JPS61242487A - Image display device - Google Patents

Abstract

PURPOSE:To reduce the power consumption, and also to reduce the deterioration of a picture quality by deflecting an electron beam which is generated from a line cathode, to plural stages at an equal interval by a deflection electrode in a vertical section. CONSTITUTION:During an effective vertical scanning period, an electron beam is emitted successively in 16H period each toward the lower line cathode 520 from the upper line cathode 52a. The emitted electron is deflected in the vertical direction to eight stages in a 2H period each successively from the upper part by electrodes V53a, V53b applied to the first vertical deflection electrode 53 placed at every other part. Accordingly, the electron beam passes through 120 pieces of circular holes which have been arranged in the vertical direction of beam track correcting electrodes A54, B55, in a 2H period each successively toward the lower part from the upper part. The electron beam whose track is corrected by two pieced of track correcting electrodes A54, B55 is modulated in accordance with a video signal by a beam flow control electrode 56, deflected to six stages in the horizontal direction, and two stages in the vertical direction, and an image is displayed as a whole.

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 a device that displays a plurality of lines by vertically deflecting an electron beam to display a television image as a whole.

Conventional technology Traditionally, 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 use in thin television receivers. It was impossible to create. 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, the present applicant proposed a new display device in Japanese Patent Application No. 56-20618 (Japanese Unexamined Patent Publication No. 57-135590) to achieve a flat display device using electron beams.

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. It displays the television image as a whole.

First, a basic configuration of the image display element used here will be explained with reference to FIG. This display element consists of, in order from the back to the front, a back electrode (1), a line cathode (2) as a beam source, a vertical focusing electrode (3) (3''), a vertical deflection electrode (4), and a beam current control. It consists of an electrode (5), a horizontal focusing electrode (6), a horizontal deflection electrode (7), a beam accelerating electrode (8), and a screen (9), which are connected to a flat glass bulb (not shown). The beam source is a line cathode (2
) is stretched horizontally so as to generate an electron beam distributed linearly in the horizontal direction, and a plurality of such linear cathodes (2) are vertically spaced at appropriate intervals ((2a) to (2a) in the figure).
(Only the four shown in (2d)) are provided. In this example, it is assumed that 15 are provided. them (2
a) to (20). These wire cathodes (2) are constructed by coating the surface of a tungsten wire with a diameter of 10 to 20 μΦ with an oxide cathode material for emitting thermionic electrons. These line cathodes (2a) to (2o) are heated so as to generate a thermionic beam by passing an electric current through them, and as described later, the line cathodes (2a) to (2o) are heated sequentially for a certain period of time. It is controlled to emit an electron beam at a time. The back electrode (1) suppresses the generation of electron beams from other line cathodes other than the line cathode 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 of conductive material applied to the inner surface of the rear wall of the glass bulb. Moreover, a planar electron beam emitting cathode may be used instead of the back electrode (1) and the linear 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 (2o), and collects the electron beam emitted from the line cathode (2). is taken out through the slit (1,0) and focused vertically. 1 horizontal line (
In Figure 0, in which electron beams for 360 picture elements are taken out at the same time, only one section of them 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 at small intervals in the horizontal direction (intervals that are almost touching each other) for multiple polarized waves. may be configured substantially as a slit. The vertical focusing electrode (3') is also similar.

A plurality of vertical deflection electrodes (4) are arranged horizontally at intermediate positions between the slits (1o),
Conductors (
13) (13') is provided. Then, a vertical deflection voltage is applied between the opposing conductors (13) (13'') to deflect the electron beam in the vertical direction.In this embodiment, the pair of conductors (13) (13'')
3") to deflect the electron beam from one line cathode (2) vertically to a position corresponding to 16 lines.
15 line cathodes (
Fifteen conductor pairs corresponding to each of 2) are constructed, and the electron beam is ultimately deflected to draw 240 horizontal lines on the screen (9).

Next, the control electrodes (5) are composed of conductive plates (15) each having a long slit (14) in the vertical direction, and a plurality of control electrodes (5) are arranged in parallel in the horizontal direction at a predetermined interval.

In this example, 180 control electrode conductive plates (15-1)
~(15-n) are provided. (Only 9 lines are shown in the figure). Each of the control electrodes (5) separates and extracts the electron beam into two picture elements in the horizontal direction, and controls the amount of electron beam passing therethrough in accordance with a video signal for displaying each picture element. Therefore, the conductive plate for the control electrode (5) (
If 18,080 pixels 15-1) to (15-n) are provided, 360 pixels can be displayed per horizontal line. In addition, in order to display images in color, each picture element is R, G, B
Each control electrode (5)
has two picture elements of R and G.

Each video signal of B is added sequentially. In addition, 180 sets (2 pixels per set) of video signals for 1 line are simultaneously applied to each of the 180 conductive plates (15-1) to (15-n) for the control electrode (5). One line of video is displayed at one time.

The horizontal focusing electrode (6) is connected to the slit (14) of the control electrode (5).
) is composed of a conductive plate (17) having a plurality of vertically long slits (16) facing each other, and the electron beam for each pixel divided horizontally is transmitted horizontally. Focus into a narrow beam of electrons.

The horizontal deflection electrode (7) is composed of a plurality of conductive plates (18') arranged vertically on both sides of the slit (16). '') is applied with six levels of horizontal deflection voltage to deflect the electron beam of each picture element in the horizontal direction, resulting in two sets of R and G on the screen (9).

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

The accelerating electrode (8) is composed of a plurality of conductive plates (19) installed horizontally in the same position as the vertical deflection electrode (4), and it directs the electron beam to the screen (9) with sufficient energy. Accelerate to cause a collision.

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 phosphor (20) has two phosphors of three colors R2O and B for one slit (14) of the control electrode (5), that is, for each one electron beam divided in the horizontal direction. They are provided in pairs and are applied in vertical stripes. In FIG. 3, the broken lines drawn on the screen (9) indicate the divisions in the vertical direction that are displayed corresponding to the plurality of line cathodes (2), and the two-dot chain lines indicate the divisions in the vertical direction that are displayed corresponding to the plurality of line cathodes (2). ), and as shown in an enlarged view in Figure 4, one section partitioned by these two pixels has an R of two pixels in the horizontal direction. , G, and B, and has a width of 16 lines in the vertical direction. For example, the size of one section is 11 in the horizontal direction and 9 in the vertical direction.
It is.

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

Next, the basic configuration and waveforms of each part of a drive circuit for displaying television images on this display element will be explained with reference to FIG. First, a driving portion for irradiating the screen (9) with an electron beam to emit raster light will be described.

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

Next, a composite video signal of a television signal is applied to the input terminal (23), and a vertical synchronization signal V and a horizontal synchronization signal H are separated and extracted in a synchronization separation circuit (24).

The vertical deflection drive circuit (40) includes a vertical deflection counter (2
5), a memory for vertical deflection signal storage (27), and a digital-to-analog converter (39) (hereinafter referred to as a DA converter). As input pulses to the vertical deflection drive circuit (40), a vertical synchronizing signal V and a horizontal synchronizing signal H shown in FIG. 6 are used. Vertical deflection counter (25)
(8 bits) is reset by the vertical synchronizing signal V and counts the horizontal synchronizing signal H.

This vertical deflection counter (25) counts the effective scanning period (in this case, a period of 240H) excluding the vertical blanking period of the vertical period, and this count output is supplied to the address of the memory (27). be done. The memory (27) outputs vertical deflection signal data (here, 8 bits) corresponding to each address, and the D-A converter (39) outputs the data of the sixth vertical deflection signal.
It is converted into vertical deflection signals of υ and υ' shown in the figure (FIG. 5(b) D). This circuit has memory addresses for storing vertical deflection signals corresponding to each line for 240H, and by storing regular data in the memory every 16H, it is possible to obtain 16 levels of vertical deflection signals. can.

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 create a line cathode drive pulse a''o. FIG. 7(a) shows the vertical synchronization signal V, Horizontal synchronization signal H and vertical deflection counter (25)
FIG. 7(b) shows the relationship between the lower five bits of the line cathode drive pulses a' to 0' every 16H using these signals.
In FIG. 7, which shows a method for creating a 1.0 bit, LSB indicates the lowest bit, and (LSB+1) means the bit one higher than the LSB.

The first line cathode drive pulse a' can be created by an R-S flip-flop using the vertical synchronization signal V and the output (LSB+4) of the vertical deflection counter (25), and the line cathode drive pulse b'~0 ′ uses a shift register,
This can be obtained by transferring the line cathode drive pulse a' using the inverted version of the output (L S B +3) of the vertical deflection counter (25) as a clock. These drive pulses a' to 0' are inverted and converted into line cathode drive pulses a to o, which have a low potential only during each pulse period and a high potential of approximately 20 volts during other periods (see Fig. 5). (b)E
), are added to each line cathode (2a) to (2o).

Each line cathode (2a) to (2o) is heated by a prolonged current during the high potential period of the drive pulses a to 0, and is heated so that electrons can be emitted during the low potential period of the drive pulses a to 0. State is preserved. As a result, 15 wire cathodes (2a)
From ~(20), low potential drive pulses a~0 are respectively obtained.
Electrons are emitted only during the 16H period when . During periods when high potentials are applied.

The voltage applied to the line cathodes (2a) to (2o) is higher 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 potential is more positive, the wire cathode (2
No electrons are emitted from a) to (2o). Thus,
In the line cathode (2), electrons are sequentially emitted from the upper line cathode (2a) to the lower line cathode (20) for 16H periods 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, line cathode drive pulses a~0 and vertical deflection signals υ, υ′
The relationship between the two will be explained using FIG. Figure 8 (
(a) is a waveform diagram of a line cathode drive pulse, (b) is a waveform diagram of a vertical deflection signal, and (c) is a waveform diagram of a horizontal deflection signal. Vertical deflection signal υ in FIG. 8(b).

υ' changes by IH in 16 steps during the 16H period of each line cathode pulse a to 0 in FIG. 8(a).

Both vertical deflection signals υ and υ' have a center voltage of V, and υ increases sequentially and υ' decreases sequentially.
They are designed to change in opposite directions. These vertical deflection signals υ and υ' are applied to electrodes (13) and (13') of the vertical deflection electrode (4), respectively.

As a result, the electron beams generated from each of the line cathodes (2a) to (2o) are vertically deflected in 16 steps.
As mentioned above, one electron beam is deflected on the screen (9) so that a raster of 16 lines is drawn one line at a time from the top.

As a result of the above, electron beams are emitted from the 15 line cathodes (2a) to (20) sequentially for a period of 16H starting from the top, and each electron beam is sequentially emitted one line from top to bottom within 15 sections in the vertical direction. On the screen (9), from the first line at the top to the 24th line at the bottom.
The electron beam is vertically deflected one line at a time up to the 0th line, and a total of 240 raster lines are drawn.

The vertically deflected electron beam is sent to the control electrode (5).
It is divided into 180 sections in the horizontal direction by a horizontal focusing electrode (6) and taken out. In Figure 3, one of them
The classification is shown. The amount of this electron beam passing through each section is controlled by a control electrode (5), and is focused horizontally by a horizontal focusing electrode (6) into a single narrow electron beam. The light is deflected in six steps in the direction and sequentially illuminates the R2O, B capacitive light body (20) for two picture elements on the screen (9). The phosphors corresponding to each of (15-1) to (15-n) of the control electrode (5), whose vertical and horizontal divisions are shown in FIG. 4, are R, G, and B for two picture elements. For convenience of explanation, one picture element is R1, G, B1, and the other is R, G2, .
B.

shall be.

Next, the horizontal deflection drive circuit (41) is composed of a horizontal deflection counter (28) (11 bits), a memory (29) that stores horizontal deflection signals, 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 (28) is reset by the vertical synchronizing signal V and receives the horizontal six times the pulse 6H.
count. This horizontal deflection counter (28) is
6 times during H % 240H during 1v 6/H = 1
It counts 440 times, and this count output is stored in the memory (29
) is supplied to the address.

The memory (29) outputs horizontal deflection signal data (here, 8 bits) according to the address, and the D-A converter (38) outputs the data as shown in Figure 9 (Figure 5 (b) C). ,h
' is converted into a horizontal deflection signal such as '. In this circuit, 6
There is a memory address for storing horizontal deflection signals corresponding to each of can be obtained.

This horizontal deflection signal is a pair of horizontal deflection signals ri and h' that change in six steps as shown in FIG.

Both have a center voltage of v7, h decreases sequentially, and h
′ change in opposite directions so that they increase sequentially. These horizontal deflection signals h' are applied to electrodes (18) and (18') of the horizontal deflection electrode (7), respectively. As a result, each horizontally segmented electron beam is applied to the R, G of the screen (9) during each horizontal period.

B, R, G, B (R1, G1. BL, R2, G,, B
The light is horizontally deflected so that the phosphor of 2) is sequentially irradiated for H/'6 periods. Thus, in each line raster, the electron beam is R,...
G1. B1. Each of the R, G, B phosphors (20) is sequentially irradiated.

Therefore, the electron beam is set to R1, G for each horizontal section of each line.
1. By modulating with the B, , R, , G, , B video signals, 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 and the G-Y color difference signal is demodulated. The signals are matrix-synthesized, and further, they are combined with the luminance signal Y to produce RlG and B primary color signals (hereinafter R,
G, B video signals) are output. Those R,G
, B. Each video signal is processed by 180 sample and hold circuits (3
1-1) to (3t-n). Each sample hold circuit (31-1) to (31-n) is for R, G, B1, and R2, respectively.

It has six sample and hold circuits for G2 and B2. These sample and hold outputs are respectively applied to holding memories (32-1) to (32-n).

On the other hand, the reference clock oscillator (33) is composed of a PLL (phase-locked loop) circuit, etc., and in this example, the reference clock 6fsc is six times the color subcarrier fSc.
and a double reference clock 2fsc is generated. The reference clock is controlled to always have a constant phase with respect to the horizontal synchronizing signal H.゛Reference clock 2fs
c is added to the deflection pulse generation circuit (42), and a signal 6H which is six times the horizontal synchronizing signal H and a signal switching pulse rz*gle bt, rt+gze bz (Fig. 5(b)B) every H/6 are added. I'm getting a pulse. On the other hand, reference clock 6f
sc is applied to the sampling pulse generation circuit (34), where it is delayed by one clock cycle by a shift register, and is then delayed for an effective horizontal scanning period (approximately 50 μ5 ec) of the horizontal period (63,5 μ5 ec). 108 to
0 sampling pulses R, 1, G1□t' B11
．． R12, G1. , B12. R, 1, G, □.

B, □, R,,,G! 2. B,,”Rn,,Gnl,B
n,,Rn,.

Gn, , Bn, (FIG. 5(b) A) are sequentially generated, and then one transfer pulse t is generated. These sampling pulses R1□~Bn,2 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 determined by the horizontal synchronizing signal H.
It is controlled so that it always remains constant ↓.

These 1080 sampling pulses R1□ to Bn each form 180 sets of sample hold circuits (31-1).
-(31-n), and as a result, each sample-hold circuit (31-1) to (31-n) has an R1 value of 2 pixels for each of 180 pixels divided into 1 line. , G1. B1. R2, G2. Each video signal of B is individually sampled and held. The sample-held 180 pairs of R1, G1. B
,,R2゜G,,B, the video signals are stored in 180 sets of memories (32-1) ~ after completing the sample hold for one line.
(32-n) are transferred all at once by the transfer pulse t,
Here, it is held for the next horizontal period. This held R1°G□, B□, R2, G2. The signal B2 is applied to switching circuits (35-1) to (35-n). The switching circuits (35-1) to (35-n) each have R,, G,, B1°R,, G2. It is constructed of a tri-state or analog gate having individual input terminals of B and B and a common output terminal that sequentially switches and outputs them.

The output of each switching circuit (35-1) to (35-n) is 180 sets of pulse width modulation (PWM) circuit (37-1)
~(37-n), where the sample-held R1. G engineering, B1. R,,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 r1p g, + bxt rxr
It is desirable that the pulse width be sufficiently smaller than the pulse width of gz+bz, and for example, a pulse width of about 1:10 to 1:100 is used.

The outputs of the pulse width modulation circuits (37-1) to (37-n) are used as control signals for modulating the electron beam to the 180 conductive plates (15-1) to the control electrodes (5) of the display element.
(15-n) respectively. Each switching circuit (35-1) to (35-n) receives a switching pulse rxp gte bxt X'zv gze bz applied from a switching pulse generating circuit (36).
Switching is controlled at the same time by The switching pulse generation circuit (36) is the aforementioned deflection pulse generation circuit (42).
Signal switching pulse from rue gte bxy I'
Each horizontal period is divided into 6 and a switching circuit (35-
1) to (35-n), R Eng Glg BL9
A switching signal rt*gxs bxtrze is used to time-divide and sequentially output each video signal of Rye Gag L and supply it to the pulse width modulation circuits (37-1) to (37-n).
Generate gze bz.

What should be noted here is that the switching circuit (35-1
) to (35-n) R1, G1. B1.
R.

G2. B2 video signal supply switching and electron beam R,,G□t Bit' by the horizontal deflection drive circuit (41)
R11G2. The horizontal deflection for switching the irradiation onto the phosphor B2 is synchronously controlled so that it completely matches both the timing and the order. As a result, when the electron beam is irradiating the R□ phosphor, the irradiation amount of the electron beam is controlled by the R1 video signal, and the G
1. B1. R,,G2. B are controlled in the same way, and R1, G1 . B1゜R2$02 = B
The light emission of the two fluorescent light bodies is R1, G1°B1. R
2, G, and B2, and each picture element is displayed by emitting light according to the input video signal. There are 180 sets of such controls for one line (
36 pixels per line)
An image of 0 pixels is displayed, and then the screen (9
), one image will be displayed on top.

and one or more such operations are performed on one or more of the 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.

Problems to be Solved by the Invention In the display device configured as described above, the vertical landing position of the electron beam (the vertical position W of the scanning line) depends analogously on the vertical deflection electrode voltage, and also depends on the mechanical assembly. A very high degree of accuracy is also required. If the vertical deflection voltage deviates even slightly from the value for normal vision, or if the mechanical precision deteriorates due to assembly defects or thermal deformation,
The spacing between the scanning lines changes discontinuously at the joints of the line cathodes, and the boundaries of each vertical section on the screen become greasy, resulting in significant deterioration in image quality.

The reason why such horizontal discontinuous lines appear on the screen is clearly that the screen is vertically divided into a plurality of sections. Therefore, in order to avoid this difficulty, it is conceivable to not divide the screen, that is, to use a single line cathode, but in order to scan the entire screen with a single line cathode, a large deflection angle is required. , the image display device also becomes thick, which is impractical.

Another method is to increase the number of horizontal border lines until they become visually difficult to see.For example, if there are 120 or more border lines (horizontal lines) on the screen,
There will be no major deterioration in image quality. However, even with this method, the screen is divided into 120 parts in the vertical direction, and 120 corresponding line cathodes are required, which is still not practical in terms of assembly and power consumption.

The present invention υ is that the number of wire cathodes actually strung is small, yet it is possible to obtain an image equivalent to the effect of strung enough wire cathodes (hereinafter abbreviated as virtual wire cathodes) to avoid deterioration of image quality. The present invention provides a display device.

Means for Solving the Problems In order to achieve the above object, the present invention divides the screen on the screen vertically into a plurality of sections, and horizontally extends a line cathode for each vertical section. , the electron beam generated in each line cathode is further deflected in multiple stages at equal intervals in the vertical direction by a first deflection electrode within each vertical section, and another group of electrodes following the first deflection electrode, that is, the first deflection Another group of electrodes includes a focusing electrode for focusing the electron beam received in the vertical direction by the electrode on the screen and a second deflection electrode for further deflecting the electron beam in the horizontal and vertical directions. The pitch in each vertical direction is equal to the pitch of the imaginary line cathodes formed by the first deflection electrode, so that the electron beams generated from more than 100 imaginary line cathodes can be controlled. It is configured to work as it does.

Effects With this configuration, although the number of wire cathodes actually strung is small, it has the same effect as a wire cathode strung with more than 100 wire cathodes, reducing image quality deterioration with less power consumption. It is possible to realize fewer image display devices.

EXAMPLE An example of the present invention will be described below based on the drawings. In this example, 15 wire cathodes were actually stretched and 1 virtual wire cathode was installed.
There were 20 pieces. This display element, as shown in FIG.
In order from the rear to the front, there is a back electrode (51), a line cathode (52) arranged vertically as a beam source ((52a) to (52d) are shown in the figure), and each line cathode (52). First vertical deflection electrodes (53) are arranged to sandwich and deflect the electron beam generated by each line cathode (52) in multiple stages at equal intervals in the vertical direction within each vertical section.
, the electron beam deflected in the vertical direction by the first vertical deflection electrode (53) is corrected by the electrode A (
54), B (55), beam flow control electrode (56)
, a second vertical deflection electrode (57).

It consists of a horizontal deflection electrode (58) and a screen (59) arranged, which are connected to a flat glass bulb (
(not shown) is housed in an evacuated interior.

Among the above electrode groups, two beam trajectory correction electrodes A (
54), B (55), beam flow control electrode (56), second vertical deflection electrode (57), and horizontal deflection electrode (58) have the same shape in the vertical direction, as if 120 wire cathodes were strung together. It has a shape that is repeated 120 times.

In particular, the correction electrode A (54) has circular windows extending vertically into 12
0° horizontally lined up at 180, and the correction electrode B (55
) is also the same, but the window diameter is smaller than that of the modified electrode A (54).

Next, a method of driving this display element will be explained.

As shown in FIG. 2, the driving method for each line cathode is exactly the same as in the conventional example, and therefore the line cathode (52) is moved from the upper line cathode (52a) to the lower line cathode during the effective vertical scanning period. (52o) is sequentially released for each 16H period. The emitted electrons are transferred to every other first vertical deflection electrode (
53) are applied to the electrodes V 53a and V 53b to vertically deflect the light in 8 steps for each 2H period from above. Therefore, beam trajectory correction electrode A (54),
An electron beam passes through 120 circular holes arranged in the vertical direction of B (55) sequentially from above to below for 2H periods.

The two beam trajectory correction electrodes A (54) and B (55) absorb the slight deflection deviation caused by the first vertical deflection electrode (53) and the difference in the incident angle of the correction electrode A (54) due to the difference in deflection angle. Correction electrode A
(54) has a large circular hole diameter and applies a low voltage;
Correction electrode B (55) has a small diameter circular hole, and by applying a high voltage, it forms a strong convex lens, and the position of the electron beam after passing through correction electrode B (55) is adjusted to correction electrode A.
(54), B (55) has a function that depends only on the position of the circular hole.

Two beam trajectory correction electrodes A (54), B (55)
The electron beam whose trajectory has been corrected by
56) according to the video signal, and further deflected in six steps in the horizontal direction and two steps in the vertical direction in this embodiment, to display the image as a whole.

The beam flow control electrode (56) is connected to electrode A as shown in FIG.
(54) and B (55), or a configuration in which the beam trajectory is corrected after the beam flow is modulated by the beam flow control electrode is also possible.

Effects of the Invention According to the present invention, although the number of wire cathodes actually strung is small, it has the same effect as, for example, when 120 wire cathodes are strung, so consumption is reduced. An image display device with less deterioration in image quality can be realized using electric power.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing one embodiment of an image display element used in the image display device of the present invention, FIG. 2 is a waveform diagram for explaining the operation of the image display device, and FIG. 3 is a conventional image display device. An exploded perspective view showing an example of an image display element used in a display device, FIG. 4 is an enlarged view of a phosphor screen of the image display element, and FIG. 5 is a block diagram showing the basic configuration of a drive circuit of the image display element. Waveform diagrams of each part, Figure 6 is a waveform diagram to explain the operation of the vertical deflection drive circuit, Figure 7 is a waveform diagram to explain the operation of the line cathode drive circuit, Figure 8 is a waveform diagram of each drive signal, 9th
The figure is a waveform diagram for explaining the operation of the horizontal deflection drive circuit. (52)... Line cathode, (53) (57)... Vertical deflection electrode, (54) (55)... Beam trajectory correction electrode, (56)... Beam flow control electrode, (58) ...
Horizontal deflection electrode, (59)...Screen, (20)
...phosphor, (24) ... synchronous separation circuit, (26)
... line cathode drive circuit, (30) ... color demodulation circuit, (
40) Vertical deflection drive circuit, (41) Horizontal deflection drive circuit, (42) Deflection pulse generation circuit Agent Yoshihiro Morimoto Figure 4 Mizunoho Shun #l 4 minutes , 4 Figure S (b) t-p Figure 1-11 Figure 7

Claims (1)

[Claims] 1. The screen on the screen is vertically divided into a plurality of sections, each vertical section has a line cathode for generating an electron beam, and the electron beam generated by each line cathode is transmitted within each vertical section. It has a first deflection electrode for deflecting the electron beam in multiple stages at equal intervals in the vertical direction, and a focusing electrode for focusing the electron beam deflected in the vertical direction by the first deflection electrode on the screen, and a horizontal and a second deflection electrode for further deflection in the direction and the vertical direction, and the shape of the electrode group including the focusing electrode and the second deflection electrode has a pitch equal to the vertical pitch of the first deflection electrode. An image display device that is repeated vertically.