JPS644392B2 - - 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. This invention relates to a device that displays a plurality of lines and displays a television image as a whole, and provides a device that can correct the display position of each line on the screen to correctly match a predetermined line position. The purpose is to

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. That was impossible. 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, 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. 2i~2ta. These line cathodes 2 have a diameter of, for example, 10 to 20μφ.
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 2a to 2a, and extracts the electron beam emitted from the line cathode 2 through the slit 10.
and vertically focused. The slit 10 may be provided with crosspieces 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 control electrode conductive plates 15a to 15m are provided (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. In addition, in order to display images in color, each picture element is R, G,
The image is displayed using phosphors of three colors, B, and 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, and the video for one line is displayed at one time.

The horizontal focusing electrode 6 is composed of a conductive plate 17 having a plurality of vertically long slits 16 (320 slits 16) 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. 1 divided by these two
As shown in an enlarged view in Figure 2, each section has R, G, and B phosphors 20 for one picture element in the horizontal direction, and has a width of 16 lines in the vertical direction. . The size of one section is, for example, 1 mm in the horizontal direction and 16 mm in the vertical direction.

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 is applied to the back electrode 1, and −V 1} is applied to the vertical focusing electrode 3, 3′.
DC voltages are applied to V ₃ , V ₃ ', V ₃ to the horizontal focusing electrode 6, V ₈ to the accelerating electrode 8, and V 9 to the screen ₉ .

Next, a composite video signal of a television signal is applied to the input terminal 23, and a synchronization separation circuit 24 separates and extracts a vertical synchronization signal V and a horizontal synchronization signal H. The vertical drive pulse generation circuit 25 is configured with a counter that is reset by a vertical pulse and counts horizontal pulses, etc., and is configured during an effective vertical scanning period (here, 240 hours) excluding the vertical retrace period of the vertical period. 15 drive pulses each having a length of 16H period are generated sequentially during a period of 16H. This drive pulse rotor is applied to the line cathode drive circuit 26, where it is inverted so that it is at a low potential only during each pulse period and approximately at a low potential during the other periods.
The line cathode driving pulses made at a high potential of 20 volts are converted into line cathode driving pulses 2', 2', 2', 3',
b...Added to 2ta. Each line cathode 2,...2
A current is passed between the high potentials of the drive pulses I′ and T′ to heat the
The heated state is maintained so that electrons can be emitted even during periods when the potential of the capacitor is low. As a result, electrons are emitted from the 15 line cathodes 2i to 2ta only during the 16H period in which low potential drive pulses i' to ta' are applied to each of them. 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 higher potential of the line cathode 2 is positive,
No electrons are emitted from the 2 ta. Thus, in the line cathode 2, during the effective vertical scanning period, from the upper line cathode 2a to the lower line cathode 2a,
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 counts the horizontal synchronizing signal that is slit by each of the vertical drive pulse generators, a conversion circuit that converts the count output from D/A, and the like. , 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 A~2 is directed 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 for 16H periods in order from those above the 15 line cathodes 2A to 2T.
Each electron beam is deflected one line at a time from the top to the bottom within the 15 sections in the vertical direction, so that on the screen 9, the electron beams are deflected one line at a time from the 1st line at the top to the 240th line at the bottom. The electron beam is vertically deflected line by line, creating a total of 240 raster lines.

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, q, b. Here, as an example, each pulse width is approximately 17 μsec.
3 during the effective horizontal scanning period of 50μsec.
Three pulses r, q, and b are generated. These horizontal drive pulses r, q, and b are applied to the horizontal deflection drive circuit 29. This horizontal deflection drive circuit 29 is switched by horizontal drive pulses r, q, 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 and 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, in the horizontal deflection electrode 7, one conductor 18 or 18' is used for deflecting the electron beams of two adjacent sections, and the electron beams are mutually connected to each other. Since it is designed to produce a deflection effect in the opposite direction, if the electron beam of 320 sections is deflected in the order of R→G→B in the odd numbered sections, the electron beam in the even numbered sections is deflected in the opposite direction. The beam is deflected in the opposite direction every other section, such that it is deflected in the order of B→G→R.

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 320.
31n. Each sample and hold circuit group 31a to 31n has three circuits for R, G, and B.
It has several sample and hold circuits. The sample and hold outputs of these sample and hold circuit sets 31a to 31n are each held by a memory set 32a.
~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 cycle at a time, so that the reference clock is 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.

One line of R, G, and B video signals held in the memories 32a to 32n are applied to 320 switching circuits 35a to 35n, respectively. The switching circuits 35a to 35n each have R, G,
B individual input terminals and a common output terminal that sequentially switches and outputs them, and the output of each switching circuit 35a to 35n is sent to the control electrode 5 of the display element as a control signal for modulating the electron beam.
are individually applied to each of the 320 conductive plates 15a to 15n. Each switching circuit 35a to 35
n are simultaneously switched and controlled by a switching pulse applied from a switching pulse generating circuit 36. The switching pulse generation circuit 36 receives pulses r,
R, G, B are controlled by R, G,
Each video signal of B is time-divided and outputted alternately and sequentially,
Switching signals r, q, and b are generated to be supplied to control electrodes 15a to 15n. However, among the switching circuits 35a to 35n, the odd-numbered switching circuits 35a, 35c, . . . are switched in the order of R→G→B, and the even-numbered switching circuits 3
5b, 35d...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 the 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. This control is performed simultaneously on 320 picture elements for one line to display one line of video, and an additional 240 picture elements are displayed.
This is done 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, but due to assembly errors during display element manufacturing, the vertical deflection is not uniform, and as a result, each line on the screen 9 is The spacing may become uneven, or the position of each line may shift up or down.

Therefore, an object of the present invention is to provide a device that can correctly display each raster line on the screen 9 at a predetermined position and at a predetermined interval in such a case. .

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 37 is reset at the leading edge of each of the vertical drive pulse generators 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 38 is provided with 16 output terminals, from which 16 levels of output voltage for vertical deflection are taken out, and the analog switches 39α to 39
It is taken out via 9π. Each of the analog switches 39α to 39π 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 40, the amplitude is adjusted by a variable resistor 41, and further amplified by a class B amplifier circuit 45 composed of transistors 42, 43, and 44. The vertical deflection signal v' from the output terminal 46 is also generated by a completely similar circuit, but
In the above case, analog switches 39α' to 39
The only difference is that π' is switched in the reverse order by the switching pulses α to π, thereby creating a step-like output v' with successively lower levels, which is output from the output terminal 46'. .

The vertical deflection signal v thus created is expressed by 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.

However, if an error occurs in the mounting dimensions of each electrode plate of the vertical deflection electrode 4 during assembly of the display element, resulting in variations in the distance between the conductors 13 and 13' and the position in the front and rear directions, the screen 9 In this case, each line of the raster is not drawn at a predetermined position, but is shifted upward or downward. FIG. 6 shows the shifted state. In the figure, the solid lines indicate the predetermined positions of each line, and the dashed-dotted lines indicate the positions of shifted lines. In FIG. 6, only four vertical divisions A, B, C, and D are shown, and within each division, only five lines are shown. In Category A, each line is displayed shifted toward the center of the category, in Category B, it is displayed shifted in the opposite direction from the center, and in Category C, the lines are displayed shifted downwards as a whole. In category 2, the display is centered on the lower two-fifths of the area and shifted toward that position.

Therefore, the present invention makes it possible to electrically correct the deviation in the display position of each line in the raster, and one embodiment of the vertical deflection drive circuit 27 for realizing this is shown in FIG. In this circuit, variable resistors 41a to 41a for adjusting the amplitude of the vertical deflection signal v are provided for each section in the vertical direction, and are connected to analog switches whose conduction is controlled by vertical drive pulses. 47a to 47 are used to switch and couple each section, and variable resistors 48a to 48 are provided for each vertical section to adjust the center level of the vertical deflection signal v. The vertical drive pulse is ~
Analog switch 49 whose conduction is controlled by the
A to 49 data are used to switch and combine each section. The capacitor 50 is for DC blocking. In addition, in the figure, the vertical deflection signal v
Although only the circuit for generating the vertical deflection signal v' is shown, a similar adjustment means is also provided for the circuit for generating the vertical deflection signal v'.

With this configuration, the amplitudes and DC levels of the vertical deflection signals v and v' in each section are adjusted by adjusting the variable resistors 41a to 41a and 48a to 48a for each section in the vertical direction. By doing so, it is possible to independently correct the display position of each line of the raster for each division so that it matches a predetermined position.

For example, in the case of the example shown in FIG. The deflection width can be reduced by adjusting the resistor 41b to reduce the amplitude of the signal v, and in category c, the deflection width can be reduced by adjusting the variable resistor 48c to increase the DC level of the signal v. It is only necessary to move the deflection position upward as a whole, and in category 2, the variable resistor 41
D is adjusted to increase the amplitude of the signal v to increase the deflection width, and variable resistor 48 D is adjusted to increase the DC level of the signal v to move the deflection position upward as a whole. Bye.

Of course, in addition to adjusting the vertical deflection signal v, it is also necessary to adjust the vertical deflection signal v' as well.

In this way, even if the display position of each line of the raster deviates due to a dimensional error in the mounting position of the vertical deflection electrode 4 during assembly of the display element, it is possible to By adjusting the amplitude and DC level of the deflection signal, each line can be displayed correctly at a predetermined position, and the television image can be displayed correctly.

Note that the means for independently adjusting the amplitude and DC level of the vertical deflection signal for each section in the vertical direction is not limited to the circuit shown in the illustrated embodiment, and may be modified as desired by a circuit that performs the same function. Just use it. Further, the position where the adjustment means is coupled may be arbitrarily selected within the range where the function can be achieved.

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, the vertical By making it possible to adjust at least one of the amplitude of the deflection signal and its DC level for each section, it is possible to prevent the position of the display line from shifting due to dimensional errors when assembling the display element. The image can be easily corrected so that it is displayed at a predetermined position, and a good image can be displayed.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing the basic configuration of an example image display element used in the image display device of the present invention;
Figure 2 is an enlarged view of the screen, Figure 3 is a block diagram showing the basic configuration of the drive circuit of the device, and Figure 4 is a block diagram showing the basic configuration of the drive circuit of the device.
The figure is a circuit diagram showing the basic configuration of the vertical deflection drive circuit in the same circuit, Figure 5 is a sectional view showing its vertical deflection operation, Figure 6 is a front view showing its raster display mode, and Figure 7 is an improved version. FIG. 3 is a circuit diagram of a vertical deflection drive circuit. 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, 37... Counter, 38, 38'... Variable resistor, 39α to 39π,
39α', 39π'...Analog switch, 41i~4
1..Variable resistor, 40, 42, 43, 44..Transistor, 45..B class amplifier circuit, 46..Output terminal, 47.--47.--Analog switch, 48.--48.--Variable resistor, 49.. ~49T...Analog switch.

Claims (1)

[Claims] 1. A screen is divided vertically into a plurality of sections, an electron beam is generated in each section, and each electron beam is deflected in the vertical direction for each section to form a plurality of lines. A display element configured to display the above is provided, and adjustment means is provided for adjusting at least one of the amplitude and DC level of the vertical deflection signal for vertically deflecting the electron beam in each of the above sections. An image display device characterized by: 2. The image display device according to claim 1, wherein in the display element, the timing at which the electron beam is generated is different in each of the plurality of sections. 3. The image display device according to claim 1, wherein a stepped waveform signal is used as the vertical deflection signal.