JPS6318826B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus and method for depositing a conductive film on the inner surface of a tubular portion of a transparent tube and forming electrodes using a laser beam.

Conventionally, when forming an electrostatic deflection electrode by depositing a conductive film on the inner surface of the tubular part of a transparent tube, such as an image pickup tube, and irradiating this conductive film with a laser beam, the tubular part is rotated along a predetermined pattern. A control device was configured to relatively move and control the feed amount in the direction and the direction perpendicular to the rotation direction.

In this way, controlling the relative movement of the laser beam along the electrode pattern requires a sophisticated numerical control method using a computer, etc. Therefore, programming software that performs coordinate transformation for the electrode pattern must be developed. In addition, it is not only a configuration consisting of a collection of expensive control devices such as a coordinate input device, arithmetic control device, and a pulse motor drive device, but also a highly accurate positioning and feeding mechanism must be provided for the moving parts of the machine. The disadvantage is that high-speed machining is difficult due to high-precision and relative movement control.

The present invention eliminates the above-mentioned drawbacks and provides an apparatus for forming internal electrodes of a transparent tube and a method for forming the same, which does not require an expensive control device or a highly accurate positioning and feeding mechanism.

FIG. 1 shows a configuration diagram of a conventional method for forming an inner electrode of an image pickup tube, in which 1 indicates a laser beam, 2
2 is an image pickup tube, and a conductive film 2a is deposited on the inner surface. Reference numeral 4 denotes a base on which the image pickup tube 2 is mounted, and is rotated reciprocally around the tube axis of the image pickup tube by a first pulse motor 6 and a second pulse motor 8, and rotates along the tube axis direction (longitudinal direction). The scanning locus of the laser beam 1 on the conductive film 2a forms a zigzag pattern. 6a is a drive device for the first pulse motor 6, which rotates the tube reciprocally around the tube axis; 8a is a drive device for the second pulse motor 8, which rotates the precision feed screw 10 along the tube axis direction, and rotates the precision feed screw 10 along the tube axis direction. The table 4 is moved left and right, and each control signal is controlled by the coordinate input device 12 and the arithmetic control device 14 so that the table 4 moves relatively along the electrode pattern according to predetermined programming. It is becoming more and more common.

FIG. 2 is a cross-sectional perspective view schematically showing an apparatus for forming inner electrodes on a transparent tube according to the present invention, in which reference numeral 20 denotes a movable table 22 capable of reciprocating movement, which is a bearing, and holders 24 provided on both sides hold the transparent tube. Both ends of 26 and mask 4
2 is held, and movement in the tube axis direction is fixed by operating a fixed handle 23, and rotational power from a synchronous motor 28 is transmitted to a rotating shaft 32 via a belt 30. A reduction gear 34 is configured to reduce the rotational power from the motor 28 and transmit it to the feed screw 36 so that the movable table 20 can be moved in the tube axis direction. 50 is a laser beam.

FIG. 3 is a perspective view showing a cross section of the main part of the transparent tube.
48 is a conductive film deposited on the inner surface of the transparent tube 26.

FIG. 4 is a perspective view of the laser beam mask.

Next, to explain the operation, a mask 42 made of copper-based metal with high thermal conductivity and having a window portion 44 shown in FIG. 4 is provided around the outer periphery of the transparent tube 26 shown in FIG. Install the motor 28
By rotating in one direction, the rotational power is transmitted through the belt 30, causing the rotating shaft 32 to rotate in one direction, continuously rotating the transparent tube 26, and at the same time,
The rotational power reduced by the reduction gear 34 drives the feed screw 36 to move the movable table 20 in the tube axis direction. When the transparent tube 26 is rotated, the amount of movement of the transparent tube 26 in the tube axis direction is less than the removal width in the tube axis direction in which the conductive film 48 is removed by the laser beam 50 . The laser beam 50 is moved by the feed screw 36, and due to their continuous action, the laser beam 50 is continuously irradiated to one point.
A mask 42 on which a predetermined electrode pattern is formed is provided around the outer periphery of the transparent tube 26 so that the entire surface of the conductive film 48 of the transparent tube 26 is irradiated.
Only the laser beam transmitted through the window portion 44 removes the conductive film and forms the electrostatic deflection electrode of the image pickup tube.

The laser beam mask 42 is formed by etching a metal tube processed into a thin cylindrical shape to form a predetermined electrode pattern. Alternatively, it is made by etching a predetermined electrode pattern on a thin flat plate and processing it into a cylindrical shape.In order to prevent damage from laser beams, a copper-based metal with high thermal conductivity is used, and the surface reflects light. It forms a plating layer with a high ratio.

In the conventional technology as shown in FIG. 1, since precise positioning and feeding is required, two expensive pulse motors 6, 8 and their drive devices 6a, 8a must be used, and relative movement control is required. According to the present invention, there is no need for precise positioning and feed, and only one motor needs to be turned on, and an inexpensive synchronous motor is used. It is possible. In addition, the mechanical structure is simple and the laser beam scans the entire surface in a fixed period of time.
Even if the electrode pattern becomes more complex, the processing time does not increase and remains constant. Moreover, the speed can be easily increased, and the equipment can be constructed at low cost, so it has a great practical effect in reducing man-hours and costs. It is.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an apparatus for forming inner electrodes of an image pickup tube according to a conventional manufacturing method, FIG. 2 is a partially cutaway perspective view showing an embodiment of an apparatus for forming inner electrodes of a transparent tube according to the present invention, and FIG. 4 is a cutaway perspective view of a main part of a transparent tube, and FIG. 4 is a perspective view of a laser beam mask. 50... Laser beam, 26... Transparent tube, 48
... Conductive film, 42 ... Laser beam mask, 44
...Window, 28...Motor.

Claims (1)

[Scope of Claims] 1. An apparatus for depositing a conductive film on the inner surface of a tubular portion of a transparent tube to form an electrode, comprising: a drive mechanism that continuously rotates the transparent tube and controls movement in the longitudinal direction; The method includes a laser beam for removing a conductive film and a mask provided around the outer periphery of the transparent tube and having a window portion defining the shape of an electrode to be formed on the inner surface of the transparent tube, and irradiates the entire surface of the mask with the laser beam. 1. An apparatus for forming an inner surface electrode of a transparent tube, characterized in that the electrode is formed in a predetermined shape by transmitting light through a window, removing a conductive film of the transparent tube, and forming an electrode in a predetermined shape. 2. The apparatus for forming an inner surface electrode of a transparent tube according to claim 1, wherein the transparent tube is an imaging tube. 3. The apparatus for forming an inner surface electrode of a transparent tube according to claim 1, wherein the mask is made of a copper-based metal having high thermal conductivity. 4. In the method of depositing a conductive film on the inner surface of the tubular part of a transparent tube and removing it by irradiating the conductive film with a laser beam to form a predetermined electrode, a mask that shields and transmits the laser beam is placed around the outer periphery of the transparent tube. A method for forming an inner surface electrode of a transparent tube, characterized in that the conductive film is removed using a laser beam through the mask to form a predetermined electrode shape.