JPH0773036B2 - Cathode ray display - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray display device having a linear cathode, and more particularly to an electrode structure for focusing its electron flow.

[Conventional technology]

FIG. 5 is a perspective view showing an electrode structure for focusing an electron flow emitted from a linear cathode in a conventional cathode ray display device disclosed in, for example, Japanese Patent Laid-Open No. 60-149272.

In the figure, (1) is a planar electrode, (2) is a linear cathode, and (3) is a focusing with a gap (3a) forming an electrostatic lens system for focusing the electrons emitted from the linear cathode (2). Electrodes, (4) an anode, and (5) a phosphor, which are deposited on the inner surface of the panel glass (6), emit light by an electron beam incident through the anode (5).

FIG. 6 is a side cross-sectional view of this conventional example, showing the electric field distribution and the trajectory of the electron flow together. The broken line a in the figure is
The electric field distribution formed by this electrode structure is shown, and the solid line b shows the trajectory of the electrons that move according to this electric field distribution.

Next, the operation will be described.

When a certain electric potential is applied to the focusing electrode (3), a parallel electric field formed between the anode (4) and the focusing electrode (3) changes from the gap (3a) of the focusing electrode (3) to the linear cathode (2). A semi-cylindrical electric field is formed in the vicinity of the linear cathode (2) and the focusing electrode (3) in the direction of, and an electrostatic lens system for focusing the electron flow is formed by this electric field. Therefore, the electrons emitted from the linear cathode (2) toward the anode (4) are accelerated while being focused by the electrostatic lens system, and the linear cathode (2) focused on the anode (4) is accelerated. Image is formed, which causes the phosphor (5) to emit light.

[Problems to be solved by the invention]

The conventional cathode ray display device is provided with a focusing electrode (3) for forming an electrostatic lens system for focusing the electrons emitted from the linear cathode (2). However, there is a problem in that the structure of the cathode ray display device becomes complicated and the cost becomes higher accordingly.

The cathode ray display device according to the present invention includes a linear groove-shaped electrode provided in a concave shape with respect to the surface of the flat electrode so that the opening surface thereof substantially coincides with the flat electrode surface. Is arranged almost on the opening surface of the.

[Action]

The groove-shaped electrode formed on the flat electrode surface in the present invention is
A static electric field that transforms a parallel electric field formed between a planar electrode and an anode into a semi-cylindrical electric field centering on the linear cathode in the vicinity of the linear cathode to focus electrons emitted from the linear cathode. Forming an electro-lens system.

Example of Invention

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of an embodiment of the present invention. In the figure, (7) is a V-shaped groove-shaped electrode formed at a position facing the linear cathode (2) of the flat electrode (1), and is formed integrally with the flat electrode (1) in this embodiment. Therefore, the opening surface of the groove-shaped electrode (7) coincides with the surface of the flat electrode (1), and the linear cathode (2) is located near the opening of the groove-shaped electrode (7). , Is disposed on the opening surface.

FIG. 2 is a side sectional view of this embodiment showing the electric field distribution and the trajectory of the electron flow. In the figure, the broken line c indicates the electric field distribution, and the solid line d indicates the electric field distribution. It shows the trajectory of the electrons that do.

Next, the operation will be described.

When a certain electric potential is applied to the flat electrode (1) on which the groove electrode (7) is formed, a parallel electric field formed between the anode (4) and the flat electrode (1) is generated. A semi-cylindrical electric field is formed in the vicinity of the linear cathode (2) by bending into the inside of the linear cathode (2), and the electrostatic lens system has a function of focusing the electron flow by this electric field. Is formed. Therefore, the electrons emitted from the linear cathode (2) toward the anode are accelerated while being focused by this electrostatic lens system, and an image of the linear cathode (2) is formed on the anode (4). As a result, the phosphor (5) emits light.

The positional relationship between the grooved electrode (7) and the linear cathode (2) is important, and the linear cathode (2) needs to be provided near the opening of the grooved electrode. There is an almost optimum position on a plane including a plane electrode, which is indicated by. From this position, as it goes inside the groove-shaped electrode, the electron lens works strongly, so that a focus can be made at a position close to the linear cathode, and at the position of the anode, the electron beam is rather widened. Further, the potential near the cathode decreases, and the amount of electron emission decreases rapidly. On the other hand, when the linear cathode (2) is moved to the anode side from the surface including the plane electrode, the effect of the electron lens is gradually weakened and the width of the electron beam is gradually widened. However, the electron emission will increase. Therefore, the optimum position of the linear cathode is approximately on the plane including the plane electrode which is the boundary between the inside and the outside of the groove electrode, but the outside is preferable to the inside of the groove electrode.

Thus, this embodiment provides V on the surface of the planar electrode (1).
Since the electrostatic lens system having the focusing action can be formed without providing the conventionally required focusing electrode only by forming the V-shaped groove-shaped electrode (7), the electrode structure is simplified, and The machining accuracy of the V-shaped grooved electrode (7) is
Since it does not need to be highly accurate, an inexpensive cathode ray line display device can be obtained.

In the above embodiment, the cross-sectional shape of the groove-shaped electrode (7) is
A V-shaped inverted triangle is shown, but the shape is not limited to this. For example, a semi-cylindrical shape as shown in FIG. 3 (a) or a rectangular shape as shown in FIG. 3 (b). It may have a shape or an inverted trapezoidal shape as shown in FIG.

Further, in the above-mentioned embodiment, the groove-shaped electrode (7) is integrally formed with the flat electrode (1). However, as shown in FIG. Separately from the planar electrode (1), a potential for stable electron emission from the linear cathode (2) is applied to 7), and at the same time, a semi-cylindrical electric field centered on the linear cathode (2) is formed. It may be done.

〔The invention's effect〕

As described above, according to the present invention, the predetermined groove-shaped electrode is formed on the planar electrode, and the linear cathode is arranged almost on the opening surface of the groove-shaped electrode. A semi-cylindrical electric field centering on the linear cathode is formed in the vicinity of the cathode, the structure of the electrode is simplified, and an inexpensive cathode line display device having a necessary precision focusing function without requiring high precision processing is provided. There is an effect to be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention, FIG. 2 is a side sectional view for explaining the operation of this embodiment, and FIG. 3 (a).
(C) is a perspective view showing another embodiment of the grooved electrode which is the main part of the present invention, and FIG. 4 is a side sectional view showing another embodiment of the grooved electrode which is the main part of the present invention. 5 is a perspective view of a conventional cathode ray display device, and FIG. 6 is a side sectional view for explaining the operation thereof. (1) ... Planar electrode, (2) ... Linear cathode, (4) ... Anode, (5) ... Phosphor, (7) ... Groove-shaped electrode. In each drawing, the same reference numerals indicate the same or corresponding parts.

Claims (4)

[Claims] 1. A flat electrode, a linear groove-shaped electrode provided in a concave shape with respect to the surface of the flat electrode such that an opening surface thereof substantially coincides with the flat electrode surface, the flat electrode and the groove-shaped electrode. A parallel electric field is formed between the linear cathode arranged parallel to the electrode and substantially on the opening surface of the grooved electrode, and the plane electrode surface to focus the electron flow emitted from the linear cathode. A cathode ray line display device having an anode. 2. The cross-sectional shape of the grooved electrode is an inverted triangle, a semicircle,
The cathode ray display device according to claim 1, which has an inverted trapezoidal shape or a rectangular shape. 3. The cathode ray display device according to claim 1, wherein the flat electrode and the grooved electrode are integrally formed. 4. The cathode ray display device according to claim 1, wherein the flat electrode and the grooved electrode are electrically insulated and different voltages are applied.