公开(公告)号：US20050162993A1

公开(公告)日：2005-07-28

申请号：US11025682

申请日：2004-12-28

申请人： Stephen Farnsworth ,  Werner Spaeth ,  Kirk Cook

发明人： Stephen Farnsworth ,  Werner Spaeth ,  Kirk Cook

IPC分类号： G11B5/596 ,  G11B7/00

CPC分类号： G11B5/59677

摘要： A lensless optical servo system (100) has an unfocused light source (102) and patterned photodetectors (104, 106, 108). The unfocused light is reflected by the markings on an LS-120 disk (40) and the reflected light carries the pattern of the markings the considerable distance in its far-field to the photodetectors (104, 106, 108). The convolution of this light pattern and a mating geometric pattern (110, 112, 114) on the photodetectors (104, 106, 108) causes the photodetectors to generate signals representing the position of the track on the disk. According to a presently preferred embodiment, a laser diode (102) and three detectors (104, 106, 108) are formed on the same silicon substrate (101). Sinusoidal metalization (110, 112, 114) is applied to the detectors (104, 106, 108) in the radial direction. The period of the sinusoidal metalization is two times the tracking pitch of the disk radially and tangentially. The metalization on the first detector is approximately ninety degrees behind the metalization on the second detector and the metalization on the third detector is approximately ninety degrees ahead of the metalization on the second detector. Preferably, each detector (104, 106, 108) is provided with two sinusoidal patterns (110a, 110b, 112a, 112b, 114a, 114b), approximately one hundred eighty degrees out of phase with each other, and spaced apart in the tangential direction.

摘要翻译： 无镜头光学伺服系统（100）具有未聚焦光源（102）和图案化光电检测器（104,106,108）。 未聚焦的光被LS-120盘（40）上的标记反射，并且反射光将其远场中的相当距离的标记的图案携带到光电检测器（104,106,108）。 这种光图案和在光电检测器（104,106,108）上的匹配几何图案（110,112,114）的卷积导致光电检测器产生表示盘上磁道位置的信号。 根据目前优选的实施例，激光二极管（102）和三个检测器（104,106,108）形成在同一硅衬底（101）上。 在径向上将正弦金属化（110,112,114）施加到检测器（104,106,108）。 正弦金属化的周期是径向和切向的盘的跟踪间距的两倍。 第一检测器上的金属化在第二检测器上的金属化之后大约九十度，并且第三检测器上的金属化比第二检测器上的金属化大约九十度。 优选地，每个检测器（104,106,108）被提供有彼此相差近似180度的两个正弦图案（110a，110b，112a，112b，114a，114b），以及 沿切线方向间隔开。

公开(公告)号：US06664538B1

公开(公告)日：2003-12-16

申请号：US09569971

申请日：2000-05-11

申请人： Stephen Farnsworth ,  Kirk Cook

发明人： Stephen Farnsworth ,  Kirk Cook

IPC分类号： G01B1114

CPC分类号： G01D5/38

摘要： An optical position detector system has a light emitting diode source, two detectors, and a diffraction grating which is frequency mismatched with the frequency of a reference grating. According to one embodiment for use in a reflective system, the source and two detectors are mounted on a single body and a single diffraction grating is placed over the source and detectors. There is no need to control the locations or phase differences between the source grating and the detector gratings because a single grating us used for all three. The spatial frequency of the single grating is chosen such that it is different from the frequency of the reference grating but still produces a signal having a maximized amplitude with the desired phase shift. Two alignments which formerly required tight tolerance are no longer necessary with the system of the invention. In addition, a fabrication feature of introducing a discrete phase step between the gratings covering both detectors is not necessary. In a second embodiment, for a transmissive system, a source with a source grating is mounted on one body and the two detectors are mounted on another body with the reference grating located therebetween. A single grating is applied over the two detectors and only the detector grating is mismatched with the reference grating.

摘要翻译： 光学位置检测器系统具有发光二极管源，两个检测器和与参考光栅的频率频率失配的衍射光栅。 根据用于反射系统的一个实施例，源和两个检测器安装在单个主体上，并且单个衍射光栅放置在源和检测器上。 不需要控制源光栅和检测器光栅之间的位置或相位差，因为我们用于所有三个光栅的单个光栅。 选择单个光栅的空间频率使得其与参考光栅的频率不同，但仍然产生具有期望相移的具有最大振幅的信号。 本发明的系统不需要以前需要紧公差的两个对准。 此外，不需要在覆盖两个检测器的光栅之间引入离散相位步骤的制造特征。 在第二实施例中，对于透射系统，具有源光栅的源安装在一个主体上，并且两个检测器安装在另一个主体上，其中参考光栅位于其间。 在两个检测器上施加单个光栅，只有检测器光栅与参考光栅不匹配。