JPH06111411A - Tape recording / playback device - Google Patents

Abstract

(57) [Summary] [Purpose] To increase the tape speed during search. [Structure] 11 is a take-up reel, 12 is a reel motor for rotating the take-up reel, 13 is an FG detection circuit for detecting the rotation speed of the take-up reel, and 14 is a detected FG (frequency generator) output as a voltage. F / V converter for conversion, 21
Is a supply reel, 22 is a reel motor for rotating the supply reel, 23 is an FG detection circuit for the supply reel, 24 is an F / V converter for converting the detected FG into a voltage, and 15 is two Fs.
Comparator for comparing the output of the / V converter, 16 is a motor driver for driving the reel motor 12, 17 is an F / V
It is a servo amplifier that controls the driver by looking at the output of the converter 14 and the number of rotations of which can be switched by a switching signal from the outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape feeding device capable of searching a tape-shaped magnetic recording medium at high speed.

[0002]

2. Description of the Related Art Conventionally, in tape feeding at the time of FF search in a digital audio tape recorder (DAT), the take-up reel has been driven by decelerating the rotation of the capstan motor, and therefore the angular velocity is constant. And the reel diameter increases near the end of the tape.
The speed of tape feeding was also increasing. On the other hand, since the tape speed is limited due to the reading of data, the number of rotations of the reel for winding the tape is naturally limited.

Therefore, the tape speed is the highest at the end of the tape, and the winding operation is performed at the start end of the tape with the number of revolutions kept at the same value. Therefore, the tape feeding speed at that time is smaller than the limit value. Was becoming.

[0004]

At this time, the number of rotations of the reel could not take a very large value in order to guarantee reading of data near the end of the tape. Specifically, it is as follows when expressed numerically. The tape speed is normally up to 200 times, and at the end of the 120-minute tape, the take-up reel rotation speed Rt is Rt = (200 × 8.15E-3) / (π × Dt) = 14.82 (s ^{− 1} ) Where Dt is the final winding diameter of the take-up reel, 3
It is 5.0 mm. At this number of revolutions, the tape feed speed V at the beginning of the tape is (hub diameter 15.0 mm), V = 14.82 × (π × 15.0) = 698.38 (mm / s) As a result, N≈85.7 (times), which means that the driving speed is lower than half of the data readable limit value, which slows down the overall search speed.

In order to solve this problem, a method is possible in which the tape speed at that time is calculated from the rotational speeds of both reels, and the rotational speed of the reel at that time is determined from the result, but the tape speed is derived. A complicated calculation was required to derive the reel rotation speed and the reel rotation speed.

The present invention has been made to solve the above problems, and provides a tape-shaped recording / reproducing apparatus capable of increasing the tape speed during search without calculating the tape speed or the tape winding diameter. The purpose is to get.

[0007]

According to the present invention, a specific tape position is detected by comparing the rotation speeds of both reels, and different reel rotations determined by a circuit before and after that position are detected. The number of tapes is made to travel, and a suitable search speed is given in each area. That is,
According to the tape position, a constant number of rotations is prepared in multiple stages without sequentially calculating it.

[0008]

According to the present invention, the tape speed at the time of search can be increased by switching the reel to be driven to the preset number of rotations only by the switch operation.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG.
In FIG. 1, 11 is a take-up reel, 12 is a reel motor for rotating the take-up reel, 13 is an FG detection circuit for detecting the rotation speed of the take-up reel, and 14 is a detected FG.
An F / V converter for converting the output of the (frequency generator) into a voltage, 21 a supply reel, 22 a reel motor for rotating the supply reel, 23 an FG detection circuit for the supply reel, 24
Is an F / V converter that converts the detected FG into a voltage, 15 is a comparator that compares the outputs of the two F / V converters, 1
6 is a motor driver for driving the reel motor 12, 17
Controls the driver by looking at the output of the F / V converter 14,
It is a servo amplifier whose rotation speed can be switched by a switching signal from the outside.

Next, the operation of FIG. 1 will be described.

First, when a search in the FF direction is started by a command from a CPU (not shown), the servo amplifier 17 sets a circuit constant and controls the output of the driver 16.
When the reel motor 12 rotates, the take-up reel 11 rotates to generate a reel FG, which is generated by the FG detector 1.
3 detects and shapes the waveform into a rectangular wave. The rectangular wave output is converted by the F / V converter 14 into a voltage output according to the frequency. It is assumed that a small voltage output can be obtained when the frequency is high. Then, looking at the output voltage of the F / V converter 14, the servo amplifier gives feedback so that the operation of the motor driver 16 becomes constant.

At this time, the supply reel starts to rotate because the tape is wound. The supply reel rotates while keeping the tape tension constant by a slip mechanism (not shown). Therefore, as with the take-up reel, the FG according to the number of rotations of the reel is generated.
Occurs. Then, the FG detector 23 for the supply reel detects and shapes the waveform, and outputs a rectangular wave. This output is F /
The V converter 24 converts the voltage into a voltage corresponding to the FG frequency. It is assumed that a small voltage output can be obtained when the frequency is high. Receiving this voltage, the servo amplifier 17 supplies the motor drive current to the motor driver 16 so that the drive current decreases when the input voltage is high. Driver 16
Applies the input current according to the motor, and rotates at high speed when the current is large. Therefore, if the reel rotation speed is too high, the output voltage of the F / V converter 14 becomes high,
The servo amplifier 17 reduces its output current, and as a result, the driver 16 is fed back to suppress the rotation speed of the motor and keep the rotation speed of the reel constant.

Next, the comparator 15 has two F / Vs.
The voltage outputs of the converters are compared, and if (output of 14)> (output of 24), L is output, and if (output of 14) <(output of 24), H is output. Here, (output of 14) = (output of 24) becomes when the winding diameters of both reels become equal, and therefore corresponds to the central point of the total tape length of the tape inserted at this time.

Here, for example, assuming that the tape is near the leading end, (output of 14)> (output of 24), so the output of the comparator becomes L. In response to the L output of the comparator 15, the rotation speed switching circuit 18 changes the constant of the servo amplifier 17 so that the motor rotates at the first rotation speed, and (14 output) <(24 output). At this time, the output of the comparator 15 becomes H, and in response to this signal, the servo amplifier changes the circuit constant so as to rotate the motor at the second rotation speed.

This operation will be described with reference to FIG. Figure 2
Here, 111 is an input terminal, 112 to 118 are resistors, 119 is an operational amplifier, 121 and 122 are switches, 123 is a capacitor, 124 is a large current transistor, and 125 is an output terminal.

The resistor 112 is connected between the input terminal 111 and the negative input of the operational amplifier 119, and the resistor 113 is connected between the output of the operational amplifier 119 and the negative input. The output of the operational amplifier 119 is the transistor 1
The transistor 124 is connected to the base end of the transistor 24, and the transistor 124 has an emitter end connected to the constant power supply Vcc and a collector end connected to the output end 12.
It is 5. The capacitor 123 is connected between the collector end and the base end of the transistor 124. On the other hand, the selection end d of the switch 122 is connected between a resistor 117 and a resistor 118 that divide the constant power source and the ground into resistors, and the selection end c of the switch 122 is connected to another switch 121. The selection terminals a and b of the switch 121 are resistors 11 that divide the constant power source and the ground into resistors.
4, connected to the contacts of the resistors 115 and 116 to supply different bias voltages to the operational amplifier 119. Here, (voltage of terminal a)> (voltage of terminal b) of the switch 121.

The signal arriving at the input terminal 111 is supplied to the resistor 11
2 and the resistor 113 determine the amplification factor, and the operational amplifier 11
It is inverted and amplified at 9. At this time, normally the switch 1
22 is connected to the d side, and the plus input of the operational amplifier 119 is biased by the bias voltage of the resistors 117 and 118. This bias voltage is set so as to have a normal tape running speed.

The output of the operational amplifier 119 is connected to the base end of the large current transistor 124, and the transistor 1
Drive 24. The collector end of the transistor 124 outputs a current to the output end 125 according to its bias. Here, the capacitor 123 is a capacitor for phase correction.

If the number of rotations of the reel is high, the input voltage drops from the above description, the voltage rises at the output end of the operational amplifier, and the base-emitter voltage of the transistor 124 becomes small, so that the output end 125 is output. The output current becomes small, and as a result, the current supplied to the motor decreases, so the rotation of the motor is decelerated, and the servo is configured.

Next, when a search command is sent from a CPU (not shown), the switch 122 operates so as to connect to the c side. The start switch 121 is connected to the a side, and the bias voltage V1 set by the three resistors 114, 115 and 116 is applied to the plus input of the operational amplifier 119. This voltage causes the tape to run at a tape speed higher than the normal tape speed, and the reel to rotate at a constant speed. Next, as described above, when the tape starts to be wound before the intermediate point, the output of the comparator 15 in FIG. 1 becomes L. The switch 1 in the servo amplifier receives this signal.
21 is connected to the b side. Three resistors 114, 1 on the b side
The plus input of the operational amplifier 119 is biased with the bias voltage V2 set by the signals 15 and 116. At this time, the operational amplifier 119 functions as a non-inverting amplifier with respect to the change in bias voltage, and the transistor 1 is different from the previous voltage V1.
The base voltage of 24 will be reduced, resulting in an increase in output current.

If the output of the comparator 15 becomes H, the switch 121 in the servo amplifier is connected to the side a. At this time, the positive input of the operational amplifier 119 is biased with the bias voltage V1, but the output is reduced as compared with when the bias voltage is V2.

Here, the bias voltage V1 is set so that the tape speed becomes the maximum allowable speed at the final end of the tape, and the bias voltage V2 is set so that the tape speed becomes the maximum allowable speed at the midpoint of the tape. .

Here, the number of revolutions of the take-up reel at each stage of a 60 m tape will be concretely shown. First, the maximum allowable speed of the tape is a maximum of 200 as shown in the conventional example.
Up to double speed. The winding diameters at the midpoint and the final end of the 60 m tape are 26.9 mm and 35.0 mm, respectively. First reel operation given by bias voltage V2
Since the tape speed is 200 times faster at the midpoint, R = (200 × 8.15E-3) / (π × 26.9E-
3) = 19.3 (s ⁻¹ ). Also, the second rotational speed after switching is 200 times the tape speed at the final end, so R = (200 × 8.15E-3) / (π × 35.0E-
3) = 14.8 (s ⁻¹ ), the motor may be rotated. Therefore three resistors 1
14, 115 and 116 are set so that the rotation of the reel has the above values.

Of course, the above values may be changed if the tape double speed limit is changed under other conditions. First
The reel rotation speed may be any value as long as it is larger than the rotation speed of the second reel.

When the target ID can be read from the tape running at high speed in this way, the reel rotation is braked by a brake mechanism (not shown) to reach the target tape position.

At the time of REW, although not shown, a similar servo loop exists on the supply reel side and the same switching operation is performed.

This time, for the sake of simplicity, both reels are driven by dedicated motors.
Other configurations may be used. For example, by transmitting the rotation of the capstan motor to the reel that winds the planetary gear,
The rotation speed may be switched in the middle of the servo loop of the rotation of the capstan.

Further, although the circuit constant value in the servo amplifier is changed in this embodiment, other blocks such as F are used.
The circuit constant of the / V converter may be changed.

[0029]

As described above, according to the present invention, by simple detection, the driven reel is switched to a preset number of rotations only by a switch operation, thereby making it possible to perform complicated calculations such as tape speed calculation and tape winding diameter calculation. The tape speed at the time of search can be increased without performing calculation, and the search time can be shortened.

Here, the time taken for winding the tape up to the middle point will be compared. Taking a 60 m tape as an example, since the number of windings to the midpoint is 458, the winding time in the conventional example is T (conventional example) = 458 / 14.8 = 30.9 (seconds), whereas in the present invention, it is T (Invention) = 458 / 19.3 = 23.7 (seconds), which has an effect of shortening by 20% or more.

[Brief description of drawings]

FIG. 1 is a block diagram showing the main configuration of an embodiment of the present invention.

FIG. 2 is a circuit diagram for explaining the block diagram of FIG. 1 in detail.

[Explanation of symbols]

 11 Take-up reel 12,22 Reel motor 21 Supply reel 13,23 FG detection circuit 14,24 F / V converter 15 Comparator 16 Driver 17 Servo amplifier 18 Rotation speed switching circuit

Claims (3)

[Claims] 1. A means for detecting the number of rotations of a supply reel and a take-up reel, a means for calculating the maximum number of rotations of the reel from the detected number of rotations of both reels, and a maximum rotation of the reel according to the detected number of rotations of the reel. A tape having means for switching the number, means for setting the maximum number of rotations of the supply reel and take-up reel, and means for rotationally driving the supply reel or the take-up reel at the set maximum number of rotations. Recording / reproducing apparatus. 2. A means for detecting the number of rotations of the supply reel and the take-up reel, a means for comparing the detected number of rotations of both reels, a means for switching the maximum number of rotations of the reel according to the comparison result, and a supply reel. And a means for setting the maximum rotation speed of the take-up reel, and means for rotationally driving the supply reel or the take-up reel at the set maximum rotation speed. 3. A means for detecting the rotational speeds of the supply reel and the take-up reel, a means for calculating the maximum rotational speed of the reel from the detected rotational speeds of both reels, and a means for switching the maximum rotational speed according to the tape length. And a tape-shaped recording / reproducing apparatus comprising means for setting the maximum rotation speed of the supply reel and the take-up reel, and means for rotationally driving the supply reel or the take-up reel at the set maximum rotation speed. .