JPS6229283A - Image display device - Google Patents

Abstract

PURPOSE:To optionally select a vertical over-scan quantity by providing a circuit that changes the pulse periods of vertical sections in the uppermost and the lowermost part of a picture plane out of linear cathode driving pulses that generate electron beams at every vertical section at the picture plane on a screen. CONSTITUTION:The first linear cathode driving pulse (a'') is generated by a signal V'' which is the one that a vertical synchronizing signal V is delayed by 3H at a timing generating circuit 51 and the output (LSB+4) of a vertical deflecting counter 25. Pulses (b'-o') are obtained by setting the pulse (a'') as the inverted clock of the output (LSB+3) of the counter 25 using a shift register 54, and the pulse (o'') is generated at a gate circuit 56 using a signal V''' which is the one that a horizontal synchronizing signal H is counted by 237H at a counter 55 and the pulse (o') from the register 54. The driving pulses (a'', b'-n', and o'') are inverted at an inverted amplifier 53 and they are set at low levels only in each pulse period, and in the period other than that, the linear cathode driving pulses (a''', b-n and o''') which are set at a high potential of 20 volts are added on each of the linear cathodes.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention generates an electron beam for each division when a screen on a screen is vertically divided into a plurality of divisions, and generates an electron beam for each division. The present invention relates to an apparatus for displaying a plurality of lines by vertically deflecting a beam to display a television image as a whole.

Conventional technology 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, making it difficult to receive thin television images. It was impossible to create a machine. 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. It has not yet been reached.

Therefore, in order to achieve a flat display device using electron beams, the present applicant filed Japanese Patent Application No. 56-20618 (
A novel display device was proposed in Japanese Patent Application Laid-Open No. 57-135590.

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 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 has a back electrode 1. Line cathode 2 as beam source, vertical focusing electrode 3.3'
, a vertical deflection electrode 4, a beam flow control electrode 6, a horizontal focusing electrode 6, a horizontal deflection electrode 7, a beam acceleration electrode 8, and a screen plate 9. The interior is housed in a vacuum. The line cathode 2 as a beam source is stretched horizontally so as to generate an electron beam distributed linearly in the horizontal direction. In the figure, only four wires 2-2 are shown). In this embodiment, it is assumed that 16 pieces are provided. Let's call them 2i~2yo. These wire cathodes 2 are, for example, tungsten wires with a diameter of 10 to 20 μΦ, and an oxide cathode material for thermionic emission is coated on the surface thereof.

These line cathodes 2A to 2Y are heated so as to generate a thermionic electron beam by passing an electric current through them, and as will be described later, the electron beams are generated sequentially for a certain period of time starting from the line cathode 2I. controlled to emit. The back electrode 1 suppresses generation of electron beams from line cathodes 2 other than the line cathode 2 that is 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 out. This back electrode 1 may be formed by a coating film of a conductive material adhered to the inner surface of the rear wall of the glass pulp. 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 1o facing each of the line cathodes 2a to 2yo, and takes out the electron beam emitted from the line cathode 2 through the slit 1o, and , vertically focused.

Electron beams for one horizontal line (36 pixels) are taken out 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 a row of through holes provided horizontally at small intervals (so that they almost touch each other). Alternatively, it may be configured as a slit. The 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 the insulating substrate 12. has been done. Then, a vertical deflection voltage is applied between the opposing conductors 13 and 13',
Deflect the electron beam vertically. In this embodiment, the electron beam from one line cathode 2 is vertically deflected to a position corresponding to 16 lines by a pair of conductors 13, 13'.

The 16 vertical deflection electrodes 4 constitute 15 pairs of conductors corresponding to each of the 15 line cathodes 2, and the electron beams are deflected to draw 240 horizontal lines on the screen 9. do.

Next, the control electrodes 5 are composed of conductive plates 16 each having a vertically long slit 14, and a plurality of control electrodes 5 are arranged in parallel in the horizontal direction at predetermined intervals. In this embodiment, 180 conductive plates 15a to 16n for control electrodes are provided (only nine are shown in the figure). Each of the control electrodes 5 extracts the electron beam horizontally by dividing it into two picture elements each, and controls the amount of electron beam passing therethrough according to the video signal for displaying each picture element.

Therefore, if 180 conductive plates 16a to 15n for the 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 6 has two picture elements of R, G, and B. Each video signal is applied sequentially.

In addition, 180 pairs of video signals for one line (2 pixels per pair) are simultaneously applied to each of the 180 conductive plates 15a to 15n for the control electrode 6, and the video for one line is simultaneously applied. Is displayed.

The horizontal focusing electrode 6 is composed of a conductive plate 17 having a plurality of vertically long slits 16 (180 slits) facing the slits 14 of the control electrode 6, 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 electrodes 7 include a plurality of conductive plates 18.1 arranged vertically on both sides of the slit 16.
Consisting of 8', each electrode 18.18
A six-step horizontal deflection voltage is applied to the screen 9 to deflect the electron beam of each picture element in the horizontal direction.
Two sets of R and G above.

Each of the phosphors B is sequentially irradiated to emit light. In this embodiment, the deflection range is two picture elements wide for each electron beam.

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 9X with sufficient energy.

The screen 9 is constructed by applying a phosphor 20 that emits light when irradiated with an electron beam to the back surface of a glass plate 21, and adding a metal back layer (not shown).

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

In FIG. 3, 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 6. The area displayed horizontally.

Indicates the minute. As shown in the enlarged view in Figure 4, one section partitioned by these two has an R of two pixels in the horizontal direction.
, G, and B, and has a width of 16 lines in the vertical direction. The size of one compartment is, for example, 1 inch in the horizontal direction and 10 meters in the vertical direction.

Note that in FIG. 3, the length in the horizontal direction is greatly expanded relative to the length in the vertical direction for clarity.

In addition, in this embodiment, only one pair of R, G, and B phosphors 20 are provided for one control electrode 6, that is, for one electron beam, for two picture elements, but of course, one picture element The control electrode 6 may be provided with R, G, B for one picture element or three picture elements or more.
Video signals are applied sequentially, and horizontal deflection is performed in synchronization with the video signals.

Next, the basic configuration of a drive circuit for displaying television images on this display element will be described with reference to FIG. 5. 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, -v1 to the back electrode 1, v3. ■3', horizontal focusing electrode 6 is v6, accelerating electrode Y is v8, screen 9
Apply the DC voltage of ■9 to .

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 4o includes a vertical deflection counter 26.
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 4o is as follows:
A vertical synchronizing signal (2) and a horizontal synchronizing signal (H) shown in FIG. 6 are used. The vertical deflection counter 25 (8 pits) is reset by the vertical synchronizing signal V and counts the horizontal synchronizing signal H. This vertical deflection counter 26 is counted during an effective scanning period (here, U24) excluding the vertical retrace period of the vertical period.
This count output is supplied to the address of the memory 27. Vertical deflection signal data (here, 10 bits) corresponding to each address is output from the memory 27, and the data is converted to V as shown in FIG. 6 by the DA converter 39.

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

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 generate a line cathode drive pulse [
I~Yo]. FIG. 7(,) shows the vertical synchronization signal V,
The relationship between the horizontal synchronizing signal H and the lower 5 bits of the vertical deflection counter 26 is shown.

7) shows a method of creating line cathode drive pulses [A' to Y'] every 16H using these signals.

In Figure 7, LSB indicates the lowest bit, (LSB 11)
means a pit one level 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 ■ and the output (LSB+4) of the vertical deflection counter 25.
The line cathode drive pulses [A' to 'Y'] are transferred using a shift register using the inverted version of the output (LSB+3) of the vertical deflection counter 26 as the line cathode drive pulse [A']. Obtainable. 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 voltage of about 20 volts during other periods. , are added to each line cathode 2i to 2yo.

Each line cathode 2I to 2Y is heated by a current flowing through it during the high potential of the drive pulse [I to YO].
The heating state is maintained so that electrons can be emitted during the low potential period of the electric field. As a result, 16 line cathodes 2-2
From Y to Y, electrons are emitted only during the 1eH period when a low potential drive pulse [I to Y] is applied to each of them. During the period when a high potential is applied, the back electrode 1 and the vertical focusing electrode 3
Since the high potential applied to the line cathodes 2A to 2Y is more positive than the potential at the line cathode 2, which is determined by the bias voltage applied to the line cathodes 2A to 2Y, No electrons are emitted from yo. 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 line cathode drive pulses [I to Y] and the vertical deflection signal v,
The relationship with v' will be explained using FIG. Vertical deflection signals v, v' are 1e of each line cathode pulse [I to Y]
During the H period, it changes in steps of 1H and changes in 16 steps.

The vertical deflection signals V and V' both have a center voltage of v4, so that V increases sequentially and V' decreases sequentially.
They are designed to change in opposite directions. These vertical deflection signals V (!: 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 move in 16 steps in the vertical direction. 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, electron beams are emitted for each 16H period from the top of the 15 line cathodes 2I to 2Y, and each electron beam is sequentially emitted for one line from top to 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 divided into 180 sections by the control electrode 5 and the horizontal focusing electrode 6 and extracted. Figure 3 shows one of these categories. The amount of electron beam passing through each section is controlled by a control electrode 6, and is focused in the horizontal direction by a horizontal focusing electrode 6 to become one thin electron beam.
The light is deflected horizontally in six steps by the horizontal deflection means described below, and is sequentially irradiated onto the R, G, and B fluorophores 20 corresponding to two picture elements on the screen 9. FIG. 4 shows the vertical and horizontal divisions. Each of the control electrodes 6 15a~
The phosphor corresponding to 15n has R, G, and B for two picture elements, but for convenience of explanation, one picture element is RGB and the other is R.
2, G2. Let's call it B2.

11 1+ 1 Next, the horizontal deflection drive circuit 41 is composed of a horizontal deflection counter (11 bits), a memory 29 storing a horizontal deflection signal, and a DA converter 38. As shown in FIG. 9, 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 2 is reset by the vertical synchronizing signal V and counts the horizontal six times pulse 6H. This horizontal deflection counter 28 is counted K e times during 1H, 1
240H×e/H=1440 times during v, and this count output is supplied to the address of the memory 29. The memory 29 outputs horizontal deflection signal data (here, 8 bits) according to the address, and the D-A converter 38 converts it into a horizontal deflection signal such as h/ as shown in FIG. .

This circuit has memory addresses for storing horizontal deflection signals corresponding to each of 5 x 240 lines, and by storing 6 pieces of regular data for each line in the memory, 6-step horizontal waves are generated in 1H period. A deflection signal can be obtained.

As shown in Fig. 9, this horizontal deflection signal is a pair of horizontal deflection signals ri and h' that change in 6 steps, both of which have a center voltage of v7, where h decreases sequentially and h' increases sequentially. They change in opposite directions as they move forward. These horizontal deflection signals, h/, are electrodes 1 and 1 of horizontal deflection electrode 7, respectively.
8' is added.

As a result, each horizontally segmented electron beam can be applied to the R, G, B, R of the screen 9 during each horizontal period.

It is horizontally deflected so that the phosphors of G and B (R1, G1.B1.R2, G2.B2) are sequentially irradiated with H/e.

Thus, in each line raster, the horizontal direction 18
The electron beam for each section of 0 is R1, G1°B1. R2
, G2. Each phosphor 2o 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 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
The G-Y color difference signals are demodulated, the G-Y color difference signals are matrix-synthesized, and these are further combined with the luminance signal Y to form R, G, and H primary color signals (hereinafter R, G,
A B video signal) is output. Those R,G,
B Each video signal is processed by 180 sample and hold circuit sets 3
Added to 1a-31111. Each sample and hold circuit set 31a-3In is for R1, G1, and B1.
It has six sample and hold circuits for R2, 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 constituted by a PLL (phase-locked loop) circuit, etc., and in this embodiment, the reference clock 6fgC is six times as large as the color subcarrier fgo.
It generates a reference clock 2f which is twice as large as C. The reference clock is controlled to always have a constant phase with respect to the horizontal synchronizing signal H. The reference clock 2f is added to the deflection pulse generation circuit C42, and the i of the signal 6H, which is six times the horizontal synchronizing signal H, is
Signal switching pulse r1. gl, bl, B2゜G
A pulse of 2 l B2 is obtained. On the other hand, reference clock 6
f is added to the sampling pulse generation circuit 34, where it is delayed by one clock cycle by a shift register, and is converted into a horizontal period (63.5 μsec).
1 during the effective horizontal scanning period (approximately 50μ5ec)
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 by.

These 1080 sampling pulses Ra1 to Bn2 correspond to 180 sample and hold circuit sets 31a to 3, respectively.
1n, and as a result, each sample-and-hold circuit set 31a to 31n has R1, G1 . B1.
R2, G2. Each B2 video signal is individually sampled and held.

The sample-held 180 pairs of R,,G1゜B
1. R2, G2. After completing the sample and hold for one line, 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 R1. G1. B
1. R2, G2. The signal of B2 is sent to the switching circuit 35a.
~35n added. Switching circuits 35a to 35
n are R1, G1°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-35n is applied to 180 sets of pulse width modulation (PWM) circuits 37a-37n, where 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 pulse r1 +q
1, blr"2zq2, is preferably sufficiently smaller than the pulse width of B2, for example, 1:10
~1:100 is used.

The outputs of the pulse width modulation circuits 37a to 37n are individually applied to the 180 conductive plates 15a to 15H of the control electrode 5 of the display element as control signals for modulating the electron beam. The switching circuits 368 to 35n are simultaneously controlled by switching pulses rI T911b11r2+"21b2 applied from the switching pulse generating circuit 36. The switching pulse generating circuit 36 receives a signal from the deflection pulse generating circuit 42 described above. R1.g1.b1.r2.g2.B2 divides each horizontal period into 6 and switches the switching circuits 35a to 35n by H/6.
1°B1. R2, G2. Switching signals r1 +q1, b, +r2 + are provided so that each video signal of B2 is time-divisionally outputted sequentially and supplied to the pulse width modulation circuits 37a to 37n.
q2, B2 is generated.

What should be noted here is that the switching circuit 35a-3
R1 in 6n. G1. B1. R2, G2°B2 video signal supply switching and electron beam R1, G1 . B1. The horizontal deflection of R2, G2 and B2 for switching the irradiation to the phosphor is synchronously controlled so that they completely match both in timing and order. As a result, when the electron beam is irradiating the R1 phosphor, the irradiation amount of the electron beam is controlled by the R1 video signal, and the G1. B1. R2, G2. B
2 is controlled in the same way, and the R, , G,
, B1. R2°G2. B2 The light emission of each party light is R1+G1+B1. R2, G2. Each picture element is controlled by the B2 video signal, 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 per line, and then sequentially for 240 minutes of lines starting from the upper line to display the image on the screen 9. One image will be displayed.

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

Problems to be Solved by the Invention However, in the above configuration, the vertical scanning period is determined by the product of the number of pulses from the line cathode drive circuit and the number of deflection stages of the vertical deflection signal. The scanning amount is also fixed, and there is a problem in that the vertical overscan amount cannot be arbitrarily selected.

In view of the above problems, the present invention arbitrarily changes the ON period of the pulse from the line cathode drive circuit only in the uppermost vertical section and the lowermost vertical section on the screen, thereby reducing the amount of vertical overscan. The present invention provides an image display device having means that can be arbitrarily selected.

Means for Solving the Problems In order to solve the above problems, the image display device of the present invention includes:
Among the linear cathode drive pulses from the linear cathode drive circuit that generates an electron beam for each vertical segment of the screen divided into multiple vertical segments, the pulse period of the uppermost vertical segment on the screen is changed. and a circuit for varying the pulse duration of the bottom vertical section.

Effect of the Invention With the above-described configuration, the present invention adjusts the ON period of the line cathode drive pulse from the line cathode drive circuit that generates an electron beam for each vertical section of the screen divided into a plurality of vertical sections. the top vertical section on the screen,
Since the bottom vertical section can be changed arbitrarily, the amount of vertical overscan can be arbitrarily selected. For example, a case where the vertical scan amount is desired to be 3.2 inches will be explained next.

Vertical effective scanning period = 262.5-21 = 241,
When the 5H vertical overscan amount is 3.2 inches, the vertical scanning period is as follows: (15-2) x 16 = 208...A Vertical scanning period to be determined - A = 26...
Now, assuming that the value of B is distributed equally between the upper and lower parts, and the number of deflection stages of the vertical deflection signal is set to 13 stages each, in other words, the ON period of the line cathode drive pulse from the line cathode drive circuit is , the vertical scanning period is 23 by making it narrower than the others in accordance with the 13 stages of deflection of the vertical deflection signal.
4H can be realized.

Embodiment Hereinafter, an image display device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a line cathode drive circuit of an image display device in an embodiment of the present invention. In FIG. 1, 51 is a timing generation circuit, 52 is an R-S flip 70 block circuit, 53 is an inverting amplifier, 54 is a shift register, 65 is a counter, and 56 is a gate circuit.

The operation of the image display device configured as described above will be described below with reference to FIGS. 1 and 2.

First, FIG. 2 shows a method for generating line cathode drive pulses. The first line cathode drive pulse [A"] is a signal V" obtained by delaying the vertical synchronization signal V by 3H by the timing generation circuit 51. and the output of the vertical deflection counter 25 (L
SB+4) and an R-S flip-flop circuit 52.

The line cathode drive pulses [mouth' to 'yo'] are sent to the shift register 64.
can be obtained by transferring the line cathode driving pulse [A'] using the inverted version of the output (LSB+3) of the vertical deflection counter 26 as a clock.

The line cathode drive pulse [Yo'] is gated by the gate circuit 66 using the signal v111 obtained by counting 237H of the horizontal synchronizing signal H by the counter 55 and the line cathode drive pulse [Yo'] from the shift register 54. You can create your own.

This drive pulse [A"1"~I", Y"] is inverted by an inverting amplifier 63 and kept at a low potential only during each pulse period, and during other periods, the line cathode is set at a high potential of about 20 volts. It is converted into a driving pulse [a'2b~force, y''] and applied to each line cathode 2a~2yo.

Although the above description deals with the case where the vertical scanning period is 234H, the delay time of the timing generation circuit 51 and the count number of the counter 56 can be arbitrarily selected separately.

As described above, according to this embodiment, the on-period of the line cathode drive pulse from the beam source that generates the electron beam for each vertical division of the screen on the screen is divided into a plurality of vertical divisions. By providing a circuit that arbitrarily changes only the uppermost vertical section and the lowermost vertical section, the amount of vertical overscan can be arbitrarily selected.

Effects of the Invention As described above, the present invention provides a method for generating electron beams from the line cathode drive circuit that generates electron beams for each vertical section of the screen on the screen. By providing a circuit that changes the pulse period of the top vertical section and a circuit that changes the pulse period of the bottom vertical section, line cathode driving of the top vertical section and the bottom vertical section on the screen can be performed. Since the on-period of the pulse can be arbitrarily selected, the vertical scanning period, in other words, the amount of vertical overscan can be arbitrarily selected.

[Brief explanation of the drawing]

FIG. 1 is a line cathode drive circuit diagram of an image display device according to an embodiment of the present invention, FIG. 2 is a waveform diagram for explaining the operation of the line cathode drive circuit of FIG. 1, and FIG. 3 is a bold diagram. Figure 5 is a circuit diagram showing the basic configuration of a drive circuit for displaying television images on a conventional image display element, Figure 6 is an input pulse waveform diagram of the vertical deflection drive circuit, and Figure 7 is a diagram showing the vertical synchronization signal and horizontal A waveform diagram showing a method of creating a line cathode drive pulse using a synchronization signal and an output signal of a vertical deflection counter, FIG. 8 is a waveform diagram showing the relationship between a line cathode drive pulse and a vertical deflection signal,
FIG. 9 is an input pulse waveform diagram of the horizontal deflection drive circuit. 61...timing generation circuit, 62...R
-S flip-flop circuit, 63...inverting amplifier, 64...shift register, 65...river counter, 56...gate circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 4
Raw-m-Screen 20- E9e Body No. 6 Fig. 7 (a, 2 15B+/IJlh2 1 TS L5B+4 16' H (b) Non-Fig. 9 Procedural Amendment (λK) November 20, 1985 1 Display of the case 1985 Patent Application No. 167025 2 Name of the invention Image display device 3 Person making the amendment Relationship to the case Patent application Colonel Address 1006 Oaza Kadoma, Kadoma City, Osaka Name (582) Matsushita Electric Industrial Co., Ltd. company representative
Toshihiko Yamashita 4 Agent 571 Address Matsushita Electric Industrial Co., Ltd., 1006 Kadoma, Kadoma City, Osaka Prefecture (no change in content)

Claims (1)

[Claims] a screen coated with a phosphor that emits light when irradiated with an electron beam; an electron beam source that generates an electron beam for each vertical division of the screen on the screen; separation means for separating the electron beam generated by the electron beam source into each horizontal section and irradiating the screen; a beam flow control electrode 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; , a focusing electrode for controlling the size of light emitted by the electron beam on the phosphor surface in each pixel, a back electrode for controlling the amount of electron beam from the electron beam source, and an acceleration electrode for accelerating the electron beam to irradiate it to the screen. The on-period of the line cathode drive pulse from the electron beam source that generates an electron beam in each vertical section of the screen divided into a plurality of vertical sections is set at the top of the screen. An image display device configured to arbitrarily change only the vertical division and to arbitrarily select the amount of vertical overscan.