JPS58137944A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To suppress generation of cold emission and sharply reduce sparking frequency inside of a tube by making an external form of a grid, which impresses anode voltage smaller than the external form of the grid adjacent thereto. CONSTITUTION:By making the size of the fourth grid 81 in the direction of the axis X shown in the figure smaller than that of the third grid 7, a line of electric force 18 getting from the fourth grid 81 to the second grid 6 or the first grid 5 weakens markedly by the effect of third grid 7. Also by making an external form of the part which is not buried in bead glass 11 in the direction of Y axis shown in the figure, of the fourth grid 81 smaller than the third grid 7, the line of electric force 18 breaking into the second grid 6, etc. from the fourth grid 81 can be weakened so that the cold emission from the terminal of the electrode of the second grid 6 etc. and the outgoing leads thereof reduces thus to further improve a withstand voltage characteristic.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention line, Ilm on a given grid to which an anode voltage is applied.
Anode voltage Q16~4010 prefecture to other grids in contact with! JL
This relates to a cathode ray tube that applies voltage.

11th! d is the general m of the conventional one-rutifocus method.
- Shows a cross-sectional view of a cathode ray tube, in which (1) is the neck tube of the cathode ray tube, the free end of which is closed by a stem (2). Inside this neck tube (1), the heater (3), the cathode (4), the first grid (
5), second lattice (6), eighth lattice (7), fourth lattice (8
), a sixth grating (S), and an anode (7) are arranged and held at a predetermined interval by bead glass tta. A convergence cup (6) is welded to the anode (toward), and a spacer (
2), the anodes are connected to the internal conductive membrane (b). Furthermore, an arc shield (to) is provided on the inner wall side of the neck tube (1) of the bead glass (b), and one end of this arc shield (to) is welded to the eighth grid (7). .

In addition, 1li4 lattice (8) and convergence cup (
2), and the eighth lattice (7) and the fifth lattice (9) are connected to each other by inner leads.

9. Figure 2 is a sectional view taken along line A-Afi in Figure 1, showing the llFr1l shape in the direction perpendicular to the tube axis of the neck tube (1) of the 's4 grid (8) to which the anode voltage is applied. The cross-sectional shape of the eighth grating (7) to which the focusing voltage is applied is also substantially the same as the cross-sectional shape of the fourth grating (8).

In the above configuration, an anode voltage of about 261 iV between the anodes and about 8.5 iV on the eighth grid (7). Ilm[) focusing voltage,
2nd lattice (6) K about eoov, 1st lattice (5) about -1
A voltage of 00v is applied to each. At this time, lines of electric force (b) due to a high voltage of about 25 V applied from the anode to the fourth grid (8) via the inner lead (transfer) are j
g8 As shown in the figure, the gap between the third grid (1) and the inner wall of the neck pipe (1) is notified, or the eighth grid (7) and the arc shield (towards ) and the inner wall of the neck tube (1), passing through the nine gaps (to),
The second grating (6), the first grating (6) and the cathode (4) are reached. To this end, a cold emission is induced by the ends of the electrodes such as the second grid (@) and the edges, and the inner wall of the neck tube (1) is charged and a creeping discharge is generated. This phenomenon occurs particularly when the thickness of the neck tube (1) of the eighth lattice (7) in the tube axis direction is small, or when the inner wall of the neck If (1) is damaged by electrode sputtering, etc. This is noticeable when the temperature rises and the insulation of the inner wall surface of the neck tube (1) deteriorates, and the electric force IIN (b) from the fourth lattice (8) becomes stronger.
I don't want to cause many cold deaths,
This invention was made to improve the above-mentioned drawbacks by significantly lowering the withstand voltage characteristics of cathode ray tubes.
It is an object of the present invention to provide a cathode ray tube with improved withstand voltage characteristics by reducing the strength of electric lines of force that penetrate from a grid to which a p% anode voltage is applied to other grids and the cathode.

Embodiments of the present invention will now be described with reference to FIGS. 4 to 6.

FIG. 4 is a longitudinal sectional view showing an example of the cathode ray tube of the present invention.
The same parts as in FIGS. 1 to 8 are given the same numbers. (81) is the fourth grid to which the anode voltage is applied, and the external shape of the neck tube (1) in a plane perpendicular to the tube axis is as follows:
As is clear from Figure 5.

It is formed smaller than the external shape of the neck f(1) of the @8 grid (7) to which a focusing voltage is applied with respect to the tube axis.

(2) is an aperture of the fourth lattice (81) through which the electron flow passes.

Next, the operation of the above configuration will be explained.

The dimension of the fourth lattice (81) in the X-axis direction shown in FIG.
By making the grid (7) smaller, as shown in FIG.
The electric force that reaches the second grating (6), the first grating (5), etc. through the inner wall of F (1) or the inner wall of the neck tube (1), respectively, reaches the eighth grating (7). ), making it much weaker than conventional cathode ray tubes. Therefore, cold emissions from the ends of electrodes such as 1s2 grids and their lead wires are significantly reduced, and the withstand voltage characteristics of the cathode ray tube are improved accordingly.

In addition, by making the outer shape of the portion of the fourth grating (81) that is not embedded in the bead glass (b) in the Y-axis direction shown in FIG. 5 smaller than that of the eighth grating (7), the fourth grating (81) to the 8th grid (7), the arc shield (g) and the neck pipe (
1) through the gap surrounded by the inner wall of the second lattice (6).
Since the electric force am penetrating into the electrodes, etc., can be weakened, cold ions from the ends of the electrodes, such as the second grid (6), and their lead wires (not shown), etc., can be reduced, as described above. Moreover, the withstand voltage characteristics are further improved.

By the way, what is the external shape of the part that is not embedded in the 4th lattice (80 bead glass (b))?

By reducing the aperture (2) of the fourth grating (81) to a dimension slightly larger than the diameter of the aperture (2) without deforming it, the outer shape of this fourth grating (81) and the third grating can be changed. (7) The difference from the external shape of the portion not embedded in the bead glass (b) can be increased, so the effect is even greater. In particular, the neck pipe (1) of the 8th lattice (7)
) becomes 75 wm or less in the tube axis direction, the electric lines of force of the fourth grid (81) will be connected to the second grid (6) and the first grid (6).
Since it becomes easier to reach the electron beam, it can be applied to a nine-cathode ray tube equipped with an electron gun having such a structure, and a remarkable effect can be obtained.

The cathode ray tube of this embodiment and the conventional cathode ray tube of this type each have an anode voltage of 80 m1V and a fourth grid (81).
and (8) as well as 10 as a focusing voltage.
0 was applied to the third grid (7), and the number of sparks in the tube was actually measured and compared. When the environmental temperature was room temperature,
The number of sparks could be compared to the conventional one.

In the above embodiment, a multi-focus type cathode ray tube was described, but it is of course applicable to a pi-potential focus type cathode ray tube.
In addition, in the embodiment, the outer shape of the fourth lattice (81) is changed to the third lattice (81).
7), but conversely, the same effect can be obtained even if the outer shape of the 8th lattice is made larger than the outer shape of the anode in the 4th lattice.

As described in detail above, this invention suppresses the occurrence of cold emissions and sparks in the tube by making the outer shape of the grid to which the anode voltage is applied smaller than that of the neighboring grid. The number of cycles can be significantly reduced compared to conventional ones, and a cathode ray tube with excellent withstand voltage characteristics can be provided.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a conventional cathode ray tube, and Figure 2 is the same as Figure 1.
A-Am sectional view, Figure 8 is an enlarged view of the main part of Figure 1, Figure 4
6 is a longitudinal cross-sectional view showing one embodiment of the cathode ray tube of the present invention, FIG. 6 is a cross-sectional view taken along the line B--B in FIG. 4, and FIG. 6 is an enlarged view of the main part of FIG. 4. (1)... Neck tube, (4)... Cathode, (7)...
・Grating for applying the fruit bundle pressure, (81)...Grating for applying one pressure to the anode, A...Anode. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Shin Kuzuno (1 other person)

Claims (1)

[Claims] (1) In a cathode ray tube in which a focused voltage of 15 to 40 − of the anode voltage is applied to another grid adjacent to a predetermined grid to which an anode voltage is applied, in a plane perpendicular to the tube axis of the neck tube. A cathode ray tube characterized in that the outer shape of the predetermined grating is smaller than the outer shape of the adjacent grating.