Matsushita Electronics Corporation

Takashi Kinoshita

Masamichi Kimura

Tsutomu Utsumi

Welding is conducted by rolling a roller electrode of a roller-type resistance welder while contacting an electrode surface of the roller electrode against an outer edge of the mask frame via the shadow mask. This method eliminates the need for complex control, and allows smooth and reliable welding at predetermined positions with a simple configuration. By forming the weld nugget on the side of the edge, a flat portion remains when the shadow mask is torn off the mask frame in case of a failure of the shadow mask. Thus, a second welding with a flat portion of the original height is possible, and the mask frame can be reused with the same precision for the welding position.

Method for manufacturing a color cathode ray tube

A method for manufacturing a color cathode ray tube capable of surely applying a predetermined tension force to a shadow mask and preventing the generation of wrinkles and a manufacturing apparatus of the color cathode ray tube. The method includes applying a compression force to a mask frame formed in a frame shape in the direction in which a gap between at least a pair of facing sides is reduced; and welding and fixing a shadow mask to the upper surface of the mask frame with a tension force applied in the direction opposite to the compression force. In this method, a place to which the compression force is applied is the upper end of the external surface of the mask frame. Thus, a repulsion force in the direction in which a shadow mask is stretched can surely be obtained after the compression force is released, as compared with the case where the same level of compression force is applied to the lower end. Consequently, it is possible to prevent the deterioration of the tension force of the shadow mask.

Growing community of inventors

Takatsuki, Japan

Takashi Kinoshita