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:
Sep. 25, 1984
Filed:
Feb. 22, 1982
Nobuyoshi Nagura, Anjyo, JP;
Taneichi Kawai, Anjyo, JP;
Aisin Seiki Kabushiki Kaisha, Kariya, JP;
Abstract
Digital data is recorded onto a cassette tape by utilizing an audio cassette tape recorder under the control by a microprocessor. The microprocessor assigns '0' digital data bit a time sequence of a shorter pulse of a single period (T.sub.1) and having a duty cycle of 50% and a longer pulse of a single period (T.sub.2) and having a duty cycle of 50%. Assigned to '1' data bit is a time sequence of a single period of T.sub.2 pulse and a single period of T.sub.1 pulse. An analog signal applied to the recording unit of the audio cassette tape recorder initiates a gradual increase in its level at a point of transition from the low level L to the high level H of either T.sub.1 or T.sub.2 pulse, and returns to a start level at a point of transition from the H to the L level and also initiates a gradual decrease in the level. In this manner, a waveform conversion is performed. As a result of such waveform conversion, a signal reproduced from the cassette tape has a waveform which can be easily determined to represent either one of the binary data bits. The use of pulses having duty cycles of 50% as reference waves minimizes a level fluctuation in the reproduced signal which may be caused by a time constant of the reproducing unit of the tape recorder.