JPH0676755A - Electron gun and driving method thereof - Google Patents

Abstract

PURPOSE:To provide an electron gun, for which a drive chassis for driving the electron gun provided with a quadrupole electrode system, can be manufactured at low cost, and for which an external connection terminal group needs not to be newly designed. CONSTITUTION:The voltage changing cyclically is applied to electrodes 1a, 1b of a quadrupole electrode system 1 from a drive chassis 10, while the constant voltage, for which the high voltage from a high voltage power source 11 is reduced by a voltage dividing resistor 5, is applied to electrodes 1c, 1d. Since a power source for supplying voltage from the drive chassis to the quadrupole electrode system is only one system, the drive chassis can be provided at low cost. Since an external connection terminal to be insulated is only one point, an external connection terminal group needs not to be newly provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, in an electron gun having a quadrupole electrode system, supplies a voltage to be applied to the quadrupole electrode system from a built-in voltage dividing resistor and adjusts the applied voltage. The present invention relates to an electron gun and a driving method thereof.

[0002]

2. Description of the Related Art FIG. 3 is a schematic view of an electron gun having a conventional quadrupole electrode system, and an electron beam forming electrode system and a focusing electrode system are not shown for simplicity. In FIG. 3, 1 is a quadrupole electrode system, 1a to 1c are electrodes, 2 is an electron beam, and 9 is an envelope containing the electron gun, and the inside thereof is evacuated to a high vacuum.

An anode button 1 is provided inside the envelope 9.
High voltage power supply 1 for accelerating electron beam 2 through 2
A high voltage of 1 is supplied from the drive chassis 10. A voltage obtained by superimposing a modulation voltage 6 whose voltage value changes periodically on a constant voltage from a constant voltage power supply 7 is supplied from the drive chassis 10 to the electrodes 1a and 1b through the external connection terminal 3. A constant voltage from the constant voltage power source 8 is supplied from the drive chassis 10 to the electrodes 1c and 1d through the external connection terminal 4b.

In the conventional electron gun constructed as described above, the constant voltage from the constant voltage power sources 7 and 8 generally has a voltage value close to each other, and the electrodes 1a and 1b are equivalent to the modulated voltage 6 to be superimposed. Voltage changes, and the distribution of the quadrupole lens formed by the quadrupole electrode system 1 changes accordingly, so that the shape of the electron beam 2 becomes vertically long as shown by the wavy line in the figure, or horizontally long.

The shape change of the electron beam 2 is synchronized with the deflection cycle of a deflection system (not shown) which is installed outside the envelope 9 and deflects the electron beam 2, so that the deflection system operates. It is possible to reduce the deflection aberration exerted on. At this time, all the voltages applied to the quadrupole electrode system 1 are applied from the drive chassis 10 through the external connection terminals 3 and 4b.

[0006]

In the electron gun having the conventional quadrupole electrode system, the drive chassis 10 needs a plurality of power supply systems for separately generating the constant voltages by the constant voltage power supplies 7 and 8, and therefore, There was a problem of high cost.

Further, the voltage applied to the external connection terminals 3 and 4b is generally as high as several KV, so that insulation is required between the external connection terminals and other external connection terminals to which a low voltage is applied. Therefore, it is necessary to newly design these external connection terminal groups. As approximate techniques, Japanese Utility Model Publication No. 55-93962 and Japanese Utility Model Publication No. 55-14 are used.
There is a 2883 publication.

The present invention has been made in order to solve the above-mentioned problems and requires only one power source for supplying a voltage from the drive chassis to the quadrupole electrode system, and one insulation point for the external connection terminal. The purpose of the present invention is to obtain an electron gun having a quadrupole electrode system that can use the external connection terminal group used in an electron gun that does not have a conventional quadrupole electrode system. It is an object of the present invention to provide a driving method of an electron gun capable of adjusting a constant voltage applied to an electrode system.

[0009]

An electron gun according to the present invention includes a quadrupole electrode system including an electrode to which a constant voltage is applied and an electrode to which a dynamically changing voltage is applied,
A voltage dividing resistor for dividing a high voltage supplied from the outside and supplying a constant voltage of the voltage applied to the quadrupole electrode system is provided.

Further, a variable resistor is provided on the ground side of the voltage dividing resistor so that the constant voltage applied to the quadrupole electrode can be adjusted.

[0011]

In the electron gun constructed as described above, the constant voltage of the voltage applied to the quadrupole electrode system is supplied from the voltage dividing resistor for dividing the high voltage. The power supply for supplying the voltage to the quadrupole electrode system from one system is sufficient.

Further, by adjusting the variable resistor provided on the ground side of the voltage dividing resistor, it becomes possible to adjust the constant voltage applied to the quadrupole electrode system.

[0013]

【Example】

Example 1. FIG. 1 is a schematic view of an embodiment of an electron gun according to the present invention, and an electron beam forming electrode system and a focusing electrode system are not shown for simplicity. In FIG. 1, 1 is a quadrupole electrode system, 1a to 1d are electrodes, 2 is an electron beam, 5 is a voltage dividing resistor, and these are enclosed in an envelope 9 evacuated to a high vacuum.

The electrodes 1a and 1b have external connection terminals 3
The modulation voltage 6 whose voltage value changes periodically is superimposed on the constant voltage from the constant voltage power supply 7 and is supplied from the drive chassis 10.

Further, a high voltage from a high voltage power source 11 for accelerating the electron beam 2 through the anode button 12 is supplied from the driving chassis 10 to the inside of the envelope 9. Generally, this high voltage is about 20 to 30 KV.

Further, one end of the voltage dividing resistor 5 is connected to the anode button 12 and a high voltage of the high voltage power source 11 is applied thereto, and the other end of the voltage dividing resistor 5 is connected to the ground through the external connection terminal 4a. The constant voltage obtained by appropriately selecting the voltage division ratio and reducing the high voltage of the high voltage power supply 11 is the electrode 1c,
Applied to 1d.

Therefore, the power source for supplying the voltage from the driving chassis 10 to the quadrupole electrode system 1 is only one system for applying the voltage to the electrodes 1a and 1b, and the external connection terminal which needs insulation is only the external connection terminal 3. is there.

In the electron gun constructed as described above, a cyclically changing voltage is applied to the electrodes 1a and 1b of the quadrupole electrode system 1 from the driving chassis 10 to cause the electrode 1 to move.
Since a constant voltage appropriately divided by the voltage dividing resistor 5 is applied to c and 1d, the electron beam 2 is changed in shape to be vertically long or horizontally long as shown by the wavy line in FIG.

By synchronizing this shape change with the deflection cycle of a deflection system (not shown) provided outside the envelope 9, the deflection aberration exerted on the electron beam by the deflection system can be reduced. That is, the electron gun of Example 1 has the same deflection aberration reducing effect as the electron gun having the conventional quadrupole electrode system described with reference to FIG.

Example 2. A constant voltage obtained by appropriately reducing the high voltage from the high-voltage power supply 11 by the voltage dividing resistor 5 is applied to the electrodes 1c and 1d, but in practice, it should be applied because of variations in manufacturing the electron gun. Since the constant voltage value is not constant, it is desirable that the constant voltage can be adjusted externally.

This method will be described with reference to FIG. 2 that are the same as those in FIG. 1 are denoted by the same reference numerals. A variable resistor 13 is provided between the ground-side external connection terminal 4a of the voltage dividing resistor 5 and the ground. By changing the resistance value of the variable resistor 13, the voltage division ratio to the high voltage from the high voltage power supply 11 changes, so that the constant voltage value applied to the electrodes 1c and 1d can be changed.

Although a voltage is generated at the external connection terminal 4a by providing the variable resistor 13, the voltage dividing resistor 5
By appropriately selecting the resistance value ratio of the variable resistor 13 and the variable resistor 13, it is possible to set the voltage value generated at the external connection terminal 4a to a level that does not require insulation.

[0023]

Since the present invention is constructed as described above, it has the following effects.

By supplying a constant voltage of the voltage applied to the quadrupole electrode system of the electron gun from the voltage dividing resistor provided in the electron gun, the power supply system for the quadrupole electrode system of the drive chassis is one system. It can be completed and can be manufactured at low cost, and since there is only one external connection terminal to be insulated, there is no need to newly design an external connection terminal group.

By providing a variable resistor on the ground side of the voltage dividing resistor and adjusting the variable resistor, the voltage applied to the quadrupole electrode system can be easily adjusted.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an electron gun according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of an electron gun to which a variable resistor is applied in the electron gun according to the second embodiment of the present invention.

FIG. 3 is a schematic view of a conventional electron gun.

[Explanation of symbols]

 1 quadrupole electrode system 1a electrode 1b electrode 1c electrode 1d electrode 2 electron beam 3 external connection terminal 4 external connection terminal 5 voltage divider resistor 6 modulation voltage 7 constant voltage power supply 9 envelope 10 drive chassis 11 high voltage power supply 12 anode button 13 Variable resistor

Claims (2)

[Claims] 1. An electron beam forming electrode means for forming and accelerating an electron beam, a focusing electrode means for focusing an electron beam, an electrode to which a constant voltage is applied and an electrode to which a dynamically changing voltage is applied. An electron gun comprising quadrupole electrode means forming a quadrupole lens, and a voltage dividing resistor for dividing a high voltage supplied from the outside to supply a constant voltage to the quadrupole electrode means. 2. In the electron gun, a variable resistor is provided on the ground side of the voltage dividing resistor, and the constant voltage applied to the quadrupole electrode means can be adjusted by adjusting the variable resistor. The method of driving an electron gun according to claim 1, wherein: