Sony Corporation

Oji Paper Co., Ltd.

Agency of Industrial Science and Technology Ministry of International

Osamu Takeuchi

Hideo Kusama

Kazuo Yamazaki

Kunitaka Toyofuku

Kunihiro Ichimura

Takahiro Yukawa

Koji Kanbayashi

Hiroshi Ito

Akira Saka

An improved current dependent type color cathode ray tube which utilizes a color phosphor screen which has at least two phosphors that have current density versus brightness characteristics which differ from each other and which emit light of different colors and including an electron gun which emits an electron beam which impinges on the color phosphor screen and wherein the current density of the electron beam of the gun varies in response to color signals so as to cause the emission of the desired colors to produce a color image and wherein the focusing voltage of the electron gun is varied so that the just focussing state occurs at the highest drive current within the drive current range and the focal length associated with the focussing voltage at the just focussing state is displaced by more than 5% from the focal length represented by the lowest drive current.

Current dependent type color cathode ray tube

A partially saponified polyvinyl acetate having at least one stilbazolium group-containing photosensitive unit represented by the following general formula: ##STR1## (wherein R.sub.1 is hydrogen atom, an unsubstituted or substituted alkyl group, an alkenyl group or an aralkyl group, R.sub.2 is hydrogen atom or an unsubstituted or substituted alkyl group, Y is a conjugated base of an inorganic or organic acid, m is an integer of 1 to 6, and n is 0 or 1) and an acetal unit represented by the following general formula: ##STR2## (wherein R.sub.3 is hydrogen atom or an alkyl group); the acetal units being contained therein in an amount of approximately 0.5 to 10.0 mol % with respect to mole of the polyvinylalcohol units thereof; the stilbazolium group-containing units being contained therein in an amount of approximately 0.5 to 5.0 mol % with respect to mole of the polyvinylalcohol units thereof; and having a degree of polymerization of approximately 500 to 3,000 and a degree of saponification of approximately 60% or higher. This polyvinyl acetate can be used as photosensitive resinous materials or compositions suitable for the fluorescent screen of a cathode ray tube.

Photosensitive resinous materials containing stilbazolium groups

Growing community of inventors

Hino, Japan

Osamu Takeuchi