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28 条记录 (耗时 0.021 秒)

    Waveform processing circuit
    1.
    发明授权
    Waveform processing circuit 失效
    波形处理电路

    公开(公告)号：US4785252A

    公开(公告)日：1988-11-15

    申请号：US916644

    申请日：1986-10-08

    申请人： Hiroshi Fuji ,  Takashi Iwaki ,  Tsuneo Fujiwara ,  Toshihisa Deguchi ,  Shozou Kobayashi

    发明人： Hiroshi Fuji ,  Takashi Iwaki ,  Tsuneo Fujiwara ,  Toshihisa Deguchi ,  Shozou Kobayashi

    IPC分类号： G11B5/035 ,  G11B20/10 ,  H03K5/00 ,  H03B1/00

    CPC分类号： G11B5/035 ,  G11B20/10009

    摘要： A waveform processing circuit includes a switching circuit having first and second inputs and one output. The first input receives head portions and data portions contained in a reproduced signal from an optical head. The second input receives a level signal representing the level of the head portion or the level of the signal carrying the head portion. The switching circuit is switches between a first state in which the first input and the output are connected, and a second state in which the second input and the output are connected. A control signal producer produces a first control pulse indicating the presence of the data portion. The first control pulse is applied to the switching circuit for actuating the switching circuit to establish the first state when the first control pulse is present, and to establish the second state when the first control pulse is not present, so that the switching circuit continuously produces the signal having a level within the range of the head portion. Thus, no abrupt change caused by transient phenomena will be observed in a high pass filter connected to the switching circuit.

    摘要翻译： 波形处理电路包括具有第一和第二输入和一个输出的开关电路。 第一输入接收来自光学头的再现信号中包含的头部和数据部分。 第二输入接收表示头部的电平的电平信号或承载头部的信号的电平。 切换电路是在连接第一输入和输出的第一状态与第二输入和输出连接的第二状态之间进行切换。 控制信号产生器产生指示数据部分的存在的第一控制脉冲。 当存在第一控制脉冲时，第一控制脉冲被施加到用于致动切换电路以建立第一状态的开关电路，并且当不存在第一控制脉冲时建立第二状态，使得开关电路连续产生 该信号具有在头部的范围内的电平。 因此，在连接到开关电路的高通滤波器中不会观察到由瞬态现象引起的突然变化。

    Digital signal reproduction apparatus for reading magneto-optical discs
    6.
    发明授权
    Digital signal reproduction apparatus for reading magneto-optical discs 失效
    用于读取磁光盘的数字信号再现装置

    公开(公告)号：US5166838A

    公开(公告)日：1992-11-24

    申请号：US498710

    申请日：1990-03-26

    申请人： Hiroshi Fuji ,  Takeshi Yamaguchi ,  Kunio Kojima ,  Toshihisa Deguchi ,  Shigeo Terashima ,  Tsuneo Fujiwara

    发明人： Hiroshi Fuji ,  Takeshi Yamaguchi ,  Kunio Kojima ,  Toshihisa Deguchi ,  Shigeo Terashima ,  Tsuneo Fujiwara

    IPC分类号： G11B20/10

    CPC分类号： G11B20/10009

    摘要： A digital signal reproduction apparatus includes a first differential circuit for differentiating a reproduction signal reproduced from a recording medium. This differential circuit outputs a first order differential signal. A second differential circuit differentiates the first order differential signal of the reproduction signal and outputs a second order differential signal. A comparator compares the second order differential signal with a predetermined level to produce a window signal. A peak detecting circuit detects zero-cross points in the first order differential signal and outputs a peak detecting signal. A gate gates the peak detecting signal with the window signal to output a reproduction data signal.

    摘要翻译： 数字信号再现装置包括用于区分从记录介质再现的再现信号的第一差分电路。 该差分电路输出一阶差分信号。 第二差分电路区分再现信号的一阶差分信号并输出​​二阶微分信号。 比较器将二阶差分信号与预定电平进行比较以产生窗口信号。 峰值检测电路检测一阶差分信号中的零交叉点，并输出峰值检测信号。 门通过窗口信号对峰值检测信号进行门极输出再现数据信号。

    Track access and laser beam alignment system for an optical recording and reproduction apparatus
    7.
    发明授权
    Track access and laser beam alignment system for an optical recording and reproduction apparatus 失效
    用于光学记录和再现装置的轨道访问和激光束对准系统

    公开(公告)号：US5107472A

    公开(公告)日：1992-04-21

    申请号：US376412

    申请日：1989-07-05

    申请人： Tsuneo Fujiwara ,  Masaru Nomura ,  Toshihisa Deguchi ,  Kunio Kojima ,  Takeshi Yamaguchi

    发明人： Tsuneo Fujiwara ,  Masaru Nomura ,  Toshihisa Deguchi ,  Kunio Kojima ,  Takeshi Yamaguchi

    IPC分类号： G11B7/0033 ,  G11B7/085 ,  G11B7/14 ,  G11B11/105

    CPC分类号： G11B11/10563 ,  G11B7/0033 ,  G11B7/085 ,  G11B7/14

    摘要： A track access operation system for an optical recording and reproducing apparatus using a medium having a plurality of guide grooves and ID sections utilized for identifying a particular guide groove. The intensity of reflected light and transmitted light from each of a plurality of light beams projected on the recording medium is monitored for determining the location of the beam on the disk. The system is designed such that at least either the plurality of light beams or the plurality of ID sections of the guide grooves are so arranged such that more than half of the light beams or more than half of the ID sections do not overlap in a parallel direction along the guide grooves whereby the number of light beams simultaneously projected on the ID sections is limited to less than half of the total number of light beams projected on the recording medium. Accordingly, even when the collection of light beams move in a perpendicular direction to the guide grooves, the number of pulses in the pulse signal is not influenced by the ID signals but coincident with the number of the guiding grooves through which the light beams have actually passed. With use of the optical memory system having such an arrangement, an accurate measurement of light beam movement is obtained resulting in high accuracy of access operations.

    Analog-to-digital conversion circuit for use in information reproduction apparatuses
    8.
    发明授权
    Analog-to-digital conversion circuit for use in information reproduction apparatuses 失效
    用于信息再现装置的模数转换电路

    公开(公告)号：US5673046A

    公开(公告)日：1997-09-30

    申请号：US294357

    申请日：1994-08-23

    申请人： Hiroshige Hirajima ,  Hiroshi Fuji ,  Tsuneo Fujiwara

    发明人： Hiroshige Hirajima ,  Hiroshi Fuji ,  Tsuneo Fujiwara

    IPC分类号： G11B7/005 ,  G11B11/105 ,  G11B20/10 ,  H03M1/06 ,  H03M1/36 ,  G11B20/00 ,  G11B5/09

    CPC分类号： G11B20/10009 ,  H03M1/0607 ,  G11B11/10515 ,  G11B7/005 ,  H03M1/365

    摘要： An A/D conversion circuit for use in an information reproduction apparatus, includes an envelope generator for extracting an upper-side envelope signal and a lower-side envelope signal from a reproduced signal read out from a recording medium, and an A/D converter for converting the reproduced signal into digital data by using a reference voltage that is obtained from a difference between an upper-side reference voltage and a lower-side reference voltage. In the analog-to-digital conversion circuit, the upper-side reference voltage is set to the level of the upper-side envelope signal, while the lower-side reference voltage is set to the level of the lower-side envelope signal. With this arrangement, the difference between the level of the upper-side envelope signal and the level of the lower-side envelope signal fluctuates together with an amplitude fluctuation component and a low-frequency superimposed component in a fluctuation of the reproduced signal. The reproduced signal is converted into digital data by using the difference as a reference voltage. This makes it possible to cancel the fluctuation of the reproduced signal. Thus, this arrangement makes it possible to obtain digital data free from deviations, as well as ensuring a proper response even to a quick fluctuation in the reproduced signal.

    摘要翻译： 一种在信息再现装置中使用的A / D转换电路，包括：包络发生器，用于从从记录介质读出的再现信号中提取上侧包络信号和下侧包络信号;以及A / D转换器 用于通过使用从上侧参考电压和下侧参考电压之间的差获得的参考电压将再现信号转换为数字数据。 在模数转换电路中，将上侧基准电压设定为上侧包络信号的电平，将下侧基准电压设定为下侧包络信号的电平。 利用这种布置，上侧包络信号的电平和下侧包络信号的电平之间的差与振幅波动分量和再现信号的波动中的低频叠加分量一起波动。 通过使用差作为参考电压将再生信号转换成数字数据。 这使得可以消除再现信号的波动。 因此，这种布置使得可以获得没有偏差的数字数据，以及即使对于再现信号的快速波动也确保适当的响应。

    Record face identifying device for magneto-optic record medium
    9.
    发明授权
    Record face identifying device for magneto-optic record medium 失效
    用于磁光记录介质的记录面识别装置

    公开(公告)号：US4993012A

    公开(公告)日：1991-02-12

    申请号：US201908

    申请日：1988-06-03

    申请人： Hiroshi Fuji ,  Tomiyuki Numata ,  Tsuneo Fujiwara ,  Kentaroh Tsuji

    发明人： Hiroshi Fuji ,  Tomiyuki Numata ,  Tsuneo Fujiwara ,  Kentaroh Tsuji

    IPC分类号： G11B11/10 ,  G11B11/105

    CPC分类号： G11B11/10597

    摘要： A magneto-optic record signal processing system uses a linearly polarized light beam to be projected onto a magneto-optic medium and a recorded signal is reproduced by analyzing the polarized conditions of a reflected light beam from the medium. This processing system also includes a recording face identifying device for determining the recording face of the magneto-optic record medium. To determine the recording face, an initialized area projecting device projects a light beam onto an initialized area of a magneto-optic record medium. A transducing circuit then converts a slant in a polarization plane of a reflected light beam from the initialized area into a light intensity. A photo-detector detects the light intensity outputted from the transducing means and a comparator compares the output from the photo-detector with a reference level to determine the magnetization of the recording face.