JPH04179033A - image display device - Google Patents

Abstract

PURPOSE:To reduce the power consumption of line cathodes and lessen the non-uniformity in brightness between the line cathodes, by conducting vertical deflection on the same flat surface as that of the line cathode, and causing a plurality of blocks to be allotted to a single line cathode. CONSTITUTION:The apparatus has a screen 23 having a line cathode 2a and a fluorescent material, vertical deflection electrodes 30a, 30b put on the same flat surface as that of the line cathode 2a and intended for effecting vertical deflections of electron beams generated from the line cathode 2a, and deflection electrodes 7a, 7b, 8a, and 8b for effecting horizontal and vertical deflection within a region extending up to the screen 23. Further, the apparatus has electron beam flow back electrodes 4a to 4i for controlling a generating amount of light by controlling the amount of electron beams irradiated onto the screen 23. Namely, a number of vertical blocks can be allotted by a single line cathode by effecting a first vertical deflection on the same flat surface as that of the line cathode 2a. This enables reduction in number of the line cathodes 2a and in the power consumption, and also enables lessening the variation in brightness between the line cathodes.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is a method for displaying a plurality of lines by vertically deflecting an electron beam for each section when a screen is vertically divided into a plurality of sections. The present invention relates to a device for displaying an image as a whole.

2. Description of the Related Art The basic structure of a conventional image display device will be described with reference to FIG.

The display element includes, in order from the rear toward the anode side, an electron beam flow control back electrode 4, a line cathode 2 as an electron beam source,
A beam extraction electrode 3, a horizontal deflection electrode 7, a vertical deflection electrode 8, a screen plate 10, etc. are arranged and configured, and these are housed inside a vacuum container.

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.
A plurality of line cathodes 2 are further provided at intervals in the vertical direction (in this description, only four line cathodes 2A to 22 are shown). In this configuration, the spacing between the line cathodes is 3 m, and the number of line cathodes is 30, and the number of line cathodes is 2 to 27. The distance between the linear cathodes cannot be freely increased, but is regulated by the distance between the vertical deflection electrode 8 and the screen 10, which will be described later. As the configuration of these line cathodes 2, 10
An oxide cathode material is applied to the surface of a tungsten plate with a diameter of ~30 μm. As will be described later, the line cathodes are controlled to sequentially emit electron beams from the upper line cathode 2a to the lower line cathode 27 for a fixed period of time. The beam extraction electrode 3 has a number of through holes 12 provided at regular intervals in the horizontal direction facing each of the line cathodes 2a to 27, and the electron beam emitted from the line cathode 2 is directed through the through holes. 1
Take it out through 2.

The electron beam flow control back electrode 4 controls the amount of electron beams generated from the line cathode 2 in accordance with the picture elements of the video signal in synchronization with the timing of horizontal deflection, which will be described later.

The horizontal deflection electrode 7 is composed of a plurality of conductive plates 70 arranged vertically along both horizontal sides of the through hole 17, and a horizontal deflection voltage is applied to each conductive plate. is being applied.

The electron beam for each picture element is deflected in the horizontal direction, and sequentially irradiates the R, G, and B phosphors on the screen 10 to emit light.

In this configuration, each electron beam is deflected by two trios.

The vertical deflection electrode 8 is composed of a plurality of conductive plates 8 and 80 arranged horizontally at vertically intermediate positions of the through holes 17, and a vertical deflection voltage is applied thereto.
The electron beam is deflected vertically. In this configuration, the electron beam generated from one line cathode is deflected by eight lines in the vertical direction by a pair of electrodes 8a and 80. and 3
One vertical deflection electrode 8 constitutes 30 pairs of vertical deflection conductors corresponding to each of the 30 line cathodes, and 240 horizontal scanning lines are drawn vertically on the screen 10. There is. As explained above, in this configuration, a plurality of horizontal deflection electrodes 7 and a plurality of vertical deflection electrodes 8 are each stretched in a comb shape. Further, by setting the distance to the screen 10 longer than the distance between the horizontal and vertical deflection electrodes, it becomes possible to irradiate the screen 10 with the electron beam with a small amount of deflection. As a result, the horizontal and vertical deflection electrode screens 10 are constructed by coating the back surface of a glass plate with phosphor in stripes. Although not shown, a metal back and carbon are also coated.

Is phosphor subject to electron beam legislation? The t-girder of the ig electrode 4 is designed to irradiate two trios of three-color phosphors, RlG and B, by deflecting the main electron beam in the horizontal direction, and apply it vertically in stripes. are doing.

In FIG. 4, the broken lines drawn on the screen 10 indicate the vertical divisions displayed corresponding to each of the plurality of line cathodes 2, and the one-dot chain line indicates each of the plurality of electron beam control back electrodes 4. Indicates the correspondingly displayed horizontal division. FIG. 5 shows an enlarged view of one section divided by dashed lines and dashed-dotted lines.

As shown in Figure 5, in the horizontal direction, R and G for two trios.
, B has a width of 8 lines in the vertical direction. In this example, the size of one block is 1 in the horizontal direction and 3 in the vertical direction.

In FIG. 5, the phosphors of each of the three colors R, G, and B are shown in a stripe shape, but they may be arranged in a delta shape. However, when arranged in a delta shape, it is necessary to apply horizontal and vertical deflection waveforms that are compatible with the arrangement.

In FIG. 4, the size ratio of the compressor is different from the actual image displayed on the screen for convenience of explanation.

In addition, in this configuration, two trios of R, G, and B phosphors are provided for each electrode of the electron beam flow control back electrode 4, but the phosphor is composed of one or more than three trios. Also good. However, the electron beam control back electrode 4
One trio or three or more trios of R, G, and B video signals are sequentially applied to the display element, and it is necessary to deflect the water surface in synchronization with this. This will be explained with reference to the figures. First, a driving portion that irradiates the screen 10 with an electron beam to display an image will be explained.

The power supply circuit 22 is a circuit for applying a predetermined bias voltage to each electrode of the display element.
A DC voltage of (1)8 is applied to the screen 10. The line cathode drive circuit 26 creates line cathode drive pulses (I-MA) using the vertical synchronization signal (2) and the horizontal synchronization signal H. FIG. 7 shows the timing diagram. As shown in FIG. 7 (I to M), each line cathode 2A to 27 is heated by a current flowing during the drive pulse's high potential period, and is heated during the drive pulse's low potential period. The heated state is maintained so as to emit electrons. As a result, electrons are emitted from the 30 line cathodes 2a to 27 only during eight horizontal scanning periods to which low-potential drive pulses (i to ma) are applied, respectively.

During periods when a high potential is applied, the electron beam control back electrode 4 applies a higher potential to the line cathodes 2a-27 than the potential at the periphery of the line cathode 2 determined by the bias voltage applied to the beam extraction electrode 3. Since the potential of
It is only necessary to sequentially switch the potential for 8 scanning periods until 0.
Next, the deflection voltage generation circuit 40, whose deflection part will be explained, is as follows.
Direct memory access controller (hereinafter referred to as DMA controller) 41, deflection voltage waveform storage memory (
42 (hereinafter referred to as deflection memory), digital-to-analog converter (hereinafter referred to as D/A converter) 43h, 43v, etc., and generates a vertical deflection signal v2V' and horizontal deflection signals ri and h'. Regarding the vertical deflection signal, considering overscan, 2 in 1 field.
40 horizontal scanning periods are displayed. Further, the memorial address area storing vertical deflection position information corresponding to each line is divided into a first field and a second field, each having one set of memory capacity. When displaying, read the data from the corresponding deflection memory 42 and
The A converter 43v converts the signal into an analog signal and applies it to the vertical deflection electrode 7. The vertical deflection position information stored in the deflection memory 42 is composed of almost regular data for every 8 horizontal scanning periods, and the D/A converted waveform also becomes a vertical deflection signal of approximately 8 stages. However, as mentioned above, 2
It has a memory capacity equivalent to one field, so that the position can be finely adjusted for each horizontal scanning line.

Regarding the horizontal deflection signal, it is necessary to horizontally deflect the electron beam in six stages during one horizontal scanning period, and a memory is provided so that the deflection position can be finely adjusted for each horizontal scanning. Therefore, assuming that 480 horizontal scanning periods are displayed between one frame,
480× 6 =2880 bytes of memory are required, but since the data of the first field and the second field are shared, 1440 bytes of memory are actually used. When displaying, the deflection information corresponding to each horizontal scanning line is read out from the deflection memory 42, converted into an analog signal by the D/A converter 43V, and then sent to the horizontal deflection electrode 6.
In addition to To summarize, during the display period excluding the vertical retrace period of the vertical period, the electron beam emitted from the line cathode to which a low-potential drive pulse is applied among the line cathodes 2A to 27 is transmitted to the beam extraction electrode. 3 into 120 sections in the horizontal direction, forming 120 electron beam rows. The beam amount of this electron beam is controlled by the electron beam control back electrode 4 for each section as described later, and a pair of horizontal deflection signals that change in approximately six steps as shown in FIG. horizontal deflection electrode fi, 7
0 etc., R1 of the screen 10 during each horizontal display period,
Fluorophores such as G1, B1 and R2, G2, B2, etc. are sequentially
Irradiation is performed for each horizontal display period/6.

Thus, each horizontal line raster divides the electron beam in each of the 120 segments into R1, CI, Bl and R2, G2,
By modulating with the video signal corresponding to B2,
A color image can be displayed on the screen 10.

Next, the modulation control portion of the electron beam will be explained. First, in Fig. 6, signal input terminals 23R123G, 23B
The R, 'G, and B video signals added to are applied to 120 sample-and-hold circuit sets 31a to 31n. Each sample hold group 31a to 31n is R1
It is composed of six sample and hold circuits: 1, Gl, Bl, R2, G2, and B2. The sampling pulse generation circuit 34 has a horizontal period (63.5 μs
), during the horizontal display period (approximately 50 μs), the 120
There are 720 sample-hold circuits (120 x 5
) sampling pulses Ral to Rn2 are sequentially generated. Each of the 720 sampling pulses is 12
0 set of sample hold circuits &[6 in 131a to 31n
As a result, each sample-and-hold circuit group receives the R1, G1, B1, R2, G2, and B2 video signals for each two picture elements when one line is divided into 120 parts. Sampled and held. 120 sample-held pairs of R1, GISBl, R
After completing the sample hold for one line, the video signals of 2, G2, and B2 are transferred all at once to 120 sets of memories 32a to 32n by a transfer pulse t, where they are held for the next one horizontal scanning period. The held signal is applied to 120 switching times *35a-35n. The switching circuits 35a to 35n each have R1, G1 . B1, R2
, G2, and B2, and a common output terminal that sequentially switches and outputs them, and the switching pulses r1, gl, bl, R2, B2, applied from the switching pulse generation circuit 36,
Switching is controlled simultaneously by B2.

The switching pulse rLgLbl, R2, B2, B
2 divides each horizontal display period into 6 and divides each horizontal display period into 6 horizontal display periods/6
Switching the switching circuits 35a to 35n each time R1,
The video signals Gl, Bl, R2, G2, and B2 are time-divided and sequentially output, and supplied to the pulse width modulation planes B57a to 37n. The outputs of each of the switching circuits 35a to 35n are connected to 120 sets of pulse width modulation (hereinafter referred to as PWM) circuits 3.
7a to 37n, R1, G1, B1, R2, G
According to the magnitude of each video signal of 2 and B2, the pulse width is modulated and output. The outputs of the pulse width modulation circuits 37a to 37n are individually applied to the 120 conductive plates of the electron beam control back electrode 4 of the display element as control signals for modulating the electron beam.

Next, horizontal deflection and display timing will be explained. R1, G1, B in switching circuits 35a to 35n
1, R2, G2, B2, and electron beams R1, G1, B1 . ,
Synchronization control is performed so that the switching timing and order of the horizontal deflection to the phosphors of R2, G2, and B2 are completely matched. As a result, when the electron beam is irradiating the R1 phosphor, the irradiation amount of the electron beam is controlled by the R1 control signal, and G, B1, R2, G2, and B2 are similarly controlled. Raw R1, G1, Bl
, R2, G2, and B2, the emission of each party light is R1 of the picture element,
The light emission of each of the G1, B1, R2, G2, and B2 party lights is controlled by the video signals of R1, Gl, Bl, R2, G2, and B2 of that picture element, and each picture element receives the input video signal. The light is emitted and displayed accordingly. Such control is executed for 120 sets (2 picture elements each) for one line for a period of time to display an image of 240 picture elements per line, and is further carried out sequentially for the 240 lines of the L field starting from the upper line. An image is displayed on the screen 10. Further, the above operations are repeated for each field of the input video signal, and a television signal or the like is displayed on the screen 10. The basic clock necessary for this configuration is supplied from the pulse generation surface 839 shown in FIG.
Timing is controlled by horizontal synchronization signal H1 and vertical synchronization signal ■.

Problems to be Solved by the Invention However, in the image display device configured as described above, the number of line cathodes is large, power consumption is also large, and the brightness between the line cathodes is reduced due to variations in the stretched brightness of the line cathodes. The problem was that many unevenness occurred.

In view of the above-mentioned problems, the present invention provides an image display device with reduced power consumption and less uneven brightness by having a plurality of blocks in one line cathode.

Means for Solving the Problems In order to solve the above problems, the image display device of the present invention includes a line cathode, a screen including a phosphor that emits light when irradiated with the electron beam, and a screen that includes a line cathode and a phosphor that emits light when irradiated with the electron beam. a vertical deflection electrode placed on the same plane as the line cathode for vertically deflecting the emitted electron beam; a deflection electrode that deflects the emitted electron beam horizontally and vertically up to the screen; It is equipped with an electron beam flow control back am pole that controls the amount of electron beam to control the amount of light emission.

Effect: By adopting the above-described configuration, the present invention reduces the number of line cathodes and reduces power consumption, and by having many blocks with the same line cathode, it reduces brightness variations between line cathodes. be able to.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

FIG. 1 is an exploded perspective view showing the basic structure of an image display device according to an embodiment of the present invention, and FIG. 2 is a circuit diagram of a basic drive circuit of an image display device according to an embodiment of the present invention. FIG. 3 shows waveforms at various timings of the image display device in one embodiment of the present invention.

In Fig. 1, 4A to 4 are electron beam control back electrodes that control the amount of electron beam, 2A is a line cathode that generates an electron beam, 30A to 30 are first vertical deflection electrodes, and 3 is a line cathode that generates an electron beam. Beam extraction electrodes, 5-70 are horizontal deflection electrodes, 8-80 are second vertical deflection electrodes, 23 is a screen, and these components are sealed in a glass container at 10.11 and evacuated. .

In Figure 2, 22 is 1iif! Circuit, 31 a ~
31 n is a sample hold circuit, 32 a to 32 n are memories, 34 is a sampling pulse generation circuit, and 35 a to 3
5n is a switch, 36 is a switching pulse generation circuit,
37a to 37n are PWM circuits, 39 is a pulse generation circuit,
4I is a DMA controller, 42 is a deflection memory, 43h
, 43V is a digital to analog converter (D/A), 26
is a line cathode drive circuit.

The operation of the image display device configured as described above will be described below with reference to FIGS. 1, 2, and 3.

First, FIG. 1 shows the electrode configuration of this image display device, in which the electron beam generated from the line cathode 2a is applied with a potential according to the video signal to the electron beam control back electrodes 4a to 4a. The electron beam is controlled by the line cathode 2
The beam is vertically deflected in the vertical direction of the beam extraction electrode 3 by the first vertical deflection electrodes 30A to 30 on the same plane as A, so as to sequentially pass through three through holes in one embodiment,
At the same time the electron beam is extracted by the beam extraction electrode 3, it is accurately separated into each horizontal section, and the electron beam is applied between the horizontal deflection electrode 70 and the vertical deflection electrode 2.8a to 80. electrostatic deflection horizontally and vertically due to the potential difference. Further screen 2
A high voltage is applied to the metal bank layer No. 3, and the electron beam is accelerated to high energy and collides with the metal back, causing the phosphor to emit light.

When a television screen is divided vertically and horizontally into a matrix to form a collection of subdivisions 25, one electron beam separated as described above is associated with each subdivision, and the electron beams are divided into subdivisions. By deflecting and scanning only the inside, the entire image can be displayed on the screen. In addition, by controlling the RGB video signals corresponding to each picture element over time using the electron beam control back electrode voltage 4 as described above,
Television videos can be reproduced.

As described above, according to this embodiment, by performing the first vertical deflection on the same plane as the line cathode 2a, it is possible to hold more vertical blocks with one line cathode than in the past. This makes it possible to reduce the number of line cathodes and reduce the power consumed by the line cathodes. Furthermore, since one linear cathode has a plurality of blocks in the vertical direction, it is possible to reduce variations in brightness due to wiring errors between the linear cathodes.

The R, G, and B video signals input from the terminals 23R, 23G, and 23B in the basic drive circuit of the image display device according to the embodiment of the present invention shown in FIG. circuit 3
After sample and hold in 1a to 31n, memory 32a to 3
Transferred to 2n. In this case, the entire memories 32a to 32n store one line of memory, and the switches 35a to 35
The signals are sent to the nPWM circuits 37a to 37n and applied to the electron beam flow control back electrodes 4a to 4. Also, the line cathode drive pulses 2-1 are generated by the line cathode drive circuit 26 using the vertical synchronization signal V and the horizontal synchronization signal H.
2E, the line cathodes corresponding to each of the electron beam flow control back electrodes 4A to 4E emit electrons, and at the same time, the electron beams pass through a plurality of through holes in the vertical direction of the beam extraction electrode 3. The digital data outputted by the DMA controller 41 and the deflection memory 42 is converted into analog data by a D/A converter, vl and vl'.
The signal is amplified and deflected by applying it to the vertical deflection electrode 1.

The electron beam that has passed through the beam extraction electrode 3 is
After converting the digital data output by the controller 41 and the deflection memory 42 into analog data using a D/A converter, h, h' and v2. By amplifying v2゜, respectively,
The light is applied to the horizontal deflection electrode 7 and the vertical deflection electrode 8 to receive horizontal and vertical deflection, and then is irradiated onto the screen 23 to emit light.

As described above, whereas the conventional line cathode has a block in the vertical direction, the image display device with this configuration has a line cathode and a plurality of blocks in the block. Therefore, the power consumed by the line cathode can be reduced. Furthermore, since the linear cathode has a plurality of blocks, it is possible to reduce variations in brightness among the linear cathodes caused by stretching errors of the linear cathodes.

Effects of the Invention As described above, according to the present invention, by performing vertical deflection on the same plane as the line cathodes, the number of line cathodes can be reduced, and the power consumption of the line cathodes can be reduced accordingly. Furthermore, since one line cathode has more blocks than the conventional one, it is possible to reduce brightness unevenness between line cathodes caused by wiring cathode errors.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing the basic structure of an image display device according to an embodiment of the present invention. FIG. 2 is a circuit diagram of a basic drive circuit of an image display device according to an embodiment of the present invention. are waveform diagrams of various timings of an image display device in an embodiment of the present invention, FIG. 4 is an exploded perspective view showing the basic structure of a conventional image display device, FIG. 5 is an enlarged view of the screen, and FIG. is a basic drive circuit diagram of the image display device, and FIG. 7 is a timing diagram of various waveforms. 2... Line cathode, 3... Beam extraction electrode, 4... Beam flow control back electrode, 7...
...Horizontal deflection electrode, 8...Second vertical deflection electrode, 23...Screen, 30...First
vertical deflection electrode. Name of agent: Patent attorney Akira Kokaji and two others
Rope box (23'-screen 1st figure rt v mouthpiece 2 figure 24-Z = --'Mk M & 23-screen 4th section vIJ w&5 figure 2θ 6th figure breath w# threat'': Jbe -ZlLl [g-1411 Ward

Claims (1)

[Claims] A screen coated with a phosphor that emits light when irradiated with an electron beam, and a plurality of line cathodes that generate an electron beam in each vertical division of the screen above the screen. a first vertical deflection electrode for vertically deflecting the electron beam generated by the line cathode; and a first vertical deflection electrode for vertically deflecting the electron beam, and separating the electron beam into each horizontal section and irradiating the electron beam onto the screen. a separating means, a horizontal deflection electrode that deflects the electron beam horizontally in a plurality of stages before reaching the screen, and controlling the amount of the separated electron beam irradiated to the screen for each horizontal section; A beam flow control electrode that controls the amount of light emitted from each picture element on the screen, and a second vertical deflection electrode that performs vertical deflection, separate from the first vertical deflection electrode, are installed on the same plane as the line cathode. An image display device characterized by: