KR100255456B1 - Large screen disply and its element cell - Google Patents

Abstract

PURPOSE: A discharge element is provided to realize very high brightness by making electrons from a cathode be controlled by a control electrode so as to radiate a fluorescent layer in a vacuum container directly. CONSTITUTION: An element cell(1) comprises a vacuum container(2) of a cylindric shape, a cathode(3), a control electrode(4) and a fluorescent layer(5). The fluorescent layer(5) is formed on an inner surface of the cylindric vacuum container(2), and the cathode(3) is prepared at the center of the vacuum container(2). The control electrode(4) has a cylindric mesh shape and is formed to surround the cathode(3). The cathode(3) can be formed to have a string or bar shape where an electron emitting material is coated or infiltrated.

Description

Discharge element and large area display device using same

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device, and more particularly, to a representative display device (LSD; Large Screen (or Area) Display) and a discharge device used as an element cell thereof.

The development trend of the image display apparatus, which was mainly dominated by the CRT, has been progressed in both directions of light and small size for realizing a portable image display, that is, miniaturization and large size for the implementation of a large display.

The large area of the device itself, such as a CRT and a flat panel device, is known to be unsuitable for realizing a large display device because the manufacturing cost increases dramatically in proportion to the cube of the size, and various alternative means have been implemented.

The first one used to implement a large display device is a projection TV as shown in FIG. 1, which is an enlarged projection of an image of a projection tube T onto a screen S through an optical system L. FIG. In order to shorten the length of an optical path, the reflector M is generally used.

However, such a projection TV has a high energy density of the projection tube T, so the cooling problem of the projection tube T and the optical system L is large, and the life of the projection tube T itself is short. It is impossible to increase the size and there are many limitations on the intensity of ambient light.

Accordingly, in the projection TV, the use of the projection TV itself using the projection tube T is gradually decreasing. It is composed of LCD projector and the like and its use as a portable presentation device is changing.

Meanwhile, illustrated in FIG. 2 is a multi-screen device, in which a plurality of unit device panels P are formed in a matrix form to implement a large area image device.

In this case, CRTs, PDPs, and LED panels are mainly used as unit device panels. The biggest problem of the multi-screen device is that partition lines are clearly displayed between the unit device panels, which greatly reduces image recognition.

In other words, the outside of the image elements such as the cathode ray tube or the PDP has a considerable width, and thus an ineffective region cannot be formed. Therefore, when the image elements are arranged in a matrix, the ineffective regions form a thick partition line for dividing a large image. To interfere with the recognition of the image.

Accordingly, as shown in FIG. 3, the LSD or the LAD implements a large image device having no partition line by arranging a plurality of small element cells X. FIG. It was first called by jumbotron under the name Sony, Japan.

4 and 5 illustrate various conventional examples of the device cell X1 of the LSD.

First, a light emitting diode (LED) (G, R) is shown in FIG. 4 (a). A red LED (R) and a green LED (G) are adjacent to each other in the device cell (X1). A plurality is arranged in the wall W for preventing interference with a cell, respectively.

As can be seen from this arrangement, the LED device cell (X1) is not reproducible blue, and can be implemented as the red color between red (R) and green (G) and R, G. The reason is that the blue LED has only appeared recently (1996), and it is also difficult to be practical due to the price of 10 times that of other LEDs.

Accordingly, the LSD using the LED device cell X1 is not suitable for implementing a color image and is mainly used as a sign board.

On the other hand, shown in FIG. 4 (b) is a device cell (X2) using a flat matrix CRT of Mitsubishi Electric, Japan. For example, as shown in FIG. LSD is constructed by forming a device cell (X2) with a small CRT having a small CRT having two G four pixels) and arranging them in a matrix form.

The device cell (X2) is a VFD (Vacuum Fluorescent Device), but the shape is different, but has almost the same structure and operation as the miniaturized CRT as shown in Figure 4 (c), the fourth (c) In the device cell X3 of FIG. 1, the fluorescent layer 102 of a single color is arranged on the panel 101, and the electron beam B emitted from the electron gun 103 is sequentially scanned to the fluorescent layer 102 by the deflection plate 104 or the like. By scanning, one device cell X3 that emits a single color is implemented.

However, the device cell X3 of FIG. 4 (c) has low luminous intensity and excessively complicated driving, and thus, the device cell X3 has not been put to practical use as an LSD.

However, in the configuration of FIG. 4 (b), since the pixel array of the element cell X2 itself is formed in a field shape, at least one pixel R, G, and B must be overlapped to achieve white balance. This is difficult, and thus there is a problem of poor color reproducibility.

Accordingly, Sony succeeded in the practical use of the jumbotron with the configuration of the element cell X4 shown in FIG. 5, which is shown in FIG. 5 (a). It is easy to achieve white balance like a stripe device with pixels.

The driving of each flash point 110 is basically the same as the CRT as shown in FIGS. 5 (b) and 5 (c), and the electrons emitted from the cathode K are divided into a plurality of control electrodes G1 to G3. Are controlled to emit the fluorescent layer 112 of each pixel (R, G, B). Reference numeral 111 denotes a partition wall that divides the pixels R, G, and B, and the configuration of FIG. 5 (c) uses the plate-shaped control electrodes G1 to G3 as the configuration of FIG. 5 (b). It is an improvement.

On the other hand, shown in Figure 6 is the device cell (X5) using the glow discharge (Glow discharge) that was announced during the development of jumbotron development of Sony, but has not been put to practical use.

The device cell X5 is filled with helium in the cylindrical container 120, and the cathode K, the anode A, and the first and second mesh electrodes G1 and G2 are filled. It is arranged by arrangement. The device cell X5 uses a gas discharge phenomenon like a PDP. To achieve high brightness, the device cell X5 should have a distance of 1 mm or less between the anode A and the second mesh electrode G2. There was a structural problem in which arcing occurred well between A and G2), which was not realized.

In the above-described conventional structures, except for the element cell X3 of FIG. 4 (c) and the element cell X5 of FIG. 6, a plurality of pixels are all provided in one element cell X1, X2, X4, and driven. There is a problem in that the driving circuit is complicated because the complicated driving of the pixels inside the pixels after selecting the element cells X1, X2, and X4 is necessary, and the maintenance cost such as replacement in case of partial damage is increased. .

In addition, the element cell X3 of FIG. 4 (c) has problems such as low luminance and difficulty in deflection, and the element cell X5 of FIG. 6 cannot be put to practical use due to structural problems.

Therefore, the implementation of a suitable device cell that can be used for the implementation of the LSD is required, the basic requirements of the device cell is high brightness, excellent color reproducibility, and compatibility of the unit configuration, and low power consumption and low manufacturing cost would be more desirable .

A device cell capable of meeting most of these requirements may be a CRT or VFD of the same principle, that is, a structure in which accelerated electrons excite a phosphor directly. Such an electron excitation phosphor can realize high brightness. In addition, it is excellent in color reproducibility and inexpensive, and since the history of the image display device can be called the history of the CRT itself, there is an advantage of wide selection of phosphors and easy availability.

1 is a light path diagram showing a projection TV as an example of a large display.

2 is a front view illustrating a multi-screen device as another example of a large display device.

3 is a front view showing the configuration of the LSD.

4 (a) and 4 (c) are diagrams showing the configuration of element cells used in the apparatus of FIG.

5 (a) to 5 (c) are views showing the configuration of other device cells used in the apparatus of FIG.

6 is a cross-sectional view showing the configuration of another device cell eh.

7 (a) and 7 (b) are a side cross-sectional view and a planar cross-sectional view showing the structure of the device cell of the present invention.

8 (a) and 8 (b) are views showing one configuration of the LSD according to the device cell of the present invention, and an embodiment of the device cell suitable thereto.

9 (a) and 9 (b) are views showing another configuration of the LSD according to the device cell of the present invention and an embodiment of the device cell suitable for this.

10 (a) and 10 (b) are exploded cross-sectional views and planar cross-sectional views showing another configuration of the device cell of the present invention.

* Explanation of symbols for main parts of the drawings

1: device cell (discharge device of the present invention) 2: vacuum container

3,3 ′: cathode 4: control electrode

5,5 ′: fluorescent layer 6: metal back

7: stem pin 8: cylindrical electrode

10: support plate 20: plug

30: socket

The device cell of the present invention for satisfying the above conditions is a transparent cylindrical vacuum vessel,

A cathode arranged longitudinally in the center of the vacuum vessel,

At least one control electrode in the form of a cylindrical mesh coaxially surrounding the cathode,

A fluorescent layer of a predetermined emission color stacked on the inner surface of the vacuum vessel

It is characterized by comprising a.

According to this configuration, the electrons emitted radially by the cathode are controlled by the control electrode surrounding the cathode to directly emit the fluorescent layer on the inner surface of the vacuum vessel.

As a result, light emission is generated in the electric pole of the vacuum container, and thus, a very high luminance can be realized, and immediately driving is possible by applying a driving voltage without any other configuration such as deflection.

EXAMPLE

Such a detailed configuration and advantages of the device cell of the present invention, and the details of the large-area display device using the same will become more apparent from the following description of the preferred embodiments with reference to the accompanying drawings.

7 (a) and 7 (b), the device cell 1 of the present invention forms the fluorescent layer 5 on the inner surface of the cylindrical vacuum container 2, and the cathode 3 at the center thereof. And it is configured with a cylindrical mesh (ie, mesh-shaped control electrode 4) surrounding it around the cathode (3).

The cathode 3 may be configured in the form of a string or bar to which the electron-emitting material is coated or impregnated, but more preferably also in the form of a mesh.

On the other hand, the vacuum container 2 is finished with an end wall 2b of the same material extending from one side (upper part) to the side wall 2a, and the other side (lower part of the drawing) supports the side wall 2a in a sealed state. A stem plate 2c is supported to support a plurality of stem pins 7 for connecting the electrodes K and G to an external circuit. Preferably the vacuum vessel (2) is a colorless or colored transparent insulating material; For example, it is made of an optical glass material, and the stem plate 2c is made of the same glass material as the side walls 2a and the wall 2b, or other insulating material, for example, has a higher strength and brittleness than glass. It can be composed of a large ceramic or the like.

The device cell 1 of the present invention is configured to emit a predetermined single color, that is, the device cell 1 having a light emitting color of each of R, G, and B colors is separately configured, and a matrix arrangement is implemented to implement a color image. LSD is configured.

In this case, there may be three methods for implementing the emission color in the device cell 1. In the first method, the phosphor of the phosphor layer 5 is composed of phosphors having R, G, and B light emission colors. In this case, the electron-excited phosphor can be used as it has been used for conventional color CRT (CPT). It can be easily implemented.

The second method is a method of dispersing pigments of body color corresponding to each of R, G, and B emission colors when forming the vacuum container 2, which is a transparent material. At this time, the fluorescent layer 5 is preferably composed of a high luminance white phosphor.

The third method is a combination of the first method and the second method, that is, using the phosphor of the corresponding color in the fluorescent layer (5) and simultaneously including the pigment of the corresponding color in the vacuum vessel (2). This method makes it possible to exhibit very good color reproducibility.

In the device cell 1, hot electrons generated at the cathode 3 are excited by the control of the control electrode 4 to excite the fluorescent layer 5 to emit light. In particular, the mesh type cathode 3 has a large amount of hot electrons. Can be emitted to implement a luminance sufficient for image display.

However, more preferably, a metal back 6 is formed on the inner surface or the outer surface of the vacuum vessel 2 such as the inner surface of the fluorescent layer 5 by using a metal such as Al to connect to a positive power source. Then, the hot electrons generated from the cathode 3, that is, the cathode, are accelerated by the metal back 6, thereby exhibiting even better luminance.

The metal back 6 also serves to prevent damage of the fluorescent layer 5 by electron collision and to discharge free electrons in the device cell 1.

The device cells 1 of FIGS. 7A and 7B preferably form an LSD in the same manner as in FIG. 8.

That is, since the element cell 1 of FIG. 7 emits light in the circumferential direction of the vacuum container 2, the circumferential direction should be arranged so as to face the user U. As a result, the element cells 1 are layered in a state in which each element cell 1 is upright with respect to the support plate 10 as shown in FIGS. 8 (a) and 8 (b). Are arranged.

In this case, the light emitted from the device cell 1 is radially distributed. In order to concentrate the light toward the user U, the reflector 11 is attached to the support plate 10 as shown in FIG. 8 (b). It is preferable. The reflector 11 may be configured by, for example, bending a high gloss metal plate in a parabolic semicircular shape, and wrapping the device cell 1 on the opposite side of the user U to receive light generated from the device cell 1. Will be focused on the side.

In the layer arrangement, each device cell 1 is preferably composed of at least three types each having R, G, and B emission colors, and alternately arranged to implement color images. Of course, monochrome arrangements are possible.

In this LSD, each element cell 1 is installed in an upright state on the support plate 10. For convenience of installation and maintenance of the element cell 1, the element cell 1 has a stem below the stem plate 2c. A connecting pin 21 connected to a pin (not shown in FIG. 8) is provided with a plug 20 installed in a horizontal direction, and the support plate 10 also has a horizontal direction in which the plug 20 is inserted and coupled. It is preferable to have the socket 30 of.

The advantage of this LSD is that each device cell 1 can constitute one pixel point (one pixel point constitutes one pixel in the case of monochrome display, and three pixel points R, G, and B constitute one pixel in the case of color display). In addition, the driving of each element cell 1 applies a negative voltage to the cathode 3 (in the case of the metal bag 6, a positive voltage is applied to the metal back 6), and the control electrode 4 is cut off. By selectively applying a cut-off voltage, light emission can be controlled, and its configuration and driving are extremely simple.

For example, to implement SVGA resolution of 1024 × 768, 1024 × 768 element cells (three times the color display) are arranged on the support plate 10, and a simple 1024 × 769 It can be driven in a matrix manner.

In addition, since the fluorescent layer 5 is excited by the accelerated hot electrons of the device cell 1 of the present invention, the electron beam-excited fluorescent substance used for a general CRT can be used as it is, so that the fluorescent layer 5 can be easily obtained and has a wide range of selection. It is wide and the price is extremely low.

Such a device cell 1 can be manufactured in the size of several mm to several cm (more than the size is more easy, but the practicality is not practical because the width of the application is narrower) without any difficulty in the current technology level, for example For example, when the pitch between the device cells 1 (the sum of the height of the device cells 1 and the average interval) is 1 cm, the LSD having the resolution of 1024 × 768 may be implemented in a large size of 10.24m × 7.68m. In our prediction, it can be realized that the LSD (jumbotron) shown in FIGS. 3 to 5 can be implemented at a manufacturing cost of about one to tenths of moisture.

Meanwhile, in order to implement an LSD having an arbitrary size using the device cell 1 as a general purpose, the device cell 1 may be preferably installed in a horizontal direction as shown in FIG. 9 (a). In this case, as shown in FIG. 9 (b), the fluorescent layer 5 'is also formed on the end wall 2b of the element cell 1, and the metal back 6 is also formed on the end wall (if necessary). It can extend to the fluorescent layer 5 'of 2b).

In particular, when the fluorescent layer 5 'and the metal bag 6 extend to the end wall 2b, the fluorescent layers 5 and 5' can be formed by the precipitation method during manufacturing. (6) can also be formed by overall sputtering, which makes production extremely easy.

At this time, the stem pin (7) in the stem plate (2c) of the element cell 1 extends as it is without a separate plug (20 in Fig. 8 (a)) as in the case of Figure 7 (a) and is also horizontal to the support plate (10) The socket 30 in the direction is provided. In this case, a well 12 may be provided on the support plate 10 to surround each device cell 1, which may serve as a partition wall for preventing interference between the device cells 1, and an appropriate reflective layer as necessary. It can also serve to focus the generated light toward the user (U) side.

The device for supporting the device cell 1 and the support plate 10 of the present invention may have a variety of different configurations, and FIG. 10 shows a combination of these modified configurations.

In FIGS. 10 (a) and 10 (b), the cathode 3 'is configured in the form of a winding, in which the filament is formed as it is or with a double winding, and then the pores are formed on the surface thereof. It can be comprised by the method of coating a layer and impregnating a negative electrode material.

On the other hand, in FIG. 10, instead of having a separate metal back 6, the cylindrical electrode 8 surrounding the outer circumference of the vacuum vessel 2 supports the device cell 1 and accelerates the hot electrons at the same time. do. The cylindrical electrode 8 has a diameter in which at least a lower portion of the element cell 1 can be inserted by a conductive metal plate, and a positive voltage is applied thereto, whereby hot electrons from the cathode 3 'are inserted in the state where the element cell 1 is inserted. Is accelerated with respect to the fluorescent layer 5. In addition, when the cylindrical electrode 8 is made of a high gloss metal, it also serves as a reflective layer.

Preferably, at least one incision groove 8a is formed in the cylindrical electrode 8, and the inner diameter thereof is formed to be slightly smaller than the outer diameter of the vacuum container 2. Then, when the vacuum container 2 is inserted, the cylindrical electrode 8 opens and is inserted, and in the inserted state, the vacuum container 2 is maintained in a firmly coupled state without being separated by the elastic restoring force of the cylindrical electrode 8.

According to this configuration, if the vacuum vessel 2 is provided with only two or three stem pins 7 of the stem pins to apply the negative voltage to the cathode 3 'and the stem pins to apply the cutoff voltage to the control electrode 4. In addition, the socket 30 on the side of the support plate 10 has a structure for supporting the cylindrical electrode 8 and a positive voltage connection configuration and for inserting and supporting the stem pin 7 of the vacuum vessel 2.

As described above, according to the present invention, a device cell capable of using only a low voltage, high brightness, and easy to obtain CRT tube can be used, and its configuration and driving are extremely simple using the same. An effective LSD can be provided.

Claims (15)

A discharge device used as a unit cell of a large-area display device, comprising: a cylindrical vacuum container, a fluorescent layer formed on the inner surface of the vacuum container, a cathode provided at the center of the vacuum container to emit hot electrons, and the cathode Discharge element characterized in that it comprises a surrounding control electrode of the cylindrical mesh form. The discharge device of claim 1, wherein the cathode is formed in a mesh form in which an electron-emitting material is coated or impregnated. The discharge device of claim 1, wherein the cathode is formed of a winding in which an electron-emitting material is coated or impregnated. The discharge device according to claim 1, wherein a positive voltage is applied to an inner surface or an outer surface of the vacuum vessel to form a metal back to accelerate hot electrons from the cathode. The discharge device according to claim 1, wherein the vacuum container is inserted into a cylindrical electrode of a conductive metal to which a positive voltage is applied. The method of claim 5, wherein the inner diameter of the cylindrical electrode is slightly smaller than the outer diameter of the vacuum vessel, at least one incision groove is formed in the cylindrical electrode, the cylindrical electrode is elastically the vacuum vessel when the vacuum vessel is inserted Discharge element, characterized in that for supporting. A large-area display device comprising the discharge device according to claim 1 as a device cell, wherein the device cells are arranged in a matrix on a support plate so that each device cell constitutes one flash point. Large area display. 8. The large-area display device according to claim 7, wherein each of the device cells is formed of a single color of light emission. The method according to claim 7, wherein the device cell is composed of a device cell having a light emitting color of R, G, B, the large area, characterized in that the R, G, B device cells alternately arranged to implement a color image Display. 8. The large-area display device according to claim 7, wherein each of the device cells is coupled to the support plate in an upright state. The large-area display device according to claim 10, wherein each of the device cells is provided with a plug having a connecting pin extending in a horizontal direction, and the support plate is provided with a horizontal socket in which the plug is inserted and connected. The large-area display device according to claim 10, wherein the support plate is provided with a reflector surrounding the outer circumference of the device cell. The large-area display device according to claim 7, wherein each of the element cells is arranged and connected in a horizontal direction with respect to the support plate. The large area display device of claim 13, wherein a well is formed on the support plate to prevent interference between the device cells. The large-area display device according to claim 7, wherein each of the device cells is driven in a matrix manner.

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