Sony Corporation

Nippon Telegraph and Telephone Corporation

Kenichi Takeuchi

Shoji Araki

Atsushi Nakayama

Shin Saito

A television telephone system utilizes a tone signal of a predetermined duration. The tone signal has a plurality of frequencies and is positioned at the starting portion of a transmission signal. The tone signal reduces the possibility of mis-detection of signals during reception and allows video signals to be transmitted more satisfactorily.

Mis-detection of a video switchover key signal

A luminescence detecting device including a luminescence sensitive member made of a transparent resin or the like and containing at least two different kinds of organic phosphors dispersed therein. The first organic phosphor is operative to absorb fluorescence from incident radiation such as the index phosphor stripes from a reflex color cathode ray tube, and has a response spectrum which overlaps with the wavelength range of the incident fluorescence. The first phosphor is designed to emit fluorescence in a higher wavelength range upon excitation by the incident fluorescent radiation. The second phosphor is responsive to the fluorescence emitted by the first phosphor since the spectra of the two phosphors overlap. The second type of organic phosphor emits its own range of fluorescence in a particular wave band and can be detected by a luminescence sensing portion of the device to provide a signal which can be used to control the operation of the cathode ray tube.

Luminescence detecting devices

A beam-index type color cathode ray tube device which comprises a color cathode ray tube having a front panel portion and a screen panel portion provided with a phosphor screen shaped rectangularly to include a plurality of color phosphor stripes accompanied with index phosphor on its inner surface facing the front panel portion, a luminescence receiving plate member disposed at the outside of said screen panel portion of receiving fluorescence from the index phosphor and producing secondary fluorescence. The luminescence receiving plate member is shaped to have first and second cut-out side portions which are positioned to be close respectively to two corners of the phosphor screen each including a part of one of the top and bottom ends of the same so as to look toward a central part of the luminescence receiving plate member. A first fluorescence detector is attached to the first cut-out side portion for detecting the secondary fluorescence produced in the luminescence receiving plate member. A second fluorescence detector is attached to the second cut-out side portion for detecting the secondary fluorescence produced in the luminescence receiving plate member.

Growing community of inventors

Tokyo, Japan

Kenichi Takeuchi