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:
Apr. 22, 1997
Filed:
Apr. 25, 1995
Kyoung H Lee, Anyang, KR;
Samsung Electronics Co., Ltd., Kyungki-Do, KR;
Abstract
A focusing control apparatus has a controller and a memory so as to store the control signal of a previous step in the memory. The control signal detected by a photo-detector is changed according to the changes of temperature and light intensity input from a light source. The apparatus performs focusing control by summing in an adder signal output by the controller, which signal is the stored signal on which a computation has been performed, and the new signal input. The apparatus detects and controls an offset signal of the focusing error signal by providing a low-pass filter between the adder and the controller. A feedback circuit including an anti-aliasing circuit is further provided between the output of the adder and the controller, whereby a new focusing control signal is transmitted by correcting the signal stored in the memory after a computation has been performed thereon by the controller. Therefore, the focusing control signal transmitted to the driver of the object lens is stably maintained and the design of a control compensator can be simplified by the use of the feedback circuit.