KR100255457B1 - Large screen disply and its element cell - Google Patents

Abstract

PURPOSE: A display device is provided to illuminate a fluorescent layer by electron beams emitted from an electron gun by shielding an entire surface of a vacuum container with a front plate, on which a fluorescent layer is formed. CONSTITUTION: A left side of a vacuum container(2) having a long tube shape is closed by a transparent front plate(3), an inner surface of which a fluorescent layer(4) is formed on. An electron gun(5) is disposed in a right side of the vacuum container(2). The electron gun(5) consists of a plurality of control electrodes(G1-G3) and a cathode(K), which radiates hot electrons. The control electrodes(G1-G3) control radiation of the hot electrons and condense and accelerate the radiated hot electrons to form an electron beam(B). A metal back(6) is formed on an inner surface of the fluorescent layer(4) and is supplied with a positive voltage.

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 large screen (or area) display (LSD) 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 that 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. This enlargement is impossible 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.

Here, 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 the recognition of images.

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 in blue, and red (R) and green (G) can be implemented as an orange color between R and 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.

7 is a cross-sectional view showing the basic configuration of the discharge device of the present invention.

8 (a) and 8 (b) are exploded perspective and bonded state cross-sectional views of a structure for constructing an LSD using the discharge device shown in FIG. 7 as an element cell.

9 is a front view of an LSD according to another embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

1: unit cell 2: vacuum container

3: front plate 4: fluorescent layer

5: electron gun G1 ~ G3: control electrode

K: cathode 6: metal back

7: stem pin 10: support plate

11: circular insertion part 12: socket

The discharge device of the present invention for satisfying such conditions is

Long tube type vacuum container,

A plate-shaped transparent front plate which shields the front of the vacuum vessel;

A fluorescent layer formed on the inner surface of the front plate,

Located at the rear of the vacuum vessel, characterized in that it comprises an electron gun consisting of a cathode for emitting hot electrons and a plurality of control electrodes for forming, electron beam for controlling, focusing and accelerating hot electrons from the cathode to emit a fluorescent layer .

This configuration is similar to the configuration of a simplified CRT having no deflection means, whereby the electron beam emitted from the electron gun emits the entire fluorescent layer inside the front plate.

Accordingly, such a discharge element can be used as a monochromatic element cell that emits light immediately by applying a driving voltage, and can easily be driven by a simple matrix method by easily forming an LSD with an array of element cells having each of R, G, and B emission colors. It becomes possible.

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.

In FIG. 7, the discharge element of the present invention constituting the element cell 1 of the LSD has a plate-shaped front plate in which a fluorescent layer 4 is formed on the inner surface of the elongated tubular vacuum container 2 (the left side of the drawing). It is sealed by (3) and has the structure which the electron gun 5 was arrange | positioned inside the back (right side of drawing).

The electron gun 5 includes a cathode K that emits hot electrons, and a plurality of control electrodes G1 to G3 that control the emission of the hot electrons therefrom and connect and accelerate the emitted hot electrons to form the electron beam B. FIG. It is composed.

Preferably, a metal back 6 is formed on the inner surface of the fluorescent layer 4 by using a metal such as Al to apply a positive voltage thereto. The metal back 6 accelerates the electron beam B and prevents burnout of the fluorescent layer 4, as in the case of the CRT, and discharges the glass electrons inside the device cell 1.

In view of such a configuration, the device cell 1 of the present invention has a basic configuration of a CRT without a deflection device, so that the electron beam B emitted from the electron gun 5 directly directs the fluorescent layer 4 of the front plate 3. By emitting light on the whole surface, one light emission color is displayed accordingly.

The device cell 1 of the present invention is not simply adopting an unbiased CRT but has some structural characteristics. That is, since the plate-shaped front plate 3 closes the front surface of the tubular vacuum container 2, the formation of the fluorescent layer 4 and the metal back 6 can be simply made by the printing method, and the element cell 1 ) Is also easy to manufacture.

In other words, the fluorescent layer 4 can be directly printed on the front plate 3 without using a cumbersome slurry process or precipitation method as in the prior art. In addition, the metal back 6 can also be formed by directly printing a metal layer on the fluorescent layer 4 without using a large sputtering method and equipment, as in the prior art. The front plate 3 can be simultaneously introduced into the deposition chamber to form a film at a time, thereby making it possible to manufacture at low cost.

In this way, the front plate 3 on which the fluorescent layer 4 and the metal back 6 are formed is bonded to the elongated tubular vacuum container 2 to form the element cell 1 of the discharge element of the present invention. At this time, the inside of the vacuum chamber 2 is exhausted to the required vacuum by a separate exhaust.

On the other hand, the configuration of the electron gun 5 is basically an unbiased configuration in which the fluorescent layer 4 of the front plate 3 is entirely emitted, so that the focusing of the control electrodes G1 to G3 is the cathode K. It is sufficient to collect hot electrons emitted from the fluorescent layer 4, that is, to form a fairly large beam spot.

Accordingly, the control electrodes G1 to G3 cross-over the G1 electrode to which a cut-off voltage for selectively controlling hot electron emission from the cathode K is applied, and the hot electrons emitted therebetween. The G2 and G3 electrodes will suffice to form a bundle of hot electrons, i.e., an electron beam.

On the other hand, the higher the amount of hot electron emission from the cathode (K) is preferable for the implementation of high brightness, accordingly, the cathode (K) is preferably composed of an impregnated cathode having a much better thermal electron emission characteristics than the oxide cathode.

Although the specific configuration of the cathode (K) is not shown, a CRT attached to the front of the cylindrical sleeve (sleeve) attached to the pellet (impregnated impregnated material) and the heater (heater) for heating it inside the sleeve Following the composition of the cathode will not be a problem.

The device cell 1 can be configured to a size of several mm to several cm, the basic configuration is similar to the simple CRT, but the reason for the name of the discharge element is as follows. That is, when a discharge (vacuum discharge) is generated between the CRT and the case requiring the deflection, this causes local abnormal light emission that obstructs the image display, but it causes the single fluorescent layer 4 to emit light unbiased. In this case, the generation of discharge increases the amount of visible light, which leads to an increase in luminance.

In other words, the light emitting device of the present invention can be said to be a hybrid type device that uses a vacuum discharge while simultaneously exciting and emitting the fluorescent layer 4 by an electron beam. This vacuum discharge depends on the spacing and shape of the control bases G1 to G3, the metal back 6, and the auxiliary electrodes (not shown) drawn therefrom. It will be embodied by the study and supplemented by subsequent applications.

However, the basic principle is that (potential difference / distance) between two points (between electrodes such as the control electrodes G1 to G3, the metal back 6, or the auxiliary electrodes drawn therefrom) is above a certain threshold in a predetermined vacuum atmosphere. This discharge is promoted by the shape of the electrode where the vacuum discharge is generated, for example, the sharp point. In the configuration of FIG. There is no question that a vacuum discharge can occur together.

Such a discharge element is a lead terminal for connecting each electrode (cathode K, control electrodes G1 to G3 and metal back 6, etc.) to an external circuit, as shown in FIG. It consists of a device cell (1) of the unit attached to the stem pin (stem pin) 7 as shown.

Here, the cross section of the element cell 1 may be composed of a square or a rectangle, but at least due to the problem of the unbiased beam spot being circular, the strength problem due to the high vacuum, and the convenience of obtaining a material such as a glass tube. The vacuum vessel 2 consists of cutting and fusion of a glass tube of circular cross section, more preferably of circular cross section. Meanwhile, the front plate 3 may be configured in a circular shape as shown in accordance with the shape of the vacuum container 2 and the shape of the beam spot. However, the front plate 3 may have various advantages.

When the front plate 3 is composed of a square, the alignment is extremely easy when the LSD is constructed, and the surface is formed in a continuous plane so that the weather resistance against the rain or the like during the external installation of the LSD is excellent. There is an advantage to be improved.

In this case, since the fluorescent layer 4 may be formed only at the corresponding portion of the vacuum container 2, which is indicated by a dotted line, the light emitting region according to this will be limited thereto. This does not cause a significant obstacle to the perception of remote viewing of a large image display device installed on a roof of a building such as an LSD, but may also include a light diffusing means depending on the necessity of image continuity. Would be desirable.

The light diffusing means is a method of forming the front plate (3) with a concave lens, or translucent glass such as liver glass, by forming a stripe-shaped fine groove in the front plate (3) to form the front plate (3) The light generated from the circular fluorescent layer 4 is dispersed and transmitted throughout the square front plate 3 by a method of forming a fresnel lens and a method of forming a translucent diffusion layer on the front plate 3. You can do it. In particular, the method of forming a translucent diffusion layer on the front plate 3 can serve as a protective layer of the front plate 3, and by dispersing the dye of the corresponding emission color to form a color filter to improve the luminance and color reproducibility You can contribute. Of course, such optical dispersing means may be provided in the circular front plate 3.

Back to Figure 8, we look at the preferred configuration of the LSD.

The discharge device of the present invention is composed of a device cell (1) having a single emission color, it can be arranged in a matrix form LSD. For the configuration of a monochromatic LSD, a single color device cell (1) is composed of a color LSD In order to achieve this, the device cells 1 having the light emission colors of R, G, and B may be alternately arranged.

In particular, in the case of the color LSD, each of the R, G, and B element cells 1 constitutes a circular or square firing point, and is arranged in a staggered matrix structure as shown in FIG. 8 (a) or FIG. It is preferable that the device cells 1 form a dot trio of an equilateral triangle so that the three device cells 1, which are the lighting points of each color, constitute one pixel.

The support plate 10 constituting the LSD by supporting each element cell 1 preferably stores the vacuum vessel 2 of the element cell 1, and the stem pin 7 of the element cell 1 is disposed at an inner end thereof. A circular insert 11 having a socket 12 to be connected is provided.

This configuration is completed by supporting and connecting the device cells 1 at the same time by simply inserting the device cells 1 into the circular insertion portion 11 of the support plate 10, which is particularly advantageous for the manufacture and maintenance of LSD. have. Here, it should be noted that the circular insertion portion 11 is a concept encompassing not only the shape of the circular hole shown but also all the supports of the elastic or inelastic method having the inner circumference of the circular or cylindrical shape.

At this time, if the outer diameter of the front plate 3 of the element cell 1 is larger than the outer diameter of the vacuum vessel 2 (the square front plate 3 of FIG. 9 is naturally larger), the circular insert 11 of the support plate 10 It is preferable that the front plate 3 serves as a limiting plate for confirming the insertion depth and the adequacy of the coupling between the stem pin 7 and the socket 12 during insertion coupling.

In the driving of the LSD, the voltage to be applied for driving each device cell 1 is applied to the heater voltage for the cathode K, the cutoff voltage for the G1 electrode of the control electrodes G1 to G3, and the G2 and G3 electrodes. Two focusing voltages of the predetermined potential difference, and the positive voltage of the metal back 6 for acceleration.

However, only the cutoff voltage of the G1 electrode needs to be changed for the selective driving of the plurality of device cells 1 during the operation of the LSD. Therefore, the rest is applied to the constant voltage and only the selective application of the cutoff voltage to the G1 electrode is performed. The cell 1 can be selected.

That is, the LSD constituted by the device cell 1 of the present invention can be operated by an extremely simple matrix drive that is selective of the cutoff voltage for each device cell 1, that is, on / off.

The present invention as described above is inexpensive, easy to obtain and select, and can not only use a fluorescent tube for high-brightness tube, but also provides a device cell capable of high brightness by using a fluorescent layer emission and vacuum discharge together. In addition, if the device cell is easy to manufacture and maintain, the LSD of high brightness can be easily driven by a simple matrix method.

Claims (19)

A discharge element used as a unit cell of a large area display device, comprising: a long tubular vacuum vessel, a plate-shaped front plate that shields the entire surface of the vacuum vessel, a fluorescent layer formed on the inner surface of the front plate, and the vacuum. Positioned at the rear of the container, the cathode including a cathode emitting hot electrons and a plurality of control electrodes forming an electron beam for controlling, focusing and accelerating hot electrons from the cathode to emit the fluorescent layer; Discharge element. The discharge device according to claim 1, wherein a metal back is formed on an inner surface of the fluorescent layer to which a positive voltage for accelerating the electron beam is applied. The discharge device according to any one of claims 1 to 3, wherein a vacuum discharge is generated between a control electrode or the metal back of the electron gun. The discharge device according to claim 1, wherein the fluorescent layer of the front plate is formed by a printing method. The discharge device according to claim 2, wherein the metal back is formed by any method of printing or deposition. The electrode of claim 1, wherein the plurality of control electrodes of the electron gun comprise a G1 electrode for controlling hot electron emission of the cathode, and a G2 and G3 electrode for crossover focusing the hot electrons emitted therebetween. Discharge element. The discharge device according to claim 1, wherein the cathode is formed of an impregnated cathode. The discharge device according to any one of claims 1 to 3, wherein each control electrode of said electron gun and said metal back are externally connected by a plurality of stem pins provided at the rear end of said vacuum container. The discharge device according to claim 1, wherein the vacuum container has a circular cross section. The discharge element according to any one of claims 1 to 9, wherein the front plate is formed in a circular shape having an outer diameter larger than the outer diameter of the vacuum container. The discharge element according to any one of claims 1 to 9, wherein the front plate is constituted by a square having an outer diameter larger than the outer diameter of the vacuum vessel. The discharge device according to claim 1, wherein an optical dispersing means is provided on the front plate. 13. The discharge according to claim 12, wherein the optical scattering means comprises any one or a combination of two or more of the method of forming the front plate by a concave lens, a translucent glass, or a Fresnel lens. device. 13. The discharge device according to claim 12, wherein the light diffusion means forms a translucent diffusion layer on the front plate. 15. The discharge device according to claim 14, wherein a dye corresponding to the emission color of the fluorescent layer is dispersed in the diffusion layer so that the diffusion layer constitutes a color filter. A large-area display device using the discharge device according to claim 1 to 15 as a device cell, wherein the vacuum container of the device cell is inserted and a round insert having a socket to which the stem pin of the device cell is coupled is connected at an inner end thereof. A large area display device comprising a plurality of device cells inserted into a matrix on a supporting plate having a portion. 17. The large-area display device according to claim 16, wherein the insertion of the element cell into the circular insertion portion is limited by the front plate of the element cell. 17. The large-area display device according to claim 16, wherein the device cells have R, G, and B emission colors, and the device cells of each of the R, G, and B emission colors are arranged in an array matrix so as to form a dot trio. 17. The large-area display device according to claim 16, wherein the plurality of device cells are selected by selectively selecting a cutoff voltage for the G1 electrode of the electron gun of each device cell by matrix driving.

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