Image display system

Claim 2

An image display system, comprising: an electron tube having a face plate provided on the inner side thereof with a screen layer, said screen layer being composed of a plurality of fluorescent material areas enclosed by a cathode chromic material area in a plane, said cathode chromic material producing color centers when bombarded by an electron beam; means for sweep scanning an electron beam over said screen layer; an optical pen disposed in front of said eleCtron tube for detecting light generated as said fluorescent material areas of said screen is scanned by the electron beam; and means for controlling the electron beam produced by said sweep scanning means in accordance with the output signal of said optical pen to switch the bombardment of the electron beam from said plurality of fluorescent material areas to said cathode chromic material area, to thereby display the trace of said optical pen on said face plate.

Claim 3

An image display system according to claim 1, wherein said sweep scanning means comprises one electron gun for producing one electron beam, and wherein the switching of the bombardment of the electron beam is effected by deflecting the electron beam for an instant and by changing the target position of the bombardment.

Claim 4

An image display system according to claim 1, wherein said sweep scanning means produces two electron beams, one of said electron beams being arranged to scan said plurality of fluorescent material areas and the other of said electron beams being arranged to bombard said cathode chromic material area adjacent to the scanned fluorescent area, and wherein said other electron beam is produced only when said optical pen produces an output.

Claim 5

An image display system according to claim 1, wherein said plurality of fluorescent material areas on the face plate of said electron tube are formed in the shape of stripes disposed in parallel with the direction of horizontal scanning of said beam.

Claim 6

An image display system according to claim 1, wherein said plurality of fluorescent material areas are formed in the shape of dots.

Claim 7

An image display system according to claim 1, wherein said sweep scanning controlling means includes an amplifying circuit for effecting positive feedback of the output of said optical pen thereto thereby to increase the intensity of the electron beam and to cause color luminescence of said cathode chromic material.

Claim 8

An interstation image display system for transmitting and receiving a displayed image between at least two image display stations connected by a communication line, each of the image display stations comprising: an image display system including; an electron tube having a face plate provided on the inner side thereof with a screen layer, said screen layer composed of a plurality of fluorescent material areas enclosed by a cathode chromic material area, said cathode chromic material producing color centers when bombarded by an electron beam, means for sweep-scanning said screen layer, an optical pen disposed in front of said electron tube for detecting light generated as said fluorescent material area of said screen is scanned by the electron beam, and means for controlling said sweep scanning means in accordance with the output signal of said optical pen to switch the bombardment of the electron beam from said plurality of fluorescent material areas of said cathode chromic material area to thereby display the trace of said optical pen on said face plate; synchronizing means for achieving synchronization between said two image display stations; demodulating and separating means connected to the corresponding means of the other image station through said communication line for demodulating and separating optical pen position signals, sync. signals and telephone signals; and an optical signal coupler connected to said means for controlling said scanning means and to said demodulating and separating means for selectively displaying only patterns produced from at least one of said stations.

Claim 9

An interstation image display system for transmitting and receiving a displayed image between at least two image display stations connected by a communication line, each of the image display stations comprising: an image display system including; an electron tube having a face plate provided on the inner side thereof with a screen layer, said screen layer composed of a plurality of fluorescent material areas enclosed by a cathode chromic material area, said cathode chromic material producing color centers when bombarded by an electron beam, means for sweep-scanning said screen layer, an optical pen disposed in front of said electron tube for detecting light generated as said fluorescent material area of said screen is scanned by the electron beam, and means for controlling said sweep scanning means in accordance with the output signal of said optical pen to switch the bombardment of the electron beam from said plurality of fluorescent material areas of said cathode chromic material area to thereby display the trace of said optical pen on said face plate; synchronizing means for achieving synchronization between said two image display stations; demodulating and separating means connected to the corresponding means of the other image station through said communication line for demodulating and separating optical pen position signals, sync. signals and telephone signals; and an optical signal coupler connected to said means for controlling said scanning means and to said demodulating and separating means for selectively displaying only patterns produced from at least one of said stations.