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:
Dec. 07, 1999
Filed:
May. 08, 1997
Mehrdad Nayebi, Palo Alto, CA (US);
Duc Ngo, San Jose, CA (US);
Sony Corporation, Tokyo, JP;
Sony Electronics, Inc., Park Ridge, NJ (US);
Abstract
A horizontal synchronization pulse generation circuit generates a horizontal synchronization pulse to be added to an encoded composite video signal. An input receiving circuit receives an encoded input video signal representing video information received from input video signals. An output video signal represents the encoded input video signal in all portions of the signal except the horizontal synchronization period. During the horizontal synchronization period a current is switched through a path resistor and used to generate the voltage level of the horizontal synchronization pulse. The voltage drop across the path resistor during the horizontal synchronization period is applied directly to the output video signal thereby generating a horizontal synchronization pulse. The current switched through the path resistor is generated by a voltage drop across a current resistor. The ratio of the path resistor to the current resistor is matched, allowing the required signal accuracy to be achieved in the voltage drop across the path resistor and generating the appropriate voltage drop across the path resistor according to the current flowing through the current resistor. The horizontal synchronization pulse generation circuit does not clamp the voltage level of the encoded input video signal, but instead generates the horizontal synchronization pulse in reference to the level of the encoded video signal.