公开(公告)号：US5629919A

公开(公告)日：1997-05-13

申请号：US429877

申请日：1995-04-27

申请人： Takao Hayashi ,  Toru Nakamura ,  Hideki Aiko ,  Akira Matsubara

发明人： Takao Hayashi ,  Toru Nakamura ,  Hideki Aiko ,  Akira Matsubara

IPC分类号： G11B7/12 ,  G11B7/135 ,  G11B11/105 ,  H01S5/022 ,  H01S5/183 ,  G11B7/00

CPC分类号： G11B7/1353 ,  G11B11/10543 ,  G11B7/123 ,  G11B7/1365 ,  H01S5/02296 ,  H01S5/0264 ,  H01S5/183

摘要： In an optical head, a light emitting element emits an optical beam, and the beam is condensed by a condensing element onto an information recording medium. A first plate beam-splitting element has a splitting ratio of P polarization to S polarization, and it splits at least a part of the beam reflected by the information recording medium along a direction different from that of a direction returning to the light emitting element. A second plate beam-splitting element is provided in parallel to the first plate beam-splitting element, and it splits the beam split by the first plate beam-splitting element into at least two beams having polarization planes perpendicular to each other. The two beams are detected by a pair of photosensors. Because the first and second beam-splitting elements are set in parallel to each other, an optical path from the light emitting element to the information recording medium is separated from that of a reflected beam from the medium with a very small angle, and the optical elements can be located at adjacent positions to each other. Thus, the optical head can be made compact to a large extent. Further, the optical head can be sealed for high reliability.

摘要翻译： 在光学头中，发光元件发射光束，并且光束被聚光元件冷凝到信息记录介质上。 第一板分束元件具有P偏振与S偏振的分离比，并且其沿着与返回到发光元件的方向不同的方向分裂由信息记录介质反射的光束的至少一部分。 第二板分束元件平行于第一板分束元件设置，并且将由第一板分束元件分裂的光束分成具有彼此垂直的偏振面的至少两个光束。 两束光束由一对光电传感器检测。 由于第一和第二光束分离元件彼此平行设置，从发光元件到信息记录介质的光路与来自介质的反射光束的光路以非常小的角度分离，并且光学 元件可以位于彼此相邻的位置。 因此，可以在很大程度上使光学头紧凑。 此外，光学头可以被密封以获得高可靠性。

公开(公告)号：US5430699A

公开(公告)日：1995-07-04

申请号：US200456

申请日：1994-02-23

申请人： Akira Matsubara ,  Takao Hayashi ,  Yutaka Murakami ,  Toru Nakamura ,  Hideki Aiko

发明人： Akira Matsubara ,  Takao Hayashi ,  Yutaka Murakami ,  Toru Nakamura ,  Hideki Aiko

IPC分类号： G11B7/095 ,  G11B7/00

CPC分类号： G11B7/0956 ,  G11B7/0935

摘要： The relative tilt of an optical disk and a movable objective lens holder is measured as an output of a differential amplifier which subtracts an output of first photodetectors and which detect the reflected light from optical disk from an output of second photodetectors and which detect the reflected light from a reflector mounted on movable objective lens holder. The signal from differential amplifier is used to tilt movable objective lens holder so that the movable objective lens holder compensates the tilt of optical disk.

摘要翻译： 测量光盘和可移动物镜座的相对倾斜度作为差分放大器的输出，该差分放大器减去第一光电检测器的输出，并从第二光电检测器的输出检测来自光盘的反射光，并检测反射光 从安装在可移动物镜座上的反射器。 来自差分放大器的信号用于倾斜可动物镜保持器，使得可移动物镜保持器补偿光盘的倾斜。