Matsushita Electric Industrial Co., Ltd.

Tsutomu Nishida

Kazuyasu Yamamoto

Naoji Okumura

Masahiro Kawashima

Kazumi Kawashima

Yasuaki Sakanishi

Naoki Shintani

A screen device suited to use in a projection type display device for a high-definition television set. The screen device includes a screen on which television images are projected, and a screen frame to which this screen is attached at the central section thereof. Incorporated into this screen frame are speakers which are used as the front speakers of a sound reproduction system of the type which is commonly known as the 3-1 type 4-channel system.

Screen device

A focus adjustment changeover circuit for a projection display television receiver having red, green and blue-emission CRTs includes a changeover switch for selecting an operating mode in which a level of current is supplied to the static focus coil of the blue-emission CRT such as to precisely focus the electron beam of that CRT, so that projection lens focus adjustment for that CRT can be easily performed with a test pattern signal being projected, and an operating mode in which the current supplied to that static focus coil causes the electron beam of the blue CRT to be slightly defocused, so that white balance adjustment of the television receiver can be executed while a television picture is projected.

Focussing adjustment changeover circuit for projection TV receiver

Growing community of inventors

Ibaraki, Japan

Tsutomu Nishida