JPS5853462B2 - image display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image display device in which an electron beam emitted from a substantially planar electron source is controlled by an electron beam control electrode, accelerated and impinged onto a phosphor surface to display an image. .

Conventionally, as a matrix type flat display device, EL,
Devices using plasma, liquid crystal, etc. have been developed, but they still do not have sufficient performance in terms of brightness, luminous efficiency, color display, etc., and image display like TV operation is at the end of its practical use. However, there have been reports of attempts to construct flat display devices using electron beams.

FIG. 1 shows the main components of an example of a conventionally known display device of this type.

In the figure, 1 is a flat electron source, for example, a hot cathode, a field emission cold cathode, etc. are used.

Reference numeral 2 denotes a grid-like electrode plate having a large number of through holes 6, which is used to apply a positive voltage to the flat electron source 1 and extract an electron beam.

A portion of the electron beam passes through the through hole 6 and reaches the surface of the first electron beam control electrode plate 30 .

The first electron beam control electrode plate 3 and the second electron beam control electrode plate 4 each have a large number of through holes 6a and 6b.
are provided regularly in the vertical and horizontal directions, and strip-shaped electrodes 7 and 8 are provided in each column and row, at appropriate intervals so as to be perpendicular to each other, and at each orthogonal intersection. The through holes 6at and 6b provided in both electrode plates are arranged so as to coincide with each other.

Now, the electron beam that has reached the surface of the first electron beam control electrode plate 30 has its beam current modulated in accordance with the signal voltage applied to each electrode 7, and passes through the through hole 6a to the second electron beam control electrode. It reaches the surface of the plate 40.

The electron beam is modulated by the second electron beam control electrode plate 4 by the same operation as the first electron beam control electrode plate 3 and passes through the through hole 6b.

The electron beam passing through the through hole 6b is accelerated by the accelerating electrode plate 5 to which a high voltage is applied.
It collides with the phosphor film 9 deposited on the surface to emit light.

Since the luminance of light emission is proportional to the electron beam current of each pixel, it is possible to obtain an image corresponding to the signal voltage applied to each electrode provided on the beam control electrode plate 3.4 of both types.

A transparent insulating substrate, such as a glass substrate, is used as the substrate 9 on which the accelerating electrode plate 5 is provided, and a transparent electrode is provided on the surface of the substrate 9, and a metal back method, such as that used in a normal cathode ray tube, is used.

Generally, in this type of display device, a so-called matrix type display device, the resolution of the image is determined by the size and pitch of the through holes provided in the electron beam control electrode or its substrate.

Therefore, the higher the resolution and the clearer the image, the smaller the diameter and the pitch of the through holes are required.

Therefore, in order to obtain a clear image on a display screen of a certain size, it is necessary to provide the through holes 6a, 6b and the electrodes 7p and 8 groups densely, and the number of holes and the number of electrodes must be set closely. Need to increase significantly.

For example, if you try to display both TV images, the minimum
00 through holes are required and each electron beam control electrode plate requires 500 electrodes.

Furthermore, if a color display is to be performed, three times as many through holes and electrodes will be required.

Current materials and processing techniques are limited to two to three lines per space, and therefore do not provide sufficient resolution.

In addition, increasing the number of holes and the number of electrodes significantly increases the number of drive circuits for driving each electrode and the number of connections between the drive circuit and each electrode, which poses a major problem in mounting. In addition, there are many unresolved problems such as the fact that it can cause malfunctions.

In view of these various problems, the present invention arranges a deflection electrode for deflecting the controlled electron beam on the electron beam control electrode plate, and deflects the electron beam vertically or horizontally. An object of the present invention is to provide an image display device that can be deflected from side to side and can obtain a clear image with high resolution on an image display plate covered with a light emitting body.

Further, the present invention provides an image display device in which the number of through holes and the number of electrodes can be significantly reduced while maintaining high resolution.

The present invention will be described in detail below with reference to the drawings.

FIG. 2 shows an embodiment of an image display device according to the present invention.

10 is a planar electron source, which may be a flat hot cathode or a field emission cold cathode, but from the viewpoint of economy and reliability, tungsten wires coated with an oxide electron emitting material are spaced at appropriate intervals. A pseudo-plane cathode is used in which a plurality of cathodes are strung almost in parallel while maintaining the same.

11 is an anode substrate, and a mesh-like electrode 16 is attached to a predetermined portion.

A positive voltage is applied to the mesh-like electrode 16 with respect to the cathode, and an electron flow with a substantially uniform current density is extracted from the planar electron source 10.

It is desirable that the mesh-like electrode 16 has as large an effective area as possible in order to increase the transmittance of the electron beam.

Further, it is preferable to use a mesh-like electrode having holes at positions that correspond to the through holes of the first electron beam control electrode plate 120.

A cross-sectional perspective view of the first electron beam control electrode plate 12 and the second electron beam control electrode plate 14 is shown in FIG.

Striped through holes 22 are provided in the insulating substrate at predetermined intervals, electrodes 17 are provided on the inner wall surface of the through holes, and each electrode is connected to a corresponding control circuit.

Each electrode is insulated from each other. The electrodes are formed by vacuum evaporation, sputtering, electroless plating, or the like.

An ordinary glass plate, ceramic plate, etc. can be used as the insulating substrate, and through holes can be provided by photo-etching technology or the like.

Hole drilling using the P1 photoetching technique has a drawback in that the hole diameter varies greatly, causing uneven brightness and color shift, especially when used as a TV image display device that requires halftone display.

To solve these drawbacks, photosensitive crystallized glass is used.

Photosensitive crystallized glass is known under the trade name ``Photoceram.'' After being irradiated with ultraviolet light, it is heat-treated to crystallize the area irradiated with ultraviolet light and take advantage of the difference in etching speed with the non-crystallized area. Make a hole.

Thereby, precise through holes can be provided regardless of the thickness of the substrate.

In addition, it is particularly effective when providing ladder-like through holes to maintain mechanical strength, and when manufacturing the electron beam deflection electrode plate 13.

The reason for this is that since highly accurate processing is possible, the pair of deflection electrodes have good parallelism, and the deflection angle of the electron beam can be made uniform.

This is extremely difficult to do with ordinary photoetching of glass plates.

Each of the electron beam control electrodes 12, 14 is connected to a drive circuit for controlling the electron beam.

The electrodes of the pair of electron beam control electrode plates are arranged substantially perpendicular to each other.

An electron beam deflection electrode plate 13 is located between both electrode plates 13 and 140.
is provided.

A cross-sectional perspective view of the electron beam deflection electrode plate 13 is shown in FIG.

Striped through holes 23 are provided in the insulating substrate at predetermined intervals.

The intervals between the through holes are set to match the holes in the electron beam control electrode plate.

The inner wall surface of the through hole 23 is provided with electrodes 18a and 18b for deflecting the electron beam by an electric field.

The electrodes 18a and 18b form a pair of deflection electrodes and are connected in a comb-like manner.

In the above embodiments, the electrodes are formed by providing through holes in the insulating substrate, but they may also be formed by stretching metal wires or metal plates.

The image display board 15 has a structure in which a phosphor film 20 is deposited on a transparent substrate, for example, a glass substrate, and a conductive film such as aluminum is deposited on the surface of the transparent substrate, which is made conductive by a so-called metal back method, or a glass substrate is used. It can be formed by a structure in which a transparent conductive film is attached on a substrate and a phosphor film is attached to the surface of the transparent conductive film.

The phosphor film can be made into a color display plate by sequentially depositing phosphors that emit red, green, and blue in stripes.

Next, the operating principle will be explained.

Electrons emitted from the planar electron source 10 are accelerated by the electrode 16, which is an anode, and the electron beam that has passed through the mesh-like electrode is almost perpendicularly incident on the first electron beam control electrode plate 12.

A voltage that is more negative than the potential of the planar electron source, which is a cathode, is always applied to each electrode 17 of the first electron beam control electrode plate 12, so that the incident electron beam is transmitted through the through hole of this control electrode plate. 22 and flows into the electrode 16.

It is in a so-called cut-off state.

However, if a zero or positive potential is applied to one of the m-th electrodes in the electrode 17, electrons can only pass through the through-hole that has the m-th electrode, and the plate with the width of the through-hole An electron beam with a shape is obtained.

The plate-shaped electron beam is incident on the middle electrode pair of the electron beam deflection electrode plate 13 corresponding to the m-th electrode.

Whether the potential difference between the pair of electrodes 18a and 18b is zero, positive, or negative (
18a or 18b), the electron beam is divided into 21a, 21b, or 21c as shown in FIG.

That is, three light emitting lines appear on the surface of the display panel 15.

This is not explained in 1, but since the deflection angle of the electron beam changes depending on the potential difference between the pair of deflection electrodes, as explained in FIG.
Furthermore, by continuously changing the potential difference, it is possible to continuously obtain light emitting lines on the display panel.

The above description has been made regarding the case where the second electron beam control electrode plate 14 is not present or when the electron beam can pass through the entire control electrode plate 14. Next, the case where a signal voltage is applied to the electrode plate 14 will be described.

This control electrode plate 14 is the first electron beam control electrode plate 12.
It has a similar function.

That is, each electrode 1 of the second electron beam control electrode plate 14
When a negative potential is applied to 7 with respect to the planar electron source 10,
The electron beam that has passed through the electron beam deflection electrode plate 13 cannot pass through the through holes provided in each electrode of this control electrode plate 14 .

However, when a zero or positive potential is applied to one of the n-th electrodes of the control electrode plate 14, the electron beam passes only through the through hole provided in the n-th electrode and reaches the surface of the display panel 15.

Similarly, when a zero or positive potential is applied to a plurality of electrodes 17, a plurality of bright spots appear on the display panel 15. [Obtainable.

At this time, since the control electrode plate 14 is provided with a through hole substantially perpendicular to the through holes provided in the control electrode plate 12 and the deflection electrode plate 13, the electron beam deflected by the deflection electrode plate 13 is 21a, 21b.

21c can all pass through this through hole and reach the display board 15.

This is the reason for using rectangular or striped through holes instead of the conventional circular through holes.

Based on the same principle, the second electron beam control electrode plate 1
A similar effect can be obtained by disposing the deflection electrode plate 13 between the display panel 15 and the display panel 15.

It will be easily understood that the electron beam can be deflected two-dimensionally, vertically and horizontally, by inserting a deflection electrode plate between each of the scattered raindrops.

Now, the image display device of the present invention is most effective when used as a TV image display device.

An example in which this device is used as a TV image display device will be described below.

A conceptual diagram of the drive system for TV image display according to this embodiment is shown in the fifth figure.
As shown in the figure.

This device has 250 vertical electron beam control electrodes and 250 horizontal electron beam control electrodes.

Further, the display method is a constant scan line simultaneous display method generally implemented in matrix type display devices.

Furthermore, corresponding to each electrode of the vertical and horizontal electron beam control electrodes.

Equipped with vertical and horizontal deflection electrodes. Both electrodes have the structure shown in FIG. 4, and each deflects an electron beam in the vertical direction and the horizontal direction by a voltage applied between the electrodes.

In FIG. 5, the video signal input to the synchronization separation circuit 51 is transmitted to the control signal processing circuit 52 and the image signal processing circuit 53.
is input.

The image signal processing circuit 53 decomposes the image signal for one horizontal scanning line into 750 signal sequences, 1, 4, 7, etc.
...The 748th signal is stored in the storage device 54a as 2, 5, 8.
．． ...The 749th signal is stored in the storage device 54b,
The 3rd, 6°9, . . . 750th signals are sequentially stored in the storage device 54c.

The image signal stored in each storage device is sequentially transferred to the horizontal drive circuit 56 via the switching circuit 55 in synchronization with the signal from the control signal generation circuit 52, and the image signal voltage is applied to the 250 horizontal electron beam control electrodes. is applied.

At this time, if the scanning time of one horizontal scanning line is 63 .mu.s as in normal TV image display, the signal voltage from each memory device is sequentially applied for 21 .mu.s of one horizontal scanning time.

On the other hand, one of the signals sent from the control signal generation circuit 52 is input to the horizontal deflection drive circuit 57, and deflection voltages as shown in FIG. 6 are simultaneously applied to the 250 pairs of horizontal deflection electrodes.

As a result, for example, during the first 21 μS, the display board 150
A voltage is applied to deflect the electron beam to the left when facing the plane, the deflection angle is zero for the next 21 μS, and to the right for the next 21 μS.

Repeat the above operations in sequence.

The timing of this deflection is performed in synchronization with the switching circuit 55.

The above describes a method in which the image signal for one horizontal scanning line is divided into three parts and applied sequentially. However, in the case of a color image signal, the red, green, and blue signals are stored in three storage devices, respectively, and the signals are sequentially applied. It is possible to perform a color display by deflecting the image signal and colliding it with a phosphor that emits red, green, or blue light, and storing the image signal in an arbitrary number of storage devices, and sequentially deflecting the image signal at an arbitrary time interval within the scanning time. It will be easy to understand that it can be displayed in a similar manner.

Next, vertical scanning will be explained.

In the case of normal TV image display, signal voltages are sequentially applied to the vertical control electrodes from top to bottom every 63 μs.

On the other hand, a signal voltage as shown in FIG. 7 is simultaneously applied to the pair of vertical deflection electrodes 250 by the vertical deflection drive circuit 58.

That is, for the first 16.6 ms, a deflection voltage that deflects the electron beam upward is applied, and for the next 16.6 ms, a signal voltage that deflects the electron beam downward is applied.

The above operations are then repeated one after another.This is because an interlaced signal is being sent as a TV signal.
The deflection voltage is adjusted so that one field of image is created by deflecting upward, the next one field of image is created by downward deflection, and both images are superimposed to obtain one frame image.

In this way, the image display device 59 can sequentially obtain TV images.

Here, an embodiment in which the phosphors are deflected in the horizontal direction for color display has been described, but it is also possible to repeatedly arrange the phosphors corresponding to each color in the vertical direction and use the same deflection electrode both horizontally and vertically.

In this case, the deflection voltages are superimposed.

Note that 60 is a vertical drive circuit. As is clear from the above description, 500×750 pixels can be obtained using 250×250 electron beam control electrodes and two deflection electrode plates.

In other words, the resolution is doubled in the vertical direction and tripled in the horizontal direction.

Furthermore, since the number of electrodes can be reduced to obtain the same resolution, the manufacturing of the electrode plate becomes significantly easier, and at the same time, the drive circuit becomes simpler, which makes it less expensive.

At the same time, implementation becomes easier and failures and the like are reduced.

Further, another embodiment of the vertical scanning method will be described.

In the above embodiment, a case has been described in which the deflection is performed in two stages in the vertical direction, that is, upward and downward, but deflection in three or more stages can also be easily implemented.

One method is to apply a signal voltage for a plurality of scan times, for example, four scan times, to a set of vertical electron beam control electrodes, and to apply a plurality of stages, for example, four stages of deflection voltage to the vertical deflection electrode, in synchronization with the vertical scanning signal. Apply.

By sequentially performing such operations on the vertical electron beam control electrode and the deflection electrode, it is possible to scan one frame.

This scanning method is particularly effective for small screen display devices that require high resolution.

In other embodiments, a sawtooth deflection voltage applied to a set of vertical electron beam control electrodes has a period of one horizontal scan time or multiple horizontal scan times, such as four horizontal scan times or multiple scan times, such as four scan times. Apply.

Similar operations are then performed for each vertical electron beam control electrode in sequence.

With this type of scanning method, the entire screen is filled, and when displaying an image with a small number of scanning lines compared to the screen size, for example, in the case of a large meter-sized display panel, each scanning line is This is effective because it allows you to obtain an unobtrusive and smooth screen.

As is clear from the above description, the display device of the present invention can provide a high-density, high-resolution screen, and can also significantly reduce the number of electrodes compared to conventional devices, making the drive circuit simple and inexpensive. This has extremely excellent effects, such as easier implementation, fewer connection terminals, and fewer failures.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a conventional example, Fig. 2 is an exploded perspective view of an image display device according to an embodiment of the present invention, Fig. 3 is a cross-sectional perspective view of an electron beam control electrode plate, and Fig. 4 is an electron beam control electrode plate. A cross-sectional perspective view of a beam deflection electrode plate, FIG. 5 is a block diagram of applying a signal voltage in the case of TV image display, and FIG. 6 is a waveform diagram of a horizontal deflection voltage.
FIG. 7 is a waveform diagram of the vertical deflection voltage. DESCRIPTION OF SYMBOLS 10... Planar electron source, 12... First electron beam control electrode plate, 13... Electron beam deflection electrode plate, 14...
...Second electron beam control electrode plate, 15...Image display board, 16. 17. 18a, 1 sb...-electrode, 53... image signal processing circuit, 54 a, 54 b
, 54c...Storage circuit, 56...Horizontal drive circuit, 57...Horizontal deflection drive circuit, 58...Vertical deflection drive circuit, 60...Vertical drive circuit.

Claims (1)

[Scope of Claims] 1. Electron beam control means comprising a substantially planar electron source, a control electrode group for controlling selective passage of the electron beam extracted from the electron source, and a plurality of deflection electrode pairs. a deflection means in which a through hole for passing the electron beam is formed;
a display means that emits light upon collision of the electron beam; the display means deflects the electron beam passing through the electron beam passage through hole of the deflection means according to the electric field strength of each electron beam passage through hole; An image display device that emits light by colliding with an object. 2. Claim 1, characterized in that the substantially planar electron source is constructed by stretching a plurality of metal wires.
The image display device described in Section 1. 3. The image display device according to claim 1, wherein the electron beam passing through hole is a striped through hole. 4. Claim 1, characterized in that the electron beam control means is constructed by providing a plurality of striped through holes in an insulating substrate, and forming electron beam control electrodes on the walls of the through holes. The image display device described in . 5. The image display device according to claim 1, wherein the electron beam control means is constituted by a stretched conductor. 6. A patent characterized in that the electron beam deflection means is constituted by a plurality of striped through holes provided in an insulating substrate, and a pair of electron beam deflection electrodes formed on the inner wall surface of each of the through holes. An image display device according to claim 1. 7. The image display device according to claim 1, wherein the electron beam deflecting means is constituted by a stretched conductor wire or a conductor plate. 8. The image display device according to claim 4 or 6, characterized in that photosensitive crystallized glass is used as the material of the insulating substrate. 9. A substantially planar electron source, an electron beam control means comprising a control electrode group for controlling selective passage of the electron beam extracted from the electron source, and a plurality of electron beam passage through holes formed by a plurality of deflection electrode pairs. a deflection means in which a hole is formed;
A display device that emits light upon collision of the electron beam, and a drive device that deflects the electron beam by applying a plurality of steps or a sawtooth deflection voltage to the electron beam deflection device, the device comprising: a display device that emits light when the electron beam collides with the electron beam; An image display device characterized in that an electron beam passing through the through-hole is deflected according to the electric field strength of each through-hole for electron beam passage, and is caused to collide with the display means to emit light. 10. The image display device according to claim 9, wherein the substantially planar electron source is constructed by stretching a plurality of metal wires. 11. The image display device according to claim 9, wherein the electron beam passing through hole is a striped through hole. 12. a substantially planar electron source, an electron beam control means for controlling selective passage of the electron beam extracted from the electron source, and a deflection means for deflecting the electron beam in correspondence with the electron beam control means; a display means that emits light by the collision of the electron beam; a driving means for applying a step deflection voltage of m stages (where m>2 is an integer) synchronized with horizontal scanning to the deflection means; - an image signal of a horizontal period valve; means for converting into mXn (n is a natural number) image signal groups;
m+2)th..., mith (i-1 to n)
an image display device comprising: m storage means for storing signals respectively; and display driving means for separately displaying signals from the storage means in correspondence with steps of the deflection voltage. 13. The image display device according to claim 12, wherein m=3, and the image signal is divided into red, green, and blue color signals and stored in three storage means. . 14 A substantially planar electron source, an electron beam control means for controlling selective passage of the electron beam extracted from the electron source, and a second electron beam for deflecting the electron beam in a horizontal direction corresponding to the electron beam control means. one deflection electrode, a second deflection electrode vertically deflecting, and a stepped first deflection electrode with a horizontal scanning period varying between three levels on said first deflection electrode.
a driving means for applying a step-shaped second deflection voltage whose level changes every vertical scan to the second deflection electrode, and separating the image signal into red, green, and blue color signals; three different storage means for storing data; a means for extracting an output signal from the storage means in synchronization with the step of the first deflection voltage and controlling the amount of electron beam using the signal; Accordingly, an image display device comprising display means on which red, green, and blue light emitters are deposited, each of which emits light during each level period of the first deflection voltage.