JPH0413812B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flat image display device using one linear thermionic electron source.

BACKGROUND ART Conventionally, as an image display device, a monochrome picture tube or a color picture tube such as a shadow mask type picture tube has been put into practical use. However, the generation, modulation, and focusing of electrons,
Since the long electron guns, each of which deflects independently and sequentially vertically, are located at the rear of the picture tube, the picture tube has a long depth, which has the disadvantage of increasing the volume of the entire device with this type of picture tube. .

For this reason, various cathodoluminescent type flat image display devices have been proposed. For example, JP-A-55-69944 discloses a linear hot cathode, first and second deflection electrodes, an electron beam control electrode, an electron beam acceleration electrode, and a display plate coated with a phosphor layer. An image display device using a flat electron source is shown. In this configuration, the partition electrode is divided into a back electrode to which a negative voltage is applied and a pair of vertical deflection electrodes to which a deflection voltage is superimposed on the negative bias voltage. It has a cathode configuration in which the electrodes are located.

Furthermore, JP-A No. 55-33734 discloses a cathode consisting of a linear hot cathode, a cylindrical electrode (partition electrode) to which a negative voltage is applied surrounding the hot cathode, and an electron extraction electrode to which a positive voltage is applied. A flat image display device having the following configuration is shown. In this cathode configuration, the voltage applied to the electron extraction electrode is +20V, and the voltages applied to the cylindrical partition electrode are -10V, -20V, and -30V.
It is shown that as the voltage becomes negative, the distribution of the electron beam concentrates in the center of the electron extraction electrode.

However, these image display devices include a plurality of linear cathodes and a plurality of horizontal and vertical deflection plates, and control of deflection and modulation is also complicated. Also, it is difficult to align the positions of the electron beam extraction electrode and the control electrode.
Furthermore, since a large number of cathodes are used, the screen is likely to be divided, resulting in uneven brightness, and the large number of electrodes also makes manufacturing difficult.

The present invention provides a flat-type image display device with a simple structure without the above-mentioned drawbacks, a small depth, and low crosstalk. Electrons are emitted from the linear thermionic electron source by applying a video signal voltage to every other row of back electrodes corresponding to , and applying a voltage that blocks electrons to every other back electrode. The structure of the cathodoluminescent method is simple: the amount of electrons is controlled horizontally, and a pair of deflection plates above and below the linear thermionic electron source focuses and deflects the electrons vertically, and the phosphorescent anode in the front is irradiated with light. The present invention provides a flat monochrome or color image display device.

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

FIG. 1 is a perspective view of the main components of the present invention. Reference numeral 1 indicates a rear wall, which is made of an insulator such as a thick glass material. 11r, 11g, 11b, 12
r, 12g, and 12b are row-shaped back electrodes separated from each other, and are made of metal or a transparent conductor.

Back electrode 11r, 11g, 11b, 12r, 1
2g and 12b are formed so as to extend alternately from the upper and lower ends of the back wall 1 to near the center of the back wall.
For example, odd-numbered back electrodes 11r, 11b,
11g is formed to extend downward from the upper end of the back wall 1, and even-numbered back electrodes 12g, 12r,
12b is formed to extend upward from the lower end of the back wall 1. In this case, the odd-numbered electrodes and the even-numbered electrodes are formed adjacent to each other at the center of the back wall 1. The length of this adjacent portion may be set to be approximately the same as the width of each back electrode.

Note that the back electrodes may be formed to extend from the upper end to the lower end of the back wall so that odd-numbered electrodes and even-numbered electrodes are alternately adjacent to each other over the entire surface of the back wall. Reference numeral 2 denotes a front wall, which is made of a transparent insulator such as a thick glass material. 21r, 21g, 2
1b, 22r, 22g, 22b are respectively red,
Line-shaped color phosphors of green and blue; 44 is a light absorber.
45 is an anode electrode made of a thin metal film such as a vapor-deposited aluminum film. Reference numeral 3 denotes a support frame for supporting the linear cathode 4 and the pair of deflection electrodes 5 and 6 with supports 5' and 6', and is made of an insulating material such as thick glass. It is held and configured as a side enclosure of the vacuum container. 4 is a linear hot cathode, which is a tungsten wire several tens of microns in diameter coated with an oxide electron emitting material. Deflection electrodes 5 and 6 are 1
Back electrodes 11r, 11b, 11 with a pair of electrostatic deflection plates
arranged close to g, 12r, 12b, 12g,
The linear hot cathode 4 is located at the center of the gap between the deflection plates 5 and 6, and on the same plane as the surfaces of the deflection plates 5 and 6 closer to the back electrodes.

The positional relationship and dimensions of each part will be explained with reference to FIGS. 2 and 3. In FIGS. 2 and 3, the same parts as in FIG. 1 are designated by the same reference numerals, and explanations thereof will be omitted. 46 is an electron beam. The thickness t of the deflection plates 5 and 6 is about 1 mm, and they are provided so as to substantially cover the back wall 1. This is to form a parallel electric field between the front wall 2 and the deflection electrodes 5 and 6, thereby increasing deflection sensitivity and focusing sensitivity. The deflection electrodes 5 and 6 are the second
Although the figure shows a case where the arrangement is approximately parallel to the rear wall 1, it is not necessarily necessary to arrange the arrangement parallel to the rear wall 1.
The sides of the deflection electrodes 5 and 6 opposite to the linear cathode 4 may be inclined so as to approach the back wall 1. By increasing the amount of tilt, the amount of deflection of the electron beam can be increased. In this case as well, it is preferable that the deflection electrodes 5 and 6 substantially cover the back wall.

The ends of the deflection electrodes 5 and 6 on the linear cathode 4 side are provided with inclined surfaces 51 and 61 on the fluorescent surface side so that the electron beam 45 can be deflected over a wide angle.

The spacing L _G between the deflection electrodes 5 and 6 is set to approximately twice the spacing L _R between the linear cathode 4 and the back electrodes 11 and 12, and the spacing L _R is set between the back electrodes 11r, 11b, 11g,
It is set equal to or smaller than the width W of 12r, 12b, and 12g.

Back electrodes 11r, 11b, 11g, 12r, 1
2b, 12g and array phosphors 21r, 21b, 21
g, 22r, 22b, and 22g are arranged in one-to-one correspondence, and the width thereof is determined corresponding to the size of one pixel. The anode electrode 45 formed on the fluorescent surface constitutes an electron extraction electrode.

Deflection distance is D (mm), deflection voltage V _D (V), fluorescent surface voltage is V _A (KV), deflection electrode spacing is L _G (mm), deflection electrode thickness is t (mm), deflection Let _{the distance} from the _{center of} Set.

FIG. 4 shows an example of the basic wiring of the image display device according to the present invention. Components in the figure that are the same as those in FIG. 13 is a synchronization separation circuit that separates the composite video signal into a video signal and a horizontal synchronization signal;
Separate into vertical synchronization signals. Reference numeral 14 denotes a video demodulation circuit, which generates red, green, and blue video color signals from, for example, an NTSC signal. 15 is a vertical deflection circuit of several hundred to several
A positive and negative sawtooth wave of 1000V and 60Hz is generated and applied to the deflection plates 5 and 6. This vertical deflection circuit 15 performs an operation in conjunction with horizontal synchronization to shift the vertical deflection position by one half of the horizontal scanning line for each field. 16, when the deflection is maximum, the distance of the electron beam to the fluorescent surface is longer than that at the center,
This circuit generates a correction voltage synchronized with vertical deflection to prevent defocusing. Reference numeral 17 denotes a pulse generator for generating various pulses for video processing using a horizontal synchronizing signal. 18 is an A/D converter that converts the blue analog video signal into a digital video signal, and two sets of 1H line memories.
19 is an A/D converter and two sets of 1H line memory for green, and 20 is an A/D converter and two sets of 1H line memory for red. The digital signals from each A/D converter are divided into two sets.
It is written alternately in the 1H line memory, divided into two systems of odd and even numbers, and the odd and even numbers are read out every 1/2H line, and the modulation/switching circuit 2
Enter 3, 24, 25, 26, 27, 28. 23
24 is a circuit for odd-numbered electrodes blue, 24 is a circuit for green, and 25 is a circuit for red. 26 is a circuit for even number electrode blue, 2
7 is the green circuit, and 28 is the red circuit. 29
is an odd-numbered electrode blue drive circuit that generates a modulation voltage to be applied to the back electrode 11b. 30 is the green circuit,
Reference numeral 31 denotes a red circuit that generates modulation voltages to the back electrodes 11g and 11r, respectively. 32 is an even-numbered electrode green drive circuit that generates a modulation voltage to be applied to the back electrode 12g. 33 is a circuit for red, and 34 is a circuit for blue, which generates a modulated voltage to the back electrodes 12r and 12b. 35
is a brightness unevenness correction circuit that generates a correction voltage synchronized with horizontal deflection in order to prevent brightness unevenness caused by, for example, a potential gradient at both ends of a long linear hot cathode in the horizontal direction of the screen.

Next, the operation will be explained. The linear hot cathode 4 is heated to about 700° C. by a power of 3 V and 30 mA from a DC power source 7, and hot electrons are generated from the oxide cathode.
The back electrodes 11 and 12 are uniformly maintained at, for example, OV by the brightness adjustment power source 9, and the upper and lower deflection electrodes 5 and 6 are
The same voltage, for example, the upper and lower deflection electrode voltages V _D =-200V, is applied by the focusing power source 8 to the accelerating power source 10.
When a phosphor voltage V _A =2 KV is applied to the phosphor surface 21, a focused luminescence image in a horizontal straight line is obtained at the center of the phosphor surface 21.

Next, when a positive and negative sawtooth wave of about 1000 V is applied from the vertical deflection circuit 15 to the upper and lower deflection electrodes 5 and 6, the linear electron beam is accelerated in the latter stage and vertically moves upward or downward on the fluorescent surface 21 while being focused. deflect in the direction

This situation is shown in FIG. Now, the back electrode 11
The distance between r and the linear cathode 4 is 4 mm, the distance between the deflection plates 5 and 6 and the cathode 4 is 3 mm, and the gap between the back wall and the front wall is 20 mm. 2 KV is applied to the aluminum film 25, and the deflection electrode 9 is 412V, -932V to deflection electrode 10
When applied, the electron beam 35 is accelerated upward and deflected 19.5 mm upward from the center. When a voltage of -930V is applied to the deflection electrode 5 and a voltage of 526V is applied to the deflection electrode 6, the electron beam 35 is deflected downward by 22.6 mm.
Therefore, each of the upper and lower deflection electrodes 5 and 6 has positive and negative approximately
By adding a 1000V sawtooth wave, a linear electron beam can be vertically deflected over the entire surface of the screen, allowing vertical scanning.

On the other hand, scanning in the horizontal direction is performed as follows. Now odd numbered electrodes 11r, 11b, 11g
If an ON signal, that is, an OV pulse, is input to the even-numbered electrodes 12g, 12r, and 12b, and an OFF signal, for example, -30V, is input to the even-numbered electrodes 12g, 12r, and 12b, on the fluorescent surface, the portions corresponding to the odd-numbered electrodes 11r, 11b, and 11g The electron beam 46 of
b, reaches 21g and only these phosphors emit light; the other phosphors do not emit light. This situation is shown in FIG.

Linear hot cathode 4 and back electrodes 11r, 11b, 11
g, 12r, 12b, 12g distance L _R and back electrode 11r, 11b, 11g, 12r, 12b,
Since the width W of 12g is set almost the same,
The modulated electron beam 35 reaches the corresponding row of phosphors 21r, 21b, and 21g without spreading.
Note that if the distance l between the back wall 1 and the front wall 2 is large, the electron beam 46 may spread somewhat and reach the adjacent rows of phosphors 22g, 22r, and 22b; Electrodes corresponding to the body (electrodes 11r, 11b, 11 in the figure)
g) is turned on for all pixels simultaneously for 1/2 horizontal time,
Adjacent electrodes (electrodes 12g, 12r, 12 in the figure)
If b) is cut off, the electron beam 46 will not emit light upon hitting an adjacent phosphor and cause color mixture. Crosstalk can be similarly prevented in the case of black and white images where the entire fluorescent surface is a single color phosphor. Electron beam 46 hitting light absorber 44
Of course it doesn't emit light.

Next, even numbered electrodes 12g, 12r, 12b
Add a pulse of OV as an ON signal to the other electrode,
That is, odd numbered electrodes 11r, 11g, 11b
When -30V is applied as an OFF signal to , the column phosphors 22g, 22r, 22b corresponding to the even-numbered electrodes 12g, 12r, 12b emit light, and the other column phosphors do not emit light. Thereafter, the same operation may be repeated by switching every half cycle of one horizontal scanning time.

Of course, this switching may be performed continuously in the order of arrangement from one end, and one horizontal scan may be completed when the switching is completed sequentially from one end to the other end.

As described above, the present invention includes a back wall on which a plurality of row-shaped back electrodes separated from each other are formed, a phosphor formed facing the row-shaped back electrode, and a metal thin film formed thereon. a linear hot cathode disposed in a central portion near the back wall between the two walls in a direction perpendicular to the direction of the column electrodes on the back wall;
A pair of plate-shaped deflection electrodes are provided at the ends of the filament hot cathode side with a slope that opens toward the phosphor screen, and the phosphor screen is arranged in red, green, and blue rows in one-to-one correspondence with the back electrode. an image processing means consisting of at least a 1/2 horizontal line memory, a modulation/switching circuit, which is configured by alternately arranging phosphors, and is connected to an odd numbered electrode group and an even numbered electrode group of the columnar back electrodes, respectively; Two systems are provided, and one system of video processing means applies the color video signal to the back electrode corresponding to each row of phosphors, and the other system applies a voltage that blocks electrons to the back electrode. This image display device is characterized by a small number of electron beam deflection plates, control electrodes, etc., an extremely simple configuration that does not use a shadow mask, etc., a thin depth, and a flat plate type image display with little crosstalk. It provides equipment. In addition, since the electrode on the fluorescent surface constitutes an electron extraction electrode, the electron transmittance is almost 100%.
This makes it possible to obtain extremely bright images.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing an image display device according to an embodiment of the present invention, FIGS. 2 and 3 are a cross-sectional side view and a cross-sectional plan view of main parts of the image display device according to the present invention, and FIG. FIG. 2 is a wiring diagram including a drive circuit system of an image display device according to the present invention. 1... Rear wall, 2... Front wall, 4... Linear cathode, 5, 6... Deflection electrode, 11r, 11b, 11
g, 12r, 12g, 12b... back electrode, 21
r, 21g, 21b... fluorescent material, 44... light absorber, 45... metal electrode.

Claims (1)

[Claims] 1. A back wall having a plurality of row-shaped back electrodes separated from each other, a phosphor formed facing the row-shaped back electrode, and a metal thin film formed thereon. On the front wall, one linear hot cathode arranged in a direction perpendicular to the direction of the column electrodes on the back wall in the center between the two walls near the back wall, and a fluorescent screen at the end of the linear hot cathode side. It is equipped with a pair of plate-shaped deflection electrodes that are open on the sides and form an inclination, and the phosphor screen is composed of red, green, and blue row-shaped phosphors arranged in alternating order in one-to-one correspondence with the back electrode. , two systems of video processing means each consisting of a 1/2 horizontal line memory and a modulation/switching circuit are provided, each connected to an odd-numbered electrode group and an even-numbered electrode group of the columnar back electrodes, and one system of video processing means is provided. An image display characterized in that the color image signal is applied to the back electrode corresponding to each row of phosphors through the line, and a voltage for blocking electrons is applied to the back electrode via another line. Device. 2. The image display device according to claim 1, wherein the distance between the linear hot cathode and the back electrode is equal to or smaller than the width of the back electrode. 3. The image display device according to claim 1, wherein one end of the back electrode extends alternately above and below the back wall, and the other ends are formed adjacent to each other. 4. The image display device according to claim 1, wherein the distance between the deflection electrodes is approximately twice the distance between the linear hot cathode and the back electrode. 5. Claim 1, in which the linear hot cathode is arranged in the center of both deflection electrodes on the side of the back electrode side of the deflection electrode.
The image display device described in Section 1. 6. The image display device according to claim 1, wherein the deflection electrode is provided to substantially cover the entire rear wall.