JP2591674B2 - Playback device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing apparatus provided with a tracking means for finely adjusting a relative position between a head and a tape.

2. Description of the Related Art Conventionally, in order to correct tracking of a rotary head with respect to a recording track on a tape, a tape position is controlled by controlling a rotation speed of a capstan, and a track of a head arranged around a rotary drum is used. Has been proposed in which the position of the recording track is changed by a bimorph or the like to directly follow the recording track. However, it is difficult to correct a minute bend of the recording track by the tracking means by controlling the rotation speed of the capstan, and if the rotating head is swung by a bimorph or the like, a brush for supplying power to the bimorph or the like is used. And the like, there is a problem that the cost increases and the stability is lacking. In recent years, as in Japanese Patent Application No. 63-222463 filed by the present applicant, the position of the guide post is slightly moved by a piezoelectric element or the like, and the tape is moved in the running direction according to the bending of the recording track. A device that corrects the tracking by doing so has been considered.

[Problems to be Solved by the Invention] However, even in the above-mentioned conventional one in which the guide post is moved, the winding angle of the tape around the guide post that moves the tape by a small amount must be large to some extent, It is desirable that the guide post be disposed as close as possible to the drum and be a guide post that does not move during loading. For this reason, such a guide post must be newly provided due to the tape running path. However, there is a disadvantage that the tension of the tape is increased and the possibility of damaging the tape is increased.
In particular, in a mode in which the tape tension is not generally controlled, such as a tape high-speed feed mode such as FF / REW,
The tension increase is extremely large.

The present invention has been made in order to solve such a problem. The tape is wound around the tracking guide post only when necessary, and in a mode that does not require tracking adjustment, the tape tension is increased more than necessary. The purpose of the present invention is to provide a reproducing apparatus that does not increase.

Means for Solving the Problems According to the present invention, in order to achieve the above object, there is provided an apparatus for performing playback by winding a tape around a rotating drum having a head at a predetermined angle, wherein the rotating drum in a tape running direction is provided. A first guide post provided on the entry side and the exit side of the tape, respectively, and capable of moving a very small amount to correct the tracking of the head with respect to the recording track formed on the tape; Second and third guide posts provided two by two so as to be arranged with the first guide post interposed therebetween,
At the time of reproduction, the second and third guide posts are arranged so that the tape comes into contact with the first post, and when tracking is corrected, one of the first posts is the second and third guide posts. The tape between the third guide post is operated in the loosening direction, and the other of the first posts is operated in the direction for pushing out the tape between the second and third guide posts, thereby feeding the tape at a high speed. The reproducing device, wherein the second and third guide posts are arranged so that the tape between the second and third guide posts does not contact the first guide post. In

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, the tracking correction in the embodiment of the present invention will be described with reference to FIG. 2, FIG. 3, and FIG.

FIG. 2 is a plan view showing a tape running path during normal recording and reproduction, FIG. 3 is a side view showing a structure of a tracking guide post, and FIG. 4 is a schematic view showing a positional relationship between a recording track and a reproducing head. is there.

In FIG. 2, reference numerals 1 and 2 denote tracking guide posts, and reference numerals 3 and 4 denote movable auxiliary posts for winding the tape T around the tracking guide posts 1 and 2. 5-8
Pull the tape T from the cassette CA is a loading post for winding the rotary drum D _r which is rotated by known means, the tape tension sensing pin provided on the tension control lever 9, the 10 capstan 11 It is a pinch roller. 20 and 22 are fixed guide posts which form a tape running path together with the loading posts 5 to 8;
Is a movable guide post that also forms a tape running path.

In FIG. 3, reference numeral 12 denotes a bush into which the tracking guide posts 1 and 2 are press-fitted. The bush 12 is supported on a base 14 fixed on a chassis 13 via a laminated piezoelectric element 15.

At the time of the tracking correction, in the case of FIG. 4A, the rotary head 17 is at a position delayed with respect to the tape running direction with respect to the recording track 16 to be traced. In this case, the tracking guide post 2 is moved in the direction of arrow C in FIG. 2 by the piezoelectric element 15, and the tracking guide post 1 is moved in the direction of arrow B in FIG. Is pulled on the upstream side of the rotary drum, and the tape moves a very small amount on the rotary drum in a direction opposite to the running direction. That is, in FIG. 4 (a), the tape moves in the direction of arrow 18 and the tracking is corrected.

Next, as shown in FIG. 4 (b), when the rotary head 17 is at a position advanced with respect to the recording track 16 in the tape running direction, the tracking If the guide post 1 is moved in the direction of arrow A in FIG. 2 and the tracking guide post 2 is moved in the direction of arrow D in FIG. 2, the tape moves a small amount in the direction of arrow 19 (see FIG. 4 (b)). Tracking is corrected.

FIG. 5 is a block diagram showing a control circuit for detecting a tracking error of the head of the rotary head drum 2 with respect to the track of the tape T, rotating the tracking guide post according to the error amount, and correcting the error. .

In the figure, the reproduction RF signal reproduced from the tape T by the rotary head 17 mounted on the rotary head drum D _r is amplified to a predetermined level by the preamplifier 30,
A high-frequency luminance signal component and a chroma signal component are removed by a filter 31 at the next stage, and a pilot signal component composed of, for example, four different frequencies f _{1 to} f ₄ recorded on tracks on the tape T is passed. You. 4 the frequency of the signal of the pilot signal f ₁ ~f ₄ is supplied to the next stage of the parallel modulator 32, in parallel modulated by the reference pilot signal is output as two beat signals between the reference pilot signal. After these beat signals are detected by the detection circuit 33, the difference between the detection outputs of the two beat signals is obtained by the operation amplifier 34, and further sampled and held by the sample and hold circuit 35 to output a tracking error signal. The tracking error signal is smoothed by a low-pass filter 36, and the response and stability characteristics of the control loop are determined and supplied to a drive control unit 37 for driving and controlling the piezoelectric element 15, and the drive control unit 37 The piezoelectric element 15 is driven via the driver 38 based on the error signal, and the tracking guide posts 1 and 2 are moved in a direction to reduce the tracking error. As a result, the tape is moved with respect to the rotary head 17 of the rotary drum _{Dr in} the direction in which the tape travels, in the direction in which the tape travels, or in the direction in which the tape travels.
That is, DTF is performed.

In the figure, S is a switch for turning off the driving of the piezoelectric element in a high-speed feed mode in which tracking adjustment is not performed, as described later.

In addition, when the tape is moved in the length direction, the time axis fluctuation component appears as a little jitter, but especially in the case of digital recording / reproduction, the time axis fluctuation component is reduced to TBC (T
Since the correction can be performed by using an ime base corrector, etc., the allowable limit of jitter is larger than that of analog recording, and no particular problem occurs.

The tracking correction is performed by the above operation for the tracking deviation detected by the existing method such as the four-frequency system performed in a so-called 8 mm VTR. , 2 are not operated except during recording and playback. Therefore, in a high-speed running mode such as FF / REW, which does not require tracking adjustment, as shown in FIG. 1, the auxiliary posts 3 and 4 are moved in the directions of arrows F and F in FIG. Post 1,2
So that the tape is separated from the tape path.

At this time, also in the tracking control circuit of FIG. 4, the switch S is opened and the driving of the piezoelectric element is turned off. As a result, unnecessary power consumption and misalignment of the guide posts 1 and 2 can be prevented.

[Effects of the Invention] As described above, according to the present invention, it is possible to easily correct the tracking at the time of reproduction, and to prevent an unnecessary increase in the tape tension when the tape is fed at a high speed. is.

[Brief description of the drawings]

FIG. 1 is a plan view showing a tape path in a tape high-speed running mode such as FF / REW in an embodiment of the present invention, FIG. 2 is a plan view showing a tape path in the same reproducing mode, and FIG. FIGS. 4A and 4B are side views showing the structure of the guide post, FIGS. 4A and 4B are schematic diagrams showing the deviation between the storage track and the reproducing head, and FIG. 5 is a block diagram showing a drive control circuit for the tracking guide post. In the figure. 1,2: Guide post for tracking 3,4: Auxiliary post for tape path formation 15: Laminated piezoelectric element 16: Recording track 17: Rotating head

Claims (1)

(57) [Claims] An apparatus for reproducing a tape by wrapping a tape around a rotary drum provided with a head at a predetermined angle, provided on an entrance side and an exit side of the rotary drum in a tape traveling direction, respectively, and formed on the tape. A first guide post that can be moved by a very small amount to correct the tracking of the head with respect to the recorded recording track, and two first guide posts that are arranged to sandwich the respective first guide posts in the tape running direction. Second and third guide posts are provided, and at the time of reproduction, the second and third guide posts are arranged so that the tape contacts the first post. The one of the first posts is operated in a direction in which the tape between the second and third guide posts is loosened, and the first post is moved. Is operated in a direction to push out the tape between the second and third guide posts. When the tape is fed at high speed, the tape between the second and third guide posts is moved to the first position. A reproducing apparatus, wherein the second and third guide posts are arranged so as not to contact the guide posts.