Kabushiki Kaisha Toshiba

Shuuji Makimoto

Masahiro Yokota

Tadahiro Kojima

Kouichi Soneda

Nobuyuki Tai

Shinji Ohama

Yonemichi Ochiai

A shadow mask opposed to a phosphor screen of a panel has a rectangular mask body and a rectangular mask frame fixed to the periphery of the mask body. The mask body has a pair of long side edges and a pair of short side edges, and the long side edges are respectively welded to long side walls of the mask frame while the short side edges are respectively welded to short side walls of the mask frame. The long and short side walls of the mask frame are respectively supported on the panel by mask holders. Each mask holder has a fixed portion welded to the mask frame and an engaging portion engaged with a stud pin of the panel. Welding positions between the long side edges of the mask body and the long side walls of the mask frame are shifted from the short axis, and welding positions between the short side edges of the mask body and the short side walls of the mask frame are shifted from the long axis.

Color cathode ray tube

A holder elastically supporting a mask frame of a shadow mask has a holder body and a bimetal plate. The holder body is formed by bending an elongate metal plate in two opposite directions along first and second bending lines inclined at an angle to the longitudinal axis of the holder body, and has an engaging portion in engagement with a stud pin, a fixed portion fixed to the mask frame, and a slope portion extending aslant between the engaging portion and the fixed portion. The holder body moves the mask frame toward a phosphor screen along the central axis, when the mask frame is thermally expanded. The bimetal plate includes a first metal plate on the mask-frame side and a second metal plate on the holder-body side, the first and second metal plates having different thermal expansion coefficients and being stuck together. The bimetal plate is located between the fixed portion and the mask frame, for moving the mask frame away from the phosphor screen along the central axis of the face panel when heated.

Elastically supporting holder for a color cathode-ray tube

A color cathode-ray tube comprises a mask unit arranged between a face panel and an electron gun. The mask unit comprises a shadow mask and a mask frame supporting the shadow mask with being applied with tension. The shadow mask is formed of a substantially rectangular thin plate, arranged to face a phosphor screen formed on an inner surface of the face panel, and has a number of electron beam apertures through which electron beams emitted from the electron gun pass. The mask frame comprises a substantially rectangular frame body which has a pair of first sidewalls facing each other and a pair of second sidewalls facing each other, and a pair of mask fixing sections secured to a pair of opposite side edge portions of the shadow mask and extending along the side edge portions. The pair of mask fixing sections extend substantially in parallel with the first sidewalls, respectively and have connecting sections each of which connects a middle portion of the mask fixing section to a middle portion of the corresponding first sidewall.

Growing community of inventors

Fukaya, Japan

Shuuji Makimoto