JPH0252476B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention generates an electron beam for each division when a screen is vertically divided into a plurality of divisions, and generates an electron beam for each division. This invention relates to a device that displays a television image as a whole by vertically deflecting an electron beam to display a plurality of lines.

(Conventional structure and its problems) Conventionally, cathode ray tubes have been mainly used as display elements for displaying color television images, but conventional cathode ray tubes have a very long depth compared to the screen size. However, it was impossible to create a thin television receiver. In addition, 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 yet been put into practical use.

Therefore, with the aim of achieving a flat display device using electron beams, when the screen on the screen is vertically divided into multiple sections, an electron beam is generated for each section. In the 1990s, a system was invented that displayed a plurality of lines by deflecting each electron beam in the vertical direction to display a 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 is arranged in order from the back to the front.
A rear electrode 1, a line cathode 2 as a beam source, vertical focusing electrodes 3, 3', a vertical deflection electrode 4, a beam flow control electrode 5, a horizontal focusing electrode 6, a horizontal deflection electrode 7, a beam accelerating electrode 8, and a screen 9 are arranged. 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 (2A to 2D are shown) are provided. In this example, it is assumed that 15 are provided. Let's call them 2i~2yo. These line cathodes 2 are, for example, 10~
It consists of an oxide cathode material for thermionic emission coated on the surface of a 20 μφ tungsten wire. These line cathodes 2I to 2Y are heated so as to generate a thermionic beam when a current is passed through them, and as will be described later, the line cathodes 2
The electron beams are controlled to be emitted sequentially from A to A for a fixed period of time. The back electrode 1 suppresses the generation of electron beams from line cathodes 2 other than the line cathode 2 that is controlled to emit the electron beam for a certain period of time,
It also functions to push out the generated electron beam only in the forward direction. The back electrode 1 may be formed by a coating of a conductive material applied to the inner surface of the rear wall of the glass bulb. Further, instead of the back electrode 1 and 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 10 facing each of the line cathodes 2I to 2Y, and extracts the electron beam emitted from the line cathode 2 through the slit 10, and focus in a direction. An electron beam for one horizontal line (360 pixels) is extracted at the same time. In the figure, only one section in the horizontal direction is shown. The slit 10 may be provided with crosspieces at appropriate intervals in the middle, or may be substantially configured as a slit by a row of many through holes arranged horizontally at small intervals (nearly touching intervals). may be done. Vertical focusing electrode 3'
is also similar.

A plurality of vertical deflection electrodes 4 are arranged horizontally in the middle of each of the slits 10, and are each composed of conductors 13 and 13' provided on the upper and lower surfaces of an insulating substrate 12. has been done. And the opposing conductors 13, 13'
A vertical deflection voltage is applied between them to deflect the electron beam in the vertical direction. In this embodiment, the electron beam from one line cathode 2 is vertically deflected to positions corresponding to 16 lines by a pair of conductors 13, 13'. And, by 16 vertical deflection electrodes 4, 15
Fifteen conductor pairs corresponding to each of the book line cathodes 2 are constructed, and the electron beam is ultimately deflected to draw 240 horizontal lines on the screen 9.

Next, the control electrodes 5 are composed of conductive plates 15 each having a vertically long slit 14, and a plurality of control electrodes 15 are arranged in parallel in the horizontal direction at predetermined intervals. In this embodiment, 180 conductive plates 15a to 15n for control electrodes are provided (only 9 are shown in the figure). Each of the control electrodes 5 transmits the electron beam by two picture elements in the horizontal direction. The pixels are separated and taken out, and the amount of passage thereof is controlled in accordance with the video signal for displaying each picture element. Therefore, if 180 conductive plates 15a to 15n for control electrodes 5 are provided, 360 picture elements can be displayed per horizontal line. In addition, in order to display images in color, each picture element is displayed using phosphors of three colors R, G, and B, and each control electrode 5 has R, G, and B phosphors for two picture elements.
G and B video signals are sequentially added. Also,
180 sets of video signals for one line (two picture elements per set) are simultaneously applied to each of the 180 conductive plates 15a to 15n for the control electrodes 5, and the video for one line 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 slits 16) facing the slits 14 of the control electrode 5, and collects electrons for each picture element divided in the horizontal direction. Each beam is focused horizontally into a narrow electron beam.

The horizontal deflection electrode 7 is made up of a plurality of conductive plates 18, 18' arranged vertically on both sides of the slit 16, and each electrode 18, 18' has six levels of horizontal deflection. A voltage is applied to horizontally deflect the electron beam for each pixel, and on the screen 9 two sets of R,
The G and B phosphors are sequentially irradiated to emit light. In this example, the deflection range is two picture elements wide for each electron beam.

The accelerating electrode 8 is composed of a plurality of conductive plates 19 provided horizontally at the same position as the vertical deflection electrode 4, and accelerates the electron beam so that it collides with the screen 9 with sufficient energy.

The screen 9 is constructed by coating the back surface of a glass plate 21 with a phosphor 20 that emits light when irradiated with an electron beam, and adding a metal back layer (not shown). The phosphor 20 is arranged for each slit 14 of the control electrode 5, that is, for each horizontally divided electron beam.
Two pairs of phosphors in each of the three colors R, G, and B are provided, and are applied in stripes in the vertical direction. In FIG. 1, 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 displayed. As shown in the enlarged view in Figure 2, one section partitioned by these two has R, G, and B phosphors 20 for two pixels in the horizontal direction, and 16 lines in the vertical direction. It has a width of
For example, the size of one section is 1 in the horizontal direction.
mm, and the vertical direction is 10 mm.

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

Further, in this example, one control electrode 5, that is, one
R, G, B phosphors 20 for the electron beam of the book
Although only one pair for two picture elements is provided, of course, one picture element or three or more picture elements may be provided, in which case the control electrode 5 has one picture element or three or more pictures R, G, and B video signals are sequentially applied, and horizontal deflection is performed in synchronization with the R, G, and B video signals.

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 described.

The power supply circuit 22 is a circuit for applying a predetermined bias voltage (operating voltage) to each electrode of the display element,
-V ₁ to the back electrode 1, and -V 1 to the vertical focusing electrodes 3 and 3'.
DC voltages of V ₃ , V ₃ ', V ₆ to the horizontal focusing electrode 6, V ₈ to the accelerating electrode 8, and V ₉ to the screen 9 are applied.

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

The vertical deflection drive circuit 40 includes a vertical deflection counter 25, a memory 27 for storing vertical deflection signals, and a digital-to-analog converter 39 (hereinafter referred to as a DA converter). As input pulses to the vertical deflection drive circuit 40, a vertical synchronizing signal V and a horizontal synchronizing signal H shown in FIG. 4 are used. The vertical deflection counter 25 (8 bits) receives the vertical synchronization signal V.
The horizontal synchronizing signal H is counted. This vertical deflection counter 25 counts the effective scanning period (here, a period of 240 hours) excluding the vertical retrace period of the vertical period,
This count output is supplied to an address in memory 27. Vertical deflection signal data (here, 8 bits) is output from the memory 27 in accordance with each address, and is converted by the DA converter 39 into vertical deflection signals v and v' shown in FIG. In this circuit 240H
There is a memory address for storing the vertical deflection signal corresponding to each line of minutes, and by storing regular data in the memory every 16H minutes, it is possible to obtain a 16-step vertical deflection signal.

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

The first line cathode drive pulse I' is the vertical synchronizing signal V
and output of vertical deflection counter 25 (LSB+4)
The line cathode drive pulses LO' to YO' can be created using an R-S flip-flop, etc., and the line cathode driving pulses LO' to YO' can be created by using a shift register to convert television A' to the inverted version of the output (LSB + 3) of the vertical deflection counter 25. It can be obtained by transferring the clock. These drive pulses I'~Yo' are inverted and made low potential only during each pulse period, and converted into line cathode drive pulses I~Yo that are at a high potential of about 20 volts during other periods, and each line cathode 2 I~ Added to 2yo.

Each line cathode 2i to 2yo is heated by a current flowing through it during the high potential period of the drive pulses I to YO, and the heated state is maintained so that electrons can be emitted during the low potential period of the drive pulses I to YO. Ru. As a result, electrons are emitted from the 15 line cathodes 2i to 2yo only during the 16H period when low-potential drive pulses are applied to each of them. During the period when a high potential is applied, the potential at the line cathode 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 applied high potential becomes positive, no electrons are emitted from the line cathodes 2I to 2Y. Thus, in the line cathode 2, electrons are sequentially emitted from the upper line cathode 2a toward the lower line cathode 2y every 16H period during the effective vertical scanning 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 focused in the vertical direction to form a flat electron beam.

Next, the relationship between the line cathode drive pulses y to y and the vertical deflection signals v and v' will be explained using FIG. 6. FIG. 6a is a waveform diagram of a line cathode pulse, b is a waveform diagram of a vertical deflection signal, and FIG. 6c is a waveform diagram of a horizontal deflection signal. The vertical deflection signals v and v' in FIG. 6b change in steps of 1H during the 16H period of each line cathode pulse E to Y in FIG. 6A, and change in 16 steps. Vertical deflection signal v and
Both v' and V' have a center voltage of _V4 , and are configured to change in opposite directions so that v increases sequentially and v' decreases sequentially. These vertical deflection signals v and v' are applied to electrodes 13 and 13' of the vertical deflection electrode 4, respectively, and as a result, the electron beams generated from the respective line cathodes 2a to 2o are deflected in 16 steps in the vertical direction. As mentioned above, on the screen 9, one electron beam is deflected so as to sequentially draw a raster line of 16 lines one line at a time from the top.

As a result of the above, an electron beam is emitted for a period of 16 hours from the top of the 15 line cathodes 2A to 2Y, and each electron beam is sequentially emitted for one line from the top to the bottom within 15 sections in the vertical direction. As a result, the electron beam is vertically deflected one line at a time on the screen 9 from the first line at the top end to the 240th line at the bottom end, thereby drawing a raster of 240 lines in total.

The electron beam thus vertically deflected is horizontally deflected by 180 degrees by the control electrode 5 and the horizontal focusing electrode 6.
It is divided into sections and taken out. Figure 1 shows one of these categories. The amount of electron beam passing through each section is controlled by a control electrode 5, and horizontally focused by a horizontal focusing electrode 6 into a single narrow electron beam, which is then controlled by horizontal deflection means described below. The light is then deflected in six steps in the horizontal direction and is sequentially irradiated onto each of the R, G, and B phosphors 20 corresponding to two picture elements on the screen 9. FIG. 2 shows the vertical and horizontal divisions. The phosphors corresponding to each of 15a to 15n of the control electrode 5 are R, G, and B for two picture elements, but for convenience of explanation, one picture element is shown here.
Let R ₁ , G ₁ , B ₁ be R ₂ , G ₂ , B ₂ .

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

The horizontal deflection counter 28 is reset by the vertical synchronizing signal V and counts horizontal six times pulses 6H. This horizontal deflection counter 28 is
6 times during 1H, 240H x 6/H = 1440 during 1V
The count output is supplied to an address in the memory 29. Horizontal deflection signal data (here, 8 bits) corresponding to the address is output from the memory 29, and converted by the D-A converter 38 into horizontal deflection signals such as h and h' shown in FIG. . This circuit has a memory address for storing horizontal deflection symbols corresponding to 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 time. horizontal deflection signals can be obtained.

This horizontal deflection signal is a pair of horizontal deflection signals h and h' that change in 6 steps as shown in FIG. 7, both have a center voltage of V ₇ , and h gradually decreases.
h' increases in sequence and changes in opposite directions. These horizontal deflection signals h, h' are applied to electrodes 18 and 18' of the horizontal deflection electrode 7, respectively.
As a result, each horizontally divided electron beam is transmitted to the R, G, B,
It is horizontally deflected so that R, G, and B (R ₁ , G ₁ , B ₁ , R ₂ , G ₂ , B ₂ ) phosphors are sequentially irradiated with H/6 each. Thus, in each line raster, the electron beam is R ₁ ,
Each phosphor 20 of G ₁ , B ₁ , R ₂ , G ₂ , and B ₂ is sequentially irradiated with light.

Therefore, an electron beam is applied to each horizontal section of each line.
A color television image can be displayed on the screen 9 by modulating the video signals R ₁ , G ₁ , B ₁ , R _{2 ,} G ₂ , and B 2 .

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,
Here, the color difference signals of R-Y and B-Y 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,
B primary color signals (hereinafter referred to as R, G, and B video signals) are output. Each of these R, G, and B video signals are processed by 180 sample and hold circuit sets 31a to 3.
Added to 1n. Each sample hold circuit group 3
1a to 31n are for R ₁ , G ₁ , B ₁ , R ₂ respectively
It has six sample-and-hold circuits for G, _G2 , and _B2 . These sample and hold outputs are respectively applied to holding memory sets 32a-32n.

On the other hand, the reference clock oscillator 33 is composed of a PLL (phase locked loop) circuit, etc., and in this example generates a reference clock 6f _{SC that is six times the color subcarrier f SC and} a reference clock 2f _SC that is twice the color subcarrier f SC. .
The reference clock is controlled to always have a constant phase with respect to the horizontal synchronizing signal H. The reference clock 2f _SC is added to the deflection pulse generation circuit 42, and the signals 6H and 6/H, which are six times the horizontal synchronization signal H, are
The signal switching pulses r ₁ , g ₁ , b ₁ , r ₂ , g ₂ , b ₂ are obtained for each signal switching pulse. On the other hand, the reference clock 6f _SC is applied to the sampling pulse generation circuit 34, where it is delayed by one clock cycle by a shift register, so that the effective horizontal scanning period (approximately 50 μsec) of the horizontal period (63.5 μsec) is delayed. In the meantime, 1080 sampling pulses Ra ₁ to Bn ₂ are sequentially generated, and then one transfer pulse t is generated. This sampling pulse Ra ₁ ~ Bn ₂ is one of the images to be displayed.
It corresponds to each picture element when a line is divided into 360 picture elements in the horizontal direction, and its position is controlled so that it is always constant with respect to the horizontal synchronizing signal H.

These 1080 sampling pulses Ra ₁ to Bn ₂ are connected to 180 sample and hold circuit sets 31a.
31n, and as a result, R ₁ , G ₁ , B ₁ , R for each two picture elements when one line is divided into 180 are added to each sample-and-hold circuit set 31a to 31n. ₂ , _G2 , and _B2 are individually sampled and held. The sample-held 180 pairs of R ₁ , G ₁ , B ₁ , R ₂ , G ₂ ,
After the sample and hold for one line is completed, the _B2 video signal is transferred all at once to 180 sets of memories 32a to 32n by a transfer pulse t, where it is held for the next horizontal period. This retained R ₁ , G ₁ ,
B ₁ , R ₂ , G ₂ , B ₂ signals are sent to the switching circuit 35
Added to a~35n. Switching circuit 35
a to 35n are R ₁ , G ₁ , B ₁ , R ₂ , G ₂ ,
It is composed of a tri-state or analog gate having two individual input terminals and a common output terminal which sequentially switches and outputs the _B2 input terminals.

The output of each switching circuit 35a to 35n is
180 sets of pulse width modulation (PWM) circuits 37a to 3
7n, and here, the reference pulse signal is pulse width modulated according to the magnitude of the sampled and held R ₁ , G ₁ , B ₁ , R ₂ , G ₂ , B ₂ video signal and is output. It is desirable that the repetition period of the reference pulse signal is sufficiently smaller than the pulse width of the signal switching pulses r ₁ , g ₁ , b ₁ , r ₂ , g ₂ , b ₂ , for example, 1:10 to 1:10. A ratio of about 1:100 is used.

The output of the pulse width modulation circuits 37a to 37n is used as a control signal for modulating the electron beam to the 180 conductive plates 15a to 15 of the control electrode 5 of the display element.
n separately. Each of the switching circuits 35a to 35n receives a switching pulse r ₁ , which is applied from the switching pulse generation circuit 36.
Switching is controlled simultaneously by g ₁ , b ₁ , r ₂ , g ₂ , and b ₂ . The switching pulse generation circuit 36 generates a signal switching pulse from the deflection pulse generation circuit 42 described above.
It is controlled by r ₁ , g ₁ , b ₁ , r ₂ , g ₂ , b ₂ ,
Each horizontal period is divided into 6 and the switching circuits 35a to 35n are switched by H/6, and R ₁ , G ₁ , B ₁ ,
The switching signals r _{1 ,} g ₁ , b _{1 ,} r ₂ , g _{2 ,} b Generate ₂ .

What should be noted here is that the switching circuit 3
R ₁ , G ₁ , B ₁ , R ₂ , G ₂ , B ₂ in 5a to 35n
video signal supply switching and horizontal deflection drive circuit 4
The horizontal deflection of the electron beams R ₁ , G ₁ , B ₁ , R ₂ , G ₂ , B ₂ irradiated onto the phosphor by 1 is controlled synchronously so that they completely match both in timing and order. It is that you are. As a result, when the electron beam is irradiated onto the R ₁ phosphor, the amount of the electron beam is controlled by the R ₁ video signal, and also for G ₁ , B ₁ , R ₂ , G ₂ , and B ₂ . Similarly controlled, R ₁ , G ₁ , B ₁ , R ₂ , G ₂ ,
B ₂ The emission of each phosphor is caused by the R ₁ , G ₁ , B ₁ ,
Each picture element is controlled by the R ₂ , G ₂ , and B ₂ video signals, and each picture element is displayed by emitting light according to the input video signal. Such control is performed simultaneously for 180 sets of one line (2 picture elements each) to display an image of 360 picture elements for one line, and then sequentially for 240 lines starting from the upper line. One image will be displayed.

The above operations are repeated for each field of the input television signal, and as a result,
The screen 9 is similar to a normal television receiver.
The television footage of the video is shown above.

By the way, in the conventional example explained above, FIG.
As shown in , each line cathode 2i to 2yo has one end a
A driving pulse is applied to the line cathode, and the other end b is grounded via a diode D, and the driving pulse is applied in the same direction to each line cathode. The wire cathode naturally has electrical resistance, so when the drive pulse is at a high potential, the potential at the a end is higher than the b end due to the heating current flowing from the a end to the b end, and the drive pulse is at a low potential. In this case, the electric current caused by the electrons emitted from the linear cathode 2 flows from the b end to the a end, so that the potential at the b end is higher than that at the a end. This potential gradient does not pose a problem during a period when the drive pulse is at a high potential, but becomes a problem during a period when the drive pulse is at a low potential and electrons are emitted from the line cathode 2. That is, during this period, the line cathode 2 and the vertical focusing electrode 3 (see Figure 1)
Since the potential difference between the two ends is set so that the potential of the vertical focusing electrode 3 is higher than that of the normal line cathode 2, it is smaller on the b end side than on the a end side. Therefore,
The velocity of the electron beam emitted from the line cathode 2 is smaller on the side b than on the side a, and this result appears as a difference in the amount of vertical deflection, as shown in FIG. 8b. The irradiation range K ₁ to _{K 15} of one section in the vertical direction of the second electron beam becomes gradually narrower from end b to end a.

Therefore, at the connection between the electron beam irradiation ranges K ₁ to K ₁₅ of the adjacent line cathodes,
Non-uniform gaps (hereinafter referred to as horizontal lines Y) occur, which poses a major visual problem.

(Object of the Invention) The present invention eliminates such conventional drawbacks, and aims to provide an image display device in which horizontal lines do not pose a visual problem without adding any circuits.

(Structure of the Invention) The present invention is characterized in that pulses for driving each line cathode are applied from different directions to adjacent line cathodes, and thereby horizontal lines can be formed without adding any circuit. This can be done so that it does not cause any visual problems.

(Description of Embodiment) An embodiment of the present invention will be described below with reference to the drawings. In FIG. 9a, it is assumed that 15 wire cathodes 2 are provided. A drive pulse from the line cathode drive circuit 26 is applied to the a end of the line cathode 2a, and the b end is grounded via a diode D. On the other hand, in the adjacent line cathode 2R, the drive pulse is applied to the b end, and the a end is grounded via the diode D. Hereinafter, drive pulses are applied alternately to the a and b ends of adjacent line cathodes. First, in the line cathode 2a, during the period when the drive pulse is at a low potential and electrons are emitted, the potential at the b end is higher than the a end potential, as in the conventional example, so that the potential between the line cathode and the vertical focusing electrode increases. The potential difference is smaller at end b than at end a (vertical focusing electrodes usually have a higher potential than linear cathodes), and the speed of electrons emitted from the linear cathode is a
The b end is smaller than the end. Therefore, the amount of deflection that the electron beam receives when passing through the vertical deflection electrode is a
The range K ₁ that the electron beam irradiates in the vertical direction on the screen is larger on the b side than on the edge side, and is
The a-end side is narrower than the end side. On the other hand, in the line cathode 2B, the drive pulse is applied to the b end, so the range K ₂ that the electron beam irradiates in the vertical direction on the screen is opposite to that of the line cathode 2B, and it is closer to the a end than the line cathode 2B. It also becomes narrower on the b-end side. As a result, the gap between the line cathodes 2a and 2b connected to the vertical irradiation range can be made almost uniform as shown in FIG. 9b. Similarly, for the following adjacent line cathodes, the horizontal lines Y are almost uniform, and an image with no visual problem can be obtained.

(Effects of the Invention) As described above, the present invention applies line cathode driving pulses to adjacent line cathodes from different directions, thereby making it possible to make horizontal lines on the screen almost uniform, thereby causing visual problems. It is possible to provide a good image display device without any problems.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of an example of an image display element used in the image display device of the present invention, Fig. 2 is an enlarged view of the fluorescent surface of the image display element, and Fig. 3 is a drive circuit of the image display element. 4 is a waveform diagram to explain the operation of the vertical deflection drive circuit, FIG. 5 is a waveform diagram to explain the operation of the line cathode drive circuit, and FIG. 6 is a waveform diagram to explain the operation of the line cathode drive circuit. FIG. 7 is a waveform diagram for explaining the operation of the horizontal deflection drive circuit, FIG. 8a is a diagram for explaining the conventional method of applying drive pulses to the line cathode, and FIG. A diagram showing the state of horizontal lines on the screen, FIG. 9a is a diagram showing the configuration of the main part of an image display device in an embodiment of the present invention, and FIG. 9b is a diagram showing the state of horizontal lines on the screen in the present invention. FIG. 2, 2 I to 2 Y... Line cathode, 4... Vertical deflection electrode, 5... Beam flow control electrode, 7... Horizontal deflection electrode, 9... Screen, 10... Slit, 20
... Fluorescent body, 23 ... Input terminal, 24 ... Synchronization 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 hold circuit, 32a to 32n...Memory, 33...Reference clock oscillator, 34...Sampling pulse generation circuit, 35a to 35n...Switching circuit, 36...Switching pulse generation circuit, 37
a to 37n...PWM circuit, 38...D/A converter, 39...D/A converter, 40...Vertical deflection drive circuit, 41...Horizontal deflection drive circuit, 42...Deflection pulse generation circuit .

Claims (1)

[Claims] 1 a plurality of line cathode electron beam generation sources, a screen having a phosphor that emits light when irradiated with the electron beam, a focusing electrode that focuses the electron beam generated by the electron beam generation source, and a screen that includes a plurality of line cathode electron beam generation sources; A display element including an electrostatic deflection electrode that deflects the beam up to the screen, and a control electrode that controls the emission intensity by controlling the amount of the electron beam irradiated to the screen,
An image display device in which the line cathode is driven by pulses, wherein the pulses for driving the line cathode are applied to adjacent line cathodes from different directions. .