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:
Aug. 08, 1989
Filed:
Jun. 06, 1988
Gerhard Wischermann, Weiterstadt, DE;
Hans-Peter Richter, Griesheim, DE;
BTS Broadcast Television Systems GmbH, Darmstadt, DE;
Abstract
A generator of circular zone plate signals for testing digital television signals, particularly those in circuits conforming with CCIR-Rec. 601, contains counters operating at horizontal and vertical sampling scan frequencies for producing an orthogonal pattern. The phase values generated by ROMs in response to the horizontal and vertical counters are combined additively and then converted into amplitude values by another set of ROMs separately for the luminance and chrominance signals. The counters also drive still another set of PROMs that provide, through a logic circuit, modulation of the luminance signal to show horizontal and vertical frequency markers that can be turned on and off by switches. The horizontal marker PROM also produces chrominance blanking signals for eliminating frequency components above half the sampling frequency.