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22 条记录 (耗时 0.014 秒)

    Optical pickup apparatus
    5.
    发明公开
    Optical pickup apparatus 失效
    光拾取装置

    公开(公告)号：EP0359670A3

    公开(公告)日：1991-07-24

    申请号：EP89402525.3

    申请日：1989-09-14

    申请人： COPAL COMPANY LIMITED ,  FUJITSU LIMITED

    发明人： Takagi, Masaaki

    IPC分类号： G11B7/09 ,  G11B7/08

    CPC分类号： G11B7/09 ,  G11B7/0932

    摘要： Light is condensed on a recording medium (20) by an objective lens (11), and light reflected from the recording medium passes through the objective lens and is split into light along two optical paths (P,5) via a condenser lens (5) and beam splitter (6). A light-receiving surface (7) having an area smaller than that of the irradiation pattern of the returned light when the objective is focused is disposed on the inner side of a focal point on one optical path, and an identical light-receiving surface (8) is disposed on the outer side of a focal point on the other optical path. The arrangement is such that the photoelectric outputs of the two light-receiving surfaces (7,8) coincide when the objective lens (11) is focused. Preferably, the light-receiving surface is divided into four portions by a straight line, which is obtained by projecting the track direction of the recording medium, and a region having line symmetry with respect to the straight line and an area smaller than that of the irradiation pattern when the objective is focused. A tracking error signal of the objective lens (11) is obtained by correcting a difference signal between light-receiving surfaces on the inner side by a low-frequency component of a difference signal between light-receiving surfaces on the outer side.

    摘要翻译： 光通过物镜（11）会聚在记录介质（20）上，并且从记录介质反射的光通过物镜并且经由聚光透镜（5）沿着两个光路（P，5）分离成光 ）和分束器（6）。 当物镜聚焦时，面积小于返回光的照射图案面积的光接收面（7）设置在一个光路上的焦点的内侧上，并且相同的光接收面（ 8）设置在另一光路上的焦点的外侧上。 当物镜（11）聚焦时，两个光接收表面（7,8）的光电输出一致。 优选地，光接收表面通过投影记录介质的轨道方向而获得的直线和相对于直线具有线对称性的区域以及小于该直线的区域被划分为四个部分 当目标集中时的照射模式。 物镜（11）的跟踪误差信号是通过将外侧的光接收表面之间的差信号的低频分量校正内侧的光接收表面之间的差信号而获得的。

    Optical head and tracking method using same
    6.
    发明公开
    Optical head and tracking method using same 失效
    使用相同的光头和跟踪方法

    公开(公告)号：EP0323320A3

    公开(公告)日：1990-05-30

    申请号：EP88403276.4

    申请日：1988-12-21

    申请人： COPAL COMPANY LIMITED

    发明人： Takagi, Masaaki c/o COPAL COMPANY LIMITED

    IPC分类号： G11B7/135 ,  G11B7/08 ,  G11B7/09

    CPC分类号： G11B7/1353 ,  G11B7/09

    摘要： An optical head (200) usable also for an WORM-type optical disk device includes a diffracting optical system (7, 8) which is located on the optical path of a light beam and which diffracts the light beam so as to produce at least three diffracted light beams, and three light-receiving elements which receive the reflected light beams of the three diffracted light beams from the surface of an optical disk. The diffracting optical system is arranged so as to establish a positional relationship in which the three or more diffracted light beams do not lie on a single straight line in the cross-sectional distribution thereof. Among the three diffracted light beams, one lying at the foremost or rearmost position in the forward rotating direction of the optical disk is employed for generating a focusing servo signal or for reading or writing data, and the remaining two are employed for generating a tracking servo signal.

    Optical pickup apparatus
    7.
    发明公开
    Optical pickup apparatus 失效
    Optische Abtasteinrichtung。

    公开(公告)号：EP0359670A2

    公开(公告)日：1990-03-21

    申请号：EP89402525.3

    申请日：1989-09-14

    申请人： COPAL COMPANY LIMITED ,  FUJITSU LIMITED

    发明人： Takagi, Masaaki

    IPC分类号： G11B7/09 ,  G11B7/08

    CPC分类号： G11B7/09 ,  G11B7/0932

    摘要： Light is condensed on a recording medium (20) by an objective lens (11), and light reflected from the recording medium passes through the objective lens and is split into light along two optical paths (P,5) via a condenser lens (5) and beam splitter (6). A light-receiving surface (7) having an area smaller than that of the irradiation pattern of the returned light when the objective is focused is disposed on the inner side of a focal point on one optical path, and an identical light-receiving surface (8) is disposed on the outer side of a focal point on the other optical path. The arrangement is such that the photoelectric outputs of the two light-receiving surfaces (7,8) coincide when the objective lens (11) is focused. Preferably, the light-receiving surface is divided into four portions by a straight line, which is obtained by projecting the track direction of the recording medium, and a region having line symmetry with respect to the straight line and an area smaller than that of the irradiation pattern when the objective is focused. A tracking error signal of the objective lens (11) is obtained by correcting a difference signal between light-receiving surfaces on the inner side by a low-frequency component of a difference signal between light-receiving surfaces on the outer side.

    摘要翻译： 光通过物镜（11）在记录媒体（20）上聚光，从记录介质反射的光经过物镜，经由聚光透镜（5）分离成沿着两条光路（P，5）的光 ）和分束器（6）。 当物镜被聚焦时，具有小于返回光的照射图案的面积的光接收表面（7）设置在一个光路上的焦点的内侧，以及相同的光接收表面 8）设置在另一光路上的焦点的外侧。 该布置使得当物镜（11）被聚焦时，两个光接收表面（7,8）的光电输出重合。 优选地，光接收表面通过投影记录介质的轨道方向获得的直线和相对于直线具有线对称性的区域和小于 当目标集中时的照射模式。 通过在外侧的光接收表面之间的差信号的低频分量校正内侧的光接收表面之间的差信号来获得物镜（11）的跟踪误差信号。

    ABSOLUTE ENCODER
    8.
    发明授权
    ABSOLUTE ENCODER 失效
    绝对编码

    公开(公告)号：EP0591550B1

    公开(公告)日：1998-03-18

    申请号：EP93908115.4

    申请日：1993-04-20

    申请人： COPAL COMPANY LIMITED

    发明人： TAKAGI, Masaaki, Copal Company Limited ,  FUKUDA, Takumi

    IPC分类号： G01D5/249 ,  G01D5/36 ,  H03M1/24

    CPC分类号： G01D5/34792 ,  G01D5/2497 ,  H03M1/26

    摘要： An absolute encoder comprises a moving member in which track groups (T2 and T1) consisting of a plurality of slit patterns bit-coded in accordance with digital code representing an absolute address such as a binary-coded quaternary code are parallelly arranged in a form from higher bits to lower bits; a light source for illuminating the member; photodetecting elements (1 and 2) which output detection signals (A0 to A3 ) for each track by receiving the illuminated light through the slit patterns; and processing means for processing the detected signals to generate bit reproducing signals (P0 to P3) and read the absolute addresses of the moving member by decoding. This processing means is provided with operating means (3 to 20) for generating the high order bit reproducing signals (P2 and P3) which are synchronized with the rising or falling of the low order bit reproducing signal (P0) by operating the low order detection signals (A0 to A0 ) obtained from the lower bit track (T1) and the high order detection signals (A2 to A3 ) obtained from the higher order bit track (T2). If the number of the tracks is increased, it is necessary to provide an arrangement in which the light which illuminates the lower order bit track is received through a magnifying optical system and at the same time, the light which illuminates the track on the high order bit side is received directly.

    Optical pickup apparatus comprising a focus adjusting apparatus
    10.
    发明授权
    Optical pickup apparatus comprising a focus adjusting apparatus 失效
    光学扫描与聚焦调节组件

    公开(公告)号：EP0454854B1

    公开(公告)日：1996-01-03

    申请号：EP90914962.7

    申请日：1990-10-15

    申请人： COPAL COMPANY LIMITED ,  FUJITSU LIMITED

    发明人： HOSOBATA, Nobuhiko ,  YOSHIKAWA, Yukio ,  TAKAGI, Masaaki

    IPC分类号： G11B7/09

    CPC分类号： G11B11/10576 ,  G11B7/0912 ,  G11B7/093 ,  G11B7/0932 ,  G11B7/094 ,  G11B7/0943 ,  G11B7/13 ,  G11B7/133 ,  G11B11/105

    摘要： A device for adjusting the focal point of an optical pickup device in which the light reflected by a recording medium is focused at points of two systems using an optical branching filter, first and second light detectors are disposed, respectively, in front of one focal point and at the back of the other focal point, and a focal point adjusting mechanism is servo-controlled in response to the outputs from the two light detectors. Each of the light detectors has a central light-receiving surface on the optical axis and a peripheral light-receiving surface in the periphery of the central light-receiving surface. According to a first method, the focal point adjusting mechanism is servo-controlled such that the deviation will become zero between the ratio of the amount of light received in the center to the total amount of light received in the center and periphery of the first light detector and the ratio of the amount of light in the center to the total amount of light in the center and periphery of the second light detector. Even if the two detectors receive different amounts of light, the difference is cancelled between the denominator and the numerator of the ratio of the amount of light in the center to the total amount of light in the center and periphery, and the device is not affected by the imbalance in the amount of light. According to a second method, the focal point adjusting mechanism is basically servo-controlled based on the difference between the amounts of light received in the centers of the two light detectors. Here, the difference in the total amount of light received by the two light detectors is calculated throughout all stages, and the difference is used to calculate a correction value multiplied by the component ratio of the amount of light in the center to the total amount of the light received in a focused condition. Since the calculated correction value is subtracted from the difference in the amount of light received in the centers, the servo output does not contain imbalance in the amount of light falling on the light detectors of the two systems, and the device is not affected by the imbalance in the amount of incident light.