发明授权
US07203138B2 Optical head device, inclination detection apparatus using the same, and optical information processing apparatus using the same
有权
光头装置,使用该装置的倾斜检测装置以及使用该装置的光信息处理装置
- 专利标题: Optical head device, inclination detection apparatus using the same, and optical information processing apparatus using the same
- 专利标题(中): 光头装置,使用该装置的倾斜检测装置以及使用该装置的光信息处理装置
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申请号: US10691317申请日: 2003-10-22
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公开(公告)号: US07203138B2公开(公告)日: 2007-04-10
- 发明人: Kousei Sano , Shin-ichi Kadowaki , Hiroaki Yamamoto , Ken'ichi Kasazumi , Seiji Nishino
- 申请人: Kousei Sano , Shin-ichi Kadowaki , Hiroaki Yamamoto , Ken'ichi Kasazumi , Seiji Nishino
- 申请人地址: JP Kadoma
- 专利权人: Matsushita Electric Industrial Co., Ltd.
- 当前专利权人: Matsushita Electric Industrial Co., Ltd.
- 当前专利权人地址: JP Kadoma
- 代理机构: Renner, Otto, Boisselle & Sklar, LLP
- 优先权: JP8-156546 19960618; JP8-159368 19960620; JP8-161331 19960621
- 主分类号: G11B7/00
- IPC分类号: G11B7/00
摘要:
An optical head device includes a light source for emitting light; a collection optical system for collecting the light emitted by the light source to an information memory medium including tracks having prescribed grooves; a light detector having a plurality of detection areas for receiving the light reflected by the information memory medium and outputting a signal in accordance with a light amount of the light received; a tracking error signal generator for receiving the signals output from the light detector and generating a tracking error signal based on the signals; and a light division element for dividing a reflected light reflected by the information memory medium. A relationship λ/(NA·Tp)≧1 is satisfied where λ is the wavelength of the light emitted from the light source, NA is the numerical aperture of the collection optical system, and Tp is the distance from a center of the track in the information memory medium to a center of the adjacent track; and the tracking error signal generator generates a tracking error signal from an area except for an overlapping area of the reflected light, the overlapping area being an area of overlapping two circles each having a radius of 1 and having a center of one circle being apart from a center of the reflected light beam at a distance of λ/(NA·2Tp) in a direction orthogonal to the track from a center of a cross-section of the reflected light, when the cross-section of the reflected light on the light division element in a circle having a radius of 1.