JPS646593B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention vertically divides a screen into a plurality of sections, generates an electron beam for each section, and deflects each electron beam vertically for each section. The present invention relates to a device that displays a plurality of lines to display a television image as a whole, and its purpose is to provide a device that can improve the resolution in the vertical direction on the screen.

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. In addition, 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 yet been put into practical use.

Therefore, in order to achieve a flat display device using electron beams, the screen on the screen is vertically divided into multiple sections and an electron beam is generated for each section. A system was devised in which the electron beam was deflected vertically to display multiple lines, thus displaying a television image as a whole.

First, a basic configuration example of the image display element used here will be explained with reference to FIG.

This display element is arranged in order from the back to the front.
A back electrode 1, a line cathode 2 as a beam source, vertical focusing electrodes 3, 3', a vertical deflection electrode 4, a beam flow control electrode 5, a horizontal focusing electrode 6, a horizontal deflection electrode 7, a beam accelerating electrode 8 and a screen plate 9. They are housed within the evacuated interior of a flat glass bulb (not shown).

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, and a plurality of line cathodes 2 (here, 2-2-4
(Only books shown) provided. In this embodiment, it is assumed that 15 pieces are provided. Let's say 2i~2yo. These line cathodes 2 have a diameter of, for example, 10 to 20 μφ.
An oxide cathode material is coated on the surface of a tungsten wire. Then, as will be described later, the electron beams are controlled to be emitted sequentially from the upper line cathode 2a for a fixed period of time. Back electrode 1
has the effect of suppressing the generation of electron beams from other line cathodes 2 other than the line cathode 2 that is controlled to emit electron beams for a certain period of time, and pushing out the generated electron beams only in the forward direction. do. The back electrode 1 may be formed by a coating of a conductive material applied to the inner surface of the rear wall of the glass bulb. Further, instead of the back electrode 1 and the linear cathode 2, a planar electron beam emitting cathode may be used.

The vertical focusing electrode 3 is a conductive plate 11 having a horizontally long slit 10 facing each of the line cathodes 2I to 2Y, and extracts the electron beam emitted from the line cathode 2 through the slit 10, and focus in a direction. The slit 10 may be provided with slits at appropriate intervals in the middle, or may be substantially configured as a slit by a row of many through holes arranged horizontally at small intervals (nearly touching intervals). may have been done. The vertical focusing electrode 3' is also similar.

A plurality of vertical deflection electrodes 4 are arranged horizontally in the middle of each of the slits 10, and are each composed of conductors 13 and 13' provided on the upper and lower surfaces of an insulating substrate 12. has been done. And the opposing conductors 13, 13'
A vertical deflection voltage is applied between them to deflect the electron beam in the vertical direction. In this embodiment, the electron beam from one line cathode 2 is vertically deflected to positions corresponding to 16 lines by a pair of conductors 13, 13'. And, by 16 vertical deflection electrodes 4, 15
Fifteen conductor pairs corresponding to each of the book line cathodes 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 vertically long slit 14, and a plurality of control electrodes 15 are arranged in parallel in the horizontal direction at predetermined intervals. In this embodiment, 320 conductive plates 15a to 15m for control electrodes are provided (only 10 are shown in the figure). Each of the control electrodes 5 extracts the electron beam horizontally by dividing it into one picture element at a time, and controls the amount of electron beam passing therethrough in accordance with a video signal for displaying each picture element. Therefore, if 320 control electrodes 5 are provided, 320 picture elements can be displayed per horizontal line. Also,
In order to display images in color, each picture element is R,
Display is performed using phosphors of three colors, G and B, and the R, G, and B video signals are sequentially applied to each control electrode 5. In addition, 320 sets of video signals for one line are simultaneously applied to the 320 control electrodes 5.
Video for each line is displayed at once.

The horizontal focusing electrode 6 is composed of a conductive plate 17 having a plurality of vertically long slits 16 (320 slits 16) opposite to the slits 14 of the control electrode 5. Each beam is focused horizontally into a narrow electron beam.

The horizontal deflection electrode 7 is composed 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 picture element. 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 accelerating electrode 8 is composed of a plurality of conductive plates 19 provided horizontally at the same position as the vertical deflection electrode 4, and accelerates the electron beam so that it collides 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 20 that emits light when irradiated with an electron beam, and adding a metal back layer (not shown). The phosphor 20 is arranged for each slit 14 of the control electrode 5, that is, for each horizontally divided electron beam.
A pair of phosphors in each of the three colors R, G, and B are provided, and are coated in stripes in the vertical direction. 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 20 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.
mm, and the vertical direction is 16 mm.

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

Further, in this embodiment, only one pair of R, G, and B phosphors 20 for one picture element is provided for one control electrode 5, that is, one electron beam, but two
Of course, two or more pairs for more than two picture elements may be provided, and in that case, R, G, and B video signals for two or more picture elements are sequentially applied to the control electrode 5.
Horizontal deflection is performed in synchronization with this.

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 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,
-V ₁ to the back electrode 1, and -V 1 to the vertical focusing electrodes 3 and 3'.
DC voltages of V ₃ , V ₃ ', V ₆ to the horizontal focusing electrode 6, V ₈ to the accelerating electrode 8, and V ₉ to the screen 9 are applied.

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 25 is composed of a counter that is reset by a vertical pulse and counts horizontal pulses, and is configured to operate during an effective vertical scanning period (here, 240 hours) excluding the vertical retrace period of the vertical period. 15 driving pulses each having a length of 16H period are generated sequentially during each period (referred to as period). These drive pulses I, B...Y are applied to the line cathode drive circuit 26, where they are inverted and brought to a low potential only during each pulse period, and at approximately 200 mV during the remaining periods.
A line cathode drive pulse I′ made at a high potential of volts,
It is converted into B'...Yo', and each line cathode 2A, 2B,...
...Added to 2yo. Each line cathode 2a, ...2yo is heated by a current flowing through it during the high potential of the driving pulses I' to Y', and can emit electrons even during the low potential period of the driving pulses I' to Y'. The heated state is maintained. As a result, 15 wire cathodes 2-2
From y to y, low potential drive pulses are applied to each
Electrons are emitted only during the 16H period when yo′ is added. During the period when a high potential is applied, the potential at the line cathode 2 is lower 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 applied high potential becomes positive, the line cathodes 2-2
No electrons are emitted from yo. Thus, in the line cathode 2, during the effective vertical scanning period, from the upper line cathode 2A to the lower line cathode 2Y,
Electrons are emitted every 16H period. The emitted electrons are pushed forward by the back electrode 1, pass through the opposing slits 10 of the vertical focusing electrode 3, and are focused in the vertical direction to form a flat electron beam.

Next, the vertical deflection drive circuit 27 is composed of a counter that is reset by each of the vertical drive pulses y to y and counts the horizontal synchronizing signal, and a conversion circuit that converts the count output from D/A. , generates a pair of vertical deflection signals v and v' that change in 16 steps by 1H during the 16H period of each vertical drive pulse. The vertical deflection signals v and v′ both have a center voltage of V ₄ , and v increases sequentially,
v′ is configured to change in opposite directions so as to decrease sequentially. These vertical deflection signals v and v' are applied to electrodes 13 and 1 of the vertical deflection electrode 4, respectively.
3', so that each line cathode 2
The electron beam generated from I~2Yo is vertically
It is deflected in 16 steps, and as mentioned earlier, on the screen 9, one electron beam is deflected so that a raster of 16 lines is sequentially drawn one line at a time from the top.

As a result of the above, electron beams are emitted from the top of the 15 line cathodes 2I to 2Y for a period of 16 hours, and each electron beam is sequentially emitted for one line from top to bottom within 15 sections in the vertical direction. By being deflected, the electron beam is vertically deflected one line at a time on the screen 9 from the first line at the top end to the 240th line at the bottom end, thereby drawing a total of 240 lines of raster.

The electron beam thus vertically deflected is horizontally deflected by 320 degrees by the control electrode 5 and the horizontal focusing electrode 6.
It is divided into sections and taken out. Figure 1 shows one of these categories. The amount of electron beam passing through each section is controlled by a control electrode 5, and horizontally focused by a horizontal focusing electrode 6 into a single narrow electron beam, which is then controlled by horizontal deflection means described below. The R, G, and B phosphors 2 on the screen 9 are deflected horizontally in three steps.
0 is sequentially irradiated.

That is, the horizontal drive pulse generation circuit 28 is composed of three cascade-connected monostable multivibrators, etc., and is triggered by a horizontal synchronization signal to generate three horizontal drives with equal pulse widths within one horizontal period. Generate pulses r, g, b. Here, as an example, each pulse width is approximately 17 μsec.
3 during the effective horizontal scanning period of 50μsec.
Three pulses r, g, and b are generated. These horizontal drive pulses r, g, and b are applied to the horizontal deflection drive circuit 29. This horizontal deflection drive circuit 29 is switched by horizontal drive pulses r, g, and b to generate a pair of horizontal deflection signals h and h' that change in three stages. Both horizontal deflection signals h and h' have a center voltage of V ₇ , and h increases sequentially,
h' change in opposite directions so that they decrease sequentially. These horizontal deflection signals h, h' are applied to electrodes 18 and 18' of the horizontal deflection electrode 7, respectively.
As a result, each horizontally divided electron beam is horizontally deflected so as to sequentially irradiate the R, G, and B phosphors of the screen 9 for 17 μsec during each horizontal period. However, in the display element of FIG. 1, one conductor 18 or 18' is used in the horizontal deflection electrode 7.
is used to deflect the electron beams of two adjacent sections, and is designed to produce a deflection effect on the adjacent electron beams in mutually opposite directions. Therefore, the electron beam of 320 sections is If the thing in the th category is deflected in the order of R→G→B, the thing in the even numbered category is deflected in the order of B→G→R.
It is deflected in the opposite direction every other section, such that it is deflected in the order of .

Thus, in each line raster, the electron beam is divided into R, G,
Each phosphor 20 of B is sequentially irradiated.

Therefore, a color television image can be displayed on the screen 9 by modulating the electron beam with R, G, and B video signals for each horizontal section of each line.

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,
Here, the RY and BY 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,
B primary color signals (hereinafter referred to as R, G, and B video signals) are output. These R, G, and B video signals are processed by 320 sample and hold circuit sets 31a to 3.
Added to 1n. Each sample hold circuit group 3
Each of 1a to 31n has 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 held by memory sets 32a to 32n, respectively.
32n.

On the other hand, the sampling reference clock oscillator 33
is composed of a PLL (phase locked loop) circuit, etc., and generates a reference clock of about 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 cycle by a shift register, etc., so that the reference clock is applied to the sampling pulse generating circuit 34, where it is delayed by one clock period by a shift register, etc. Sampling pulses a to n are sequentially generated, and then one transfer pulse is generated. These sampling pulses a to n correspond to each picture element when one line of the video to be displayed is divided horizontally into 320 picture elements, and their positions are always constant with respect to the horizontal synchronization signal H. controlled by.

These 320 sampling pulses a to n correspond to the above 320 sample and hold circuit sets 31.
a to 31n, thereby providing one line to each sample and hold circuit set 31a to 31n.
When divided into 320 picture elements, the R, G, and B video signals of each picture element are individually sampled and held. The sample-held 320 sets of R, G, B video signals are stored in 320 sets of memory 32a~
32c by a transfer pulse t,
Here, it is held for the next one horizontal period.

The R, G, and B video signals for one line held in the memories 32a to 32n are respectively applied to 320 pulse width modulation circuit sets 37a to 37n, where the sampled and held R, G, and B video signals are The reference pulse signal is pulse width modulated according to the magnitude of the pulse width and is output. It is desirable that the repetition period of the reference pulse signal is sufficiently smaller than the pulse width of the horizontal drive pulses r, g, and b in the horizontal deflection circuit, for example, 1:10 to 1:1.
About 100 are used.

The output signals of these pulse width modulation circuits 37a to 37n are sent to 320 switching circuits 35, respectively.
Added to a~35n. Switching circuit 35
Each of the switching circuits 35a to 35n has individual input terminals for R, G, and B, and a common output terminal that sequentially switches and outputs them.
The output of 35n is individually applied to the 320 conductive plates 15a to 15n of the control electrode 5 of the display element as a control signal for modulating the electron beam.
Each of the switching circuits 35a to 35n is simultaneously switched and controlled by a switching pulse applied from a switching pulse generating circuit 36. The switching pulse generation circuit 36 is controlled by the pulses r, g, and b from the horizontal drive pulse generation circuit 28 described above, and is controlled by the pulses r, g, and b from the horizontal drive pulse generation circuit 28, and the switching pulse generation circuit 36 is
The switching circuits 35a to 35n are switched every 17 μsec by dividing 50 μsec into three, and output the R, G, and B video signals alternately and sequentially in a time-divided manner.
Switching signals r, g,
generate b. However, the switching circuit 35a
~35n, the odd-numbered switching circuits 35a, 35c... are switched in the order of R→G→B, and the even-numbered switching circuits 35b, 35n are switched in the order of R→G→B.
d...35n are configured to be switched in the reverse order of B→G→R.

What should be noted here is that the switching circuit 3
The switching of the supply of R, G, and B video signals in 5a to 35n and the horizontal deflection of the horizontal deflection of the electron beam to the R, G, and B phosphors by the horizontal deflection drive circuit 29 are performed both in timing and order. This means that they are synchronously controlled so that they match perfectly. As a result, when the electron beam is irradiating the R phosphor, the irradiation amount of the electron beam is controlled by the R video signal, and G and B are similarly controlled, so that the R and G of each picture element are controlled in the same manner. , B phosphors are respectively controlled by the R, G, and B video signals of the picture elements, and each picture element is displayed by emitting light in accordance with the input video signal. Such control is performed simultaneously on 320 picture elements for one line to display one line of video, and furthermore, 240 picture elements are displayed.
This is performed sequentially for the minute lines starting from the upper line, and one image is displayed on the screen 9.

The above operations are repeated for each field of the input television signal, and as a result,
The screen 9 is similar to a normal television receiver.
The television footage of the video is shown above.

As described above, television images are displayed on this display device, and the present invention further improves the vertical resolution by doubling the resolution in the vertical direction to produce fine and fine images. The purpose of this invention is to provide a device that can display images.

Therefore, in the present invention, when performing vertical deflection, two bias voltage generation circuits and a flip-flop are controlled by the flip-flop to alternately convert the two bias voltages into vertical deflection signals every vertical period. By using the additional two switching elements, the raster display position of each line can be changed approximately twice the line spacing every vertical period.
This method is characterized in that it is moved by a factor of 1 to obtain an effect equivalent to so-called interlaced scanning.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to drawings showing the configuration of its main parts.

First, FIG. 4 shows the basic configuration of the vertical deflection drive circuit 27. The ring counter 38 is reset at the leading edge of each of the vertical drive pulses E through Y from the vertical drive pulse generation circuit 25, and then counts the horizontal synchronizing signal H and sequentially outputs signals from the 16 output terminals.
Switching pulses α to π are generated every 1H. On the other hand, the variable resistor 39 is provided with 16 output terminals, from which 16 levels of output voltage for vertical deflection are taken out, and the analog switches 40α to 40
It is taken out via 0π. Each of the analog switches 40α to 40π is sequentially turned on for 1H period by the switching pulses α to π, respectively, and a stepped output is divided into 16 stages between the lowest terminal and the highest terminal, and the level increases successively. can get. The output voltage is extracted through an emitter follower-connected transistor 41, the amplitude is adjusted by a variable resistor 42, and further amplified by a class B amplifier circuit 46 composed of transistors 43, 44, and 45. A vertical deflection signal v is output from the output terminal 47. On the other hand, the vertical deflection signal v' is also created by a completely similar circuit, except that the analog switches 40α' to 40π' are switched in the reverse order by the switching pulses α to π. As a result, a stepped output v' of successively lower level is produced and outputted from the output terminal 47'.

The vertical deflection signals v and v' thus created are transmitted to the conductive plate 13 of the vertical deflection electrode 4, as shown in FIG.
and 13', whereby the electron beam is deflected in 16 steps in each section in the vertical direction, and a raster of 16 lines is drawn with one electron beam.

Furthermore, in this device, the step-like output from the amplifier circuit 46 is taken out by cutting off the DC current by the capacitor 48, and transistors 49 and 50 for bias switching are provided on the output side, and the transistors 49 and 50 are connected to each other by a flip-flop 51 for one vertical period. The display position of the raster of each line is changed to approximately 2 times the line interval.
I am trying to move it in the vertical direction by a fraction.

That is, the flip-flop 51 is triggered by a vertical pulse to create a switching pulse Q, which is inverted every vertical period, and the respective switching pulses are applied to the bases of the transistors 49 and 50, which are alternated every vertical period. Switching to. Then, during a certain vertical period, the transistor 49 is turned on and the resistor 52, which is the first bias voltage generation circuit, is turned on.
A bias voltage determined by 54 to 54 is added to the staircase waveform output to output a vertical deflection signal υ _o with a center voltage V ₄ , and in the next vertical period, transistor 50 is made conductive to provide a bias voltage determined by resistors 55 to 57. A vertical deflection signal υ _{(o+1) with a center voltage V 4 (o+1 )} is output by adding the bias voltage obtained by adding the bias voltage to the staircase waveform output.

A switching circuit is similarly provided in the other vertical deflection signal υ' generating circuit to generate vertical deflection signals υ _o ' and υ' _(o+1) . Here, as shown in FIG. 6, the display positions α, β...π of each line when vertically deflected by the vertical deflection signals υ _o and υ _o ′, and the vertical deflection signal υ _{(o+1 )} and υ′ _(o+1) so that the display position α′β′...π′ of each line is shifted by approximately half the line interval. In order to generate two types of bias voltages that differ by a vertical deflection voltage corresponding to approximately one half of the spacing,
Resistor 5 which is the first and second bias voltage generation circuit
The magnitudes of the bias voltages 2 to 54 and 55 to 57 are determined in advance.

In this way, by making the afterglow time of the phosphor 20 applied to the screen 9 a little longer, it is possible to display an image with the line density on the screen 9 doubled. , the vertical resolution can be doubled.

Furthermore, the terms "horizontal direction" and "vertical direction" in the above explanation 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 this sense, and is not directly related to the vertical and horizontal directions on the actual screen.

As detailed above, according to the present invention, when a screen is vertically divided into a plurality of sections and an electron beam is vertically deflected for each section to display a plurality of lines, two bias voltages can be applied. By using a generating circuit, a flip-flop, and two switching elements that are controlled by the flip-flop and apply two bias voltages to the vertical deflection signal alternately every vertical period, a plurality of lines can be displayed by the vertical deflection means. Since the position is moved by approximately half the line spacing per vertical period, the number of rasters of the displayed image on the screen can be apparently doubled, improving the vertical resolution. This makes it possible to display a fine, detailed image.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing the basic configuration of an example image display element used in an image display device according to an embodiment of the present invention, FIG. 2 is an enlarged view of the screen, and FIG. 3 is a drive circuit of the device. 4 is a circuit diagram showing the specific configuration of the vertical deflection drive circuit in the same circuit, FIG. 5 is a sectional view showing its vertical deflection operation, and FIG. 6 is its raster display mode. FIG. 2... Line cathode, 3... Vertical focusing electrode, 4... Vertical deflection electrode, 9... Screen, 13, 13'... Conductor,
25... Vertical drive pulse generation circuit, 26... Line cathode drive circuit, 27... Vertical deflection drive circuit, 38... Counter, 39, 39'... Variable resistor, 40α to 40π,
40α' to 40π'... Analog switch, 42... Variable resistor, 43, 44, 45, 49, 50... Transistor, 46... Class B amplifier circuit, 51... Flip-flop, 52, 53, 54, 56, 57, 58...
resistance.

Claims (1)

[Claims] 1 A screen on a screen is vertically divided into a plurality of sections, an electron beam source that generates an electron beam in each section, and a vertical deflection electrode that deflects each electron beam in the vertical direction for each section. , a vertical deflection drive circuit that generates a step-wave vertical deflection signal for displaying a plurality of lines by deflecting each electron beam in the vertical direction for each section and supplies the vertical deflection signal to the vertical deflection electrode; Two bias voltage generation circuits generate two types of bias voltages that differ by a vertical deflection voltage corresponding to approximately one-half of the interval, and a switching pulse that is triggered by a vertical pulse and reverses every vertical period. a flip-flop; and two switching elements that are alternately switched by the switching pulses from the flip-flop and apply the two types of bias voltages of the two bias voltage generating circuits to the vertical deflection signal alternately every vertical period. An image display device, characterized in that the display position of the plurality of lines is moved in the vertical direction by approximately one half of the line spacing every one vertical period.