JPH06332393A - Image display device - Google Patents

Abstract

PURPOSE:To lower a power source voltage required for horizontal deflection high voltage power source for a high voltage amplifier in a horizontal deflection signal generator, to reduce power consumption in the high voltage amplifier, to prolong the life of components and to increase the density in mounting by providing a horizontal deflection low voltage power source capable of adjusting a horizontal focus voltage different at every image display device. CONSTITUTION:In the horizontal deflection signal generator, a D/A converter 51 receiver the horizontal deflection data of a deflection memory to convert into an analog current. Then, the output analog current of the D/A converter 51 is converted into symmetrical analog voltages by an operational amplifier 52, a resistor 54 and the operational amplifier 53, the resistor 55. Then, from the symmetrical horizontal deflection signals converted into the analog voltages, the horizontal deflection signal deflecting an electron beam horizontally is formed by the high voltage amplifiers 57, 58 to be impressed to horizontal deflection electrodes 18, 18'. At this time, the voltage of the horizontal deflection low voltage power source is adjusted so that the horizontal focus voltage different at every display device matches with the center of the voltage of the horizontal deflection high voltage power source.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generates an electron beam for each section when a screen image projected on a screen plate is divided into a plurality of sections in the vertical direction, and each electron beam is generated for each section. The present invention relates to an image display device that deflects a beam in a vertical direction to display a plurality of lines and displays an image as a whole.

[0002]

2. Description of the Related Art In recent years, various flattening devices for displaying television images have been proposed.

An image display device as a flat-type color picture tube of this type has hitherto been disclosed in, for example, Japanese Patent Laid-Open No. 135355/1982.
It has a structure as shown in the publication. The configuration will be described below with reference to the drawings.

As shown in FIG. 3, this image display device has a back electrode 1, a line cathode 2 as an electron beam emission source, an electron beam extraction electrode 3, and an electron beam emission electrode 3 in this order from the rear to the anode side.
A beam control electrode 4, a focusing electrode 5, a horizontal deflection electrode 6, a vertical deflection electrode 7, a screen plate 8 and the like are arranged and configured, and these are housed inside a vacuum container.

The operation of the flat type image display device constructed as described above will be described below. As shown in FIG. 3, the line cathode 2 as an electron beam emission source is stretched horizontally so as to generate electron beams that are linearly distributed horizontally, and the line cathode 2 is further vertical. A plurality of lines (only 7 lines 2a to 2g are shown in FIG. 3) are provided at regular intervals in the direction. In this configuration, the line cathodes are spaced at 4.4 mm and the number of line cathodes is 19, and the line cathodes are 2 to 2 in number. The distance between the line cathodes cannot be freely set to a large value, and the vertical deflection electrode 7 and the screen plate 8 which will be described later will be used.
It is regulated by the interval. As the structure of these wire cathodes 2, an oxide cathode material is applied to the surface of a tungsten rod having a diameter of 10 to 30 μm. As will be described later, the line cathode is controlled so as to sequentially emit an electron beam from the upper line cathode 2a to the lower two line cathodes at regular intervals.

The back electrode 1 suppresses the generation of electron beams from the line cathodes other than the corresponding line cathode, and at the same time, the electron beam is emitted.
It also has the function of pushing the mud only in the anodic direction. Figure 3
Although a vacuum container is not shown, it is possible to use the back electrode 1 to form a structure integrated with the vacuum container. The electron beam lead-out electrode 3 is a conductive plate 11 having a plurality of through holes 10 which are arranged in a row in the horizontal direction facing the respective line cathodes 2 a to 2 at regular intervals and are emitted from the line cathode 2. The electron beam is taken out through the through hole 10.

Next, the beam control electrode 4 is composed of a vertically long conductive plate 15 having a through hole 14 at a position facing each of the line cathodes 2a to 2c, and is horizontally arranged at a predetermined interval. Multiple pieces are installed side by side. 114 in this configuration
The beam control electrode conductive plates 15a to 15n are provided (only eight are shown in FIG. 3). The beam control electrode 4 synchronizes the passing amount of each electron beam divided in the horizontal direction by the electron beam extraction electrode 3 in correspondence with the picture element of the video signal and in synchronization with the horizontal deflection timing described later. Let me control.

The focusing electrode 5 is a conductive plate 17 having a through hole 16 at a position facing each through hole 14 provided in the beam control electrode 4, and focuses the electron beam.

The horizontal deflection electrode 6 is composed of a plurality of conductive plates 18 and 18 'vertically arranged along both sides of the through hole 16 in the horizontal direction. Voltage is applied. The electron beam for each picture element is deflected in the horizontal direction, and the R, G, and B phosphors are sequentially irradiated on the screen plate 8 to emit light. In this configuration, each electron beam is deflected by 2 trio.

The vertical deflection electrode 7 is composed of a plurality of conductive plates 19 and 19 'arranged in the horizontal direction at the respective intermediate positions in the vertical direction of the through hole 16, and a voltage for vertical deflection is applied to the vertical deflection electrode 7 to generate an electronic beam. -The beam is deflected vertically. In this structure, the electron beam generated from one line cathode is vertically deflected by 12 lines by the pair of electrodes 19 and 19 '. The vertical deflection electrodes 7 composed of 20 pieces form 19 pairs of vertical deflection conductors corresponding to the 19 line cathodes, respectively, and 228 pieces of the vertical deflection conductors 228 are arranged on the surface of the screen plate 8 in the vertical direction. Drawing a horizontal scan line.

As described above, in this structure, a plurality of horizontal deflection electrodes 6 and vertical deflection electrodes 7 are arranged in a comb shape. Furthermore, by setting the distance to the screen plate 8 longer than the distance between the horizontal and vertical deflection electrodes, the electron beam can be moved with a small deflection amount.
It becomes possible to irradiate on the surface of. This makes it possible to reduce deflection distortion both horizontally and vertically.

As shown in FIG. 3, the screen plate 8 is formed by coating the back surface of the glass plate 21 with the phosphors 20 in a stripe shape. Although not shown, metal back and carbon are also applied. The phosphor 20 deflects the electron beam passing through one through hole 14 of the beam control electrode 4 in the horizontal direction to form two phosphor pairs of three colors of R, G and B.
It is provided to irradiate the amount of trio, and is applied in stripes in the vertical direction. In FIG. 3, broken lines drawn on the screen plate 8 indicate vertical divisions corresponding to the plurality of line cathodes 2, and two-dot chain lines indicate the plurality of beam control electrodes 4. The corresponding horizontal divisions are shown. As shown in the enlarged view of FIG. 3, one section partitioned by broken lines and two-dot chain lines has two trio R, G, and B phosphors in the horizontal direction and a width of 12 lines in the vertical direction. ing. In this example, the size of one section is 1 mm in the horizontal direction and 4.4 mm in the vertical direction.

Although the phosphors of three colors R, G and B are shown in stripes in FIG. 4, they may be arranged in a delta shape. However, when they are arranged in a delta shape, it is necessary to apply horizontal deflection and vertical deflection waveform voltages suitable for them. In FIG. 4, for the sake of explanation, the dimensional ratio in the vertical and horizontal directions is different from the image displayed on the actual screen.

Further, in this structure, the phosphors of R, G, B are provided for two trios for one through hole 14 of the beam control electrode 4. However, the phosphors for one trio or three trios or more are formed. May be. However, the R, G, and B video signals of 1 trio or 3 trios or more are sequentially applied to the beam control electrode 4, and horizontal deflection must be performed in synchronization therewith.

Next, the operation of the drive circuit for driving the image display device will be described with reference to FIG.

First, the drive portion for irradiating the screen 8 with the electron beam and displaying the same will be described. The power supply circuit 22 is a circuit for applying a predetermined bias voltage to each electrode of the image display element. The back electrode 1 is V1, the electron beam extraction electrode 3 is V3, the focusing electrode 5 is V5, and the screen is a screen. A DC voltage of V8 is applied to the plate 8.

The pulse generating circuit 39 uses the vertical synchronizing signal V and the horizontal synchronizing signal H to create a line cathode drive pulse.
FIG. 6 shows an example of the timing.

The line cathode drive circuit 26 receives the line cathode drive pulse and heats the line cathode 2 while the drive pulse is at a high potential. At this time, the heated line cathode is applied to the line cathode 2 more than the potential around the line cathode 2 determined by the bias voltage applied to the back electrode 1 and the electron beam extraction electrode 3. Electrons are not emitted from the line cathode because the potential that is present is higher.

On the other hand, the line cathode 2 emits electrons while the driving pulse is at a low potential. At this time, the line cathode 2 has a potential applied to the line cathode 2 more than a potential around the line cathode 2 determined by the bias voltage applied to the back electrode 1 and the electron beam extraction electrode 3. Since it becomes lower, electrons are emitted from the line cathode 2.

As is clear from the above description, electrons are emitted from the 19 line cathodes 2a to 2t only during the 12 horizontal scanning periods in which low potential drive pulses (a tot) are applied. In order to form one screen, it is sufficient to sequentially switch the potentials from the upper line cathode 2a to the lower line cathode 2 by 12 scanning periods.

Next, the deflection portion will be described. As shown in FIG. 5, the deflection voltage generating circuit 40 includes a direct memory access controller (hereinafter referred to as a DMA controller).
41, a deflection voltage waveform storage memory (hereinafter referred to as deflection memory) 42, a horizontal deflection signal generator 43h, a vertical deflection signal generator 43v, and the like.
v'and horizontal deflection signals h, h '. In this configuration, the vertical deflection signal is displayed in one field for 228 horizontal scanning periods in consideration of overscan. Further, the memory address area storing the vertical deflection position information corresponding to each line is divided into a first field and a second field, and each set has a memory capacity. When displaying, data is read from the corresponding deflection memory 42, converted into an analog signal by the vertical deflection signal generator 43v, and added to the vertical deflection electrode 7.

The vertical deflection position information stored in the deflection memory 42 is composed of substantially regular data every 12 horizontal scanning periods, and the waveform converted into the deflection signal is also approximately 1.
Although it is a two-stage vertical deflection signal, it has a memory capacity of two fields as described above so that the position can be finely adjusted for each horizontal scanning line.

Further, with respect to the horizontal deflection signal, it is necessary to horizontally deflect the electron beam in six steps in one horizontal scanning period and a memory is provided so that the deflection position can be finely adjusted for each horizontal scanning. . Therefore, to display 456 horizontal scanning periods in one frame, a memory of 456 × 6 = 2736 bytes is required, but since the data of the first field and the second field are shared. In fact, it uses 1368 bytes of memory. At the time of display, the deflection information corresponding to each horizontal scanning line is read from the deflection memory 42, converted into an analog signal by the horizontal deflection signal generator 43h, and added to the horizontal deflection electrode 6.

The horizontal deflection signal generator 43h will now be described in detail. The horizontal deflection data in the deflection memory 42 is converted to D / A.
The converter 51 converts the analog current. The horizontal deflection signal converted into the analog current is converted into a symmetrical horizontal deflection signal by the operational amplifier 52, the resistor 54, the operational amplifier 53, and the resistor 55. The symmetrical horizontal deflection signals are voltage-amplified by the high-voltage amplifiers 57 and 58 and given to the horizontal deflection electrodes 18 and 18 ', respectively, to deflect the electron beam in the horizontal direction. The resistors 59, 60 and 61, 62 are feedback resistors that determine the amplification degree of the high voltage amplifiers 57, 58. Since the center voltage of the deflection of the horizontal deflection signal is ½ or more of the amplitude voltage of the deflection, the power source of the high-voltage amplifiers 57 and 58 is reduced so that the power consumption of the high-voltage amplifiers is reduced. Has a low power supply.

To summarize the above, during the display period excluding the vertical blanking period of the vertical period, one of the line cathodes 2A to 2C to which a low-potential drive pulse is applied is emitted. The electron beam is divided into 114 sections in the horizontal direction by the electron beam extraction electrode 3 to form 114 electron beam rows. As will be described later, the electron beam has its beam passing amount controlled by the beam control electrode 4 and is converged by the converging electrode 5 for each section.
As shown in FIG. 6, the horizontal deflection electrodes 18, 18 'to which a pair of horizontal deflection signals h, h', which change in approximately six steps, are added, and the like, R1, G of the screen plate 8 are provided in each horizontal display period.
1, B1 and R2, G2, B2 and other phosphors sequentially,
The horizontal display period / 6 is emitted at a time.

Thus, the raster of each horizontal line is 11
Displaying a color image on the surface of the screen plate 8 by modulating an electron beam for each of the four sections with a video signal corresponding to R1, G1, B1 and R2, G2, B2. You can

Next, the modulation control portion of the electronic beam will be described. First, in FIG. 5, signal input terminals 23R, 2
The R, G, and B video signals added to 3G and 23B are
It is added to 114 sets of sample-hold circuit sets 31a to 31n. Each of the sample-hold groups 31a to 31n is for R1, G1, B1, and R2, G2,
It is composed of six sample-hold circuits for B2.

The sampling pulse generating circuit 34 has a horizontal display period (about 50) of the horizontal period (63.5 μsec).
μsec), the 114 sets of sample-hold circuits 31
Each of a to 31n for R1, G1, B1, and R2
(114.times.6) sampling pulses Ra1 corresponding to the sample-hold circuits for G2, G2, and B2
Rn2 is sequentially generated. Each of the 684 sampling pulses includes 114 sample-hold circuit sets 31.
6 pieces are added to a to 31n, so that R1, G1, B1, R2 of two picture elements when one line is divided into 114 pieces in each sample hold circuit set.
The video signals of G2 and B2 are individually sampled and
Be killed. 114 sets of R1 sampled,
The video signals of G1, B1, R2, G2, and B2 are 114 sets of memories 32a through after the end of the sample hold for one line.
32n are transferred all at once by the transfer pulse t, and are held here for the next one horizontal scanning period. The retained signal is 11
It is added to the four switching circuits 35a to 35n.

Each of the switching circuits 35a to 35n is composed of a circuit having individual input terminals of R1, G1, B1, R2, G2 and B2 and a common output terminal for sequentially switching and outputting them, and a switching pulse Switching pulse r applied from the generation circuit 36
Switching control is performed simultaneously by 1, g1, b1, r2, g2, and b2. The switching pulses r1, g1,
b1, r2, g2, and b2 divide each horizontal display period into six, and each horizontal display period / 6 switching circuit 35a-3.
5n are switched and the respective video signals of R1, G1, B1, R2, G2, and B2 are time-divided and sequentially output, and supplied to the pulse width modulation circuits 37a to 37n. Each switching circuit 3
The outputs of 5a to 35n are added to 114 sets of pulse width modulation (hereinafter referred to as PWM) circuits 37a to 37n, and R1 and
The pulse width is modulated according to the magnitude of each of the video signals of G1, B1, R2, G2, and B2, and the output. The outputs of the pulse width modulation circuits 37a to 37n are 114 of the beam control electrode 4 of the display element as a control signal for modulating the electron beam.
It is added individually to the conductive plates 15a to 15n of the book.

Next, the timing of horizontal deflection and display will be described. Switching of video signals of R1, G1, B1, R2, G2 and B2 in the switching circuits 35a to 35n, and electronic beam R by the horizontal deflection signal generator 43h.
The synchronization control is performed so that the switching timing and the order of horizontal deflection of the phosphors of 1, G1, B1, R2, G2, and B2 to the phosphors completely match. As a result, when the R1 phosphor is irradiated with the electron beam, the irradiation amount of the electron beam is controlled by the R1 control signal, and G1, B1, R
2, G2, and B2 are controlled in the same manner, and the emission of each phosphor of R1, G1, B1, R2, G2, and B2 of each picture element is changed to that of R1, G1, B1, R2, G2, and B2 of that picture element. Each picture element is controlled by the video signal, and each picture element is luminescently displayed according to the input video signal. This control is simultaneously executed for 114 sets (two picture elements each) for one line, an image of 228 picture elements for one line is displayed, and one field 228 lines are sequentially performed from the upper line. Then, an image is displayed on the surface of the screen plate 8. Further, the above-described operations are repeated for each field of the input video signal, and the television signal or the like is displayed on the screen plate 8.

The basic clock required for this configuration is shown in FIG.
Is supplied from the pulse generation circuit 39 shown in FIG. 1 and the timing is controlled by the horizontal synchronizing signal H and the vertical synchronizing signal V.

[0032]

However, in the above-mentioned prior art, the voltage required for the horizontal deflection high power supply for the high voltage amplifier of the horizontal deflection signal generator is the horizontal amplitude voltage for deflecting the electron beam by 2 trio. , A horizontal offset voltage for correcting the deviation between the electron beam and the fluorescent screen, a horizontal focus voltage required for focusing the electron beam, and a voltage required for driving the circuit. Since the horizontal deflection high power supply requires a voltage obtained by adding the above-mentioned four voltages, the power supply voltage must be increased. Therefore, the power consumption of the high-voltage amplifier is large, which shortens the life of parts due to heat generation, and There was a problem that it hindered high density.

The present invention solves the above-mentioned problems of the prior art by reducing the voltage required for the horizontal deflection high power supply for the high voltage amplifier of the horizontal deflection signal generator, reducing the power consumption of the high voltage amplifier, and reducing the component life. It is an object of the present invention to provide an image display device that realizes high mounting density by increasing the mounting time.

[0034]

In order to achieve the above object, an image display apparatus according to the present invention has a structure provided with a horizontal deflection low power source capable of adjusting a horizontal focus voltage different for each image display apparatus. Is what you are doing.

[0035]

In the present invention, the horizontal deflection low power supply voltage is adjusted so that the horizontal focus voltage different for each image display device and the center of the horizontal deflection high power supply voltage coincide with each other. As a result, the voltage required for the horizontal deflection high power supply is the horizontal amplitude voltage for deflecting the electron beam by two trios, the horizontal offset voltage for correcting the deviation between the electron beam and the phosphor screen, and the voltage required for driving the circuit. Therefore, the voltage of the horizontal deflection high power supply becomes low.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the D / A converter 51
Converts horizontal deflection data into analog current. Operational amplifier 52, resistor 54, operational amplifier 53, resistor 5
The D / A converter 51 converts the output analog current into a symmetrical analog voltage. 56 is an operational amplifier 52, 5
It is the reference power source of No. The high-voltage amplifiers 57 and 58 amplify the output voltages of the operational amplifiers 52 and 53 into signals that allow the electron beams to be horizontally deflected, and apply the signals to the horizontal deflection electrodes 18 and 18 '. The resistors 59, 60 and 61, 62 are feedback resistors that determine the amplification degree of the high voltage amplifiers 57, 58. Since the center voltage of the deflection of the horizontal deflection signal is ½ or more of the amplitude voltage of the deflection, the power source of the high-voltage amplifiers 57 and 58 is reduced so that the power consumption of the high-voltage amplifiers is reduced. Has a low power supply. The lower horizontal deflection low power supply is a variable power supply capable of adjusting the horizontal focus voltage different for each image display device.

The operation of the horizontal deflection signal generator configured as described above will be described below with reference to FIG. The D / A converter 51 receives the horizontal deflection data of the deflection memory and converts it into an analog current. The output analog current of the D / A converter 51 is converted to the operational amplifier 52 and the resistor 5.
4, the operational amplifier 53 and the resistor 55 convert the analog voltage into a symmetrical analog voltage. A horizontal deflection signal for horizontally deflecting the electron beam is produced by the high-voltage amplifiers 57 and 58 from the symmetrical horizontal deflection signal converted into the analog voltage, and is applied to the horizontal deflection electrodes 18 and 18 '. Here, the voltage of the horizontal deflection low power supply is adjusted so that the horizontal focus voltage different for each image display device coincides with the center of the voltage of the horizontal deflection high power supply. Therefore, the voltage required for the horizontal deflection high power supply is the horizontal amplitude voltage for deflecting the electron beam by two trio, the horizontal offset voltage for correcting the deviation between the electron beam and the phosphor screen, and the voltage required for driving the circuit. Only the voltage which added three is sufficient.

[0039]

As described above, according to the present invention,
(EN) Provided is an image display device which realizes a high voltage of a horizontal deflection high voltage power supply for a high voltage amplifier of a horizontal deflection signal generator, a low power consumption of the high voltage amplifier, a long life of parts, and a high packing density. be able to.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a horizontal deflection signal generator according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of a conventional horizontal deflection signal generator.

FIG. 3 is an exploded perspective view of an image display device used in the present invention.

FIG. 4 is an enlarged view of a fluorescent screen of the image display device.

FIG. 5 is a block diagram of a drive circuit of the image display device.

FIG. 6 is a waveform diagram for explaining the operation of the image display device.

[Explanation of symbols]

 51 D / A converter 52, 53 Operational amplifier 54, 55 Resistor 56 Reference power supply 57, 58 High voltage amplifier 59, 60, 61, 62 Resistor 63 Horizontal deflection high power supply 64 Horizontal deflection low power supply

Claims (2)

[Claims] 1. A screen plate coated with a phosphor that emits light when irradiated with an electron beam, a plurality of line cathodes that generate the electron beam, electrodes for deflecting the electron beam, and deflection data stored therein. A deflection memory, a D / A converter for converting horizontal deflection data into an analog current, and a D / A converter.
An operational amplifier for converting an analog current of the A converter into a voltage, a resistor, a high voltage amplifier for amplifying the voltage to a voltage capable of deflecting an electron beam, a horizontal deflection high power supply which is a power source of the high voltage amplifier, and a horizontal deflection high power supply. And an image display device having a variable horizontal deflection low power supply connected so as to be stacked. 2. An electron beam generating means for generating an electron beam for irradiating the screen coated with the phosphor in each of a plurality of sections divided in the vertical direction of the screen, and an electron beam generated in each of the plurality of sections. Vertical deflection means for vertically deflecting each section, horizontal deflection means for deflecting the horizontal direction so that an electron beam is irradiated for each pixel corresponding to each of the vertically divided sections, and an input video signal. The horizontal deflection is provided with electron beam control means for controlling an electron beam by means of an electron beam to display an image on the screen according to an input video signal, and a horizontal deflection high power source stacked on a variable horizontal deflection low power source. A horizontal deflection voltage is supplied from the high power supply to the horizontal deflection means, and the voltage-variable horizontal deflection low power supply is adjusted to adjust the horizontal focus voltage to the horizontal deflection voltage. An image display device characterized in that it can be set so as to match the heart voltage.