Mitsubishi Denki Kabushiki Kaisha

Hideya Ito

Junko Itoh

Akira Yamada

Hiroyuki Sakaiya

Atsushi Hattori

Shoji Morimoto

Tetsuya Watanabe

Masayuki Miyazaki

Kenji Kawaguchi

Hiroyuki Teramoto

Hiroo Sakamoto

Shiro Takada

Kimio Hashizume

Takashi Sugahara

Akira Ichikawa

Tesshin Yazu

Kazushi Nagasawa

Cathode ray tube

A color selecting electrode assembly for color cathode ray tubes which includes an apertured grill composed of fine-strand grids, a frame over which the aperture grill is stretched and which provides a tensioning force to the apertured grill, and a supporting structure body which is mounted at one end to said frame and engages the other end with the panel side wall of a color cathode ray tube so as to support said frame, wherein the wall thickness of said apertured grill is not greater than 0.032 mm. To assure the characteristic frequency of the aperture grill, it becomes unnecessary to manufacture individually frames having rigidities corresponding to respective slit pitches of the apertured grill. The frame can be a general purpose one (i.e., one used in common with others), thereby allowing the manufacture to be simplified. Further, the suppoting member can be also used in common with others, thereby allowing the design to be simplified.

Structure of color selecting electrode assembly for color cathode ray

A color selecting electrode assembly for color cathode ray tubes includes: an aperture grill having thin slits; a frame over which the aperture grill is stretched; and supporting members in which a fixing portion at one end is attached to the frame and an engaging portion at the other end is engaged with a panel pin provided on a panel side wall so as to support the frame. An elastic portion of the supporting members is arranged in such a manner that boundary portions of the elastic portion with the fixing portion and the engaging portion become parallel to a longitudinal-direction of the slits. An engaging hole bored in the engaging portion is provided at such a position that the engaging hole intersects with an imaginary extension plane in which a joining portion of the frame and the aperture grill is extended in a direction parallel to a tube axis of a color cathode ray tube.

Supporting members for a color selecting electrode assembly

A method for manufacturing a shadow mask is used for color television picture tubes and the like. The surface of a shadow mask body, made of Fe-Ni type alloy, is ion-nitriding processed so as to make the most of the low thermal expansion property inherent in the alloy. The result is that the color purity degradation caused by the thermal expansion at temperature increases of the mask, and by the resonance of the mask itself, can be prevented, thereby realizing a shadow mask serving to render a highly refined CRT.

Method for manufacturing a shadow mask

A shadow mask mounting in a cathode ray tube includes an evacuated envelope including a funnel section, a cylindrical neck section and a faceplate of generally cup-shaped configuration, including a screen plate and a side wall perpendicular to the screen plate. The shadow mask mounting includes a shadow mask assembly including a rigid support frame and a finely perforated shadow mask mounted across the support frame, a plurality of generally elongated support members distributed around the support frame, stud pins each provided in the faceplate for anchoring one end of each support member to the side wall of the faceplate, and a generally elongated resilient member provided for each of the support members. The resilient member is for applying a biasing force, acting in a direction radially outwardly of the shadow mask, to the respective support member. Each of the support members is secured at one end to the support frame and at the other to the side wall of the faceplate whereas the resilient member has one end secured to the support frame.

Support for shadow mask in a cathode ray tube

A CRT shadow mask 9 is made by clamping the outer periphery of a blank, stretch or draw-forming the main spherical surface 9a of the mask, releasing the clamping and wipe-forming the skirt 9c of the mask, and finally press-forming a peripheral spherical border 9e inward of the skirt and having a sharper angle of inclination. The border prevents the spring-back of the high yield strength mask material and the attendant formation of creases and dimples in the mask surface. The die press for implementing the process features an inner pad 32 surrounded by an outer pad 31, both defining spherical surfaces configured to mate with those of a punch 1 for individually forming the main surface and border of the mask. The components are arranged such that a single downward stroke of the press successively implements all of the forming steps.

Punch press forming CRT shadow masks

A plurality of spaced reinforcing plates 6 are provided around the periphery of a Hip Up configured shadow mask 2 and its support frame 3 in a color picture tube assembly to strengthen and stiffen the mounting arrangement and thereby reduce Z axis deviations of the mask due to thermal deformation and/or mechanical shock.

Shadow mask mount for color picture tube

Growing community of inventors

Nagaokakyo, Japan

Hideya Ito