal deflection signal, and Figure 8 9 is a configuration diagram of a detection electrode section of an image display device according to an embodiment of the present invention, FIG. 9 is a circuit diagram of a control circuit system in the same device, and FIG.
FIG. 0 is a configuration diagram of a detection electrode section showing another embodiment of the present invention. 2.2 I~2 Y... Line cathode, 4... Vertical deflection signal, 5... Beam flow control electrode, 7...
... Horizontal deflection electrode, 9 ... Screen plate, 1
0... Slit, 20... Fluorescent material, 23
... Input terminal, 24 ... Meme separation circuit, 25 ... Vertical deflection counter, 26 ...
... line cathode drive circuit, 27 ... memory, 28
...Horizontal deflection counter, 29...
Memory, 30... Color demodulation circuit, 31a to 31n
...Sample and hold circuit, 32a to 32n.
・Mark ・Memory, 33...Reference clock oscillator, 3
4...Su/Pri) Kuhalus occurrence time 91r, 3s
a~36n...Switching circuit, 36...
...Switching, <Russ generation circuit, 37a-37
n...PWM circuit, 38...D/A converter, 39...D/A converter, 40...Vertical deflection drive circuit, 41...・Horizontal deflection drive circuit, 4
2...Deflection pulse generation circuit, 44-44Y...Switching circuit, 50a...H
1 anode, 5ob...H2 positive, 51a...
...v1 anode, 51b...v2 anode, 52...
... Insulating layer, 53 ... Fluorescent material, 54 ...
...Beam spot position, 55...°...Current voltage converter, 56...Amplifier, 57...A/
D converter, 58...Microcomputer. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 20 Figure 3 Figure 4 Table 5 Figure 2

Claims (2)

[Claims] (1) Divide the screen surface into multiple sections vertically and horizontally, generate an electron beam for each of the five sections,
A device that displays an image on the screen by deflecting each electron beam in the vertical and horizontal directions for each section, the image display device having an electrode for detecting the amount of beam deflection, Furthermore, by having a deflection amount control circuit that controls the deflection amount for each section using the detection output of the same amount as d, it is possible to prevent the beam landing position from shifting due to changes over time. Image display device. (2) The beam deflection amount detection electrode is located on the back surface of the screen 9.
Claim No. 1, characterized in that the anode (metal back) is composed of horizontal stripes and vertical stripes, and the two striped anodes have a structure separated by an insulating layer.
) image display device.