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. 28, 1977
Filed:
Apr. 23, 1976
James Charles Candy, Convent Station, NJ (US);
Yau-Chau Ching, Morganville, NJ (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
An analog signal to be converted into a high resolution digital signal is first converted to a coarsely quantized signal by a direct feedback coder. A group of successive coarsely quantized signals are then processed by a converter which produces the high resolution digital signal. In the converter, the processing is performed by an arrangement of two accumulators. The first accumulator provides an output signal indicative of the running sum of each group of coarsely quantized signals. The second accumulator has the capability of providing an accumulation of either the negative or the positive of the output signal of the first accumulator. A negative accumulation is used for a first portion of the group and a positive accumulation is used for the second portion of the group to provide a net sum. The net sum is a triangularly weighted accumulation of the successive signals in the group which occasions self-cancelling of the quantizing noise inherent to the direct feedback coder. Each net sum is used to form a code word of several digital bits in a high accuracy signal. Utilization of a third portion between the first and second portions of the group in which the second accumulator is idle provides a trapezoidal weighting in the net sum. The latter weighting provides a further improvement in resolution and accuracy.