发明名称 |
OPTICAL INFORMATION RECORDER AND REPRODUCER |
摘要 |
PURPOSE:To obtain the optimum recording exposure conditions, by reproducing the previously recorded address signal on a guide track provided to an information carrier and controlling the laser output with the reproduced address signal. CONSTITUTION:An address signal SI is separated by a signal separating circuit 34 from signals SA-SD received a photoelectric conversion through a photodetector 17. The signal SI is a code signal modulated by a PE or an MFM and demodulated by the clock supplied from a clock reproducing circuit 37 through an address signal reproducing circuit 36. A modulated series address signal (a) is stored in a series- parallel converting circuit 38 and turned into an analog signal through a D/A converting circuit 39 to be applied to a laser driving circuit 35 through a bias switching circuit 40. Thus the bias current of a semiconductor laser 3 is controlled. As a result, a proper laser output is ensured although the speed is different between the inner and outer circumferences of an information carrier 1. |
申请公布号 |
JPS5733441(A) |
申请公布日期 |
1982.02.23 |
申请号 |
JP19800108945 |
申请日期 |
1980.08.07 |
申请人 |
MATSUSHITA ELECTRIC IND CO LTD |
发明人 |
SATOU ISAO;YOSHIDA TOMIO;HARIKAE SHIYUNJI;KOISHI KENJI |
分类号 |
G11B7/00;G11B7/0045;G11B7/09;G11B7/125;G11B17/00 |
主分类号 |
G11B7/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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