JPS61218052A - Electron gun for cathode-ray tube - Google Patents

Abstract

PURPOSE:To reduce the cost of an electron gun for a cathode-ray tube by omitting a variable resistor generally installed outside the tube by using conductors to connect the folded sections of the zigzag pattern of a resistor layer and cutting desired points of the conductors by laser or a similar means to control the focusing voltage. CONSTITUTION:An inline-type bipotential electron gun which consists of a cathode 11, a first electrode 12, a second electrode 13, a focusing electrode 14, a high voltage electrode 15 and a shield cut 16, is installed in a neck 2 to which a stem where stem pins are buried is fused. In this electrode structure, conductors 35 and 36 are installed to connect the turned sections 33 and 34 of a zigzag-pattern resistor layer 32 together, so that a short circuit is produced. The resistance between terminals 32b and 32c is controlled by cutting the conductors 35 and 36, for example, at the points indicated by marks (X).

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an electron gun for a cathode ray tube, and in particular, a predetermined voltage is applied to at least a focusing electrode by resistive division of a high voltage applied to a high voltage electrode. This invention relates to an electron gun for cathode ray tubes.

[Technical background of the invention and its problems]

In general, a cathode ray tube such as a color picture tube requires a medium voltage of 5KV to 8KV to be applied to a focusing electrode in addition to a high voltage of about 20KV to 30KV applied to a high voltage electrode. Among these, high voltage is supplied from the anode terminal of the funnel, while medium voltage of 5KV to 8KV as a focusing electrode is supplied from the stem pin.

However, supplying such a medium voltage from the stem pin has various problems because the voltage supplied to other electrodes is as low as several 100 volts, and the current situation is that it complicates the structure of the stem and base. be. As one of the countermeasures against this problem, a structure in which a focused voltage is supplied by dividing a high voltage by resistors has been proposed in Japanese Utility Model Application Publication No. 55-38484.

Next, an example of a cathode ray tube electron gun having a structure in which a focused voltage is obtained by this resistance division will be explained with reference to FIG.

That is, a cathode (11) and a first electrode (12) are placed inside the neck (1) to which the stem with the stem pin (2) installed is sealed.

Second electrode (13), focusing electrode (14), high voltage electrode (15)
), an in-line pi-potential 3 electron gun consisting of a shield cup (16) is installed, and a valve spacer (17) provided on this shield cup (16) is connected to the anode terminal via an internal conductive film (18). It is connected. In such an electrode structure, a resistor (22) is provided with a resistor layer (22) in a zigzag pattern on an insulating substrate (21).
One terminal (22a) of the shield cup (16)
) is connected to the high voltage electrode (15), and the other terminal (22b
) is grounded through the stem pin ■, to the external variable resistor). Further, a terminal (22c) at a desired intermediate portion is connected to a focusing electrode (14).

This external variable resistor (a) is provided to correct variations in the focusing voltage of the terminal (22c) caused by manufacturing variations in the resistor (20) and the electron gun.

However, using this external variable resistor () increases the cost of the cathode ray tube, and there are also problems with the installation location.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned conventional problems, and involves connecting the folded portions on both sides of the zigzag pattern of the resistor layer with conductors, and cutting desired portions of the conductors with a laser beam or the like. The aim is to reduce the cost of cathode ray tubes by adjusting the focusing voltage and eliminating the need for external variable resistors.

[Summary of the invention]

That is, the present invention provides an electron gun for a cathode ray tube, which is installed in the neck and is configured to apply a predetermined voltage to at least a focusing electrode opposite to the high voltage electrode by dividing the resistance of a resistor provided between the high voltage electrode and the stem. In this step, a resistor layer is formed in a zigzag pattern on an insulating substrate so that each side has a desired resistance value, and a desired number of successive folded portions formed on the south side of this zigzag pattern are connected. An electron gun for a cathode ray tube, characterized in that it is configured to apply a predetermined voltage to a focusing electrode by cutting a desired part of the conductor, and each side of a zigzag pattern connected by the conductor. a first group having a plurality of minimum resistance values; a second group having a resistance value corresponding to the sum of at least one of the first groups; and at least one of the first group and the second group. In this embodiment, the third group has a resistance value corresponding to the sum of the groups.

[Embodiments of the invention]

Next, an embodiment of an electron gun for a cathode ray tube according to the present invention will be described with reference to FIG. In the figure, the same reference numerals as in the conventional example indicate the same parts.

That is, inside the neck ■ to which the stem with the stem pin ■ implanted is sealed, there are a cathode (11), a first electrode (12), a second electrode (13), a focusing electrode (14), and a high voltage electrode (15). , an in-line pi-potential 3 electron gun consisting of a shield cup (16) is installed, and a valve spacer (17) provided on this shield cup (16) is connected to the anode terminal via an internal conductive film (18). has been done. In such an electrode structure, a resistor (30) has a resistor layer (32) provided in a zigzag pattern on an insulating substrate (31).
One terminal (32a) is connected to the shield cup (16) or the high voltage electrode (15), and the other terminal (32b) is grounded via the stem pin (3). Further, a terminal (32c) at a desired intermediate portion is connected to a focusing electrode (14). Up to this point, it is almost the same as the conventional one, but in this fifth embodiment, the resistance value between the terminals (32b) and (32c) is higher than that of the conventional one by a desired portion, and the zigzag pattern of the resistor layer (3
Conductors (35) and (36) are provided to continuously connect multiple folded parts (33) and (34) on both sides of 2) to short-circuit them, and these conductors (35) and (36) are connected to the final For example, cut the X mark part and connect the terminals (32b) and (32c) so that the voltage is applied to the focusing electrode (14) during adjustment.
It is designed to increase the resistance value between.

Next, the side closer to the stem pin of the resistor used in another embodiment of the cathode ray tube electron gun of the present invention will be explained with reference to FIG.

That is, the resistor (40) has a resistor layer (42) provided in a zigzag pattern on an insulating substrate (41), and folded portions (43), (44) on both sides of this zigzag pattern.
Conductors (45), (46) that connect multiple pieces of
This resistor (40) has the resistors R1 to R□1 on each side of the zigzag pattern as follows. That is, Rlt
Let R,,R,,R4,R,be the value that can adjust the minimum resolution of the focusing voltage, for example, 50V, and let R6 be R,+R2+
By selecting the values R, +R, and 10R, it is possible to set the range between 0 and 500V in increments of 50V. Similarly R1
You can set the range from 0 to 1000V in 50V increments by selecting R +R, +R, +R4 +R, +R, and select R@
It is characterized in that PRI IRlo tLl is set to the same value as R7.

By changing the resistance value on each side in this way,
By cutting predetermined portions of the conductors (45) and (36), it becomes possible to adjust the focusing voltage without impairing the minimum resolution of the focusing electrode.

〔Effect of the invention〕

As described above, according to the present invention, a desired focusing voltage can be applied to the focusing electrode by resistive decomposition of the anode voltage even without an external variable resistor.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the electron gun for cathode ray tubes of the present invention, FIG. 2 is an explanatory diagram of essential parts of a resistor used in another embodiment of the electron gun for cathode ray tubes of the present invention, and FIG. FIG. 1 is an explanatory diagram showing a conventional electron gun for a cathode ray tube.

Claims (2)

[Claims] (1) In an electron gun for a cathode ray tube, which is installed in the neck and is configured to apply a predetermined voltage to at least a focusing electrode opposite to the high voltage electrode by dividing the resistance of a resistor provided between the high voltage electrode and the stem pin. , connecting a resistor layer formed in a zigzag pattern on an insulating substrate so that each side of the resistor has a desired resistance value, and a desired number of successive folded portions formed on both sides of the zigzag pattern; An electron gun for a cathode ray tube, comprising: a conductor, and a predetermined voltage is applied to the focusing electrode by cutting a desired portion of the conductor. (2) A first group whose resistance value on each side of a zigzag pattern connected by a conductor has a plurality of minimum resistance values, and a second group whose resistance value corresponds to the sum of at least one of the first groups. and at least one said first
An electron gun for a cathode ray tube according to claim 1, characterized in that the third group has a resistance value corresponding to the sum of the group and the second group.