JPH0352152A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent the cutting of a tape at the terminal end thereof by controlling the rotation of a reel on a tape supply side so that it may be constant only when it is needed and controlling it so that nearly constant speed which is approximate to the upper limited value of a tape speed may be attained when it is not needed. CONSTITUTION:In the case of getting in an area where position information is not written at the time of seraching a target point, a non-recording detection signal is outputted from a signal processing part 16. When the non-recording detection signal or a terminal end searching instruction is inputted, a microcomputer 17 makes an output active so as to switch a changeover switch 11 to rotate a reel motor 2 on the tape supply side. Then, the revolving speed of the motor 2 is detected by a revolving speed detector 7 and ferquency-voltage converted by an f-V converter 8. The converted voltage is converted in terms of voltage by a voltage conversion circuit 18 and the output from the circuit 18 is inputted in a comparison integration circuit 13 through the changeover switches 10 and 11. The converted output and a reference voltage from a reference voltage generator 12 are compared and integrated by the circuit 13 and the integrated value is outputted to a driving circuit 3 through the changeover switch 14 to drive a reel motor 1 on a tape take-up side.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording and reproducing device.In particular, the present invention relates to a control method lIcIgl suitable for tape speed control when the tape runs at high speed.
do.

[Conventional technology]

The conventional device detects the number of rotations of a supply reel and a take-up reel as described in Japanese Patent Application Laid-open No. 54-156506, and adjusts the number of rotations on the tape winding side so that the sum of the number of rotations is approximately constant. 90 However, this control did not take into account cutting the tape at the end of the tape.

[Problem to be solved by the invention]

The above-mentioned conventional technology does not take into account cutting the tape at the end of the tape, but there is a problem in that the tape cuts when the tape runs at high speed. In order to solve the above-mentioned problem, it is necessary to It is sufficient to detect this and slow down the tape speed near the end of the tape. However, if the tape speed is slowed near the end of the tape, the average speed will be slow and the access time loss will be large when accessing near the end of the tape. Figure b. And, to minimize the access ◆ time loss〇 [Means for solving the problem] Of the above objectives, accurately detecting the end of the tape and slowing down the tape speed at the end of the tape This is achieved by controlling the rotation of the supply reel at a constant level. However,
In the case of the above method, the tape speed at the end and beginning of the tape differs by the diameter ratio, and there is an upper limit to the tape speed at which the signals recorded on the tape can be read. There is a problem that the loss is large. Therefore, the purpose is to control the rotation of the tape supply hook reel to a constant level only when necessary, and to keep the rotation of the tape supply hook reel constant at a speed close to the upper limit value when it is not necessary. If the rotation of the tape supply side reel is constantly controlled by performing such control, the tape speed is fast when the tape supplied reel diameter is large,
At the end of the tape when the reel diameter is small, the tape speed becomes slow. Therefore, by controlling the rotation of the reel to be constant, the end of the tape can be detected and the tape speed can be slowed down. Even in the case of tapes with different tape lengths, the diameter of the tape supplying reel at the end of the winding is equal to the reel hap diameter, so the tape speed at the end of the winding is constant regardless of the tape length.

However, in the above method, since the tape speed at the end of the tape is slow, there is a large loss of access time when accessing near the end of the tape. Therefore, when accessing at high speed while reading signals recorded on a tape that cannot be reached at the end of the tape, the sum of the periods or the sum of the frequencies of the rotations of both the tape supply reel and the tape take-up reel must be By controlling the tape speed to be constant, the tape speed becomes almost constant, and the loss of access time can be minimized. bExplain. 1st
As shown in the figure, one embodiment of the present invention has a first drive means for running the tape in the input direction (rr) during high-speed running.
0 reel motor 1, a second reel motor 2 which is a driving means for running the tape in the B direction (REV), a drive circuit 3 for driving the first reel motor 1, and a second glue.
a drive circuit 4 that drives the 10th reel motor 2; a rotation speed detector 5 that detects the 10th rotation speed of the 10th reel motor; an f-V converter 6 that converts the rotation speed into a voltage; A rotation speed detector 7 that detects the rotation speed, a t-V converter 8 that converts the rotation speed into a voltage, an adder 9 that adds the output voltages of both the f-V converters 6 and 8, and a tape supply side reel rotation speed. When performing constant control, the voltage conversion circuit 18, 19, l* which performs voltage conversion of the output voltage of both f-V conversion a6.8, and the voltage conversion circuit 18, 190 output voltage, the output of the tape supply side The changeover switch 10% for selecting the voltage is selected by the changeover switch 11 for selecting the output voltage of the tape supply side and the output voltage of the adder 9, and the cough changeover switch 11 depending on whether or not the above control is performed. a reference voltage generator 12 that generates a voltage for comparison, a comparator/integrator 13 that integrates the difference between the comparison and the comparison. Comparison/integrator 15 (changeover switch 14 for applying the D output voltage to the tape winding υ side reel motor, signal reading section 15 for reading the signals recorded on the tape, converting the armpit reading signal into a digital signal) It is comprised of a signal processing section 16 for conversion, and a microcomputer 17 for switching the changeover switch 11 according to a non-recording detection signal outputted from the signal processing section 16 and a tape end search command signal inputted from outside the system.

A case in which a search command in the PF direction is given to this system with the above configuration from an external source, for example, by a host combination or an external key operation, will be explained below. The operations are classified into point search and end search to the end of the tape, and first, the normal operation of the target point search will be explained.

When performing a target point search, if it operates normally, it will never reach the end of the tape, so the tape speed is controlled to be almost constant at a speed close to the upper limit of the tape speed at which signals recorded on the tape can be read. In the present invention, in order to perform the above control, the frequency sum constant control of the tape supply side reel motor 2 and the tape winding side reel motor 10 is performed.The 0th period control is operated by a servo loop described later. Tape winding *v-le motor 1 and tape supply reel motor 2
The rotational speed of each is detected by the rotational speed detector 5.7, and the outputs are added to the adder 9, and the added value is It is input to the comparator/integrator 13 via the changeover switch 11. The comparator/integrator 13 compares and integrates the added value with the reference voltage output from the reference voltage generator 12, outputs the cough integral value to the drive circuit 5 via the changeover switch 14, and outputs it to the tape winding side. Drive the reel motor 1.

Next, the operation when the terminal search and target point search do not operate normally will be explained.

When the target point search enters an area where the positional information is not written, the signal processing section 16 outputs a non-recording detection signal. The microcomputer 17 activates the output when the non-recording detection signal or the end search command is input, switches the changeover switch 11, and forms a servo loop described later in which the number of revolutions of the tape supply reel motor is constant. . The rotation speed of the tape supply side reel motor 20 is detected by the rotation speed detector 7, and f
-1/Conversion@8Vc to perform b frequency-voltage conversion.The converted voltage is converted into voltage by the voltage conversion circuit 1B, and the converted output is sent to the comparator/integrator 15 via the changeover switch 10.11. input. The comparator/integrator 15 compares the conversion output with the reference voltage output from the reference voltage generator 12.
The integrated value is output to the drive circuit 5 via the changeover switch 14 to drive the tape take-up reel motor 1. According to this embodiment, it is necessary to read the signals recorded on the tape when the tape supply side reel motor 2 rotation speed is controlled to be constant. Therefore, if the tape speed at the end of the tape is set below a certain value, the tape speed at the beginning of the tape can be controlled at a fast speed that allows the signals recorded on the tape to be absorbed. By setting the voltage conversion rate of the voltage conversion circuits 18 and 19 so as to satisfy the above conditions, it is possible to reduce the access time.

〔Effect of the invention〕

According to the present invention, the tape speed can be slowed down at the end of the tape, and the slow mode is not used unless necessary, so tape cutting at the end of the tape can be prevented, and access and It has the effect of minimizing time loss0

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a tape speed control system during high-speed tape running according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... First reel motor, 2... Second reel motor, 5... Drive circuit, 4... Drive circuit, 5...
Rotation speed detector, 6... f-V converter, 7... rotation speed detector, 8... t-V converter, 9... adder, 10
... Selector switch, 11... Selector switch, 12.
...Reference voltage generator, 15... Comparison/integrator, 14.
...Selector switch, 15...Signal reading D section, 16.
...Signal processing unit, 17...Microcomputer, 18...Voltage conversion circuit, 19...Voltage conversion circuit.

Claims (1)

[Claims] 1. A tape supply side reel rotation speed detection means, a tape winding side reel rotation speed detection means, a tape drive motor,
In a magnetic recording and reproducing apparatus comprising servo means for controlling the motor according to the number of rotations of the reel and tape recording signal reading means for reading signals recorded on the tape, when the tape is running at high speed, the tape supply side reel and a first servo control means for driving the motor so as to keep constant the period sum or frequency sum of the rotations of both reels on the tape winding side; and a first servo control means for driving the motor so as to keep the rotation of the tape supply side reel constant. 2 servo control means, a switching means for switching between the first servo control means and the second servo control means, and a control means for controlling the switching means, and the tape is recorded on the tape. In the case of high-speed access while reading the recorded signal, the first servo control means is switched to drive the motor, and in the case of high-speed tape end search or high-speed running of a blank tape, the second servo control means is switched to
A magnetic recording/reproducing device characterized in that the motor is driven by switching to a servo control means.