发明名称 Optical disk control device with focal point movement control
摘要 The present invention provides an optical disk control device that can perform focus pulling in a short time for a target information surface of an optical disk having a plurality of information surfaces. An objective lens (23) is moved toward an optical disk (1) having a plurality of information surfaces (1A, 1B) by the output signal of a driving signal generating circuit (42B), passage of an initial focused focal position is detected by a focal point passage detecting circuit (44), and when the objective lens moves past that position only a predetermined amount closer to the optical disk, an n-rotation delay circuit (70) outputs a reversal instruction f. After changing directions and moving the objective lens away from the optical disk, a focus pulling-in circuit (32B) switches a signal "a" that is output to an actuator driving circuit (21) from the output signal of the driving signal generating circuit to the output signal of the control circuit, activates a control circuit and performs focus pulling-in.
申请公布号 US7480218(B2) 申请公布日期 2009.01.20
申请号 US20050553616 申请日期 2005.10.18
申请人 PANASONIC CORPORATION 发明人 YOSHIKAWA AKIRA;YAMADA SHIN-ICHI
分类号 G11B7/09;G11B7/00;G11B7/085 主分类号 G11B7/09
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