JPS6030034A - Device for exposing color picture tube - Google Patents

Abstract

PURPOSE:To improve the landing performance of an electron beam and increase the manufacturing yield by restricting the exposed area of a screen by means of a movable aperture plate and enabling an optical source to be moved to an optimum position corresponding to said exposure area. CONSTITUTION:An exposure optical source 1 can be accurately moved over a plane determined by the X and the Y axes, by the operation of worm gears 7 and 8 and motors 9 and 10. An aperture plate 11 having a central aperture and can be freely moved on a plane determined by the X and the Y axes, is installed between the optical source 1 and a panel 6. The movable aperture plate 11 is moved in X direction by the operation of a worm gear 12 and a motor 14. It is moved in Y direction by the operation of a worm gear 13 and a motor 15. An exposure area 17 can be freely changed by moving the aperture plate 11. It is recommended that the size of the aperture be as large as possible within the range that the desired characteristic is realized. The shape of the aperture is selected to be rectangular or circular according to the required performance characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exposure apparatus for forming a fluorescent screen on a color cathode ray tube.

The operating principle of a multi-electron gun color cathode ray tube is that when the electron beam emitted from each electron gun passes through a color selection electrode and collides with a fluorescent screen, it correctly excites the phosphor of the corresponding color. It is. In order to accurately achieve this, an optical exposure device is used to precisely align the positional relationship between the electron beam and the phosphor in the process of forming the fluorescent screen of the color cathode ray tube. This exposure device, as shown in FIG. 1, exposes the screen surface 4 through the opening of the color selection electrical contact 5 to form a phosphor at that position. An optical lens 2 is used between the light source 1 and the screen 4 to align the electron beam and the phosphor as precisely as possible.

This optical lens 2 is used to adjust the angle of the exposure light beam to the angle of incidence of the electron beam on the color selection electrode 5 when the cathode ray tube is operated. The incident angle of the electron beam is determined by the characteristics of the electron gun and deflection yoke used, and the curved surface of the optical lens is designed and processed to match the exposure light beam to this electron beam incident angle. Although this method is widely used and well known in the current method of manufacturing color cathode ray tubes, it has the following drawbacks.

Medium: If the characteristics of the deflection yoke are changed or the design needs to be modified, these optical lenses can no longer be used, and new lenses must be manufactured at a long time and at a high cost.

(11) There is a limit to the angle of the exposure light beam that can be realized with a normal optical lens with a continuous surface, and depending on the deflection angle and the type of deflection yoke, it may not always be possible to perfectly match the angle of the electron beam. Therefore, a compromise design may have to be made, which may sacrifice the characteristics of the cathode ray tube.

(11i+ Since an optical lens is used, scratches and dirt on the lens may be directly projected onto the screen and become defects on the cathode ray tube screen.

The object of the present invention is to provide an exposure apparatus that solves these drawbacks.

According to the present invention, in an exposure device for a multi-electron gun color cathode ray tube, the exposure area on the screen is limited by a movable aperture plate, the exposure light source is moved to an optimal position corresponding to the exposure area, and the exposure area is completely covered. An exposure device that scans over a screen and obtains optical characteristics without using a correction lens can be obtained.

FIG. 2 shows an exposure apparatus according to the present invention, in which a light source 1 is operated by a worm gear 7.8 and motors 9, 10.
It has a structure that allows it to move accurately on a flat surface.

Also, there is an X between the light source 1 and the panel 6.

The movable aperture plate 11, which has a movable aperture plate 11 that can be freely moved on a Y-plane, is driven in the X direction by a worm gear 12 and a motor 14, and in the Y direction by a worm gear 13 and a motor 15, as shown in FIG. As shown, since it has an aperture 16 in the center, the exposure area 17 can be changed freely by moving the aperture plate.The size of this aperture is as large as possible within the range in which the desired characteristics can be obtained. The efficiency of exposure is better, and the shape of the aperture can also be selected from rectangular or round depending on the required characteristics.

The role of the correction lens 2 in the conventional exposure apparatus shown in FIG. 1 is to move the apparent light source position so that the angle of the exposure light ray matches the incident angle of the electron beam. With this exposure device, it is possible to provide the same functions without using a correction lens. That is, the exposure position on the screen is limited by the movable aperture plate 11, and the light source position is moved by motors 9 and 10 in order to obtain the exposure light angle required for this exposure position. It is clear that if the exposure position is scanned over the entire screen under these conditions, a screen exposed at the optimum incident angle can be obtained over the entire screen.

However, in order to perform the above-mentioned complex operations precisely and at high speed, an electronic circuit device is required. FIG. 4 shows its block diagram.

First, the Kuji and Kupulus generators 8 generate Kuji and Kupulus, which are the standards of this system.

Next, the arithmetic unit 19 calculates beam 0. Calculations are made to determine the exposure position corresponding to the opening, and the coordinate X of the open plate is determined.

Y is determined. Signals kX, k corresponding to the coordinates of the aperture plate
Y is sent to motors Ms, M, and the aperture plate is driven. Since the function #'x+'y, which is the basis of this calculation, varies depending on the characteristics of the cathode ray tube, it is convenient to store it in a rewritable memory 22 such as a semiconductor or magnetic disk.

Next, the arithmetic unit 21 calculates the coordinates X of the aperture plate.

The positions A and B of the light source corresponding to Y are recognized, and the signal kA,
kn is sent to motors M, , M2 to move the light source. As mentioned above, it is convenient to store the functions fA and fa, which are the basis of this calculation, in the rewritable memory 22 such as a semiconductor or magnetic disk.

Here, the functions fx and fy determine the order and speed of light scanning, and these must be determined in consideration of the exposure time, the shape of the scanning aperture, etc. Note that in the conventional exposure apparatus shown in FIG. 1, an illuminance distribution adjustment filter 3 has been used to adjust the illuminance distribution of the exposure light beam, but in this apparatus, the exposure scanning speed can be determined by fx and fy. Therefore, this filter can be made unnecessary by changing the light intensity depending on the location of the screen.Furthermore, the exposure time can be adjusted by changing the frequency of the optical pulses.

Next, the functions fA and fB are used to determine the position of the light source corresponding to the exposure position on the screen, and can be calculated from the same type of data as in conventional correction lens design.

In the case of conventional continuous surface correction lenses, it was not always possible to form the exposure light beam required due to the characteristics of color cathode ray tubes, but with this device, there is no such limitation, and in this sense, it is possible to use high-performance cathode ray tubes. It provides a means for manufacturing.

Furthermore, in order to improve the accuracy of the correction lens design, it is necessary to visit or make a correction lens, and if the deflection yoke characteristics or the deflection angle are rarely changed, it is necessary to change the design of the correction lens each time. . However, since this correction lens is generally aspherical and large in size, it is expensive and takes a long time to manufacture.

In the exposure apparatus according to the present invention, the characteristics related to the correction lens can be stored in a rewritable or replaceable memory device.1. The cost and time required for correcting exposure characteristics can be greatly reduced.Furthermore, since the device according to the present invention does not require the use of correction lenses or exposure filters, scratches and dirt caused by these are projected onto the screen and are damaged by the cathode ray tube. There is no possibility of defects on the screen, and production yield can be improved.

As described above, the present invention provides a means for improving the landing performance of an electron beam on a fluorescent screen of a color cathode ray tube, reducing cost and time when changing the design of an exposure device, and improving production yield. I'll go.

[Brief explanation of the drawing]

FIG. 1 shows an exposure apparatus using a conventional correction lens and illuminance distribution adjustment filter, FIG. 2 shows the basic configuration of an exposure apparatus according to the present invention, and FIG. A9 is a plan view of the movable aperture plate used in the exposure apparatus shown in Figure 2.
, and FIG. 4 is a diagram of an electron path for driving an exposure apparatus according to the present invention. This is a diagram. 1...Light source, s...Mask, 6...
... Panel, 7°8 ... Worm gear, 9,
10,14.15...Motor.

Claims (1)

[Claims] In an exposure device for a multi-electron gun color cathode ray tube, the exposure area on the screen is limited by a movable aperture plate, the exposure light source is moved to an optimal position corresponding to the exposure area, and the exposure area is scanned over the entire screen; A color cathode ray tube exposure device characterized by obtaining optical characteristics without using a correction lens.