Chunghwa Picture Tubes, Ltd.

Hsiang-Sung Lee

Chun-Hsien Yeh

Chi-Tsan Wang

Shung-Lin Chang

To prevent rotation of a generally flat, or planar, grid having three inline beam passing apertures, where the two outer apertures are asymmetric in shape, during assembly of a multi-beam electron gun for use in a color cathode ray tube (CRT), an electron gun alignment jig having three inline generally cylindrical mandrels in combination with a generally flat spacer plate is used. Each of the three mandrels is inserted in a respective grid aperture and the grid is placed in contact with the flat spacer plate. The flat spacer plate includes a recessed portion with an alignment slot. The grid includes a lateral alignment tab adapted for insertion in the spacer plate's matching alignment slot in a tight-fitting manner. With the alignment tab inserted in the alignment slot, the three inline apertures are in precise alignment in the alignment jig and grid rotation is prevented to facilitate electron gun assembly. Also to assist in grid alignment during electron gun assembly, a grid positioning jig includes a pair of spaced movable gripping elements each adapted to securely engage a respective lateral edge of the grid for positioning the grid in the electron gun assembly jig. In one embodiment, the positioning jig includes first and second spaced, inwardly urged gripping elements adapted for insertion in respective recessed portions, or notches, in opposed lateral edges of the grid. Apparatus for attaching the grid to the positioning jig includes a movable member in a mandrel for engaging the grid adjacent an asymmetric aperture.

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Taipei, Taiwan

Hsiang-Sung Lee