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. 15, 1992
Filed:
Sep. 25, 1991
Paul Frindle, Charlbury, GB;
Sony Corporation, Tokyo, JP;
Abstract
In a digital-to-analog conversion system, an input digital signal D is separated by means of an inverter into first and second signal paths, one of which is the inverse of the other. A digital random noise signal R is then added to the direct and inverse signals to form combined digital signals R-D, R+D. The combined signals are converted into analog form by two identical D/A converter devices to provide analog signals R-D+E1, R+D+E2 (E1 and E2 representing the errors introduced in the conversion process), and these are then subtracted to form an analog output 2D-E1+E2. Thus the random noise components are removed from the analog output, and also the errors E1 and E2 tend to cancel each other leading to a reduction in distortion. Moreover, any remaining distortion is randomized and thus harmonic distortion is reduced. When the injected random noise signal has a greater resolution than the converter devices, there is also an overall increase in data resolution. A similar technique may also be applied to analog-to-digital conversion systems.