Patents by Inventor Youli Guo

Youli Guo has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20100309758
    Abstract: A tracking servo method of an optical video disc player and its special device which accomplish angle adjustment in a simple, time-saving and effort-saving manner and improve the tracking servo capability of the optical video disc player. In the tracking servo method of an optical video disc player, a laser beam is split into a main beam and two sub beams, and tracking error signal generated from the two sub beams are subtracted from tracking error signal generated by the main beam; light spot of the main beam is circular in shape, and light spots of the two sub beams are elliptical in shape. The special device has an effective grating region (1). The effective grating region (1) has a middle zone (2) and two side zones (3, 4); the middle zone (2) has two side edges which are parallel and equal in length, and the two side edges has a distance therebetween which is 10-90% of diameter of the effective grating region (1), and the middle zone (2) and the two side zones (3, 4) have different grating pitches.
    Type: Application
    Filed: September 8, 2008
    Publication date: December 9, 2010
    Inventors: Yong Zhang, Youli Guo, Xiuyu Wang, Yingxiong Wu, Liang Song, Zheng Ma