JPS58104589A - Picture display - Google Patents

Abstract

PURPOSE:To apply a voltage without causing insulation breakdown, by applying a prescribed voltage to adjacent electrodes at the same time out of electrodes constituting a picture display, and setting the voltage independently. CONSTITUTION:A display element comprises a back electrode, a line cathode, a vertical collecting electrode, a vertical deflection electrode, an electron beam flow control electrode, a horizontal collecting electrode 6, a horizontal deflection electrode 7, and an electrode 6'. Insulating spacers 37, 38 are provided among the electrodes 6, 7 and 6'. In applying a voltage, a power supply having a voltage of E1 is applied as the 1st step, then a voltage V7 is applied to the electrodes 6, 7 and 6'. Through the application of the power supply having a voltage of E2 as the 2nd step, the voltage is increased up to V'6, and the voltage is dropped to V6, by applying the power supply having a voltage of E3 as the 3rd step.

Description

Detailed Description of the Invention The present invention controls an electron beam emitted from an electron beam source such as a linear cathode using an electrode such as a deflection electrode or a control electrode, and focuses the electron beam on a fluorescent display surface of a screen. The present invention relates to a display device that emits light and displays an image by irradiating the display device in a controlled state, and aims to provide a display device that can be prevented from being destroyed during startup.

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 create thin television receivers. It was impossible to do so. 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 reproducibility of color display. , it has not yet been put into practical use.

Therefore, with the aim of achieving a device that can display color television images on a flat display device using an electronic system, the screen was divided vertically into multiple sections. An electron beam is generated for each section, each electron beam is deflected vertically for each section to display multiple lines, and further divided into multiple sections horizontally and R - The G, B, etc. phosphors are made to emit light in sequence, and the amount of electron beam irradiation to the R-G-B etc. phosphors is controlled by a color video signal, so that the television image as a whole is displayed. A device was devised to display the

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 as electron beam source2. Vertical focusing electrode 3.
3', vertical deflection electrode 4. Electron beam flow control electrode6.
Horizontal focusing electrode 6. A horizontal deflection electrode 7, an electron beam acceleration electrode 8, and a screen plate 9 are arranged.
These are housed within the evacuated interior of a flat glass pulp (not shown). A line cathode 2 serving as an electron beam source is stretched horizontally so as to generate an electron beam distributed linearly in the horizontal direction. Here, only four (2A to 22 are shown) are provided. In this embodiment, it is assumed that 15 pieces are provided. Let's say 2i~2yo. These wire cathodes 2 are constituted by coating an oxide cathode material on the surface of a tungsten wire having a diameter of 10 to 2 .mu..phi., for example.

Then, as will be described later, the electron beams are controlled to be emitted sequentially from the upper line cathode 2 for a fixed period of time. The back electrode 1 creates a potential gradient with a vertical focusing electrode 3, which will be described later, and prevents the generation of electron beams from other line cathodes 2 other than the line cathode 2 which is controlled to emit electron beams for a certain period of time. It has the function of suppressing the electron beam and pushing the generated electron beam forward only. 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, a planar electron beam emitting cathode may be used between the back electrode 1 and the line cathode 2.

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

The slit 10 may be provided with crosspieces at appropriate intervals in the middle, or may be a row of through holes provided in a large number at small intervals in the horizontal direction (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 trace position of each of the above-mentioned Surin 10, and each
The conductor 13 and 13' are provided on the upper and lower surfaces of an insulating substrate 12. Then, a vertical deflection voltage is applied between the opposing conductors 13 and 13' to deflect the electron beam in the vertical direction. In this configuration example, the electron beam from one line cathode 2 is deflected to a position corresponding to 16 lines in the vertical direction by a pair of conductors 13 and 13'.

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

Next, the control electrodes 6 are composed of conductive plates 16 each having a vertically long slit 14, and a plurality of control electrodes 6 are arranged horizontally in parallel at predetermined intervals. In this configuration example, 320 control electrode conductive plates 15a to 15n are provided (only 10 are shown in the figure). Each of the control electrodes 6 extracts the electron beam by dividing it into one picture element in the horizontal direction, and controls the amount of electron beam passing therethrough according to the video signal for displaying each picture element.

Therefore, if 32020 control electrodes 6 are provided, 320 picture elements can be displayed per horizontal line.

In addition, in order to display images in color, each picture element is R, G.
, Bl, and the R, G, and B video signals are sequentially applied to each control electrode 6.

In addition, 320 sets of video signals for one line are simultaneously applied to the 320 control electrodes 6, 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 (320 slits 16) 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 electrode 7 is made up of a plurality of conductive plates 18 arranged vertically in the middle of each of the slits 16, and a horizontal deflection voltage is applied between each conductive plate 18 for each pixel. The electron beams are respectively deflected in the horizontal direction, and the R, G, and B phosphors are sequentially irradiated on the screen 9 to cause them to emit light. In this embodiment, the deflection range is the width of one picture element for each electron beam.

The acceleration electrode 8 is composed of a plurality of conductive plates 18 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 coating the back surface of a glass plate 21 with a phosphor 2o that emits light when irradiated with an electron beam, and adding a metal back layer (not shown). The phosphors 20 are provided with one pair of phosphors of three colors R9G and H for each slit 14 of the control electrode 6, that is, for each horizontally divided electron beam. It is applied in vertical stripes. 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 2o for one pixel 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.
The vertical direction is in 16th order.

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

In addition, in this embodiment, only one pair of R, G, and H phosphors 2o is provided for one picture element for one control electrode 6, that is, one electron beam, but for two or more picture elements, Of course, two or more pairs of pixels may be provided; in that case, R, G, and B video signals for two or more picture elements are sequentially applied to the control electrode 6, and the horizontal deflection is synchronously applied to the control electrode 6. It will be done.

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 description will be given of the driving portion that irradiates the screen 9 with an electron beam to cause the phosphor to emit light and generate a raster.

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. to the vertical focusing electrodes 3, 3'. (3) Apply a DC voltage of v6 to the horizontal focusing electrode 6, V8 to the accelerating electrode 8, and v9 to the screen 9.

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 drive pulse generation circuit 26 is composed of a counter that is reset by a vertical retrace pulse and counts horizontal pulses, and has an effective vertical scanning period (here, a period of 240H) excluding the vertical retrace period of the vertical period. 16 drive pulses each having a length of 16H period [
〔〕,〔mouth〕・・・・・・〔Y〕. These driving pulses [a], [mouth]...[y] are applied to the line cathode drive circuit 26, where they are inverted and are expressed at a low potential only during each pulse period, and during other periods. Linear cathode driving pulses made at a high potential of about 20 volts [A'], [A']
・・・・・・Converted to [Yo′], each line cathode 2i, 20
．．・・・・・・Added to 2yo.

A current is passed through each line cathode 2a, 2yo between the high potential of the drive pulse [a'] to [yo'], and the low potential of the drive pulse [a'] to [yori]. The heated state is maintained so that electrons can be emitted even during the potential period. As a result, 16
Electrons are emitted from the main wire cathodes 2i to 2yo only during the 16H period when low potential drive pulses [a'] to [yo'] are applied to each of them. During the period when a high potential is applied,
l! 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 applied to the cathodes 2i to 2yo becomes positive, no electrons are emitted from the line cathodes 2i to 2yo. 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 vertically focused to form a flat electron beam.

Next, the vertical deflection drive circuit 27
It consists of a counter that is reset by each of the vertical drive pulses [A] to [Y] to count the horizontal synchronizing signal, and a conversion circuit that converts the count output to D/A. 16 with 1H in between
A pair of vertical deflection signals v, v' which vary in steps are generated. The center voltage of both vertical deflection signals V and V' is v4.
They are designed to change in opposite directions, such that V increases sequentially and V' decreases sequentially. These vertical deflection signals V and V' are applied to the vertical deflection electrode 4, respectively.
As a result, the electron beams generated from the respective line cathodes 2I to 2Y are vertically deflected in 16 steps, and are applied to the screen 9 as described above.
At the top, one electron beam is deflected so as to draw a 16-line raster one line at a time from the top.

As a result of the above, electron beams are emitted for 16H periods in order from the one above the 16 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. By being deflected, the screen 9
At the top, the electron beam is vertically deflected one line at a time from the first line at the top to the 240th line at the bottom, and a total of 240 lines are drawn.

The electron beam thus vertically deflected is horizontally divided into 320 sections by the control electrode 6 and the horizontal focusing electrode 6 and extracted. Figure 1 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 three stages by the horizontal deflection means described below, and is sequentially irradiated onto each of the R, G, and H phosphors 2° on the screen 9.

That is, the horizontal drive pulse generation circuit 28 is composed of three cascaded monostable multivibrators, etc.
Triggered by a horizontal synchronization signal, three horizontal drive pulses r, g, with equal pulse widths are generated within one horizontal period.
Generates b. Here, as an example, three pulses r, g, and b are generated during an effective horizontal scanning period of 60 μsec, with each pulse width being approximately 17 μlieG. Their horizontal drive pulses r
, q, b are applied to the horizontal deflection drive circuit 29. This horizontal deflection drive circuit 29 generates a horizontal drive pulse "1 q+ b
A pair of horizontal deflection signals RI and h' which are switched in three stages are generated. Horizontal deflection signal.

Both h' have a center voltage of v7, and change in n opposite directions to each other such that h increases sequentially and h' decreases sequentially. These horizontal deflection signals h' are applied to electrodes 18 and 18' of horizontal deflection electrode 7, respectively. As a result, each horizontally divided electron beam sequentially hits the R, G, and B phosphors of the screen 9 for 17 μs during each horizontal period.
It is horizontally deflected so that it is irradiated by a. However, the first
In the display element shown in the figure, one conductor 18 or 18' is used in the horizontal deflection electrode 7 to deflect two adjacent sections of electron beams in opposite directions. Therefore, if the electron beam of 320 sections is deflected in the order of R, G-, and B in the odd-numbered sections, then the electron beam in the even-numbered sections is deflected in the order of B. -GH is deflected in the order, and so on, and so on, so that every other section is deflected in the opposite direction.

Thus, in each line raster, the horizontal 3
The electron beams are R and G for each of the 20 sections.

Each phosphor 2o of B is sequentially irradiated with light.

Therefore, for each horizontal section of each line, the R and G electron beams are
, H, 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 referred to as R, G, B
(referred to as a video signal) is output. Those R, G, B
Each video signal has 320 sample and hold circuit sets 31a.
~31n. Each sample and hold circuit, 11
31a to 31n each have three sample and hold circuits for R, G, and B. The sample and hold outputs of these sample and hold circuit sets 31a to 31n are applied to holding memory sets 32a to 32n, respectively.

On the other hand, the sampling reference clock oscillator 33 is a PLL.
(phase-locked loop) circuit, etc., and generates a reference clock of approximately 6.4 MHz in this embodiment. The reference clock is controlled to always have a constant phase with respect to the horizontal synchronizing signal H. This reference clock is applied to the sampling pulse generation circuit 34, where it is delayed by one clock period by a shift register, etc., resulting in a horizontal period (63.5 μsec).
During the effective horizontal scanning period (approximately 60 μsec), 320 sampling pulses are sequentially generated.
One transfer pulse is then generated.

This sampling pulse a-n corresponds to each picture element when one line of the displayed barking image is divided horizontally into 320 picture elements, and its position is always constant with respect to the horizontal synchronization signal H. controlled as follows.

These 320 sampling pulses a-n correspond to the 320 sample-and-hold circuit sets 31a to 31n, respectively.
As a result, each sample-and-hold circuit set 31a to 32n receives the R, G, and B video signals of each picture element when one line is divided into 320 picture elements. sampled and held. The sampled and held 320 sets of R, G, and B video signals are transferred to the memory 3 after completing the sample and hold for one line.
2a to 32'' all at once by a transfer pulse t,
Here, it is held for the next one horizontal movement period.

One line of R and C stored in the memories 32a to 32n
The a and B video signals are applied to 320 switching circuits 35a to 35n, respectively. Switching circuit 35a
~35n are R and G, respectively.

Each switching circuit 35a has individual input terminals of B and a common output terminal that sequentially switches and outputs them.
The output of ~35n is used as a control signal for modulating the Kameko beam and is sent to the 320 conductive plates 15a of the control electrode 6 of the display element.
~15n each separately. Each switching circuit 35a to 35n is a switching pulse generation circuit 36.
They are simultaneously switched and controlled by switching pulses applied from -j. The switching pulse generation circuit 36 generates pulses from the horizontal drive pulse generation circuit 28 described above.
The switching circuits 35a to 35n'i switch R, G,
A switching signal rw qs is applied so that each video signal of
generate b. However, switching circuits 358-3
In 5H, odd-numbered switching circuits asa, s
6c... are switched in the order of RG, B, and the even numbered switching circuits 35b, 35d...
35n can be switched in the reverse order of B - Q - and H! It is.

Here, what should be noted is that the switching circuits 35a to 35a
Switching the supply of R, G, and B video signals at 35n;
The horizontal deflection of the horizontal deflection drive circuit 29 for switching the irradiation of the electron beam onto the R, G, and B phosphors is synchronously controlled so that they completely match both in timing and order. As a result, when the electron beam is irradiating the R phosphor, the irradiation amount of the electron beam is R
Controlled by the video signal, 1, G, and B are similarly controlled, and the light emission of the R, G, and B phosphors of each picture element is controlled by the R, G, and B video signals of that picture element. Therefore, each picture element is displayed by emitting light according to the input video signal. Such control is performed simultaneously for 320 picture elements for one line to display one line of video, and then sequentially performed for 240 minutes from the upper line to display one video on screen 9. That will happen.

The above operations are performed on one of the four input television signals.
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.

As described above, television images are displayed on this display device.

In addition, in the above explanation, the horizontal direction and vertical direction of candy mean that the direction in which line units are displayed when displaying an image is the horizontal direction, and the direction in which the lines are stacked is the vertical direction. It is used in the sense that it is certain, and is not directly related to the vertical and horizontal directions on the actual polar plane.

The present invention particularly relates to means for applying a voltage to adjacent deflection electrodes and focusing electrodes in such an image display device. If a voltage is applied independently to each electrode in a display element having the above-described structure, voltage breakdown of the spacer for insulating each electrode may occur, resulting in a fatal defect in the image display device. Therefore, in the present invention, a certain voltage is simultaneously applied to adjacent electrodes, and then the voltages are set independently, thereby increasing the voltage without causing dielectric breakdown. so that it can be applied. This application means can be applied to all electrodes, but in practice it may be applied between electrodes that are likely to have dielectric strength problems. Specifically, electrodes 6 and 7 in FIG. 1 and 6' between electrodes 7 and 8 (not shown), a focusing electrode and a deflection electrode are practical. FIG. 4 shows only these three electrodes. FIG. 6 shows the desired voltage and power supply configuration of each electrode, as well as the first step, second step, and so on. It shows the applied voltage in two stages of the third step.

First, when the power of El is turned on in the first step, a voltage v7 is applied to each electrode 6, 7.6'. In the second step, the power of E2 is turned on and the voltage is raised to v6', and in the third step, the power of E3 is turned on and the voltage is lowered to v6'. By the way, in the first step, the power supply of El may be switched on and off, but in the second step. In the third step, E2. It is not true that it is safer to not switch the E3's power on and off.

In fact, ■7y3ooVl v6′ 4oov, v6
Some of the insulating spacers shown in FIG. 4 have a withstand voltage as low as 160 to 200 V, and if a voltage is applied independently, there is a sufficient possibility of dielectric breakdown.

As described above, according to the present invention, it is possible to obtain a device that can be driven without causing fatal defects in the image display element when a voltage higher than the dielectric strength voltage is applied to adjacent electrodes. It is something.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of an example display element used in the image display device of the present invention, FIG. 2 is an enlarged front view of the screen, FIG. 3 is a block diagram showing the basic configuration of the drive circuit, and FIG. 6 is a sectional view showing the configuration of the main part thereof, FIG. 6 is a chart diagram explaining the operation of the image display device in an embodiment of the present invention, and FIG. 6 is a circuit diagram of a part thereof. 2... Line cathode as an electron beam source, 3,3'...
... Vertical focusing electrode, 4 ... Vertical deflection electrode, 6
...Beam flow control electrode, 6...Horizontal focusing electrode, 7...Horizontal deflection electrode, 8...
Beam accelerating electrode, 9...Screen, 2o...
...Fluorescent material, 23...Input terminal, 24...
... Synchronization separation circuit, 26 ... Vertical drive pulse generation circuit, 26 ... Line cathode drive circuit, 27 ...
. . . Vertical deflection drive circuit, 28 . . . Horizontal drive pulse generation circuit, 29 . . . Horizontal deflection drive circuit, 30.
...Color demodulation circuit, 31a-31n...Sample hold circuit silk, 32a-32n...Memory group, 34...Sampling pulse generation circuit, 35a-35n ...Switching circuit, 36
...Switching pulse generation circuit, 37.38
...Insulating spacer. Name of agent: Patent attorney Toshio Nakao and one other person JP-A-58-104589 (7) 11? ! 1 Turn horizontally for 1 meter 113 Figure 4 Figure 5 Figure 16

Claims (1)

[Claims] an electron beam generation source, 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 directing the electron beam onto the screen. An image display element is provided, which includes an electrostatic deflection electrode that deflects between the electron beam and the screen, and a control electrode that controls the emission intensity by controlling the amount of the electron beam and the screen. When applying a voltage to adjacent electrodes, the voltage is simultaneously applied up to a certain value, and then the voltage is applied independently to the electrode to which a voltage higher or lower than the applied voltage is to be applied. Image display device.