公开(公告)号：US5583650A

公开(公告)日：1996-12-10

申请号：US462877

申请日：1995-06-05

申请人： Frank A. Lane ,  Jill M. Boyce ,  Jack S. Fuhrer ,  John G. N. Henderson ,  Katsuo Mohri ,  Masafumi Nakamura ,  Takaharu Noguchi ,  Hiroo Okamoto ,  Masuo Oku ,  Michael A. Plotnick

发明人： Frank A. Lane ,  Jill M. Boyce ,  Jack S. Fuhrer ,  John G. N. Henderson ,  Katsuo Mohri ,  Masafumi Nakamura ,  Takaharu Noguchi ,  Hiroo Okamoto ,  Masuo Oku ,  Michael A. Plotnick

IPC分类号： G11B5/008 ,  G11B5/09 ,  G11B15/12 ,  G11B15/18 ,  G11B20/12 ,  G11B27/00 ,  G11B27/30 ,  H04N5/44 ,  H04N5/775 ,  H04N5/7826 ,  H04N5/783 ,  H04N5/93 ,  H04N5/945 ,  H04N7/015 ,  H04N7/26 ,  H04N7/52 ,  H04N9/78 ,  H04N9/79 ,  H04N9/804 ,  H04N9/806 ,  H04N9/82 ,  H04N9/888 ,  H04N19/89 ,  H04N5/76 ,  H04N5/78

CPC分类号： H04N21/4147 ,  G11B15/1875 ,  G11B20/1207 ,  G11B27/005 ,  G11B27/3027 ,  H04N19/37 ,  H04N19/89 ,  H04N21/4334 ,  H04N5/4401 ,  H04N5/93 ,  H04N7/015 ,  H04N7/52 ,  H04N9/78 ,  H04N9/8042 ,  H04N9/8047 ,  G11B15/125 ,  G11B2220/90 ,  G11B5/0086 ,  G11B5/09 ,  H04N5/775 ,  H04N5/78263 ,  H04N5/78266 ,  H04N5/783 ,  H04N5/945 ,  H04N9/7921 ,  H04N9/8066 ,  H04N9/8227 ,  H04N9/888

摘要： Methods of operating a digital video recording and playback device, such as a video tape recorder, to arrange trick play data into one or more groups, to generate error correction bits for each group of trick play data, e.g., a group of trick play data blocks, and to correct the data after being read back using the error correction bits is disclosed. The trick play data blocks are made to be smaller than normal play data blocks with multiple trick play data blocks being equal in size to a single normal play data block. By making a group of trick play data blocks equal in size to a single normal play data block, the group of trick play data blocks may be processed as a unit by the same error correction circuitry and in the same manner used to process individual normal play data blocks. In accordance with one embodiment, the error correction bits for a group of trick play data blocks are calculated treating the data in the group of trick play data blocks as a single unit. The error correction bits are appended to the last data block in the group of trick play data blocks. During trick play operation the trick play data blocks are read back and combined according to trick play data groups. Each group of trick play blocks is then processed using the same error correction circuitry used to process a normal play data block.

摘要翻译： 操作诸如磁带录像机的数字视频记录和回放设备的方法来将特技播放数据排列到一个或多个组中，以为每组特技播放数据生成纠错位，例如一组特技播放数据 块，并且在使用误差校正位读取之后校正数据被公开。 使特技播放数据块小于具有与单个正常播放数据块大小相等的多个特技播放数据块的普通播放数据块。 通过使一组特技播放数据块的大小与单个正常播放数据块相等，该特技播放数据块组可以通过相同的纠错电路以与用于处理各个正常播放相同的方式作为一个单元来处理 数据块。 根据一个实施例，计算一组特技播放数据块的纠错位，将特技播放数据块组中的数据作为一个单位处理。 误差校正位附加到特技播放数据块组中的最后一个数据块。 在特技播放操作期间，根据特技播放数据组读取并组合特技播放数据块。 然后使用用于处理正常播放数据块的相同的纠错电路处理每组特技播放块。

公开(公告)号：US5623344A

公开(公告)日：1997-04-22

申请号：US293639

申请日：1994-08-19

申请人： Frank A. Lane ,  Joseph E. Augenbraun ,  Jill M. Boyce ,  Jack S. Fuhrer ,  John G. N. Henderson ,  Katsuo Mohri ,  Masafumi Nakamura ,  Takaharu Noguchi ,  Hiroo Okamoto ,  Masuo Oku ,  Michael A. Plotnick

发明人： Frank A. Lane ,  Joseph E. Augenbraun ,  Jill M. Boyce ,  Jack S. Fuhrer ,  John G. N. Henderson ,  Katsuo Mohri ,  Masafumi Nakamura ,  Takaharu Noguchi ,  Hiroo Okamoto ,  Masuo Oku ,  Michael A. Plotnick

IPC分类号： G11B5/008 ,  G11B5/09 ,  G11B15/12 ,  G11B15/18 ,  G11B20/12 ,  G11B27/00 ,  G11B27/30 ,  H04N5/44 ,  H04N5/775 ,  H04N5/7826 ,  H04N5/783 ,  H04N5/93 ,  H04N5/945 ,  H04N7/015 ,  H04N7/26 ,  H04N7/52 ,  H04N9/78 ,  H04N9/79 ,  H04N9/804 ,  H04N9/806 ,  H04N9/82 ,  H04N9/888 ,  H04N19/89 ,  H04N5/76 ,  H04N5/78

CPC分类号： G11B15/1875 ,  G11B20/1207 ,  G11B27/005 ,  G11B27/3027 ,  H04N19/37 ,  H04N19/89 ,  H04N21/4147 ,  H04N21/4334 ,  H04N5/4401 ,  H04N5/93 ,  H04N7/015 ,  H04N7/52 ,  H04N9/78 ,  H04N9/8042 ,  H04N9/8047 ,  G11B15/125 ,  G11B2220/90 ,  G11B5/0086 ,  G11B5/09 ,  H04N5/775 ,  H04N5/78263 ,  H04N5/78266 ,  H04N5/783 ,  H04N5/945 ,  H04N9/7921 ,  H04N9/8066 ,  H04N9/8227 ,  H04N9/888

摘要： A digital video tape recorder ("VTR") that selects data useful for generating images during trick playback operation and records the data in trick play tape segments arranged on a tape to form fast scan tracks and multi-speed playback tracks. Each fast scan track comprises trick play tape segments located on a diagonal, relative to the length of the tape, of the same angle as the angle at which the heads of a VTR are expected to pass over the tape during trick play operation at a specific speed and direction of operation. Each multi-speed playback track comprises a plurality of trick play tape segments arranged parallel to the length of the tape. Data which is used for at least one mode of trick play operation is recorded in each trick play tape segment. Each fast scan track and multi-speed track crosses multiple normal play tracks. During playback at a wide variety of speeds and directions, the heads pass over enough trick play segments of the multi-speed playback track to generate recognizable images during trick play operation. Data is recorded in each trick play segment in a manner that optimizes the amount of data that can be routinely recovered during trick playback operation despite tracking errors.

摘要翻译： 一种数字录像机（“VTR”），其选择在特技播放操作期间生成图像的数据，并将数据记录在布置在磁带上的特技播放磁带段中以形成快速扫描轨道和多速重放轨道。 每个快速扫描轨道包括相对于磁带长度位于对角线上的特技播放磁带段，其角度与在特定播放操作期间期望VTR的磁头经过磁带的角度相同的角度 速度和操作方向。 每个多速播放轨道包括平行于磁带的长度布置的多个特技播放磁带片段。 用于至少一种特技播放操作模式的数据被记录在每个特技播放磁带段中。 每个快速扫描轨道和多速度轨道穿过多个正常播放轨道。 在以各种各样的速度和方向播放期间，头部通过多速播放轨道的足够的特技播放段，以在特技播放操作期间产生可识别的图像。 数据被记录在每个特技播放段中，以尽可能优化在特技重放操作期间常规恢复的数据量，尽管跟踪错误。

公开(公告)号：US5729649A

公开(公告)日：1998-03-17

申请号：US716784

申请日：1996-09-05

申请人： Frank Anton Lane ,  Joseph Ellis Augenbraun ,  Jill MacDonald Boyce ,  Jack Selig Fuhrer ,  John Goodchilde Norie Henderson ,  Katsuo Mohri ,  Masafumi Nakamura ,  Takaharu Noguchi ,  Hiroo Okamoto ,  Masuo Oku ,  Michael Allen Plotnick

发明人： Frank Anton Lane ,  Joseph Ellis Augenbraun ,  Jill MacDonald Boyce ,  Jack Selig Fuhrer ,  John Goodchilde Norie Henderson ,  Katsuo Mohri ,  Masafumi Nakamura ,  Takaharu Noguchi ,  Hiroo Okamoto ,  Masuo Oku ,  Michael Allen Plotnick

IPC分类号： G11B5/008 ,  G11B5/09 ,  G11B15/12 ,  G11B15/18 ,  G11B20/12 ,  G11B27/00 ,  G11B27/30 ,  H04N5/44 ,  H04N5/775 ,  H04N5/7826 ,  H04N5/783 ,  H04N5/93 ,  H04N5/945 ,  H04N7/015 ,  H04N7/26 ,  H04N7/52 ,  H04N9/78 ,  H04N9/79 ,  H04N9/804 ,  H04N9/806 ,  H04N9/82 ,  H04N9/888 ,  H04N19/89 ,  H04N5/91

CPC分类号： G11B15/1875 ,  G11B20/1207 ,  G11B27/005 ,  G11B27/3027 ,  H04N19/37 ,  H04N19/89 ,  H04N21/4147 ,  H04N21/4334 ,  H04N5/4401 ,  H04N5/93 ,  H04N7/015 ,  H04N7/52 ,  H04N9/78 ,  H04N9/8042 ,  H04N9/8047 ,  G11B15/125 ,  G11B2220/90 ,  G11B5/0086 ,  G11B5/09 ,  H04N5/775 ,  H04N5/78263 ,  H04N5/78266 ,  H04N5/783 ,  H04N5/945 ,  H04N9/7921 ,  H04N9/8066 ,  H04N9/8227 ,  H04N9/888

摘要： A digital video tape recorder ("VTR") that selects data useful for generating images during trick playback operation and records the data in trick play tape segments arranged on a tape to form fast scan tracks and multi-speed playback tracks. Each fast scan track comprises trick play tape segments located on a diagonal, relative to the length of the tape, of the same angle as the angle at which the heads of a VTR are expected to pass over the tape during trick play operation at a specific speed and direction of operation. Each multi-speed playback track comprises a plurality of trick play tape segments arranged parallel to the length of the tape. Data which is used for at least one mode of trick play operation is recorded in each trick play tape segment. Each fast scan track and multi-speed track crosses multiple normal play tracks. During playback at a wide variety of speeds and directions, the heads pass over enough trick play segments of the multi-speed playback track to generate recognizable images during trick play operation. Data is recorded in each trick play segment in a manner that optimizes the amount of data that can be routinely recovered during trick playback operation despite tracking errors.

摘要翻译： 一种数字录像机（“VTR”），其选择在特技播放操作期间生成图像的数据，并将数据记录在布置在磁带上的特技播放磁带段中以形成快速扫描轨道和多速重放轨道。 每个快速扫描轨道包括相对于磁带长度位于对角线上的特技播放磁带段，其角度与在特定播放操作期间期望VTR的磁头经过磁带的角度相同的角度 速度和操作方向。 每个多速播放轨道包括平行于磁带的长度布置的多个特技播放磁带片段。 用于至少一种特技播放操作模式的数据被记录在每个特技播放磁带段中。 每个快速扫描轨道和多速度轨道穿过多个正常播放轨道。 在以各种各样的速度和方向播放期间，头部通过多速播放轨道的足够的特技播放段，以在特技播放操作期间产生可识别的图像。 数据被记录在每个特技播放段中，以尽可能优化在特技重放操作期间常规恢复的数据量，尽管跟踪错误。

公开(公告)号：US5687275A

公开(公告)日：1997-11-11

申请号：US463336

申请日：1995-06-05

申请人： Frank Anton Lane ,  Joseph Ellis Augenbraun ,  Jill MacDonald Boyce ,  Jack Selig Fuhrer ,  John Goodchilde Norie Henderson ,  Katsuo Mohri ,  Masafumi Nakamura ,  Takaharu Noguchi ,  Hiroo Okamoto ,  Masuo Oku ,  Michael Allen Plotnick

发明人： Frank Anton Lane ,  Joseph Ellis Augenbraun ,  Jill MacDonald Boyce ,  Jack Selig Fuhrer ,  John Goodchilde Norie Henderson ,  Katsuo Mohri ,  Masafumi Nakamura ,  Takaharu Noguchi ,  Hiroo Okamoto ,  Masuo Oku ,  Michael Allen Plotnick

IPC分类号： G11B5/008 ,  G11B5/09 ,  G11B15/12 ,  G11B15/18 ,  G11B20/12 ,  G11B27/00 ,  G11B27/30 ,  H04N5/44 ,  H04N5/775 ,  H04N5/7826 ,  H04N5/783 ,  H04N5/93 ,  H04N5/945 ,  H04N7/015 ,  H04N7/26 ,  H04N7/52 ,  H04N9/78 ,  H04N9/79 ,  H04N9/804 ,  H04N9/806 ,  H04N9/82 ,  H04N9/888 ,  H04N19/89 ,  H04N5/91

CPC分类号： G11B15/1875 ,  G11B20/1207 ,  G11B27/005 ,  G11B27/3027 ,  H04N19/37 ,  H04N19/89 ,  H04N21/4147 ,  H04N21/4334 ,  H04N5/4401 ,  H04N5/93 ,  H04N7/015 ,  H04N7/52 ,  H04N9/78 ,  H04N9/8042 ,  H04N9/8047 ,  G11B15/125 ,  G11B2220/90 ,  G11B5/0086 ,  G11B5/09 ,  H04N5/775 ,  H04N5/78263 ,  H04N5/78266 ,  H04N5/783 ,  H04N5/945 ,  H04N9/7921 ,  H04N9/8066 ,  H04N9/8227 ,  H04N9/888

摘要： Methods of operating a digital video recording and playback device to identify trick play data, e.g., data that is intended for use during trick play modes of video playback device operation such as fast forward and reverse, by recording headers containing specific trick play information along with the trick play data are described. In one embodiment, the recording of headers which identify data as data intended for use during trick play as opposed to normal play operation is described. In addition to identifying data recorded data as normal play or trick play data headers associated with recorded data may identify the speed and direction of video tape recorder operation during which the specific data associated with the header is intended to be displayed at. When a data block includes data packets, a header may be used to identify various ones of the data packets as being for use during one mode of trick play operation, e.g., a first fast forward speed of operation, and other packets in the same data block as being for use during a second mode of trick play operation.

摘要翻译： 操作数字视频记录和回放设备以识别特技播放数据的方法，例如，通过记录包含特定特技播放信息的标题以及包含特定的特技播放信息的标题，以及诸如快进和反向的视频播放设备操作的特技播放模式期间使用的数据，以及 描述特技播放数据。 在一个实施例中，描述了与正常播放操作相反，标识数据作为要在特技播放期间使用的数据的标题的记录。 除了将数据记录的数据识别为正常播放或与记录的数据相关联的特技播放数据头可以识别录像机操作的速度和方向，在此期间，与标题相关联的特定数据将被显示在其上。 当数据块包括数据分组时，可以使用报头来将各种数据分组识别为在特技播放操作的一种模式期间使用，例如，第一快进操作速度和相同数据中的其他分组 作为在特技播放操作的第二模式期间使用的块。

公开(公告)号：US4843493A

公开(公告)日：1989-06-27

申请号：US838958

申请日：1986-03-12

申请人： Takashi Furuhata ,  Yasufumi Yumde ,  Fujio Okamura ,  Takaharu Noguchi ,  Toshifumi Shibuya ,  Katsuo Mohri ,  Takao Arai ,  Toshimichi Terada

发明人： Takashi Furuhata ,  Yasufumi Yumde ,  Fujio Okamura ,  Takaharu Noguchi ,  Toshifumi Shibuya ,  Katsuo Mohri ,  Takao Arai ,  Toshimichi Terada

IPC分类号： G11B15/467 ,  G11B15/473

CPC分类号： G11B15/4672 ,  G11B15/4678 ,  G11B15/4738

摘要： A method of producing a tracking control signal in a rotary head type magnetic recording and reproducing apparatus and a rotary head type magnetic recording and reproducing apparatus capable of a proper tracking by the use of the tracking control signal. First and second tracking signals are recorded on local portions of each odd-numbered track and the first tracking signal and a third tracking signal are recorded on local portions of each even-numbered track in such a manner that the second tracking signals on two odd-numbered track adjacent to any one even-numbered track are not overlapped with each other and the third tracking signals on two even-numbered tracks adjacent to any one odd-numbered track are not overlapped with each other when viewed in a direction perpendicular to the longitudinal direction of the tracks; upon scanning of a track crosstalk signals are detected from two adjacent track simultaneously with reproduction of the first and second or third tracking signals; and the detected crosstalk signals are compared by the use of timing of the reproduction of the first tracking signal for each track thereby producing a tracking control signal. The second tracking signal may have a frequency equal to that of the third tracking frequency.

摘要翻译： 一种在旋转磁头式磁记录和再现装置中产生跟踪控制信号的方法以及能够通过使用跟踪控制信号进行适当跟踪的旋转磁头型磁记录和再现装置。 第一跟踪信号和第二跟踪信号被记录在每个奇数号的轨道的本地部分上，并且第一跟踪信号和第三跟踪信号被记录在每个偶数轨迹的本地部分上， 与任何一个偶数编号的轨道相邻的编号轨道彼此不重叠，并且在与任何一个奇数编号的轨道相邻的两个偶数轨道上的第三跟踪信号在垂直于纵向的方向上观察时不彼此重叠 轨道方向; 在轨道的扫描时，与第一和第二或第三跟踪信号的再现同时从两个相邻轨道检测串扰信号; 并且通过使用每个轨道的第一跟踪信号的再现的定时来比较检测到的串扰信号，从而产生跟踪控制信号。 第二跟踪信号可以具有等于第三跟踪频率的频率。

公开(公告)号：US4338645A

公开(公告)日：1982-07-06

申请号：US90610

申请日：1979-11-02

申请人： Katsuo Mohri ,  Yoshinori Okada

发明人： Katsuo Mohri ,  Yoshinori Okada

IPC分类号： G11B27/17 ,  G11B27/34 ,  G06F15/20

CPC分类号： G11B27/34 ,  G11B27/17 ,  G11B2220/90

摘要： In a video tape recorder or audio tape recorder, the remaining tape length indicated as time or taken-up tape length indicated as time is calculated by use of microcomputer and then accurately indicated as a time length by detecting the angular velocities of a supply reel and a take-up reel. A rotational period of time of each reel is detected twice, so that the tape running speed is calculated from the two detected values and the known tape caliper thickness, thus calculating and indicating the remaining tape length indicated as time and the taken-up tape length indicated as time. The remaining tape length and taken-up tape length indicated as time in such operation modes of a tape recorder as fast forward, and rewind, as well as recording and reproduction are accurately indicated.

摘要翻译： 在磁带录像机或音频磁带录像机中，以时间表示的剩余磁带长度表示为时间，利用微型计算机计算，然后通过检测供电卷轴的角速度而准确地表示为时间长度， 收卷卷轴。 每个卷轴的旋转时间段被检测两次，从而根据两个检测值和已知的带钳厚度计算带运行速度，从而计算并指示作为时间指示的剩余带长度和卷带长度 以时间表示。 在磁带录音机的这种操作模式中指示的剩余磁带长度和卷带长度如快进和倒带以及记录和再现被准确地指示。

公开(公告)号：US4581659A

公开(公告)日：1986-04-08

申请号：US564904

申请日：1983-12-23

申请人： Nobuo Azuma ,  Kenji Satoh ,  Katsuo Mohri ,  Yoshinori Masuda

发明人： Nobuo Azuma ,  Kenji Satoh ,  Katsuo Mohri ,  Yoshinori Masuda

IPC分类号： H04N5/783 ,  G11B15/18 ,  G11B15/46 ,  G11B15/467

CPC分类号： G11B15/1875 ,  G11B15/1808

摘要： A method and apparatus for reproducing information at variable speeds from a magnetic tape by correcting a deviation between at least one video track of the magnetic tape and a rotating head during a tape stop state of an intermittent drive for a noiseless slow-still picture in a video tape recorder using pilot signals. A series of pulses produced by a frequency generator of a capstan for feeding the tape is counted during the tape feeding state of an intermittent drive in order to detect a timing of the stopping of the tape feeding. As the count number equals a set value corresponding to a regular amount of feeding of the tape during the intermittent drive, the tape feeding is controlled to stop. A tracking error signal is produced from the pilot signals reproduced from the tape by the rotating head within the tape stop state of the intermittent drive and the set value for the next tape feeding of the intermittent drive is adjusted in response to the tracking error signal.

摘要翻译： 一种方法和装置，用于通过在磁带的至少一个视频轨道和旋转磁头之间的偏差中再现来自磁带的可变速度的信息，该方法和装置在用于无噪声慢静止图像的间歇驱动的磁带停止状态 录像机使用导频信号。 在间歇驱动的带馈送状态期间，计数由用于馈送带的绞盘的频率发生器产生的一系列脉冲，以便检测送带停止的定时。 由于计数值等于在间歇驱动期间对应于规定的送带量的设定值，因此控制送带被停止。 在间歇驱动的磁带停止状态下，通过旋转磁头从磁带再生的导频信号产生跟踪误差信号，并且响应于跟踪误差信号调整间歇驱动的下一个磁带馈送的设定值。

公开(公告)号：US4507690A

公开(公告)日：1985-03-26

申请号：US382104

申请日：1982-05-26

申请人： Nobuo Azuma ,  Kenji Satoh ,  Katsuo Mohri ,  Takashi Furuhata

发明人： Nobuo Azuma ,  Kenji Satoh ,  Katsuo Mohri ,  Takashi Furuhata

IPC分类号： H04N5/7826 ,  G11B15/02 ,  G11B27/024 ,  G11B27/028 ,  H04N5/765 ,  H04N5/77 ,  H04N5/78

CPC分类号： G11B15/02 ,  G11B27/028 ,  H04N5/77 ,  G11B2220/90 ,  G11B27/024 ,  Y10S358/906

摘要： A device for controlling consecutive recording of video information containing signals, on a magnetic recording medium in a magnetic recording and reproducing apparatus, fed from a video camera with variable time spacing. The device comprises a control switch rendered non-conductive or conductive when a pause switch in the magnetic recording and reproducing apparatus is actuated or released, and a member for initializing a sync signal generator in the video camera with a signal produced in synchronism with the rotation of a head carrying disc driving motor of the magnetic recording and reproducing apparatus, whereby energy consumption is lowered and synchronization between successive video information signals is attained rapidly during the consecutive recording of video information signals from the video camera.

摘要翻译： 一种用于控制在具有可变时间间隔的摄像机馈送的磁记录和再现装置中的磁记录介质上连续记录包含信号的视频信息的装置。 该装置包括当磁记录和再现装置中的暂停开关被致动或释放时呈现非导通或导通的控制开关，以及用于利用与旋转同步产生的信号来初始化摄像机中的同步信号发生器的构件 的磁记录和再现装置的磁头驱动电动机，由此能量消耗降低，并且在从摄像机连续记录视频信息信号期间快速获得连续的视频信息信号之间的同步。

公开(公告)号：US4453186A

公开(公告)日：1984-06-05

申请号：US294059

申请日：1981-08-18

申请人： Yoshizumi Watatani ,  Shigeyuki Ito ,  Katsuo Mohri

发明人： Yoshizumi Watatani ,  Shigeyuki Ito ,  Katsuo Mohri

IPC分类号： H04N5/7826 ,  G11B20/00 ,  H04N5/91 ,  H04N5/92 ,  H04N9/835 ,  H04N5/782

CPC分类号： H04N9/8355 ,  H04N5/92

摘要： A sound signal recording and reproducing device for use in a picture signal recording and reproducing apparatus comprises a first sound signal recording and reproducing system recording a sound signal in superposed relation with a picture signal on the same track on a magnetic tape by a rotary head, and a second sound signal recording and reproducing system capable of recording a sound signal independently of the picture signal by a stationary head in a direction parallel with the traveling direction of the magnetic tape.

摘要翻译： 用于图像信号记录和再现装置的声音信号记录和再现装置包括：第一声音信号记录和再现系统，通过旋转磁头在磁带上的相同轨道上记录与图像信号重叠关系的声音信号， 以及第二声音信号记录和再现系统，其能够在与磁带的行进方向平行的方向上通过静止头部独立于图像信号记录声音信号。

公开(公告)号：US3978284A

公开(公告)日：1976-08-31

申请号：US438680

申请日：1974-02-01

申请人： Takehiko Yoshino ,  Katsuo Mohri

发明人： Takehiko Yoshino ,  Katsuo Mohri

IPC分类号： H03M5/20 ,  H03K5/007 ,  H04L25/06 ,  H04N1/00 ,  H04N5/18 ,  H04N7/08 ,  H04N7/081 ,  H04B1/00

CPC分类号： H04N1/00098 ,  H04L25/061

摘要： A multi-level code transmission system for restoring the d.c. component of a received signal by peak-clamping of the peak of the received synchronizing signal to a fixed level so as to establish the synchronization of a receiving end prior to an establishment of synchronization at the receiving end and for effecting pulse-clamping of the reference level of a following received signal after the establishment of synchronization at the timing of a clamping pulse relating to the synchronizing signal. In the case of transmitting a multi-level code signal such as an audio PCM signal together with an analogue signal such as a picture signal alternately, for example in a still picture transmission system, the d.c. level of the received signal is varied due to the low cutoff frequency characteristic of the transmission line, the result of which is the occurrence of a code error in a reproduced code signal at the receiving end. In order to obviate such a code error, the present invention uses two kinds of clamping, i.e., peak-clamping and pulse-clamping before and after the establishment of synchronization at the receiving end, respectively. According to this invention, the multi-level code signal can be reproduced with high fidelity.