JP3249259B2 - Digital signal recording device and reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital signal recording device for recording a digital signal by running a magnetic tape around a rotating cylinder at a predetermined angle, and a digital signal reproducing device for reproducing the digital signal.

[0002]

2. Description of the Related Art A magnetic recording / reproducing apparatus using a rotary cylinder (for example, a digital audio tape recorder (DA)
T), a digital VTR (digital video tape recorder)), it is important to ensure track linearity on a tape pattern in order to cope with narrower tracks for ensuring compatibility and improving recording density. Generally, in this type of equipment, approximately 180 turns of tape are wound around a rotating cylinder, and guide posts are arranged before and after the winding to stably run the tape. In order to ensure good linearity, it is necessary that the lower end of the tape extends along the lead portion of the rotary cylinder having good linearity without gaps over the entire cylinder winding angle.

[0003]

When each guide post of a tape running system including a rotary cylinder is arranged in a geometrically calculated state so that the magnetic tape is not twisted,
Near the entrance and exit of the cylinder, the height of the upper flange of the vertical guide post can regulate the magnetic tape along the lead.However, at the center of the winding angle, the downward force for aligning the magnetic tape along the lead is small. Nothing happens. In this state, when the magnetic tape is run, the magnetic head moves from the lower end to the upper end of the tape, so that the magnetic tape receives an obliquely upward force due to the frictional force of the magnetic head, and from the lead at the center of the winding angle. Floating occurs. As a result, the track on the tape pattern bends, and good linearity cannot usually be obtained.

For this reason, in this type of tape running system, instead of the tape guide arrangement as it is without geometric calculation without tape twist, guide posts are arranged intentionally shifted from the calculated values, and the tension distribution in the tape width direction is reduced. In many cases, the tape lower edge is made uneven along the leads to ensure track linearity. However, such a method requires trial and error, so that a long-term study is required, which leads to deterioration in design efficiency. Further, the correction amount of the guide post obtained in this way cannot be applied at all even if the tape running system is slightly different, and each time, there is a problem that a long-term study is required.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a digital signal recording apparatus or reproducing apparatus which can be easily designed and can prevent a magnetic tape from being lifted from a lead at the center of a winding angle around a rotary cylinder.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a digital signal recording apparatus for recording a digital signal by running a magnetic tape wound around a rotating cylinder at a predetermined angle and recording the digital signal. Storage means for storing signals for a predetermined period, read means for reading the digital signals to be recorded from the storage means in reverse time series, and a magnetic head traveling to form a recording track from the upper end to the lower end of the magnetic tape. A recording means for supplying the signal to be recorded read by the reading means to the magnetic head, wherein the recording track causes the magnetic head to travel from a lower end to an upper end of a magnetic tape. The recording track has the same shape as that of the recording track.

In a digital signal reproducing apparatus for reproducing a digital signal by winding a magnetic tape around a predetermined angle around a rotary cylinder and reproducing a digital signal, a magnetic head for scanning a signal track from the upper end to the lower end of the magnetic tape, Storage means for storing the reproduced digital signal for a predetermined period; and reading means for reading out the digital signal to be recorded from the storage means in reverse time series. Has the same shape as a signal track formed by a digital signal recording device running from the lower end to the upper end of the digital signal recording device.

[0008]

The magnetic tape receives a diagonally downward force due to the frictional force of the magnetic head. Also, compatibility of the tape format with the conventional digital signal recording device or reproducing device is ensured.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a plan view when the present invention is applied to an M loading traveling system, and FIG. 2 is a front view thereof. FIG. 3 is a diagram illustrating the trajectory of the rotary head when the magnetic tape is stationary and running when the present invention is applied, from the back surface of the magnetic tape. FIG. 4 is a functional block diagram of a circuit section including a memory section for making the recording apparatus according to the present invention compatible with a conventional tape format. FIG. 5 is a drawing in which the trajectory of the rotary head during traveling in the present invention is drawn from the back surface of the tape. FIG. 6 is a functional block diagram of a circuit unit including a memory unit for reproducing a magnetic tape recorded in a conventional tape format by the reproducing apparatus according to the present invention.

In FIG. 1, a magnetic tape 1 pulled out from a supply reel of a cassette (not shown) includes a left drawer guide 5, a back tension post 6, an entrance vertical guide 7, an entrance inclined post 8, a rotary cylinder 2, and an output cylinder. Side inclined post 9, exit side vertical guide 10, fixed guide post 1
1, through the capstan 12, the pinch roller 13, and the right pull-out guide 14, the tape is wound on the reel on the winding side of the cassette. In this traveling system, each tape guide including the rotary cylinder is arranged according to a geometric calculation value without tape twist. Rotating the magnetic tape 1 to the rotating cylinder 2,
In order to follow the lead 3, the upper side flange of the entrance side vertical guide 7 and the exit side vertical guide 10 is pressed down, and the height of the magnetic tape 1 is regulated.

As means for preventing floating from the lead 3 at the center of the winding angle, as shown in FIGS.
That is, the magnetic head 4 is rotated in the direction opposite to the running direction of the magnetic tape 1 to move the magnetic head 4 from the upper end to the lower end of the magnetic tape 1. That is, the magnetic tape 1 receives a diagonally downward force due to the frictional force of the magnetic head 4. As a result, the lower end of the magnetic tape 1 follows the entire lead 3 without any gap.

Here, in order to ensure compatibility in the tape format, the angle between the track pattern written by the locus of the magnetic head during tape running and the longitudinal direction of the tape, that is, the track angle θ is defined in the format. Value, and the tape feed speed needs to be the same as that of the conventional system for compatibility of recording time.

Further, it is necessary to record or reproduce signals on the tape from below to above the tape. However, when the rotary cylinder 2 is simply rotated in the reverse direction of the conventional system, the relative speed between the magnetic tape 1 and the magnetic head 4 is different from that of the conventional system, and the track angle θ becomes the specified value on the tape format. Not be.

Therefore, as shown in FIG. 3, the track angle .theta., Which is the angle between the pattern 1a during tape running and the longitudinal direction of the tape, becomes a prescribed value, and the track is written by the trajectory of the rotating head when the tape is stationary. The lead angle θo, which is the angle between the formed pattern 1b and the longitudinal direction of the tape, is determined from the relative speed between the tape and the rotary head.
Let o be the lead angle of lead (3). In the conventional method, the lead angle θo is smaller than the track angle θ, but the lead angle θo according to the present invention is larger than the track angle θ.

For example, the track angle θ of a general DAT having a diameter of 30 mm is 6.3832, and the lead angle θo is 6.3667. Here, a DAT with a diameter of 30 mm
Is used to calculate the lead angle of the cylinder according to the present invention, θo becomes 6.3997, and θo> θ holds.

Next, means for recording a digital signal from the upper end to the lower end of the magnetic tape will be described. FIG. 4 is a functional block diagram of a circuit section of the digital signal recording device according to the embodiment of the present invention. The signal processor 21 creates a digital signal to be recorded, and the memories 22a and 22b and the control circuit 23 reverse the time series of the signal. That is,
A digital signal recorded by a conventional digital signal recording device is output from the signal processing unit 21, and the control circuit 23
The digital signals are alternately distributed and stored in the memories 22a and 22b in units of one track, and the read time series is reversed from the memory not in the recording operation in the reverse order of the stored order. The outputs from the memories 22 a and 22 b are converted into signals that can be recorded on a magnetic tape by a recording circuit 24, and are recorded on the magnetic tape 1 via the magnetic head 4. A of the track pattern 1a during traveling shown in FIG.
Then, the data is recorded by the magnetic head 4 from above the tape to below. Here, since the signal recorded in the pattern A is discharged from the direction opposite to the order stored in the memory, the rear part of the signal is recorded in the upper part of the pattern A, and in the lower part of the pattern A, The tip of the signal is recorded. Then, they are sequentially recorded on B, C, D, and E of the track pattern 1a. Switching between the storage operation and the read operation of the memories 22a and 22b is performed using a timing signal of a magnetic head switch. Therefore, the same signal as that of the conventional tape format is recorded on the magnetic tape 1.

Next, means for reproducing a digital signal by scanning a track from the upper end to the lower end of the magnetic tape will be described. FIG. 6 is a functional block diagram of a circuit section of the digital signal reproducing apparatus according to the embodiment of the present invention. The signal reproduced from the magnetic tape 1 by the magnetic head 4 is converted by the reproducing circuit 31 into a digital signal suitable for subsequent signal processing.
Outputs from the reproduction circuit 31 are output to memories 32a and 32b,
The control circuit 33 reverses the time series of the output. That is, the reproduction circuit 31 outputs a digital signal having a time series reverse to that of the digital signal reproduced by the conventional digital signal reproduction apparatus, and the control circuit 33 alternately stores the digital signals in the memories 32a and 32b in units of one track. The digital signal is sorted and stored.
The read time series is reversed in the reverse order of the stored order. Then, the outputs from the memories 32a and 32b are converted into a final reproduced signal by the signal processing unit 34. Switching between the storage operation and the read operation of the memories 32a and 32b is performed using a timing signal of a magnetic head switch.

Although the digital signal recording apparatus and the reproducing apparatus according to the embodiment of the present invention have been described above, the memories 22a and 22b in FIG. 4 and the memory 32 in FIG.
It goes without saying that a digital signal recording / reproducing apparatus can be configured by sharing a and 32b.

[0019]

According to the construction and operation described above, even in a traveling system in which the tape guides including the cylinders are arranged according to the geometrically calculated values without the tape twist, the tape floating at the center of the cylinder winding angle is suppressed. And good linearity can be secured.

Therefore, it is not necessary to determine the inclination angle correction amount of the tape guide for making the lower edge of the tape follow the lead portion of the cylinder by trial and error, and the tape guides may be arranged according to the geometric calculation values. become.

Further, the compatibility of the conventional tape format can be ensured.

[Brief description of the drawings]

FIG. 1 is a plan view showing a mechanism section according to an embodiment of the present invention.

FIG. 2 is a front view showing a mechanism section according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram showing the operation of the embodiment of the present invention.

FIG. 4 is a functional block diagram showing a circuit unit according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram showing the operation of the embodiment of the present invention.

FIG. 6 is a functional block diagram illustrating a circuit unit according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic tape 2 Rotating cylinder 4 Magnetic head 22a, 22b Memory 23 Control circuit 24 Recording circuit 31 Reproduction circuit 32a, 32b Memory 33 Control circuit

Claims (2)

(57) [Claims] 1. A digital signal recording apparatus for recording a digital signal by running a magnetic tape wound around a rotating cylinder at a predetermined angle and storing a digital signal to be recorded for a predetermined period of time. Reading means for reading a digital signal to be read in reverse time series, a magnetic head running to form a recording track from the upper end to the lower end of the magnetic tape, and the magnetic signal for reading the signal to be recorded read by the reading means. Recording means for supplying to the head, wherein the recording track has the same shape as a recording track formed by a digital signal recording device that moves the magnetic head from the lower end to the upper end of the magnetic tape. Digital signal recording device. 2. A digital signal reproducing apparatus for reproducing a digital signal by wrapping a magnetic tape around a predetermined angle around a rotary cylinder and reproducing a digital signal, comprising: a magnetic head for scanning a signal track from an upper end to a lower end of the magnetic tape; Storage means for storing the obtained digital signal for a predetermined period of time, and reading means for reading out the digital signal to be recorded from the storage means in a reverse time series. A digital signal reproducing device having the same shape as a signal track formed by a digital signal recording device running from a lower end to an upper end.