JP2006236931A - Image receiving tube device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate electron gun assemblage and activation of a cold cathode, in an image receiving tube device equipped with a cold-cathode electron gun. <P>SOLUTION: A trimming electrode 5 with an opening 5a for passing field-emitted electrons therethrough is arranged oppositely to the cold cathode on the side of a fluorescent screen in relation to a field-emission type cold cathode 3. The diameter of the opening formed in the trimming electrode is smaller than the diameter of an emitter area 4 being an area with pairs each comprising one emitter 1 and one gate hole 2a of the cold cathode 3 arranged therein. A potential independent of that of the gate electrode 2 is applied to the trimming electrode. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a picture tube apparatus having a cold cathode electron gun.

  As shown in FIG. 8, the picture tube device generally has a glass bulb 10, a fluorescent screen 11 formed on a screen, a cold cathode electron gun 14 sealed in a neck 12, and an outer peripheral surface of the glass bulb 10. And a mounted deflection yoke 13. A shadow mask 17 is disposed to face the phosphor screen 11. The electron beam accelerated and focused by the cold cathode electron gun 14 passes through an aperture (electron beam passage hole) formed in the shadow mask 17 to form a bright spot (spot) on the phosphor screen 11. The deflection yoke 13 deflects the electron beam in the horizontal direction and the vertical direction, scans the fluorescent screen 11, and displays an image on the fluorescent screen 11. In order to prevent the trajectory of the electron beam from being influenced by an external magnetic field such as geomagnetism, an internal magnetic shield 18 is provided in the glass bulb 10.

  The cold cathode electron gun 14 includes a cold cathode that generates an electron beam and a plurality of electrodes. Among the plurality of electrodes, a high voltage of about 25 k to 35 kV is formed on the inner wall surface of the glass bulb 10 from the anode button 15 provided on the outer wall of the glass bulb 10 at the final acceleration electrode arranged closest to the phosphor screen 11. Applied through the inner conductive film. A predetermined voltage is applied from the stem portion 16 to the electrodes other than the final acceleration electrode. A voltage of about 5 to 8 kV is applied to the focusing electrode.

  As shown in FIGS. 7A and 7B, the cold cathode 3 is called a Spindt type, and a plurality of conical emitters 1 provided on a substrate made of a conductive material such as silicon, And a gate electrode 2 having a plurality of gate holes 2a opened so as to surround the tip of each emitter 1. The substrate on which the emitter 1 is formed and the gate electrode 2 are insulated from each other by an insulating layer 8. By applying a voltage difference of several tens to 100 V between the emitter 1 and the gate electrode 2, a strong electric field is generated at the tip of the cone-shaped emitter 1, and electrons are emitted from the tip of the emitter 1 (field emission). Is done.

An electron beam composed of electrons emitted from each emitter 1 passes through the opening 6 a of the first electrode 6 disposed on the phosphor screen side with respect to the cold cathode 3. At this time, the electron beam is focused under the influence of the lens electric field formed by the first electrode 6. The diameter of the opening 6a of the first electrode 6 is larger than the diameter of the emission region 4, which is a region where a pair of the emitter 1 and the gate hole 2a is disposed. The electron beam that has passed through the first electrode 6 is disposed closer to the phosphor screen than the first electrode 6 and passes through the opening 7a of the second electrode 7 that has a higher potential than the first electrode 6 (see, for example, Patent Document 1). ).
JP-A-5-343000

  However, in the conventional cold cathode electron gun as described above, if the central axis of the emission region 4 of the cold cathode 3 and the central axis of the opening 6a of the first electrode 6 are shifted, the lens electric field acting on the electron beam becomes asymmetric. The spot shape on the phosphor screen 11 is distorted and the resolution of the display image is lowered. Therefore, it is necessary to align the emission region 4 (that is, the cold cathode 3) and the first electrode 6 with high accuracy.

  However, it is difficult to handle the cold cathode 3, which is a semiconductor element, and it is difficult to assemble the cold cathode 3 and the first electrode 6 with high accuracy.

  In addition, depending on the structure of the cold cathode 3, the first electrode 6, and the second electrode 7, and the relationship between these potentials, the lens electric field formed on the front portion (the phosphor screen side) of the cold cathode 3 may be negative. is there. In this case, when the cold cathode 3 is activated, a part of the electrons emitted from the emitters 1 of the cold cathode 3 having a large emission angle are returned to the cold cathode 3 side and collide with the cold cathode 3, and are locally degassed. Cause deterioration of the degree of vacuum. This hinders activation of the cold cathode 3.

  It is an object of the present invention to provide a picture tube apparatus having a cold cathode electron gun that can facilitate the assembly of the electron gun and the activation of the cold cathode.

  The picture tube device of the present invention includes a phosphor screen and an electron gun that emits an electron beam toward the phosphor screen.

  The electron gun has a number of emitters for field emission of electrons and a gate electrode for controlling the field emission, and the gate electrode has a number of gate holes surrounding each of the number of emitters. Cold cathode electrons comprising: an emission type cold cathode; and a trimming electrode disposed on the phosphor screen side of the cold cathode so as to face the cold cathode and having an opening through which the field-emitted electrons pass. A gun.

  The diameter of the opening formed in the trimming electrode is smaller than the diameter of the emitter region, which is a region where a pair of one emitter and one gate hole is disposed, and the trimming electrode A potential independent of the gate electrode is applied.

  According to the picture tube apparatus of the present invention, it is possible to provide a picture tube apparatus having a cold cathode electron gun that can facilitate the assembly of the electron gun and the activation of the cold cathode.

  The structure of the picture tube device of the present invention is not particularly limited as long as it includes a cold cathode electron gun as an electron gun. For example, the picture tube device shown in FIG. 8 may be used. The cold cathode electron gun mounted on the picture tube apparatus of the present invention will be described below with reference to the drawings.

(Embodiment 1)
1A is a cross-sectional view showing a structure in the vicinity of a cold cathode of a cold cathode electron gun mounted on a picture tube apparatus according to Embodiment 1 of the present invention, and FIG. 1B is a perspective view thereof. In these drawings, the same components as those in FIGS. 7A and 7B showing the conventional cold cathode electron gun are denoted by the same reference numerals, and detailed description thereof will be omitted. In FIG. 1 (A) and FIG. 1 (B), illustration of the electrode arranged on the phosphor screen side with respect to the first electrode 6 is omitted.

  The cold cathode electron gun of the first embodiment facilitates the assembly of the electron gun and the activation of the cold cathode. This will be described below.

  The cold cathode electron gun of the first embodiment includes a large number of conical emitters 1 provided on a substrate made of a conductive material, and a large number of gate holes 2a that are opened so as to surround the tips of the respective emitters 1. A field emission cold cathode 3 having a gate electrode 2 having The gate electrode 2 controls the field emission of electrons from each emitter 1.

  A trimming electrode 5 is disposed on the phosphor screen 11 side with respect to the cold cathode 3 so as to face the cold cathode 3. The trimming electrode 5 has one opening 5a through which an electron beam emitted from the cold cathode 3 passes. The diameter of the opening 5a is smaller than the diameter of the emission region 4, which is a region where a pair of the emitter 1 and the gate hole 2a is disposed. A potential independent of the potential of the gate electrode 2 is applied to the trimming electrode 5.

  A first electrode 6 is arranged on the phosphor screen 11 side with respect to the trimming electrode 5 so as to face the trimming electrode 5. The first electrode 6 is formed with one opening 6a through which the electron beam that has passed through the opening 5a of the trimming electrode 5 passes. A potential independent of the trimming electrode 5 is applied to the first electrode 6.

  Since the diameter of the opening 5a of the trimming electrode 5 is smaller than the diameter of the emission region 4 of the cold cathode 3, only the electrons that have passed through the opening 5a of the trimming electrode 5 out of the electrons emitted from the emission region 4 are the first. It passes through the opening 6a of the electrode 6. That is, the trimming electrode 5 has a function of selecting electrons emitted from the emission region 4. Therefore, in this embodiment, the positional accuracy between the central axis of the opening 6a of the first electrode 6 and the central axis of the opening 5a of the trimming electrode 5 is important, and the central axis of the opening 6a of the first electrode 6 and the emission region are important. The positional accuracy with respect to the central axis of 4 can be ignored. Therefore, since the positional accuracy between the trimming electrode 5 and the first electrode 6 which is easier to handle than the cold cathode 3 which is a semiconductor element is secured, the assembly of the electron gun is easy.

  Further, if the potential of the trimming electrode 5 is made higher than the potential of the gate electrode 2, the electric field at the front portion (the phosphor screen side) of the cold cathode 3 is always positive. Therefore, when the cold cathode 3 is activated, it is possible to suppress a part of electrons emitted from the emitters 1 of the cold cathode 3 having a large emission angle from returning to the cold cathode 3 side and colliding with the cold cathode 3. Therefore, activation of the cold cathode 3 can be promoted.

  The above effect is greater as the influence of the electric field distortion due to the opening 5a of the trimming electrode 5 is smaller, that is, as the distance between the cold cathode 3 and the trimming electrode 5 is larger. However, if the distance is increased, it is necessary to increase the diameter of the emission region 4 accordingly.

  Further, an electric field approximating a parallel plate electrode electric field (an electric field formed when a pair of plate electrodes are separated from each other in parallel) is formed between the cold cathode 3 and the trimming electrode 5. Is higher than the potential of the gate electrode 2, the emittance can be reduced. Thereby, the spot diameter on the phosphor screen 11 is reduced, and it can be expected that the resolution is improved.

  For example, when the potential of the emitter 1 is 0 V, the potential of the gate electrode 2 is 60 V, and the potential of the trimming electrode 5 is 1000 V, the emittance of the electron beam passing through the trimming electrode 5 can be reduced, and the spot diameter can be reduced. Can be reduced. At this time, by setting the potential of the first electrode 6 to be equal to or higher than the potential of the trimming electrode 5 (preferably higher than the potential of the trimming electrode 5), the virtual object point formed by the parallel plate electrode electric field is imaged on the screen. be able to.

  As described above, according to the first embodiment, it is possible to provide a picture tube apparatus having a cold cathode electron gun that can facilitate the assembly of the electron gun and the activation of the cold cathode.

(Embodiment 2)
2A is a cross-sectional view showing a structure in the vicinity of a cold cathode of a cold cathode electron gun mounted on a picture tube device according to Embodiment 2 of the present invention, and FIG. 2B is a perspective view thereof. In these drawings, the same components as those in FIGS. 1A and 1B described in Embodiment 1 are denoted by the same reference numerals, and detailed description thereof is omitted. In FIG. 2A and FIG. 2B, illustration of the electrode arranged on the phosphor screen side with respect to the first electrode 6 is omitted.

  In the second embodiment, as shown in FIGS. 2A and 2B, the trimming electrode 5 to which a different potential is applied and the first electrode 6 are integrated. 1 and different. Thereby, since the positional accuracy between the first electrode 6 and the trimming electrode 5 is further improved, the assembly of the electron gun is further facilitated.

  In addition, since the insulator 9 is interposed between the trimming electrode 5 and the first electrode 6, both electrodes are electrically insulated. Thereby, another electric potential can be independently applied to both the integrated electrodes.

  The integrated structure of the trimming electrode 5 and the first electrode 6 is not limited to that shown in FIGS. 2A and 2B, and for example, the structures shown in FIGS. 3, 4, and 5 may be used. In these, the same components as those in FIG. 2A are denoted by the same reference numerals.

  As shown in FIG. 3, the first electrode 6 may be separated into two electrodes 61 and 62, and one first electrode 61 may be integrated with the trimming electrode 5. In this case, the same potential is applied to the two first electrodes 61 and 62. With this configuration, the same effect as described above can be obtained.

  As shown in FIG. 4, the first electrode 61 integrated with the trimming electrode 5 in FIG. 3 may be brought close to the opening 5 a of the trimming electrode 5. Thereby, the electric field lens formed by the trimming electrode 5 and the first electrode 6 can be strengthened.

  As shown in FIG. 5, the two first electrodes 61 and 62 of FIG. 4 may be integrated.

(Embodiment 3)
FIG. 6 is a cross-sectional view showing the structure in the vicinity of the cold cathode of the cold cathode electron gun mounted on the picture tube device according to Embodiment 3 of the present invention. In FIG. 6, the same components as those in FIG. 1A described in Embodiment 1 are denoted by the same reference numerals, and detailed description thereof is omitted. In FIG. 6, the illustration of the electrode disposed on the phosphor screen side with respect to the second electrode 7 is omitted.

  In the third embodiment, as shown in FIG. 6, the second electrode 7 is disposed on the fluorescent screen side of the first electrode 6 so as to face the first electrode 6. The second electrode 7 is formed with one opening 7a through which an electron beam, which is emitted from the cold cathode 3 and passes through the opening 5a of the trimming electrode 5 and the opening 6a of the first electrode 6 in order, passes. A potential equal to or higher than the potential applied to the first electrode 6 (preferably a potential larger than the potential applied to the first electrode 6) is applied to the second electrode 7.

  For example, the emitter potential is 0V, the gate electrode 2 potential is 60V, the trimming electrode 5 potential is 60V, the first electrode 6 potential is 0V, and the second electrode 7 potential is 900V. Further, if the diameter of the opening 6a of the first electrode 6 is 0.5 mm and the distance between the side surface of the phosphor screen 11 of the trimming electrode 5 and the side surface of the phosphor surface 11 of the first electrode 6 is 0.25 mm, the electron beam is crossed over. It becomes possible to form. This makes it possible to reduce the spot on the phosphor screen 11 and improve the resolution.

  In the present invention, the shape of the opening 5a of the trimming electrode 5 may be a shape other than a circle, for example, a rectangular shape. When the opening 5a is non-circular, the diameter is defined by the major axis direction diameter.

  The application field of the present invention is not particularly limited, and can be widely used for color cathode ray tubes such as a television or a computer display.

(A) is sectional drawing which showed the structure of the cold cathode vicinity of the cold cathode electron gun mounted in the picture tube apparatus which concerns on Embodiment 1 of this invention, (B) is the perspective view. (A) is sectional drawing which showed the structure of the cold cathode vicinity of the cold cathode electron gun mounted in the picture tube apparatus which concerns on Embodiment 2 of this invention, (B) is the perspective view. It is sectional drawing which showed another structure of the cold cathode vicinity of the cold cathode electron gun mounted in the picture tube apparatus which concerns on Embodiment 2 of this invention. It is sectional drawing which showed another structure of the cold cathode vicinity of the cold cathode electron gun mounted in the picture tube apparatus which concerns on Embodiment 2 of this invention. It is sectional drawing which showed another structure of the cold cathode vicinity of the cold cathode electron gun mounted in the picture tube apparatus which concerns on Embodiment 2 of this invention. It is sectional drawing which showed the structure of the cold cathode vicinity of the cold cathode electron gun mounted in the picture tube apparatus which concerns on Embodiment 3 of this invention. (A) is sectional drawing which showed the structure of the cold cathode vicinity of the cold cathode electron gun mounted in the conventional picture tube apparatus, (B) is the perspective view. It is sectional drawing which showed schematic structure of the picture tube apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Emitter 2 Gate electrode 2a Gate hole 3 Field emission type cold cathode 4 Emission area | region 5 Trimming electrode 5a Opening 6 1st electrode 6a Opening 7 2nd electrode 7a Opening 8 Insulating layer 9 Insulator 10 Glass bulb 11 Phosphor screen 12 Neck part 13 Deflection yoke 14 Cold cathode electron gun 15 Anode button 16 Stem portion 17 Shadow mask 18 Internal magnetic shield

Claims (5)

A picture tube device comprising a phosphor screen and an electron gun that emits an electron beam toward the phosphor screen,
The electron gun is
A field emission cold cathode having a number of emitters for field emission of electrons and a gate electrode for controlling the field emission, wherein the gate electrode is formed with a number of gate holes respectively surrounding the number of emitters; as well as,
A cold cathode electron gun comprising a trimming electrode disposed on the fluorescent screen side of the cold cathode so as to face the cold cathode and having an opening through which the field-emitted electrons pass;
The diameter of the opening formed in the trimming electrode is smaller than the diameter of an emitter region, which is a region where a pair of one emitter and one gate hole is disposed,
A picture tube apparatus, wherein a potential independent of the gate electrode is applied to the trimming electrode. The cold cathode electron gun further includes a first electrode that is disposed opposite to the trimming electrode on the phosphor screen side with respect to the trimming electrode, and an opening through which the field-emitted electrons pass is formed.
The picture tube device according to claim 1, wherein a potential independent of the trimming electrode is applied to the first electrode.   The picture tube device according to claim 2, wherein the trimming electrode and the first electrode are integrated.   4. The picture tube apparatus according to claim 3, wherein the trimming electrode and the first electrode are electrically insulated. The cold cathode electron gun further includes a second electrode disposed opposite to the first electrode on the phosphor screen side with respect to the first electrode, and having an opening through which the field-emitted electrons pass. Prepared,
5. The picture tube device according to claim 2, wherein a potential equal to or higher than that of the first electrode is applied to the second electrode.

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