The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 21, 1988
Filed:
Dec. 16, 1985
Akinori Masuko, Kawasaki, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A CPU in a subscriber terminal generates upstream data and a transmission request signal as an enable signal for sending the upstream data to a broadcast center. An oscillator generates a carrier wave while the enable signal is being held at a predetermined level. A multiplier multiplies the carrier wave with the upstream data and generates the upstream signal. A transmission level adjusting amplifier amplifies the upstream signal, and the amplified signal is sent onto a cable. A detecting means receives a signal associated with the enable signal and discriminates the presence of the carrier wave. A time constant circuit measures the period of time for which the carrier wave is present in response to output from the detecting means. A switching circuit stops supplying at least the carrier wave of a first frequency onto the cable in response to output from the time constant circuit which indicates that the carrier wave has been exceeded the predetermined period of time.