JPS6131531B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic tape transfer device, in which a recorded master tape and an unrecorded slave tape are wound onto a take-up reel with their magnetic surfaces in close contact with each other. The present invention relates to a so-called batch winding type magnetic tape transfer device that applies a transfer bias (transfer magnetic field) to both tapes and transfers signals from a master tape to a slave tape. First, the first
This batch winding type magnetic tape transfer device will be explained with reference to FIGS.

Reference numeral 1 denotes a supply reel on which a recorded master tape 2 is wound, and the supply reel 1 is driven by a motor 36. Reference numeral 3 denotes a supply reel on which an unrecorded slave tape 4 is wound, and the supply reel 3 is driven by a motor 37. 5 is master tape 2
The master tape 2 is suctioned by a vacuum source (not shown) connected to an air suction port 6.

7 is a light emitting element, 8 is a light receiving element, which detects the tape loop position in the air column 5, and controls the control circuit 3.
9, the motor 36 is controlled to keep the tape loop position in the air column 5 constant, and the tape tension of the master tape 2 is always kept constant. Reference numeral 9 designates an air column for controlling the tape tension of the slave tape 4, and it is composed of a light emitting element 11, a light receiving element 12, and an air suction port 10 in the same way as the master tape structure, and is used to control the tape tension of the slave tape 4 at all times. It is kept constant.
Note that each tape tension is determined by the air pressure of the vacuum source. A take-up reel 13 winds up the master tape 2 and slave tape 4 with their magnetic surfaces in close contact with each other. The take-up reel 13 is driven by a motor 38. In addition, an encoder 4 mounted coaxially with the motor 38
4. The light emitting element 41 and the light receiving element 42 are configured to generate a frequency signal proportional to the rotation of the motor 38, and this signal drives the motor 38 via a control circuit 43, and the speed is controlled so that the rotation is constant. . A transfer bias is applied to both tapes 2 and 4 wound on a take-up reel 13 by a magnetic field generator 18. After the transcription is completed, the respective tapes 2 and 4 are rewound onto the supply reels 1 and 3. At this time, the audio signal of the master tape 2 is reproduced by the reproduction head 23 and re-recorded on the slave tape 4 by the recording head 25. 24 is an erasing head, which erases the slave tape 4 transferred by applying a transfer bias.
This is for erasing only the audio signal.

14 and 15 press the tapes 2 and 4 to eliminate the air layer existing between the magnetic layers of the tapes 2 and 4;
These are pressure rollers for good adhesion, and are pressed against the take-up reel 13 by springs 16 and 17, respectively.

26 to 29 are guide posts for running the master tape 2, and 32 to 35 are guide posts for running the slave tape 4. 30, 31
is a position regulating roller for both tapes 2, 4, which is used to wind up both tapes 2, 4 onto the take-up reel 13 after positionally regulating them.

19 and 20 are a light emitting element and a light receiving element, respectively, which detect the transparent trailer section provided at the rear end of the master tape 2;
Numerals 1 and 22 are a light emitting element and a light receiving element for detecting the trailer portion of the slave tape 4, and the magnetic tape transfer device is automatically operated by these elements.

As described above, good transferred slave tapes can be produced in large quantities at high speed.

In such a magnetic tape transfer device, in order to automatically control the winding stop when winding both tapes 2 and 4 onto the take-up reel 13, a conventional method is used to detect the trailer portion of the master tape 2 and slave tape 4. However, since the tape speed during winding is very high, a fairly long trailer tape is required until the tapes 2 and 4 are stopped after the trailer portion is detected. However, recent magnetic recording and reproducing devices (hereinafter referred to as VTRs) have slow tape speeds and high-density recording, so
Required tape lengths are becoming shorter, especially trailer tape lengths are becoming much shorter. As an example, the trailer tape length of a VHS cassette VTR is very short, 170±20mm or 150±20mm.

That is, as mentioned above, the winding tape speed (5~
In order to stop the motor suddenly from 10m/sec), the torque of the drive motor needs to be extremely large, and the time required for stopping is very short (less than 0.05sec), due to a slight timing difference.
Abnormal tension is applied to the tape, creating the risk of it breaking. To prevent these, when winding on the take-up reel approaches the end, switch the take-up tape speed to a low speed (about 1 m/sec), then detect the trailer tape and stop it. The motor's torque is also relatively low, allowing it to stop even short trailer tapes with complete stability.

The present invention proposes a method for smoothly completing the winding operation as described above.

FIG. 3 shows only a portion of the take-up reel 13 in order to explain the basic principle of the present invention. In Figure 3,
The tape length of the master tape 2 or slave tape 4 wound on the take-up reel 13 is l cm, the thickness of the master tape 2 is t ₁ cm, the thickness of the slave tape 4 is t ₂ cm, and the radius of the hub of the take-up reel 13. r ₁ cm,
The radius at which the tape is wound on the take-up reel 13 is
r ₂ cm, and the number of revolutions of the take-up reel 13 required to wind the master tape 2 or slave tape 4 onto the take-up reel 13 to a tape length of l cm is T revolutions, then r ₂ - r ₁ = (t ₁ +t ₂ )×Tcm (1). On the other hand, the number of rotations of the take-up reel 13 is set to N (rp
s) (constant rotation), the winding tape speed v (cm/sec) when the radius is r ₂ cm is v=2π{r ₁ + (t ₁ + t ₂ )T}×N (2) Become.

On the other hand, if the winding diameter of the slave tape supply reel 3 on which the slave tape 4 is currently wound is D _S cm, and the rotation speed is N _S (rps), then v=N _S・D _S・π (3) D _S =v/N _S・π (4). As explained above, if the tape thicknesses of the master tape 2 and slave tape 4 are determined in advance, the tape winding thickness (r ₂ − _{r 1} ) of the take-up reel 13 can be determined, and the rotational speed of the take-up reel 13 can also be determined. N
(rps) at a constant speed, the tape speed v (cm/sec) at that point is the take-up reel 1
It is determined by the winding rotation speed T (rotation) of 3.
Next, the rotation speed N _S of the slave tape supply reel 3
(rps), the diameter (winding diameter) D _S cm of the slave tape 4 wound on the slave tape supply reel 3 can be calculated. That is, under the above conditions, if the total number of winding rotations T (rotations) of the take-up reel 13 and the rotation speed N _S (rps) of the slave tape supply reel 3 are detected, the tape will be taken up on the supply reel 3. The diameter (winding diameter) D _S cm of the slave tape 4 can be calculated.

Here, D _S cm cannot be smaller than the hub diameter of the slave tape supply reel 3, so
If a value (second predetermined value) D _SS cm that is slightly larger than the hub diameter is determined, v/N _S・π=D _S <D _SS (5) v/N _S・π・D _SS <1 ( 6) That is, 2×{r ₁ + (t ₁ +t ₂ )・T}×N/N _S・D
When the condition _SS <1(7) is satisfied, it is when the diameter of the supply reel 3 on which the slave tape 4 is wound becomes less than D _SS cm.

Next, the master tape 2 can be considered in the same way. Since the master tape 2 and slave tape 4 are simultaneously wound onto the take-up reel 13, the take-up tape speed v (cm/sec) is almost the same for both tapes 2 and 4. Also, a master tape supply reel 1 on which a master tape 2 is wound.
If the winding diameter is D _M cm and the rotational speed is N _M (rps), then v=N _M・D _M・π (8) D _M =v/N _M・π (9) The master tape is the same as the slave tape. If D _MS cm is a value slightly larger than the hub diameter of master tape supply reel 1 (first predetermined value), then as in equation (7), 2×{r ₁ +(t ₁ +t ₂ )・T} ×N/N _M・D
The condition of _MS < 1(10) is satisfied when the winding diameter of the supply reel 1 on which the master tape 2 is wound becomes D _MS cm or less.

As explained above, the master tape 2 and the slave tape 4 are wound on the take-up reel 13 in high-speed mode, and the winding diameter D _M cm of the master tape supply reel 1 becomes equal to or less than D _MS cm, or the slave tape supply reel 3 When the winding diameter D _S cm becomes less than D _SS cm, the mode is switched to the low speed mode at the earlier timing of both, and after that, the trailer section is detected,
By stopping the winding, it is possible to stop the winding smoothly and stably. Furthermore, the required torque of the take-up reel drive motor 38 can be significantly reduced.

In addition, if there is tape on each of the master tape reel and slave tape reel that is sufficiently longer than the required transfer length, when the winding rotation speed T reaches the third predetermined value _T3 , the high speed mode is switched from the low speed mode. , and when the fourth predetermined value _T4 is reached, the winding is stopped. In other words, this is the case when a 120-minute tape is used to transfer a tape containing a 60-minute signal. Setting of the third predetermined value T ₃ and setting of the fourth predetermined value T ₄ will be explained.

If the tape speed of a normal VTR is V _S cm/sec, the required recording length for 60 minutes is l _S = 60 x 60 x V _S cm, and the number of revolutions when L _S is wound is the third predetermined value T. ₃ , and the number of revolutions when (l _S +200) cm is wound should be set as the fourth predetermined value.

In reality, as shown in Figure 5, when the third predetermined value is reached or one of the conditions D _S < D _SS , D _M < D _MS is reached, the mode shifts from the high speed mode to the low speed mode. However, when any one of the fourth predetermined value, master trailer detection, and slave trailer detection is satisfied, the vehicle enters the stop mode from the low speed mode.

FIG. 4 shows an electrical system diagram of the magnetic tape transfer device according to the present invention.

An encoder 6 mounted coaxially with a motor 36 that drives the master tape supply reel 1
0 is the light from the light emitting element 58, and the light from the motor 36 is
The light receiving element 59 generates a signal corresponding to the rotation of the motor 36 since the light is interrupted once per rotation. on the other hand,
An encoder 63 mounted coaxially with the motor 37 that drives the slave tape supply reel 3
Similarly, the light from the light emitting element 61 is transmitted to the motor 37.
The light receiving element 62 generates a signal corresponding to the rotation of the motor 37. A counter 47 counts the number of pulses from the frequency generator 49. However, since the counter 47 is reset by the signal from the light receiving element 59, the number of pulses during one revolution of the motor 36 is counted.

That is, the counter 47 measures the rotation period of the motor 36. Similarly, the counter 48 also measures the rotation period of the slave tape supply reel drive motor 37.

The light receiving element 42 generates a signal corresponding to the rotation of the motor 38 by means of an encoder 44 and a light emitting element 41 mounted coaxially with the take-up reel drive motor 38 . However, in this case, 1 of motor 38
Generates 100 signals per revolution. Light receiving element 4
The second signal drives the motor 38 via the control circuit 43, and the speed of the motor 38 is controlled so that it rotates at a constant rate. On the other hand, the signal from the light receiving element 42 is also supplied to a 1/100 counter 45 and counted down to 1/100, so that the output of the counter 45 is generated every rotation of the motor 38. 46 is also a counter, and the total number of revolutions of the take-up reel 13 during winding is measured based on the output of the 1/100 counter 45. 5
0 to 53 are input gates, respectively, for inputting the rotation period of the master tape supply reel 1, for inputting the trailer detection signal of the master tape and slave tape, for inputting the total winding rotation number of the take-up reel 13, and for inputting the slave tape. A signal is connected to the data bus 64 from an input gate that is used to input the rotation period of the supply reel 3 and designated by the control bus 65 . 54 is an output latch;
Like the input gate, it outputs and latches the data bus 64 signal. 55 is an arithmetic processing unit (hereinafter referred to as CPU)
It is called. ), which processes the signal input from the input gate and outputs it to the output latch. 56 is a ROM for executing CPU instructions
57 is a RAM used as a signal buffer memory and arithmetic processing memory.

The slave tape side in the above configuration will be explained in more detail. The relationship between the rotation speed N _S (rps) of the slave tape supply reel 3 and the rotation period T _S (sec) of the slave tape supply reel at that time is T _S =1/N _S (11), and the frequency generator 49 frequency of 1M
Hz and T _S ' is the count number of the counter 48, then T _S = T _S '×10 ^-6 (12). In other words, equation (7) is 2・T _S ′・N {r ₁ + (t ₁ + t ₂ )・T}/D _S
It can be rewritten as _S <10 ⁶ (13). If we substitute concrete values here, r ₁ = 9cm, N = 8 (rps), t ₁ + t ₂ =
If 50×10 ⁻⁴ cm and D _SS =2.9 cm, then T _S ′(27586·T+49655172)<10 ¹² (14), which can be easily calculated as a positive integer by the CPU 55.

Similarly, on the master tape side, if the rotation period of the master tape supply reel 1 is T _M (sec), then T _M = 1/N _M (15) T _M = T _M '×10 ^-6 (16) (10) The formula is 2・T _M '・N {r ₁ + (t ₁ + t ₂ )・T}/D _M
If it is rewritten as _S < 10 ⁶ (17) and _MS = 4.6 cm, equation (17) becomes T _M ′ (17391・T+31304347) <10 ¹² (18). The CPU 55 always performs calculations of equations (14) and (18) during the high-speed winding period. When either condition is satisfied, the CPU 55 uses the output latch 54 to issue a command to the control circuit 43 for a low speed winding mode, and the motor 38 is controlled to rotate at a low speed. Next, when the light receiving element 20 or 22 detects the sensor section, the CPU 55 issues a command to the control circuit 43 to start the winding stop mode, the drive of the winding reel 13 is stopped, and the winding mode is stably completed.

On the other hand, the master tape is usually cut to match the length of the recorded program, and a trailer tape is glued to the rear end. However, slave tapes that are commercially available and have a fixed length are often used.
That is, in a magnetic tape transfer device, the slave tape cannot be shorter than the master tape. That is, in the above-described embodiment, when the condition of equation (14) is satisfied and the trailer portion of the master tape 2 is not displayed when the light receiving element 22 detects the trailer portion of the slave tape 4,
The CPU 55 drives an alarm display section 67 via an output latch 66. The alarm is given by light or sound.

Generally, commercially available slave tape lengths are classified into 30-minute programs, 60 minutes, 120 minutes, 240 minutes, etc., but an operator of a magnetic tape transfer device accidentally uses a slave tape shorter than the master tape. This can be confirmed by the alarm display. As mentioned above, it is generally impossible for a slave tape to be shorter than a master tape. However, when producing a small amount of transfer tape, the recorded master tape may be erased and reused. In this case, a signal is recorded on a portion of the head of a long tape without cutting the master tape, and is transferred by a magnetic tape transfer device. In such a case, operate the switch 68 to close the input gate 6.
A numerical value is input to the CPU 55 via 9. The value to be input is the winding rotation speed _T3 of the winding reel 13.
(rotations) and T ₄ (rotations), and when the number of rotations T (rotations) of the take-up reel 13 reaches the value T ₃ specified by the switch 68, the CPU 55 switches from the high-speed winding mode to the low-speed winding mode. Control is performed to switch to the winding stop mode when the numbers of revolutions T and total revolutions _T4 match. In the case of such control, the trailer portion of the master tape 2 and slave tape 4 should not be detected unless the operation is incorrect, but as described above, the operation causes the take-up reel 13
The light receiving element 22 may detect the trailer portion of the slave tape 4 before the number of rotations T (rotations) reaches the value T ₃ specified by the switch 68. In this case, of course, as described above, the equation (14) is established and the mode is switched to the low speed winding mode, and the mode is switched to the winding stop mode when the trailer portion of the slave tape 4 is detected. At this time, if the take-up reel rotational speed T (rotations) has not reached the value _T3 specified by the switch 68, the CPU 55 drives the alarm display section 67 via the output latch 66 to issue an alarm.

As explained above, according to the present invention, the winding diameter of the master tape 2 wound on the master tape supply reel 1 and the winding diameter of the slave tape 4 wound on the slave tape supply reel 3 are detected at the time of winding. Since the winding mode is controlled, even if the operator accidentally operates the tape, it prevents abnormal tension from being applied or damage to the master tape or slave tape, and if necessary, a warning is issued on the display. can be generated and easily manipulated.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing a batch winding type magnetic tape transfer device, Fig. 2 is an electrical system diagram for explaining Fig. 1, and Fig. 3 is an abbreviation of the take-up reel portion for explaining the present invention. FIG. 4 is a block diagram of a magnetic tape transfer device for explaining an embodiment of the present invention, and FIG. 5 is an operational flowchart for explaining an embodiment of the present invention. 1, 3... Supply reel, 2... Master tape, 4... Slave tape, 13... Take-up reel, 18... Magnetic field generator, 19, 21, 41, 5
8, 61... Light emitting element, 20, 22, 42, 5
9, 62... Light emitting element, 46, 47, 48... Counter, 49... Oscillator.

Claims (1)

[Claims] 1. After winding a recorded master tape and an unrecorded slave tape wound on each supply reel onto a take-up reel with their magnetic surfaces in close contact with each other,
In a magnetic tape transfer device that applies a transfer bias to transfer signals from a recorded master tape to a slave tape, means for controlling the speed of the take-up reel in a high-speed mode and a low-speed mode, and winding the master tape and slave tape on the take-up reel. Means for detecting the rotational speed T of the take-up reel from the start; means for detecting the rotational speed N _M or rotational period T _M of the master tape supply reel; and means for detecting the rotational speed N _S or rotational period T _S of the slave tape supply reel. means for detecting the trailer tapes of the master tape and the slave tape; said T and said N;
means for calculating the winding diameter D _M of the master tape from _M or T _M ; means for calculating the winding diameter D _S of the slave tape from the T and the N _S or T _S ; means for comparing a larger first predetermined value D _MS and D _M ; and means for comparing a second _{predetermined} value D _SS and D _S that is slightly larger than the hub diameter of the slave tape supply reel _; Alternatively, when D _SS > D _S , the rotational speed control of the take-up reel is switched from high speed mode to low speed mode, and then the winding operation is stopped by detecting the trailer tape of the master tape or slave tape. Features of magnetic tape transfer device. 2 (a) A third predetermined value in which the rotational speed T of the take-up reel is calculated and set from the recording time of the master tape.
When T becomes ₃ or more, (b) D _MS > D _M , (c) D _SS > D
Claim _{No. S} , characterized in that the high-speed control of the take-up reel is changed from the high-speed mode to the low-speed mode at the earliest timing among the three timings (a), (b), and (c) of S. The magnetic tape transfer device according to item 1. 3 After entering the low speed mode, when the number of rotations of the take-up reel exceeds the fourth predetermined value calculated from the recording time of the master tape and the trailer tape length, or when the trailer tape of the master or slave tape is detected. 3. The magnetic tape transfer device according to claim 2, wherein the magnetic tape transfer device is stopped from the low speed mode.