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41. 发明专利

JPH10208201A MAGNETIC RECORDING AND REPRODUCING DEVICE 失效
公开(公告)号：JPH10208201A
公开(公告)日：1998-08-07
申请号：JP996697
申请日：1997-01-23
申请人： HITACHI LTD , HITACHI VIDEO IND INF SYST INC
发明人： SASAMOTO MANABU , OBARA YASUNARI , TAKAHASHI SHIGERU
IPC分类号： H04N5/92 , G11B5/008 , G11B20/00
摘要： PROBLEM TO BE SOLVED: To display a picture smoothly at high speed on a monitor TV without the unnatural feeling to the user by discriminating whether the information recorded on a magnetic tape is the digital recording or analog recording. SOLUTION: When the magnetic tape capable of recording in digital is inserted, a rotational phase of a rotary drum 3 is controlled by a reference signal SREF from a digital signal processing circuit 11. The discriminations as to the kind of magnetic tape 4, a magnetic tape running speed at the recording time and the existence of analog video signal of a reproduced signal are executed by a circuit 60 for discriminating the kind of tape, a circuit 70 for discriminating the running speed of tape and a circuit 25 for detecting the analog video signal, then the signal outputted from the magnetic recording/ reproducing device is automatically changed over by changing over switches 22, 23, 24, 32, 33 and 34.

42. 发明专利

JPH10172207A MAGNETIC RECORDING REPRODUCING UNIT 失效
公开(公告)号：JPH10172207A
公开(公告)日：1998-06-26
申请号：JP33080396
申请日：1996-12-11
申请人： HITACHI LTD
发明人： ONO HIDEJI , UESUGI MASAKI , MARUYAMA AKIRA , KONUMA HIDEYUKI , OBARA YASUNARI
IPC分类号： G11B15/665
摘要： PROBLEM TO BE SOLVED: To reduce tape damage by reducing a speed of rotation of a loading motor when a magnetic tape reeled out is being housed into an inside of a cassette as compared with the time when the magnetic tape is reeled out from the inside of the cassette. SOLUTION: When a cassette is loaded, a loading motor 16 is supplied with a high voltage from a motor driver 41 to rotate at high speed and to rotate a cam gear 19 via a motor gear 18 through a worm gear 17 rotating integrally with a shaft of a motor 16. A voltage applied to the motor 16 under unloading action is set lower than that under loading action and a shifting speed of tape guide bodies 14, 15 under unloading action is set lower than in the time of loading action. Consequently tape reaction force is applied sufficiently to the guide bodies 14, 15, resulting in that the postures of the shifting guide bodies 14, 15 are stabilized more. This result leads to less possibility of tape damage occurring at parts of the guide bodies 14, 15 when a thin tape is used.

43. 发明专利

JPH0896451A TRACKING CONTROL DEVICE 失效
公开(公告)号：JPH0896451A
公开(公告)日：1996-04-12
申请号：JP23096494
申请日：1994-09-27
申请人： HITACHI LTD
发明人： OBARA YASUNARI , NAKAGAKI HARUSHIGE , ARAI TAKAO
IPC分类号： G11B15/467
摘要： PURPOSE: To exactly track a specified track by generating a tracking control signal corresponding to the difference between the number of the reference block and that of the block to be compared and controlling tracking at the time of variable-speed reproduction. CONSTITUTION: The arithmetic circuit 2 outputs the block number of the block which the reproducing head reproduces when it reaches a specified track in the case where the reproducing head scans the center of the track for variable- speed reproduction to the comparison circuit 5 as a reference block number. Based on the identification number which the track number extraction circuit 4 detects that the specified track is reached and outputs, the system control circuit 1 switches the sample-and-hold circuit 6 to sampling action to output the output of the block number extraction circuit 5 to the comparison circuit 5. The multiplication circuit 7 multiplies the difference between the block number and the reference number outputted from the comparison circuit 5 by the factor sent from the system control circuit 1 to output the phase error in the tape running direction.

44. 发明专利

JPH07320347A TRACKING CONTROLLER 失效
公开(公告)号：JPH07320347A
公开(公告)日：1995-12-08
申请号：JP10930394
申请日：1994-05-24
申请人： HITACHI LTD
发明人： OBARA YASUNARI , NAKAGAKI HARUSHIGE
IPC分类号： G11B15/467
摘要： PURPOSE:To improve the quality of a reproduced picture at the time of variable speed transition by varying the damping coefficient of the speed control before and after a rotary magnetic head reaches a track one track before a variable speed reproducing track. CONSTITUTION:When an n-times speed reproduction instruction is inputted, a system controller 6 turns the contact of a switching circuit 9 to an (a) side and identifies the instructed speed of the variable speed reproduction and inputs the instructed speed to a speed detector 2. By this process, the revolution of a capstan motor is made to rise so as to have the running speed of a tape multiplied by (n). At that time, the circuit 6 turns the switch 31 of a damping coefficient control means 15 to an A side. The contact of the switch 31 is turned from the A side to the B side simultaneously with the time when the tape speed reaches the n-times speed. With this constitution, at the time of pull-in of a track number error by a phase control loop A, a speed damping coefficient is reduced and the quick responce of the phase pull-in is obtained. Then, when the scanning phase of the rotary magnetic head is pulled into a range within one track, the switch 31 is turned from B to A.

45. 发明专利

JPH07282497A TRACKING CONTROL DEVICE 失效
公开(公告)号：JPH07282497A
公开(公告)日：1995-10-27
申请号：JP7502394
申请日：1994-04-13
申请人： HITACHI LTD
发明人： OBARA YASUNARI , TANAKA HIROMI , NAKAGAKI HARUSHIGE , NAGAYAMA KEIJI
IPC分类号： G11B15/467
摘要： PURPOSE:To generate a stable and accurate tracking control signal by comparing cross talk levels of pilot signals having a frequency f1 or f2 reproduced in accordance with scanning of a magnetic head for each same frequency. CONSTITUTION:A pilot signal D2 having a frequency f1 reproduced from an adjacent track T1 of an already reproduced side is extracted, and a cross talk level L2 of a pilot signal P2 is detected in the same way. And at the same time, a cross talk level L0 of the pilot signal P2 and a cross talk level L2 of the pilot signal P2 stored in a memory 8 are inputted to a differential amplifier 7, and a tracking control signal in accordance with this difference of levels is generated. This tracking control signal is fed back to a capstan control circuit controlling speed of a magnetic tape, and a tracking control signal of a magnetic head 2A is generated.

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