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公开(公告)号：US5629914A
公开(公告)日：1997-05-13
申请号：US407125
申请日：1995-03-20
IPC分类号： G11B7/0037 , G11B20/10 , G11B7/00
CPC分类号： G11B20/10203 , G11B20/10037 , G11B7/00375
摘要： In a pulse width modulated read signal channel for an optical disk drive, a data-transition threshold is maintained for data detection by a threshold tracking circuit that estimates the amplitude centerline data-transition threshold from the most recent maximum and minimum values of the read signal waveform. To improve the accuracy of the response of the centerline estimator, the threshold is increased or decreased based on the phase error at each read signal transition through the data-transition threshold. In addition, defects in the optical recording media are detected, and a defect present signal is used to inhibit the transition phase error input to the centerline estimator. This prevents the estimator from moving the threshold to an incorrect stable level. In addition, the defect present signal boosts the error feedback in the centerline estimator. The estimator then more quickly follows the read signal waveform. As a result, the estimator reacquires the centerline of the waveform after the read head moves past the defect without retriggering the defect detection circuit.
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公开(公告)号：US5502711A
公开(公告)日：1996-03-26
申请号：US407124
申请日：1995-03-20
IPC分类号： G11B7/005 , G11B11/105 , G11B20/14 , H03L7/07 , G11B7/00
CPC分类号： G11B20/1423 , H03L7/07 , G11B11/10515 , G11B7/005
摘要： A digital phase lock loop channel is provided for threshold detection of a pulse width modulated binary data stream that has negative and positive transitions defining one binary state of the data stream. A threshold-establishing and transition-detecting network receives this data stream and provides a first output of one polarity corresponding to the detection of a positive transition, a second output of an opposite polarity corresponding to the detection of a negative transition, and a time-of-arrival output corresponding to a positive and a negative transition. A first and a second digital PLL is provided, each PLL having a transition input, a time-of-arrival input, a phase-error input, a phase error output a data-valid output, and a data output. Each PLL has an internal digital phase detector network connected to receive its transition input and its time-of-arrival input, and each PLL is operable to generate the phase error output therefrom. Each PLL has an internal digital loop filter connected to receive the phase error output generated by its phase detector network, and to receive the phase error output that is generated by the other PLL. The output of the loop filter of each PLL is connected to the data-valid and data outputs of its respective PLL.
摘要翻译： 提供数字锁相环通道，用于阈值检测脉冲宽度调制二进制数据流，其具有定义数据流的一个二进制状态的负和正转换。 阈值建立和转移检测网络接收该数据流并且提供与正转移的检测相对应的一个极性的第一输出，对应于负转变检测的相反极性的第二输出， 到达输出对应于正和负转换。 提供第一和第二数字PLL，每个PLL具有转换输入，到达时间输入，相位误差输入，相位误差输出数据有效输出和数据输出。 每个PLL具有内部数字相位检测器网络，其连接以接收其转换输入及其到达时间输入，并且每个PLL可操作以从其产生相位误差输出。 每个PLL都有一个内部数字环路滤波器，用于接收相位检测器网络产生的相位误差输出，并接收由另一个PLL产生的相位误差输出。 每个PLL的环路滤波器的输出连接到其相应PLL的数据有效和数据输出。
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公开(公告)号：US5530601A
公开(公告)日：1996-06-25
申请号：US129531
申请日：1993-09-30
CPC分类号： H04L25/062 , G11B20/10009 , G11B5/09
摘要： A method and apparatus for detecting peaks in a signal which comprises an alternating polarity waveform including a plurality of points. A selected point in the signal is designated. Thereafter, a threshold value for the selected point is established utilizing a prior threshold value associated set off with spaces with a point prior to the selected point as follows:(m(n)=t0*ax(n)+t1*m(n-1)wherein n is the point identifier, m(n) is the threshold value, t0 is a fixed positive constant less than one, t1 is a fixed positive constant less than one, ax(n) is the absolute value of the input signal, and m(n-1) is the prior threshold value for the prior point. In this manner the threshold value may be adjusted for fluctuations in amplitude of the signal. Next, the selected point is compared with the threshold value to determine whether or not the selected point is within a predetermined distance of the threshold. If the selected point is within the predetermined distance of the threshold value, a determination is made as to whether or not the selected point represents a peak in order to ascertain the presence of a logic one at the selected point, wherein digital data may be detected in a signal.
摘要翻译： 一种用于检测信号中的峰值的方法和装置，其包括包括多个点的交替极性波形。 指定信号中的选定点。 此后，利用与所选点之前的点的空间相关联的先前阈值建立所选点的阈值，如下：（m（n）= t0 * ax（n）+ t1 * m -1）其中n是点标识符，m（n）是阈值，t0是小于1的固定正常数，t1是小于1的固定正常数，ax（n）是输入的绝对值 信号，并且m（n-1）是先前点的先前阈值，以这种方式，可以根据信号幅度的波动来调整阈值。接下来，将所选择的点与阈值进行比较以确定是否 或者所选择的点不在阈值的预定距离内，如果所选择的点在阈值的预定距离内，则确定所选择的点是否表示峰，以确定是否存在 在选定点的逻辑1，其中数字数据可以 在信号中检测。
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公开(公告)号：US5508855A
公开(公告)日：1996-04-16
申请号：US418691
申请日：1995-04-07
CPC分类号： H04L25/062 , G11B20/10009 , G11B5/09
摘要： A method and apparatus for detecting peaks in a signal which comprises an alternating polarity waveform including a plurality of points. A selected point in the signal is designated. Thereafter, a threshold value for the selected point is established utilizing a prior threshold value associated set off with spaces with a point prior to the selected point as follows:(m(n)=t0*ax(n)+t1*m(n-1))wherein n is the point identifier, m(n) is the threshold value, t0 is a fixed positive constant less than one, t1 is a fixed positive constant less than one, ax(n) is the absolute value of the input signal, and m(n-1) is the prior threshold value for the prior point. In this manner the threshold value may be adjusted for fluctuations in amplitude of the signal. Next, the selected point is compared with the threshold value to determine whether or not the selected point is within a predetermined distance of the threshold. If the selected point is within the predetermined distance of the threshold value, a determination is made as to whether or not the selected point represents a peak in order to ascertain the presence of a logic one at the selected point, wherein digital data may be detected in a signal.
摘要翻译： 一种用于检测信号中的峰值的方法和装置，其包括包括多个点的交替极性波形。 指定信号中的选定点。 此后，利用与所选点之前的点的空间相关联的先前阈值建立所选点的阈值，如下：（m（n）= t0 * ax（n）+ t1 * m -1））其中n是点标识符，m（n）是阈值，t0是小于1的固定正常数，t1是小于1的固定正常数，ax（n）是 输入信号，m（n-1）是先前点的先前阈值。 以这种方式，可以根据信号幅度的波动调节阈值。 接下来，将所选择的点与阈值进行比较，以确定所选择的点是否在阈值的预定距离内。 如果所选择的点在阈值的预定距离之内，则确定所选择的点是否表示峰，以确定在所选择的点处存在逻辑1，其中可以检测数字数据 在一个信号。
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5.发明授权Error controlled volume serial identification for varied track density systems 失效用于不同轨道密度系统的错误控制卷序列识别
公开(公告)号：US5420727A
公开(公告)日：1995-05-30
申请号：US186363
申请日：1994-01-24
CPC分类号： G11B20/1833 , G11B20/1205 , G11B27/32 , G11B2220/90
摘要： A tape drive subsystem discloses that variable length symbols can be used to reliably identify data stored on the tape. Machine controlling procedures are disclosed to encode and decode data for the reliable sensing of the serial number of a media, especially tape cartridges, having different track densities. The subsystem detects the serial number of the media and corrects, or at least detects, error patterns. A variable length symbol code is encoded in a plurality of groups with each group having a "one" being represented as an erase gap ERG signal covering a first two units of a group, and a "zero" is represented as one unit of an ERG signal, both followed by four units of an Inter Block Gap IBG signal.
摘要翻译： 磁带驱动器子系统公开了可变长度符号可用于可靠地识别存储在磁带上的数据。 公开了机器控制程序以对用于可靠地感测具有不同轨道密度的介质（特别是带盒）的序列号的数据进行编码和解码。 子系统检测介质的序列号并纠正或至少检测到错误模式。 可变长度符号码被编码在多个组中，每个组具有“1”的组被表示为覆盖组的前两个单元的擦除间隙ERG信号，并且“零”表示为ERG的一个单位 信号，两者之后是四个单位的Inter Block Gap IBG信号。
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