JPS6239490B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic tape transfer device, and more particularly to a magnetic tape transfer device, in which a recorded master tape and an unrecorded slave cassette 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 magnetic field to both tapes and transfers signals from a master tape to a slave tape.

The purpose of the present invention is to detect the reel hub diameter of a cassette tape in a batch winding type magnetic tape transfer device when a cassette tape is used as a slave tape, and to provide a stable tape running system without damaging the tape. be.

Conventionally, in a batch winding type magnetic tape transfer device, a method of detecting the reel hub diameters of the master and slave tapes and controlling the tape running speed has been proposed, for example, in Japanese Patent Application No. 104078/1983, but recently high-density recording As cassette VTRs have become more popular, batch-winding magnetic tape transfer devices have come into the spotlight as high-speed transfer devices for cassette tapes.
However, various problems have arisen when transferring a cassette tape using the above-mentioned batch winding method. One of them is that there are two types of cassette tape reel hub diameters. In other words, the hub diameter is divided into 62 mm for 30 minutes and 60 minutes, and 26 mm for 120 minutes, depending on the recording time.For example, if you try to transfer to a 30 minute cassette tape with a batch winding magnetic tape transfer device, In order to shorten the transfer time, the batch winding type transfer device has 30, 60,
Since there are three types of ``tape length selection buttons'' for 120 minutes, for example, if you want to transfer to the 30-minute cassette, you can press the button ``30,'' but if you press the button ``60,'' When you press , the tape end detection device detects the trailer tape (hereinafter referred to as trailer) of the cassette tape because the length of the cassette tape is insufficient, for example, while winding the tape at high speed (generally about 5 to 6 m/s). Even if the take-up reel is detected and the take-up reel is stopped, the trailer of recent cassette tapes is
Because it is short at ~17 cm, the take-up reel drive motor requires 100 mm.
If you do not use a motor with a braking torque of Kg/cm or more, the tape will be cut. However, since the take-up reel drive motor actually uses a braking torque of about 10 kg/cm, if you press the "tape length selection button" incorrectly, the tape may be cut, causing trouble. In order to eliminate such troubles, a special request was made in 1973.
-104078 detects the reel hub diameter of the master and slave tapes, and detects the reel hub diameter slightly larger than the reel hub diameter in advance at high speed (5 to 6 m/s).
s) to low speed (1 m/s or less). However, as mentioned above, since two types of hub diameters appeared in the slave side cassette tape, the patent application No. 104078/1980 was extremely insufficient.

The present invention eliminates the drawbacks of the conventional method described above,
To propose an effective tape damage prevention method that does not damage the tape even if the diameter of the cassette reel hub is more than one.

An embodiment of the present invention will be described below based on the drawings. FIG. 1 is a schematic diagram showing the basic operating elements of a cassette tape batch winding system, and parts unnecessary for explaining the present invention are omitted for the sake of simplicity. A cartridge case 1 houses a supply reel 3 on which a recorded master tape 2 is wound, and the supply reel 3 is driven by a motor 4. When an unrecorded slave cassette 5 is inserted from a cassette insertion slot (not shown), a photoelectric device (consisting of a light emitting element 6 and light receiving elements 6a and 6b) for detecting the start and end of the cassette 5 detects the contents inside the cassette 5. While checking the state of tape winding, the tape is pulled out from inside the cassette 5 by the tape pull-out arms 7a, 7b as shown by arrows 8a, 8b in FIG. FIG. 5 shows the rotational direction and flow of the operation of the reels 9 and 10 of the cassette 5 when the tape is pulled out by the tape arms 7a and 7b.
Here, a method for detecting the diameter of the reel hub of the cassette 5 according to the present invention will also be explained. When a cassette is inserted, the positional relationship between the magnetic tape and the trailer is checked using the light receiving elements 6a and 6b. That is, when 6a and 6b detect the magnetic tape, the tape pull-out arm 7
a, 7b are driven by the drive motor 11 in the clockwise direction (CW direction) as indicated by the arrows 8a, 8b, and at the same time, the reels 9, 10 in the cassette 5 are driven counterclockwise (CCW) by the respective drive motors 12, 13. When the light-receiving element 6b detects the trailer for detecting the end of the cassette 5, the reel hub diameter detection counter 75 (the operation is explained in detail in FIG. 7) is reset, and the trailer moves to the tape cutting position detection device ( The reel hub diameter detection counter 75 detects the time until detection by the light emitting element 14a and the light receiving element 14b), and the reel hub diameter is detected from this difference. To explain this in more detail using FIG. 3, since the mechanical distance l between the light receiving elements 6b and 14b is constant, the trailer
The time t for passing through 4b is expressed by the following equation.

t=l/πφV ......(1) l: Mechanical distance between the light receiving elements 6b and 14b φ: Cassette reel hub diameter V: Rotational speed of the reel 10 in the cassette [REV/
Sec] From equation (1), in order to detect the cassette reel hub diameter, the rotational speed V of the reel 10 in the cassette must be constant. Here, in the present invention, a low-speed geared motor with a constant rotational speed is used as the drive motor 13 for the reel 10 in the cassette, and V is kept constant. It goes without saying that this can also be achieved by using a general DC motor with speed control. As mentioned above, there are two types of cassette reel hub diameters, but when t is a hub diameter of 62φ and 26φ, 62φ is about 1/2 of that of 26φ, so by detecting t, the cassette reel hub diameter can be determined. It becomes possible to detect. If the light-receiving elements 6a and 6b detect a trailer when the cassette 5 is inserted, the cassette is not a regular cassette, so an audible or light alarm is issued. Next, when the light receiving element 6a detects a trailer and the light receiving element 6b detects a magnetic tape, it means that the tape in the cassette 5 is wound on the take-up reel 10 side, and the tape is wound on the supply reel 9 side. Since it becomes necessary to return the paper, the transfer time increases, and the efficiency decreases, a light or sound alarm is issued in this case as well. Next, when the cassette is inserted, when the light receiving element 6a detects the magnetic tape and the light receiving element 6b detects the trailer, the tape is pulled out from the cassette 5 using the drawer arms 7a and 7b, and the tape is removed from the cassette 5.
The inner reels 9 and 10 are driven clockwise, and when the light receiving element 6b detects the magnetic tape, the reel hub diameter detection counter 75 is reset and the reels 9 and 10 are driven counterclockwise.
When the tape cutting position detection devices 14a and 14b detect a trailer, the cassette of the reel hub diameter detection counter 75 is stopped, and the size of the reel hub diameter is determined based on the count value.

As explained above, in order to prevent the reel hub diameter detection counter 75 from erroneously detecting the positional relationship between the magnetic tape and the trailer tape when the cassette is inserted, the trailer 16 for end detection is always detected at 6b, and then the tape is cut. Accurate reel hub diameter detection is performed by detecting the trailer travel time to the location.

The operation after such a reel hub diameter is detected will be explained using FIGS. 1 and 3. After the connection between the slave tape 15 and the trailer 16 is positioned by the tape cutting position detection devices 14a and 14b,
The tape cutter 2 is sucked by suction blocks 17 and 18 which have a small hole for tape suction on the front side and are connected to a vacuum source (not shown) through other openings.
Cut by 0. The operation of the tape cutter 20 is controlled by a plunger 21. The mechanical positional relationship when the tape is cut is as shown in FIG. Next, the rotary table 23 on which the suction blocks 18 and 19 are mounted is rotated counterclockwise by the drive motor 28, and stops at a position where the front surface of the suction block 19 coincides with the front surface of the suction block 17. At this time, the suction block 19 holds the guide tape 27 (Figs. 1 and 3) protruding from the inner reel 26 of the take-up reel 25 having a double-shaft structure in the transfer section, and then the guide tape 27 (Figs. 1 and 3) is cut. The magnetic tape portion 15 (FIG. 3) of the slave tape and the guide tape 27 are adhered by an adhesive mechanism (not shown as it is not particularly relevant to the present invention), and the connecting portion is attached to the tape guide posts 29, 3.
0, 31, 32, an audio recording head 33, an audio erasing head 34, a tape guide post 35, and then wound into an inner reel 26. On the other hand, the recorded master tape 2 has tape guide posts 36, 37, 3 in advance.
8, 39, the audio playback head 40 is manually loaded into the master tape holder 42 of the take-up reel 25 via the tape guide post 41. The take-up reel 25 has a slit 4 for winding the slave tape 15 onto the inner reel 26 and for holding the master tape 2.
It has 3.44. After winding the connecting portion of the slave tape 15 and the guide tape 27 onto the inner reel 26, the master tape 2 and the slave tape 15 are connected to the air columns 45 and 4 provided in each running path.
6, and planar light sources 49a, 50a and planar light receiving elements 49b, 5, respectively, so that the tape loop positions 47, 48 in each air column 45, 46 are constant.
The motors 4 and 12 are controlled by the output from 0b via control circuits 51 and 52. In this way, the tape loop position is controlled at a constant level by the air columns 45 and 46 (this means that the tape tension is controlled at a constant level), and then the take-up reel 25 is connected to the inner reel 26 as shown in FIG. Connecting clutch 53 shown
The master tape 2 and the slave tape 15 are connected to each other and rotated, and the master tape 2 and slave tape 15 are connected to each other on the outer periphery of the take-up reel 25.
are wound up with their magnetic surfaces 54 and 55 in close contact with each other,
Transfer bias magnetic field generator 56 after winding a predetermined length
A magnetic field is applied to both tapes wound at the same time, the recording signal of the master tape is transferred to the slave tape 15, and then the audio signal is transferred when rewinding.
Transfer using the head-to-head method. To explain this in more detail, it is a method in which the audio signal of the master tape is reproduced by the reproduction head 40 during rewinding, and this is recorded on the slave tape 15 by the recording head 33. Here, the erase head 34 is for erasing the audio signal transferred by the transfer bias magnetic field. In this way, both tapes are rewound while transferring the audio signal, and when the rewinding is completed, the take-up reel 2
The connecting portion between the slave tape 15 and the guide tape 27 wound on the inner reel 26 of No. The tape is sucked into the tape 19 and cut by the cutter 20. After that, the rotary table 23 is driven clockwise and stopped at the position where the front surfaces of the suction blocks 17 and 18 are aligned, and the tape is cut by an adhesive mechanism (not shown). The slave tape 15 held on the suction block 17 and the trailer 16 held on the suction block 18 are bonded together, and after adhesion, the tape pull-out arms 7a and 7b are rotated counterclockwise and the reels 9 and 10 are rotated. The transfer is completed by winding the tape into the cassette. The purpose of the pressure rollers 58 and 59 is to remove the air film between the master tape 2 and the slave tape 15 in order to regulate the positions of the two tapes when the master tape 2 and the slave tape 15 are wound together. Reference numerals 60a and 60b are a light emitting element and a light receiving element, respectively, which are used to detect the transparent trailer tape provided at the rear end of the master tape 2.

As described above, high-quality transferred slave cassette tapes can be produced at high speed and in large quantities. However, as mentioned above, in order to run stably without damaging the tape, in the present invention, the diameter of the reel hub of the cassette is adjusted. We have realized a method that is useful for detecting cassettes with multiple hub diameters.

Next, the tape damage prevention method according to the present invention will be explained in more detail. First, the basic principle of the present invention will be explained using FIG. 4. FIG. 4 is a schematic diagram of the take-up reel 25 with the inner reel 26 omitted. In FIG. 4, the tape length of the master tape 2 or slave tape 15 wound on the take-up reel 25 is l.
(cm), the thickness of the master tape 2 is t ₁ [cm], the thickness of the slave tape 15 is t ₂ [cm], the take-up reel 25
The radius of the hub of is r ₁ [cm], the radius at which the tape is wound on the take-up reel 25 is r ₂ [cm], and the master tape 2 or slave tape 15 is placed on the take-up reel 25.
If the total number of rotations of the take-up reel 25 required to wind a tape length of l [cm] is T rotations, then r ₂ - r ₁ = (t ₁ + t ₂ ) x T [cm] ......(2 ) becomes. On the other hand, the number of rotations N(r,
p, s) are constant rotations, 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... ...(3) On the other hand, if the diameter of the slave tape supply reel 9 on which the slave tape 15 is currently wound is D _S [cm] and the rotation speed is N _S (r, p, s), then V=N _S・D _S・π……(4) D _S =V/N _S・π……(5) As explained above, if the tape thicknesses of the master tape 2 and slave tape 15 are determined in advance, the tape winding thickness (r ₂ − _{r 1} ) of the take-up reel 25 can be determined, and the rotational speed N of the take-up reel 25 can also be determined.
If (r, p, s) are rotated at a constant speed, the tape speed V (cm/sec) at that point is determined by the total winding rotation speed T of the take-up reel 25. Next, the rotational speed N _S of the slave tape supply reel 9
By detecting (r, p, s), the diameter D _S [cm] of the slave tape 15 wound on the slave tape supply reel 9 can be detected. That is, under the above conditions, if the total winding rotation speed T of the take-up reel 25 and the rotation speed N _S (r, p, s) of the slave tape supply reel 9 are detected, Diameter D of slave tape 15
_S [cm] can be detected. Here D _S
Since [cm] cannot be smaller than the hub diameter of the slave tape supply reel 9, it is sufficient to determine a value D _SS [cm] that is slightly larger than the hub diameter. Recent cassettes have two types of hub diameters, so if D _SS1 (second predetermined value) and D _SS2 (third predetermined value) are determined, V/N _S・π=D _S <D _SS1 (or D _SS2 )……(6) V/N _S・π・D _SS1 (or D _SS2 )<1……(7) That is, 2×{r ₁ +(t ₁ +t ₂ )・T}×N/D _S・_DSS
1 (or D _SS2 ) < 1 (8) When the condition of (8) is satisfied, the diameter of the supply reel 9 on which the slave tape 15 is wound is D _SS1 [cm]
(or D _SS2 [cm]) or less.

Next, the master tape 21 can be considered in the same way. Since the master tape 2 and slave tape 15 are simultaneously wound onto the take-up reel 25, the take-up tape speed V (cm/sec) is almost the same for both tapes 3 and 15. Also, a master tape supply reel 3 on which the master tape 2 is wound.
The diameter is D _M [cm], and the rotational speed is N _M (r, p,
s), then V=N _M・D _M・π ………(9) D _M =V/N _M・π ………(10) Like the slave, the master tape is also slightly smaller than the hub diameter of the master tape supply reel 3. If the larger value (first predetermined value) is D _MS [cm], then 2×{r ₁ + (t ₁ + t ₂ )・T}×N/N _M・D _MS as in equation (8)
<1 (11) is satisfied when the diameter of the supply reel 3 on which the master tape 2 is wound becomes less than D _MS [cm].

As explained above, the master tape 2 and slave tape 15 are wound on the take-up reel 25 in high-speed mode, and the diameter of the master tape supply reel 3 is D _M
[cm] is less than or equal to D _MS [cm], or the diameter D _S [cm] of the slave tape supply reel 9 is D _SS1
Alternatively, it is possible to stop smoothly and stably by switching to the low speed mode when D _SS2 [cm] or less or the timing of both is faster, and then detecting the trailer and stopping the winding. Additionally, the required torque of the take-up reel drive motor can be significantly reduced. In addition, if there is a tape on each of the master tape take-up reel 3 and the slave tape take-up reel 9 that is sufficiently longer than the required transfer length, when the total number of winding rotations T reaches a fourth predetermined value, the high speed mode is activated. When the speed mode is shifted to the low speed mode and the fifth predetermined value 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 fourth predetermined value and setting of the fifth predetermined value will be explained. The tape speed of a normal VTR is V _S cm/sec
Then, the required recording length for 60 minutes is l _S = 3600 x V _S
(cm), the total number of rotations when winding l _S may be set as the fourth predetermined value, and the total number of rotations when winding (l _S +200) cm may be set as the fifth predetermined value. Actually, as shown in FIG. 6, the fifth predetermined value is reached, or D _S <
When any of the conditions D _SS1 (or D _SS2 ), D _M < D _MS is met, the mode shifts from the high speed mode to the low speed mode, and either the fifth predetermined value, master trailer detection, or slave trailer detection is reached. When the conditions are met, the system enters stop mode from low speed mode.

FIG. 7 shows an electrical system diagram of the magnetic tape transfer device according to the present invention. An encoder 62 mounted coaxially with the motor 4 that drives the master tape supply reel 3 transmits light from the light emitting element 63a to the motor 4.
The light receiving element 63b
generates a signal according to the rotation of the motor 4. On the other hand, the motor 1 that drives the slave tape supply reel 9
Similarly, the encoder 64 installed coaxially with the motor 12 blocks the light emitted from the light emitting element 65a once per rotation of the motor 12, and the light receiving element 65b
Generates a signal according to the rotation of the A counter 66 counts the number of pulses from the frequency generator 67. However, since the counter 66 is reset by the signal from the light receiving element 63b, the motor 4 is reset to 1.
The number of pulses during rotation will be counted. That is, the counter 66 measures the rotation period of the motor 4. Similarly, the counter 68
Also, the rotation period of the motor 12 that drives the slave tape supply reel 9 is measured. The take-up reel 25 is installed coaxially with the drive motor 69 (the take-up reel should have a dual-shaft structure here, but it has been simplified because it is not considered particularly necessary to explain the present invention). Encoder 70 and light emitting element 71a
As a result, the light receiving element 71b generates a signal corresponding to the rotation of the motor 69. However, in this case, motor 6
9 generates 100 signals per revolution. The signal from the light receiving element 71b drives the motor 69 via the control circuit 72, and the speed of the motor 69 is controlled so that it rotates at a constant rate. On the other hand, the signal of the light receiving element 71b is 1/
Since the signal is also supplied to the 100 counter 73 and counted down to 1/100, the output of the counter 73 is generated every rotation of the motor 69. A counter 74 also measures the total number of revolutions of the take-up reel 25 during winding based on the output of the 1/100 counter 73. 75
is a reel hub diameter detection counter, and when the cassette 5 is inserted, the connecting part between the slave tape 15 and the end trailer 16 (Fig. 4) is detected by the light receiving element 6b (the light emitting element 6 is not shown in Fig. 7, but is shown in Fig. 1). At the same time, the connection detection signal of the light receiving element 6b resets the reel hub diameter detection counter 75. Next, the reel hub diameter detection counter 75
inputs the output of the frequency generator 67 and counts until the connection is detected by the tape cut detection device 14b. Therefore, due to the difference in the cassette reel hub diameter (because the motor 13 that drives the take-up reel 10 of the cassette 5 rotates at a constant speed),
Since the count value is about twice different (ratio of thin hub diameter 26φ to thick hub diameter 62φ), input this to gate 7.
6 to the data bus 77. 80~
83 is also an input gate, for inputting the rotation period of the master tape supply reel 3, for detecting the trailer portion of the master and slave tapes, and for the take-up reel 25.
The signals specified by the control bus 78 are connected to the data bus 77. Reference numeral 84 denotes an output latch, which outputs and latches the signal of the data bus 77 similarly to the input gate. Reference numeral 85 denotes an arithmetic processing unit (hereinafter referred to as CPU) which arithmetic processes the signal input from the input gate and outputs it to the output latch. 8
6 is ROM for executing instructions of CPU85
87 is a RAM used as a signal buffer memory and arithmetic processing memory.

In the above configuration, the slave tape side will be explained in more detail. The relationship between the rotational speed N _S of the slave tape supply reel 9 and the period T _S is T _S =1/N _S (12), and the frequency of the frequency generator 67 is
If it is 1MHz, then T _S = T' _S ×10 ^-6 (13). In other words, equation (8) is 2・T _′S・N{r ₁ +(t ₁ +t ₂ )・T}/D _SS
1 (or D _SS2 ) < 10 ⁶ ...... (14) If we substitute concrete values here, r ₁ = 9 cm, N = 8 [r, P, s] t ₁ + t ₂ = 50 × 10 ^-4 If cm D _SS1 = 2.9cm, T′ _S (27586・T+49655172)＜10 ¹²
......(15) and can be easily calculated as a positive integer by the CPU85. In addition, the output of the reel hub diameter detection counter 75 is calculated by the CPU 85, and if the hub diameter is thick, D _SS2 = 6.5 cm, and if the hub diameter is thin, D _SS1
The calculation can be easily done by setting = 2.9cm. Similarly, on the master tape side, if the rotation period of the master tape supply reel 3 is T _M (sec), T _M = 1/N _M ...... (16) T _M = T' _M × 16 ^-6 ... (17) Therefore, equation (11) is 2・T′ _M・N{r ₁ + (t ₁ +t ₂ )・T}/D _MS
<10 ⁶ ......(18) If D _MS = 4.6 cm, equation (18) becomes T′ _M (17391・T+31304347)<10 ¹²
......(19) becomes. The CPU 85 always executes calculations of equations 14 and 18 during the high-speed winding period. When either condition is satisfied, the CPU 85 issues a low speed winding mode command to the control circuit 72 via the output latch 84, and the motor 69 is controlled to rotate at a low speed. Next, when the light receiving elements 60b and 6a detect a trailer, the CPU 8
5 issues a command for the winding stop mode to the control circuit 72, the drive of the winding reel 25 is stopped, and the winding mode is 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, the slave tape is often a commercially available tape with a fixed length; that is, in a magnetic tape transfer device, the slave tape cannot be shorter than the master tape. Therefore, in the above embodiment, when the condition of equation (14) is satisfied and the light receiving element 6a detects the trailer of the slave tape 15, the master tape 15
If the trailer is not displayed, the CPU 85 drives the alarm display section 89 via the output latte 88. The alarm is given by light or sound. Generally available slave tape lengths are for 30 minute programs, 60 minutes,
They are classified into 120-minute and 240-minute tapes, but even if the operator of the magnetic tape transfer device mistakenly uses a slave tape that is shorter than the master tape, an alarm will be displayed to confirm this.

As mentioned above, it is generally impossible for the slave tape to be shorter than the master tape, but sometimes when creating a small amount of transfer tape and when the master tape will not be used in the future, the master tape may be erased. May be reused. In this case, without cutting the master tape, a portion is recorded on a long tape and transferred using a magnetic tape transfer device. That is, the switch 90 is operated and the signal is input to the CPU 85 via the input gate 91. The input value is the total number of rotations T for winding the take-up reel 25, and the CPU 85 switches from the high-speed winding mode to the low-speed winding mode when the total number of revolutions T of the take-up reel approaches the value specified by the switch 90. , and further controls to switch to the winding stop mode when both values match. In the case of such control, the trailers of master tape 2 and slave tape 15 should not be detected unless the operation is incorrect.
As described above, by this operation, the light receiving element 16a may detect the trailer of the slave tape 15 before the total number of revolutions T of the take-up reel 25 reaches the value specified by the switch 90. In this case as well, of course, the equation (14) holds true as described above, and this is after the mode has been switched to the low speed mode, and the mode is switched to the winding stop mode when the trailer of the slave tape 15 is detected. At this time, if the total number of revolutions T of the take-up reel has not reached the value specified by the switch 90, the CPU 85
drives the alarm display section 89 via the output latch 88 to issue an alarm.

As explained above, according to the present invention, the winding diameter of the master tape wound on the master tape supply reel during winding, and the winding diameter of the slave tape wound on the slave cassette tape supply reel (reel hub Since the winding mode is controlled by detecting the reference value corresponding to the diameter (including diameter detection), even if the operator makes a mistake, there is no possibility of abnormal tension being applied to the master tape or slave tape or damage to the master tape or slave tape. In addition, if necessary, a warning can be generated on the display for easy operation.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a batch winding type magnetic tape transfer device for cassettes constructed based on the present invention;
FIG. 2 is a schematic sectional view of the take-up reel section, FIG. 3 is a schematic diagram of the slave cassette section for explaining the present invention, and FIG. 4 is a schematic diagram of the take-up reel section for explaining the present invention. 5 and 6 are operational flowcharts for explaining an embodiment of the present invention, and FIG. 7 is an electrical system diagram for explaining the present invention. 2...recorded master tape, 4...motor,
6a, 6b... Light receiving element (photoelectric device for detecting the start and end of slave tape), 9, 10... Reel, 12, 13... Drive motor, 14b... Light receiving element (tape cutting position detecting device), 15... ...Slave tape, 16...Trailer tape, 25...
Take-up reel, 26...inner reel, 63b, 65
b, 71b... Light receiving element, 66, 68, 74...
Counter, 67... Frequency generator, 75... Reel hub diameter detection counter, 85... Arithmetic processing unit (CPU), 89... Alarm display unit.

Claims (1)

[Claims] 1. A recorded master tape and an unrecorded cassette-type slave tape wound on each supply reel are wound onto a take-up reel with their magnetic surfaces in close contact with each other, and then a transfer bias is applied. , a magnetic tape transfer device that transfers signals from a recorded master tape to a slave tape, including means for controlling the speed of the take-up reel in a high-speed mode and a low-speed mode; means for detecting the total number of revolutions T of the take-up reel; means for detecting the reel hub diameter of the cassette-type slave tape; means for detecting the rotation speed N _M or rotation period T _M of the master tape supply reel; It has a means for detecting a rotation speed N _S or a rotation period T _S and a means for detecting a master tape and _a slave tape. When the value calculated by the output of the means for detecting _M becomes equal to or less than the first reference value, or the value calculated by the output of the means for detecting the rotation speed N _S or rotation period T _S of the slave supply reel. becomes less than a second or third reference value determined by the output of the means for detecting the reel hub diameter of the cassette-type slave tape, or when the output of the means for detecting the total number of revolutions T of the take-up reel is When a fourth reference value is reached, the rotation of the take-up reel is switched from high speed to low speed, and when the output of the means for detecting the total rotation speed T of the take-up reel reaches a fifth reference value, Or a magnetic tape transfer device having means for stopping winding when detecting the trailer tape of the master tape or slave tape. 2. The magnetic tape transfer device according to claim 1, wherein when the trailer tape of the slave tape is detected faster than the trailer tape of the master tape, a sound or light alarm is issued. 3. The magnetic tape according to claim 1, characterized in that when a slave tape trailer is detected, a sound or light alarm is issued if the total number of revolutions T of the take-up reel is less than or equal to a predetermined number. Transfer device. 4 (a) Rotational speed N of master tape supply reel
(b) When the value calculated by the output of the means for detecting _M or the rotation period T _M becomes equal to or less than the first reference value, (b) the value calculated by the output of the means for detecting the rotation speed N _S or the rotation period T _S of the slave supply reel; (c) When the value calculated from the output is determined as the output of the means for detecting the reel hub diameter of the cassette-type slave tape and becomes equal to or less than the second or third reference value, (c) the total number of revolutions T of the take-up reel is detected; When the output of the means for controlling reaches a fourth reference value, the high-speed mode is switched to the low-speed mode at the earliest timing among the three timings (a), (b), and (c). A magnetic tape transfer device according to claim 1.