JP2006100116A - Cathode-ray tube device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain stable electron release (emission) action while preventing pollution of the original electron emission part at the time of the initial aging. <P>SOLUTION: An electron gun 7 is constituted of a first field emission type cold-cathode element 10 that is to become the original electron emission part, and a control electrode G1 of a cup-shape that houses the first cathode 10, a plate-like acceleration electrode G2, a focus electrode G3, and the final acceleration electrode G4, which are sequentially arranged from a side of the first field emission type cold-cathode element 10 toward a phosphor screen face side. At a position further apart from the first cold-cathode element 10, that is, at the periphery of a hole on the mutually opposing surface of the acceleration electrode G2 of the control electrode G1, a second field emission type cold-cathode element 11 is installed for the purpose of carrying out the initial aging. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cathode ray tube (CRT) device using a cold cathode as a cathode for an electron gun and a method for manufacturing the same.

  In recent years, thin displays such as liquid crystal displays and plasma displays have appeared, and the flat display market is rapidly expanding. However, CRT devices are still in use for 32 inch home TVs in terms of price and performance. There is an advantage. Also, when terrestrial digital broadcasting is newly introduced, it is expected that the display technology for television will change greatly. As the environment surrounding the television shifts to a digital system, high resolution performance is strongly demanded especially for displays.

  However, there is a possibility that the television technology that has been widely used until now cannot sufficiently meet these requirements. In other words, an electron gun is used as a heart for displaying images on a television, and the performance of the electron gun is strongly related to the resolution performance. If the current density of the cathode used in the electron gun can be improved, the effective cathode area can be reduced, and as a result, the resolution performance can be improved. Currently, hot cathodes used as electron gun cathodes have been improved with various technological improvements to improve current density, but are now approaching physical limits, and beyond this, It is difficult to dramatically improve the current density. In recent years, cathodes for electron guns for digital broadcasting that are being put into practical use are required to improve current density by about 6 to 10 times that of conventional hot cathodes. For these reasons, cold cathodes are expected as a technology that responds to a significant improvement in current density. In particular, an electric field comprising a plurality of conical emitters (cathodes) and an extraction electrode formed to surround each emitter in order to apply a voltage to each emitter so that electrons are emitted from the tip of each emitter. The emission type cold cathode device has advantages such as a high current density and a small velocity distribution of emitted electrons, and is expected to be applied as a cathode for an electron gun.

By the way, in a CRT apparatus equipped with an electron gun equipped with a field emission type cold cathode element, the field emission type cold cathode element is used in order to increase the emission current emitted from the field emission type cold cathode element to a predetermined current amount. In the past, as an initial aging method, there has been known a method of using an outgassing electron emission portion provided separately from the original electron emission portion (for example, , See Patent Document 1). In other words, conventionally, the electrons emitted from the gas emission electron emission portion collide with the anode portion and the original electron emission portion, and the gas emission (impurity of impurities adsorbed on the surfaces of the anode portion and the original electron emission portion). After performing (cleaning), vacuum sealing was performed.
Japanese Patent No. 2917898

However, the conventional field emission type cold cathode device has the following problems because the electron emission part for gas emission is arranged so as to surround the outside of the original electron emission part. That is, methane (CH ₄ ), which is the main component of the residual gas in the tube immediately after the manufacture of the CRT device, is decomposed by the electrons emitted from the gas emission electron emission section during the initial aging, and the generated carbon product produces the original The electron emission portion is contaminated (in this case, the degree of contamination is large in the vicinity of the electron emission region of the gas emission electron emission portion). As a result, the withstand voltage characteristic of the extraction electrode is deteriorated, and a leak current is generated to cause an unstable electron emission (emission) operation.

  The present invention has been made to solve the above-described problems in the prior art, and can prevent the contamination of the original electron emission portion during the initial aging, thereby obtaining a stable electron emission (emission) operation. It is an object of the present invention to provide a cathode ray tube device and a manufacturing method thereof.

  In order to achieve the above object, a cathode ray tube device according to the present invention comprises a bulb comprising a face panel having a phosphor screen surface formed on the inner surface, and a funnel connected to the rear of the face panel. A field emission type cold cathode device, and a cathode ray tube device including an electron gun built in a neck portion of the funnel, the first field emission type cold cathode device in the electron gun, Is characterized in that a second field emission type cold cathode device for performing initial aging is provided at a spaced location.

  Here, initial aging refers to the first field emission cold cathode device in order to increase the emission current emitted from the first field emission cold cathode device, which is the original electron emission portion, to a predetermined amount of current. Is the aging performed on

According to the configuration of this cathode ray tube apparatus, the second field emission type which is a dummy cold cathode element provided spatially separated from the first field emission type cold cathode element which is the original electron emission portion. Since the initial aging can be performed using the cold cathode device, the methane (CH ₄ ), which is a main component of the residual gas in the tube, is decomposed during the initial aging, and the carbon product generated by the decomposition of the methane (CH ₄ ) It is possible to prevent a certain first field emission type cold cathode device from being contaminated. As a result, during normal operation (when the lens action is applied to the electrons emitted from the first field emission cold cathode device, which is the original electron emission portion), the first field emission, which is the original electron emission portion. It is possible to obtain a stable electron emission (emission) operation from the cold cathode device. In addition, since the second field emission cold cathode device has a high degree of freedom in design, an optimum initial aging operation is obtained by selecting an optimum material and structure as the material and structure of the second field emission cold cathode device. It becomes possible.

  In the configuration of the cathode ray tube device of the present invention, electron emission is controlled by applying a voltage to the second field emission cold cathode device using at least two grid electrodes constituting the electron gun. It is preferable to configure so that. According to this preferred example, it is not necessary to newly provide voltage application means to the second field emission type cold cathode element which is a dummy cold cathode element, so that the cost can be reduced. In this case, a voltage region higher than a voltage applied when the second field emission cold cathode device exerts a lens action on electrons emitted from the first field emission cold cathode device. It is preferable to have an electron emission function that operates in the above.

  In the configuration of the cathode ray tube device of the present invention, at least the electron emission surface of the second field emission type cold cathode device is made of a material having a work function lower than that of the grid electrode material constituting the electron gun. preferable. According to this preferable example, the electron emission from the second field emission cold cathode device is facilitated.

  In the configuration of the cathode ray tube device of the present invention, the second field emission type cold cathode device is connected to the second field emission type cold cathode device from the second field emission type cold cathode device. It is preferable to further include an ion trap section for capturing ions generated due to electron emission. According to this preferred example, ion collision with the first field emission cold cathode device, which is the original electron emission portion, can be prevented, so that the electron emission from the first field emission cold cathode device ( Emission) operation can be further stabilized.

The method for manufacturing a cathode ray tube device according to the present invention is a method for manufacturing the cathode ray tube device according to the present invention, wherein the aging treatment is performed until the partial pressure of the CH ₄ residual gas in the initial aging operation becomes a predetermined value or less. It is characterized by that.

According to this method of manufacturing a cathode ray tube device, the partial pressure of CH ₄ residual gas can be greatly reduced during aging, so that the initial vacuum degree can be improved and a stable initial emission (electron emission) operation can be obtained. Is possible.

In the method for manufacturing a cathode ray tube device of the present invention, the predetermined value of the partial pressure of the CH ₄ residual gas is preferably 1 × 10 ⁻⁷ Pa.

  According to the present invention, it is possible to provide a cathode ray tube apparatus that can prevent contamination of an original electron emission portion and obtain a stable electron emission (emission) operation. Further, it is possible to improve the initial vacuum and obtain a stable initial emission (electron emission) operation.

  Hereinafter, the present invention will be described more specifically using embodiments.

  FIG. 1 is a schematic sectional view showing an electron gun equipped with a field emission cold cathode device according to an embodiment of the present invention. FIG. 2 is a schematic sectional view showing an enlarged portion of the field emission cold cathode device in FIG. FIG. 3 is a schematic sectional view showing a cathode ray tube apparatus equipped with the electron gun.

  As shown in FIG. 3, a cathode ray tube (CRT) device 1 according to this embodiment includes a face panel 2 formed of glass or the like, and a funnel 3 connected to the rear of the face panel 2 and also formed of glass or the like. The valve 4 which consists of these is provided. A phosphor screen surface 5 is formed on the inner surface of the face panel 2. An electron gun 7 is built in the neck portion 6 of the funnel 3. Further, a deflection yoke 9 for deflecting the electron beam 8 emitted from the electron gun 7 in the vertical direction and the horizontal direction is mounted on the outer periphery of the funnel 3 on the neck portion 6 side.

  As shown in FIG. 1, the electron gun 7 is equipped with a first field emission cold cathode device (hereinafter simply referred to as “first cold cathode device”) 10 which is an original electron emitting portion. The electron gun 7 is arranged in order from the first cold cathode device 10 side (right side in FIG. 1) to the phosphor screen surface 5 side (left side in FIG. 1). 10 includes a cup-like control electrode G1, a plate-like acceleration electrode G2, a focusing electrode G3, and a final acceleration electrode G4 (hereinafter these electrodes G1 to G4 are also referred to as “grid electrodes”). ). Here, stainless steel (SUS) is used as a material of each grid electrode G1-G4.

  A circular hole is formed in the control electrode G1 at a position facing the first cold cathode element 10. The acceleration electrode G2 is formed with a circular hole having a diameter larger than that of the hole coaxially with the hole formed in the control electrode G1. In addition, a circular hole having a diameter larger than that of the hole formed in the surface of the focusing electrode G3 facing the acceleration electrode G2 is formed coaxially with the hole formed in the acceleration electrode G2. Further, the surface of the focusing electrode G3 opposite to the surface facing the acceleration electrode G2 and the final acceleration electrode G4 are coaxially formed with the hole formed in the surface facing the acceleration electrode G2 of the focusing electrode G3. Each of the holes has a circular hole with a large diameter.

  Although a detailed description is omitted here as the first cold cathode element 10, a conical cold cathode element generally called a Spindt type is used. The first cold cathode element 10 is formed so as to surround a plurality of conical emitters (cathodes) and each emitter in order to apply a voltage to each emitter so that electrons are emitted from the tip of each emitter. And a lead electrode. As the material of the emitter, a semiconductor such as crystalline silicon, amorphous silicon, or polysilicon can be used. In addition, as a material for the extraction electrode, a wiring material using a refractory metal such as a low-resistance polysilicon film or a tungsten film can be used.

  In the electron gun 7 configured as described above, when a predetermined voltage is applied to each of the grid electrodes G1 to G4, it is emitted from the first cold cathode element 10 by the cathode lens formed by the control electrode G1 and the acceleration electrode G2. The formed electrons are beam-shaped and taken out as an electron beam 8. The electron beam 8 is focused on the phosphor screen surface 5 by the prefocus lens formed by the acceleration electrode G2 and the focusing electrode G3 and the main lens formed by the focusing electrode G3 and the final acceleration electrode G4. The

  For example, in the case of a 29-type CRT device, during normal operation (when a lens action is applied to electrons emitted from the first cold cathode device 10), a voltage of 0 V is applied to the control electrode G1 and the acceleration electrode G2 is applied. A voltage of 638 V is applied to the focusing electrode G3, a voltage of 7.15 kV, and a voltage of 27.5 kV is applied to the final acceleration electrode G4. Further, during normal operation, the electric field generated between the control electrode G1 and the acceleration electrode G2 is 1.7 V / μm.

  As shown in FIG. 2, in the electron gun 7 of the present embodiment, a location separated from the first cold cathode element 10, specifically, a hole on the surface of the control electrode G 1 facing the acceleration electrode G 2. A pair of second field emission cold cathode devices (hereinafter simply referred to as “second cold cathode devices”) 11 for performing initial aging are provided on the periphery of the substrate. Here, the initial aging is performed on the first cold cathode device 10 in order to increase the emission current emitted from the first cold cathode device 10 which is the original electron emitting portion to a predetermined current amount. It is aging.

  The second cold cathode element 11 includes an emitter (cathode) made of a material that easily emits a field, and a voltage is applied to the emitter via a control electrode G1 and an acceleration electrode G2, thereby allowing The electron emission from the tip is controlled. Here, the second cold cathode element 11 is configured by using CNT (carbon nanotube) as an example of an emitter material, and is formed on the control electrode G1 by photolithography and etching. Note that an emitter made of CNT can be formed on the control electrode G1 by using a simple printing method. Then, the second cold cathode device 11 is formed by forming an emitter made of CNT on the control electrode G1 made of stainless steel (SUS) by using such a method, thereby forming the second cold cathode device 11. 11. Voltages applied to the control electrode G1 and the acceleration electrode G2 during normal operation (voltage applied to the control electrode G1: 0V, voltage applied to the acceleration electrode G2: 638V, the voltage applied between the control electrode G1 and the acceleration electrode G2) It is possible to provide an electron emission function that operates in a voltage region higher than an electric field generated between them (1.7 V / μm). That is, by generating an electric field of 2 V / μm or more between the control electrode G1 and the acceleration electrode G2, an electron emission (emission) operation from the second cold cathode element 11 becomes possible. Therefore, when initial aging of the CRT apparatus 1 is performed, the electric field between the control electrode G1 and the acceleration electrode G2 is larger than the electric field (1.7 V / μm) during normal operation (for example, 2 to 3 V). / Μm), the second cold cathode device 11 can function as a dummy cold cathode device for performing initial aging. That is, by setting the electric field between the control electrode G1 and the accelerating electrode G2 to a value larger than the electric field during normal operation, electrons are emitted only from the second cold cathode element 11, and the electrons As a result, the residual gas in the tube is decomposed and ionized. The decomposed and ionized residual gas in the tube is adsorbed by a getter provided in the CRT device 1 in advance, and the degree of vacuum in the CRT device 1 is improved. Thereby, the initial aging operation of the first cold cathode device 10 can be performed stably and efficiently. Further, the phosphor screen surface 5 is irradiated by irradiating the phosphor screen surface 5 as the anode electrode while deflecting the electron beam from the second cold cathode element 11 in the vertical direction and the horizontal direction using the deflection yoke 9. Cleaning can also be performed.

  As described above, the emitter of the second cold cathode element 11 is configured using CNT. CNT has a work function lower than that of stainless steel (SUS), which is a material of the grid electrodes G1 to G4, and it is easy to control the emission starting voltage. Control of electron emission from the tip becomes easy.

  In the present embodiment, the second cold cathode element 11 for performing the initial aging is provided on the control electrode G1, but the second cold cathode element 11 is not necessarily provided on the control electrode G1. The electron gun 7 may be provided anywhere as long as it is separated from the first cold cathode element 10 which is the original electron emitting portion. For example, it may be provided on the other grid electrodes G2 to G4. Further, in the present embodiment, the emitter of the second cold cathode element 11 is configured using CNT, but it is not necessarily configured using CNT. However, when the second cold cathode element 11 is provided on the grid electrodes G1 to G4, the material of the emitter of the second cold cathode element 11 is a material having a work function lower than that of the grid electrodes G1 to G4. Is desirable. In this case, it is sufficient to configure at least the electron emission surface of the emitter using a material having a work function lower than that of the grid electrodes G1 to G4. As described above, in the configuration of the CRT device 1 according to the present embodiment, the second cold cathode element 11 as a dummy cold cathode element has a high degree of design freedom. Therefore, the material and structure of the second cold cathode element 11 are the same. It is possible to obtain an optimal initial aging operation by selecting an optimal material and structure.

  Further, in the present embodiment, electron emission from the second cold cathode element 11 is performed by applying a voltage to the second cold cathode element 11 using the two grid electrodes of the control electrode G1 and the acceleration electrode G2. However, the electron emission from the second cold cathode device 11 may be controlled using three or more grid electrodes.

  Further, in the present embodiment, the second cold cathode element 11 is configured to have a single conical emitter (cathode), but the second cold cathode element 11 is not necessarily configured as such. It is not limited. For example, a configuration including a plurality of conical emitters (cathodes) similarly to the first cold cathode element 10 may be employed.

As described above, according to the configuration of the CRT device 1 equipped with the electron gun 7 of the present embodiment, the CRT device 1 is provided spatially separated from the first cold cathode element 10 that is the original electron emitting portion. Since the initial aging can be performed using the second cold cathode element 11 which is a dummy cold cathode element, methane (CH ₄ ) which is a main component of the residual gas in the tube is decomposed and generated during the initial aging. It is possible to prevent the first cold cathode device 10 which is the original electron emitting portion from being contaminated by the carbon product. As a result, it is possible to obtain a stable electron emission (emission) operation from the first cold cathode element 10 which is the original electron emission portion during normal operation.

Further, as described above, since the acceleration electrode G2 is provided with a circular hole having a diameter larger than that of the circular hole formed coaxially with the circular hole formed in the control electrode G1, the second cold cathode is provided. A peripheral portion of a hole provided between the element 11 and the first cold cathode element 10 and formed in the control electrode G 1 is generated due to electron emission from the second cold cathode element 11. It can function as an ion trap part for trapping ions. That is, during the initial aging, positive ions are generated by collision of electrons emitted from the second cold cathode element 11 which is a dummy cold cathode element with a residual gas (such as CH ₄ or Ar) in the tube. By setting the potential of the first cold cathode element 10 which is an electron emitting portion higher than the potential of the control electrode G1, the generated cations do not return toward the first cold cathode element 10, and the control electrode Since it is trapped in the peripheral part (ion trap part) of the hole drilled in G1 (ion trap effect), ion collision with the first cold cathode device 10 can be prevented. And according to this, the further stabilization of the electron emission (emission) operation | movement from the 1st cold cathode element 10 which is an original electron emission part can be aimed at.

The CRT device 1 is manufactured by vacuum-sealing the first cold cathode element 10 and the phosphor screen surface 5 as described above. In this case, the aging process is performed until the partial pressure of the CH ₄ residual gas in the initial aging operation becomes a predetermined value or less. The predetermined value of the partial pressure of the CH ₄ residual gas is desirably 1 × 10 ⁻⁷ Pa (the partial pressure of the CH ₄ residual gas before the aging treatment is on the order of 10 ⁻⁵ Pa). According to the manufacturing method of the CRT apparatus 1, the partial pressure of the CH ₄ residual gas can be greatly reduced during aging, so that the initial vacuum degree is improved and stable initial emission (electron emission) operation is performed. Can be obtained.

  In the present embodiment, a monochrome cathode ray tube apparatus having no shadow mask has been described as an example. However, the present invention is not necessarily limited to the case of a monochrome cathode ray tube apparatus, and includes a shadow mask. It can also be applied to a color cathode ray tube apparatus.

1 is a schematic cross-sectional view showing an electron gun equipped with a field emission cold cathode device according to an embodiment of the present invention. FIG. 1 is an enlarged schematic cross-sectional view of a field emission cold cathode device portion in FIG. 1 is a schematic cross-sectional view showing a cathode ray tube apparatus equipped with an electron gun equipped with a field emission cold cathode device according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cathode ray tube (CRT) apparatus 2 Face panel 3 Funnel 4 Valve 5 Phosphor screen surface 6 Neck part 7 Electron gun 8 Electron beam 9 Deflection yoke 10 1st field emission type cold cathode element (1st cold cathode element)
11 Second Field Emission Cold Cathode Device (Second Cold Cathode Device)
G1 Control electrode (grid electrode)
G2 Acceleration electrode (grid electrode)
G3 Focusing electrode (grid electrode)
G4 Final acceleration electrode (grid electrode)

Claims (7)

A face panel having a phosphor screen surface formed on the inner surface, and a bulb composed of a funnel connected to the back of the face panel;
A cathode ray tube device including a first field emission cold cathode device and an electron gun built in a neck portion of the funnel;
2. A cathode ray tube apparatus comprising: a second field emission cold cathode device for performing initial aging at a location in the electron gun spaced apart from the first field emission cold cathode device . 2. The cathode ray tube apparatus according to claim 1, wherein the second field emission cold cathode device is controlled in electron emission by applying a voltage using at least two grid electrodes constituting the electron gun. 3. The second field emission cold cathode device has an electron emission that operates in a voltage region higher than a voltage applied when a lens action is applied to electrons emitted from the first field emission cold cathode device. The cathode ray tube device according to claim 2 having a function. 2. The cathode ray tube apparatus according to claim 1, wherein at least an electron emission surface of the second field emission type cold cathode device is made of a material having a work function lower than that of a material of a grid electrode constituting the electron gun. Ions generated due to electron emission from the second field emission cold cathode device are trapped between the second field emission cold cathode device and the first field emission cold cathode device. The cathode ray tube apparatus according to claim 1, further comprising an ion trap part for performing the operation. A method of manufacturing a cathode ray tube device according to any one of claims 1 to 5,
A method of manufacturing a cathode ray tube apparatus, comprising performing an aging process until a partial pressure of CH ₄ residual gas in an initial aging operation becomes a predetermined value or less. 7. The method of manufacturing a cathode ray tube device according to claim 6, wherein the predetermined value of the partial pressure of the CH ₄ residual gas is 1 × 10 ⁻⁷ Pa.

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