JP2666938B2 - Magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention] (Industrial application field) The present invention relates to a rotary head type magnetic recording / reproducing apparatus,
In particular, it relates to special reproduction and recording. (Prior Art) Conventionally, it is well known that a magnetic head drive during special recording / reproduction in a magnetic recording / reproducing apparatus is performed by a bimorph plate using a piezoelectric element. (For example,
JP-A-53-36209 and JP-A-59-180221) That is, an S-shaped bimorph plate is made cantilevered, and the direction of an electric field applied to the bimorph plate is partially reversed on the same element. Bend or deviate, or use two bimorph plates in parallel, dispose a towable member at the end, attach a magnetic head to the end of each of these members, Make an orthogonal deviation with respect to the longitudinal direction of the upper track, further suppress the stiffness of the tip of the magnetic head,
Various measures have been taken to reduce spacing loss. However, conventionally, one magnetic head drive device follows and deviates over the entirety of one track. In this method, the magnetic head moves between tracks in a so-called dropout section. This is to prevent noise from being mixed into the reproduced information signal and to ensure that the information signal to be specially recorded is recorded at a regular recording helical angle. And this dropout section is, for example, 0.635ms with 1 "TYPE C VTR
ec. Therefore, the response wave number of the magnetic head drive device is required to be, for example, about 1.6 KHz. For this reason, the drive voltage applied to the bimorph plate generally has a saw-tooth waveform, and the magnetic head driving device is liable to cause linking immediately after the movement of the magnetic head. This unnecessary vibration of the drive device itself must be mechanically or electrically suppressed. This is because, if this unnecessary vibration is transmitted to the magnetic head attached to the tip portion, the reproduced information signal or the recorded track is disturbed. In addition, when the time for returning the magnetic head becomes short, the charging current becomes large, and the circuit system of the driving device becomes large. On the other hand, when the information signal recorded on the magnetic tape is multi-tracked, the track pitch increases. In addition, when setting a guard band between each track,
Further increase in track pitch is inevitable. In order to achieve this with the above-described conventional technology, one method is to extend the length of a bimorph plate that is a driving element.
This leads to an increase in the size of the driving device. In addition, the above-described response frequency is lowered, and it is not preferable in view of the limited space in the rotating magnetic head drum. Furthermore, there is a method of reducing the thickness of the bimorph plate and increasing the driving voltage. However, depending on the driving frequency, the element itself generates heat, which causes a decrease in piezoelectric characteristics and loss of polarization. Is not preferred. (Problems to be Solved by the Invention) As described above, in the related art, the amount of deviation is insufficient due to the multi-tracking of the information signal to be recorded / reproduced. Further, in order to compensate for the deviation, there are problems such as an increase in the size of the magnetic head driving device, an increase in driving voltage, and a decrease in response frequency. Further, as described above, there is a problem of linking compensation caused by the dropout section. SUMMARY OF THE INVENTION It is an object of the present invention to provide a special reproducing / recording apparatus capable of coping with an increase in track pitch due to a plurality of magnetic heads. [Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, in the present invention, a magnetic tape is wound in a substantially omega shape around a rotating magnetic head drum to record and reproduce information signals. In the magnetic recording device to be performed, a plurality of magnetic head assemblies provided in the rotating magnetic head drum and provided with a magnetic head for special reproduction,
Magnetic head driving means provided on each of these magnetic head assemblies for independently driving each magnetic head assembly to be deviated perpendicularly to the longitudinal direction of the track; and It is characterized by comprising delay means for time-delaying an information signal obtained from the magnetic head, and synthesizing means for synthesizing the information signal obtained from the magnetic head and delayed by the delay means. Further, in a magnetic recording device for recording / reproducing an information signal by winding a magnetic tape in a substantially omega shape around a rotating magnetic head drum, a plurality of magnetic tapes provided in the rotating magnetic head drum and provided with a recording magnetic head are provided. A magnetic head assembly, provided on each of these magnetic head assemblies;
Magnetic head driving means for independently driving each magnetic head assembly to be deviated perpendicularly to the longitudinal direction of the track, and dividing means for dividing an information signal to be recorded on the magnetic tape into a plurality of pieces. In addition, the information signals divided by the dividing means are read out simultaneously and recorded on the magnetic tape via the magnetic heads of the plurality of magnetic head assemblies. (Operation) On a recording medium in a magnetic recording / reproducing apparatus having a rotating magnetic head drum, a track having a certain angle (recording helical angle) determined by a relative movement between a magnetic tape and a rotating magnetic head is formed. Therefore, during special reproduction / recording in which the magnetic tape is running or stopped at a speed other than the normal recording, the magnetic head scans the magnetic tape at an angle different from that at the time of recording. At this time, if the magnetic head is displaced so as to scan along the track or form the track at the recording helical angle as described above, information signals can be exchanged during special reproduction and special recording. The present invention is configured such that each magnetic head driving device is divided and takes charge of the track in the longitudinal direction of the track. For example, when arranging two magnetic head driving devices,
Divide and share the truck. In order to divide one set of multi-tracks, driving of each magnetic head group and reproduction / recording of information signals are performed simultaneously by the two devices. At this time, the position of the magnetic tape is controlled by a magnetic tape feeding device such as a capstan so that the deviation amount of each magnetic head driving device is minimized. When the magnetic tape is wound about 360 °, the substantial dropout section of each magnetic head group is about 180 °
become. For this reason, the actual dropout section of each magnetic head group can be made wider than several degrees to several tens of degrees in the method of following the entire multi-track. At the time of trick play, the information signals read from each magnetic head can be completely or individually (after appropriate processing if necessary) by appropriately driving each magnetic head drive device and magnetic tape feed device. Time delay. Next, these information signals are read out using a stable reference signal and sequentially synthesized to obtain an information signal for a set of multi-tracks recorded on the magnetic tape. In the case of special recording, all information signals for one set of multi-tracks to be recorded are temporarily allocated and stored in storage circuits for the number of magnetic head driving devices. As in the case of the trick play, the information signals stored in the storage circuit are simultaneously read out while simultaneously driving each magnetic head drive device and the magnetic tape feeder, and stored in a recording medium such as a magnetic tape. Form a multitrack. In general, a rotary transformer is used for transmitting information signals in a magnetic recording / reproducing apparatus having a rotating magnetic head drum. When a plurality of magnetic head driving devices are used for special reproduction / recording as in the present invention, a rotary transformer is required for the increased number of magnetic head driving devices. May lead to an increase in size. Therefore, in the present invention, in order to suppress the addition of a rotary transformer, a rotary transformer of a recording / reproducing magnetic head group or a rotation erasing magnetic head (group) which is not used during special reproduction / recording is replaced with a special reproduction / recording magnetic head.
Switch and use it for recording. (Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings, in which the embodiment is configured with two magnetic head assemblies and a magnetic head driving device. FIG. 2 is an external perspective view of the rotating magnetic head drum assembly. 1 (a) and 1 (b) show an example of an embodiment according to the present invention. The information signals reproduced from the two magnetic head groups 4A and 4B (represented by one magnetic head) are processed by the demodulation circuits 6A and 6B, respectively. The output from this demodulation circuit is subjected to an arbitrary time delay by delay circuits 7A and 7B, respectively. The outputs of the delay circuits 7A and 7B are combined by the combining circuit 8 to obtain a desired output information signal. Magnetic head driving devices 9A and 9B each having magnetic head groups 4A and 4B mounted on a rotating magnetic head drum 1 around which a magnetic tape 3 is wound by approximately 360 ° are arranged at intervals of approximately 180 °. FIG. 3 shows an example in which the correspondence between each magnetic head group and the multi-track is described on a magnetic tape. However, the multi-track is represented by one track. Magnetic head group 4
Trajectories when A and 4B are not displaced are indicated by arrows 14A and 14B, respectively. The magnetic head group 4A disposed at the tip of the magnetic head driving device 9A extends from the head 11 to the approximate center 12 of the multitrack 10, and the magnetic head group 4B disposed at the tip of the magnetic head driving device 9B also includes the multitrack From the center 12 to the end 13. That is, in this example, the magnetic head group 4A is moved near the head of the multitrack by the magnetic head driving device 9A.
When scanning is started with a deviation to 11, the magnetic head group 4B is simultaneously
Starts scanning near the center 12 of the multitrack. Then, when the magnetic head group 4A reaches almost the center of the multi-track, the magnetic head group 4B moves near the end of the multi-track.
Deflection and scanning. The required deflection amounts of the magnetic head groups 4A and 4B are represented by 15A and 15B, respectively. FIG. 4 shows a case where only one magnetic head driving device is used. The conditions are the same as in FIG. The trajectory when the magnetic head is not driven to deviate is indicated by an arrow 16, and the required amount of deviation is indicated by 17. It can be seen that the amount of deviation (15A, 15B) according to the method of the present invention is about half that of that (17) in the case of only one magnetic head drive. FIG. 5 shows an example of a waveform applied to each magnetic head driving device according to the present invention. Driving waveforms applied to the magnetic head driving devices 9A and 9B are as shown in 18A and 18B, respectively. The driving waveform is a substantially triangular wave. The solid line is the portion at the time of deviation, and the dotted line is the return time portion. Compared with the drive waveform 19 in the case of one magnetic head drive device as shown in FIG. 4, it can be seen that the drive voltage according to the present system requires about half the drive voltage per one magnetic head drive device. In addition, in the case of one magnetic head driving device, a sharp voltage change that causes ringing in the dropout section 20 is required. On the other hand, in the present invention, a triangular wave may be used, and it is understood that one cause of the ringing problem is solved. An information signal obtained by such a series of operations is referred to as a sixth signal.
Shown in the figure. As described above, since the magnetic head groups 4A and 4B scan the same multi-track at the same time, information signals are obtained at the same time, such as 22 from the magnetic head group 4A and 23 from the magnetic head group 4B. Since the normal information signal looks like 21, the information signal of 23 is delayed by the time t in the figure and synthesized with the dotted line portion shown after the information signal of 22. This makes it possible to obtain an information signal required for special reproduction. Next, an embodiment at the time of special recording will be described. The configuration, operation, and the like are the same as those described above, and will not be described. FIG. 7 shows a block diagram and an example of a schematic configuration at the time of special recording. Dividing circuit 24 stores information signals in storage circuits 25A, 25B
Approximately 1/2 and store. Next, each magnetic head driving device 9A,
While driving 9B with an appropriate waveform, information signals are simultaneously read from the storage circuits 25A and 25B, respectively, and recorded on the magnetic tape 3 to form a set of multi-tracks. In this way, a multi-track required for special recording can be obtained. FIG. 8 shows an example of a method of switching and using a rotary transformer during special reproduction / recording. Each of the plurality of magnetic head groups and the rotary transformer is represented by one. Magnetic head group for recording / reproduction during special reproduction / recording
The 27 rotary transformers 5B are used by the switching circuit 30 as rotary transformers of the magnetic head group 4B for special reproduction / recording. As a result, an increase in the number of rotary transformers can be suppressed. It is apparent that the same principle can be applied to the case where three or more magnetic head assemblies and magnetic head driving devices are used. The magnetic head drive device is not limited to a bimorph element. [Effects of the Invention] According to the present invention, special reproduction / recording becomes possible for a magnetic recording / reproduction system having a large track pitch by a multi-magnetic head. Since a plurality of magnetic head driving devices are used, the amount of deviation of each magnetic head group can be reduced. Therefore, the tilt of the magnetic head at the time of deflection is suppressed, and the reproduced / recorded information signal is hardly affected by the spacing loss, the magnetic head driving device can be downsized, the driving voltage can be relatively low, and so on. The effect of is obtained. Since the return time of each magnetic head group (apparent dropout section) can be widened, it can be operated even if the resonance frequency of the magnetic head drive device is low, and therefore, a plurality of magnetic heads can be arranged on the drive device. The effect that multi-track can be handled is obtained. Similarly, since the return time can be wide, the drive waveform may be a substantially triangular wave, and the effect of facilitating the control system of the magnetic head drive device as compared with the conventional technique can be obtained. Each information signal by special reproduction is temporarily stored in the time delay circuit and then read out by a stable reference signal, so that there is an effect that each information signal can be a good signal with little disturbance on the time axis. Further, since the rotary transformer for recording / reproducing or erasing is switched and used as the rotary transformer for special reproducing / recording, the effect of reducing the size of the rotary magnetic head drum assembly can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing one embodiment of the present invention, FIG. 2 is an external perspective view of a rotary magnetic head drum assembly, and FIGS. 3 to 6 show the operation of the embodiment. FIGS. 7 and 8 are diagrams for explaining a block diagram and an example of a schematic configuration in the second and third embodiments. 1 Upper drum 2 Lower drum 3 Magnetic tapes 4A and 4B Magnetic head groups 5A and 5B for special reproduction / recording Rotary transformers 7A and 7B Delay circuit 8 Synthesis circuit 9A, 9B magnetic head driving device, 24 dividing circuit 25A, 25B storage circuit 27 recording / reproducing magnetic head group 28 erasing magnetic head group 30, switching circuit

Claims (1)

(57) [Claims] A magnetic recording device for recording / reproducing an information signal by winding a magnetic tape in a substantially omega shape around a rotating magnetic head drum, comprising: a plurality of magnetic recording media provided in the rotating magnetic head drum and provided with a magnetic head for special reproduction. A head assembly, a magnetic head driving means provided on each of these magnetic head assemblies, and a magnetic head driving means for independently driving each magnetic head assembly to be deviated perpendicularly to the longitudinal direction of the track; A delay unit for time-delaying an information signal obtained from the magnetic head of the magnetic head assembly; and a combining unit for combining the information signal obtained from the magnetic head and delayed by the delay unit. A magnetic recording / reproducing apparatus characterized by the above-mentioned. 2. A magnetic recording apparatus for recording / reproducing an information signal by winding a magnetic tape in a substantially omega shape around a rotating magnetic head drum, wherein a plurality of magnetic heads provided in the rotating magnetic head drum and provided with a recording magnetic head An assembly; a magnetic head driving means provided on each of these magnetic head assemblies; and a magnetic head driving means for independently driving each magnetic head assembly to be deviated perpendicularly to the longitudinal direction of the track; and A dividing means for dividing an information signal to be recorded into a plurality of information signals, wherein the information signals divided by the dividing means are simultaneously read and recorded on the magnetic tape via the magnetic heads of the plurality of magnetic head assemblies. A magnetic recording and reproducing apparatus.