JP2803416B2 - Magnetic recording / 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 helical scan type magnetic recording / reproducing apparatus for shortening a phase settling time.

[0002]

2. Description of the Related Art The phase control of a conventional magnetic recording / reproducing apparatus when a capstan motor is started will be briefly described.

FIG. 3 is a block diagram of a conventional magnetic recording / reproducing apparatus. In FIG. 3, 1 is a magnetic tape, 2 is a capstan motor, 3 is a pinch roller which presses the capstan shaft of the capstan motor 2 to move the magnetic tape 1, and 4 records and reproduces signals on the magnetic tape 1. It is a rotating head. Reference numeral 5 denotes a motor control device for controlling the driving and running of the magnetic tape 1, and its control output is supplied to the capstan motor 2. 9 is a capstan motor 2
An operation switch for operating stop and start of the motor; 11 a stop control device for sending a stop signal of the capstan motor 2;
Is an activation control device for transmitting an activation signal for the capstan motor 2, and the operation switch 9 is connected to the stop control device 11 and the activation control device 12, and the stop signal of the stop control device 11 and the activation control device 12 Both start signals are supplied to the motor control device 5.

A conventional magnetic recording / reproducing apparatus configured as described above will be described. When a stop operation is performed by the operation switch 9 when the magnetic recording / reproducing device is in the reproducing state, a stop command is sent from the stop control device 11 to the motor control device 5. As a result, the motor control device 5 stops supplying the drive current to the capstan motor 2, and as a result, the capstan motor 2 stops.

Next, when a start operation is performed by the operation switch, a start command is sent from the start control device 12 to the motor control device 5. Thus, the motor control device 5 starts the capstan motor 2 and performs phase pull-in after the speed is settled.

[0006]

However, in the conventional configuration, since the phase state immediately after the capstan motor is started and the speed is settled is not constant, it may take time to pull in the phase, and the reproduction or recording may be performed quickly. Had a problem that it could not be started.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic recording / reproducing apparatus which solves the above-mentioned conventional problems and has a simple structure which shortens the phase pull-in time and keeps it constant.

[0008]

To achieve this object, a magnetic recording / reproducing apparatus according to the present invention comprises a capstan motor for driving and running a magnetic tape, and a pulse signal having a frequency proportional to the rotation speed of the capstan motor. Signal output means for outputting a signal, a counter for counting pulse signals output from the first signal output means, a rotary head for recording and reproducing signals on and from the magnetic tape, and a rotational position of the rotary head. Output the pulse signal according to the second
Signal output means, stop control means for starting the capstan motor and starting the count operation of the counter in synchronization with the pulse signal output by the second signal output means, and A delay unit for calculating delay time data; and a start control unit for starting the capstan motor based on the delay time data.

[0009]

According to the present invention, when the tape is stopped, a stop command is sent to the capstan motor in synchronization with a pulse signal corresponding to the rotational position of the rotary head, and the capstan motor is actually stopped after the command is sent. Until the number of pulses of the pulse signal having a frequency proportional to the rotation speed of the capstan motor is counted, the number of pulses is converted into a tape moving amount and stored. Then, at the time of starting the tape, by starting the capstan motor after the elapse of the delay time calculated from the tape movement amount from the time synchronized with the pulse signal,
The phase pull-in time after speed setting is shortened, and at the same time is kept constant.

[0010]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a magnetic recording / reproducing apparatus according to the present invention. In FIG. 1, 1 is a magnetic tape, 2 is a capstan motor, 3 is a pinch roller for pressing the capstan shaft of the capstan motor 2 to run the magnetic tape 1, and 13 is proportional to the rotation speed of the capstan motor 2. An FG signal output device that outputs a pulse signal of a frequency (hereinafter, referred to as an FG signal), 4 is a rotary head that records and reproduces signals on the magnetic tape 1, and 14 is a pulse signal ( A head switching signal output unit for outputting a head switching signal will be described below.

Reference numeral 5 denotes a motor control device for controlling the driving and running of the magnetic tape 1, and its control output is a capstan motor 2
Supplied to Further, 9 is an operation switch for operating the stop and start of the capstan motor 2, 7 is a stop control device for sending a stop signal to the capstan motor 2, and 8 is a start control for sending a start signal to the capstan motor 2. Device. The operation signal output from the operation switch 9 and the head switching signal output from the head switching signal output unit 14 are both connected to both the stop control device 7 and the start control device 8, and The stop signal and the start signal of the start control device 8 are both supplied to the motor control device 5. Further, reference numeral 6 denotes a counter for counting the number of pulses of the FG signal, and 10 denotes a time data generating device for calculating the start timing of the capstan motor 2 as a delay time.
The signal is supplied to the counter 6. Further, the count data of the counter 6 is supplied to the time data creation device 10,
The delay time data output from the time data creation device 10 is supplied to the activation control device 8.

FIG. 2 is an explanatory diagram of a stop operation and a start operation of the magnetic recording / reproducing apparatus of this embodiment. In FIG.
(A) shows the movement amount of the magnetic tape in the stop operation and the start operation of the magnetic tape by area, and (b) shows the head switching signal of the rotary head 4 on the same time axis as (a). . Also, t1 is the time when the operation is stopped by the operation switch 9 and firstly synchronized with the head switching signal, t2 is the time when the start operation is performed by the operation switch 9 and first synchronized with the head switching signal, and t3 is the time. The time when the capstan motor 2 actually starts, and the time t4 is the time when the capstan motor 2 is started and the speed is settled, and is first synchronized with the head switching signal.

X is the delay time data calculated by the time data generating device 10, T is the cycle of the head switching signal, and S1 is from the synchronization point with the first head switching signal after the stop operation is performed by the operation switch 9. The amount of tape movement until the capstan motor 2 actually stops, V is the tape movement speed in a steady state, L is the tape movement distance from when the capstan motor 2 is started until the speed stabilizes to V, Z is the time required from the start of the capstan motor 2 until the speed is settled to V, and S2 is the tape movement amount from the time when the speed of the capstan motor 2 is settled to time t4.

The magnetic recording / reproducing apparatus of the present embodiment configured as described above will be described. Now, it is assumed that the magnetic recording / reproducing apparatus is in a reproducing state. When a stop operation is performed by the operation switch 9, the stop control device 7 sends a stop command to the motor control device 5 at time t1 in synchronization with the head switching signal, and simultaneously starts the counting operation of the counter 6. The capstan motor 2 attempts to stop by sending the stop command, but cannot stop instantaneously due to the influence of inertia force or the like, and actually stops at a position slightly advanced after the stop command is sent. That is, a deviation (hereinafter, referred to as a stop error amount) occurs between the tape position when the stop command is sent and the tape stop position when the capstan motor 2 actually stops.

On the other hand, the counter 6 is a capstan motor 2
Count the number of FG pulses until stops. At this time, since the pinch roller 3 is pressed against the capstan shaft of the capstan motor 2, the stop error amount can be calculated from the count data of the counter 6.

Next, when a start operation is performed by the operation switch 9, the start control device 8 issues a start command to the motor control device 5 at a time t3 after a lapse of a predetermined delay time from a time t2 synchronized with the head switching signal. Send out. Here, the delay time X is calculated from the relational expression shown in (Equation 2).

[0018]

(Equation 2)

X: delay time data (s) n: natural number T: cycle (s) of the pulse signal of the second signal output means Y: tape moving distance (m) calculated from count data of the counter V: constant L: The speed is V (m / m) after the capstan motor is started.
s) The tape moving distance (m) until settling to (z) Z: The speed is V (m /
It is the required time (s) until settling to s). Hereinafter, the relational expression shown in (Equation 2) will be described.

In FIG. 2, the total amount of movement of the tape between times t1 and t4 when the phases of the head switching signals are equal to each other is an integral multiple of the amount of movement of the magnetic tape in a steady state per one cycle of the head switching signal. If so, the phase state at time t4 becomes equal to the phase state at time t1. This is equivalent to the fact that the phase has already settled when the tape 1 reaches the time t4, which means that the phase pull-in time always converges to zero. As a result, it is possible to shorten the phase pull-in time, which conventionally takes a long time, and to make the time constant. Summarizing such conditions in a relational expression,

[0021]

(Equation 3)

## EQU1 ## Here, since the stop error amount S1 is substantially equal to the calculated tape moving distance Y in (Equation 2),

[0023]

(Equation 4)

And S2 is:

[0025]

(Equation 5)

Since rewriting is possible as shown in the following, substituting (Equation 4) and (Equation 5) into (Equation 3) and rearranging it gives:
The relational expression shown in (Equation 2) can be derived.

In (Equation 2), the capstan motor 2
The tape moving distance L and the required time Z from the start of operation until the speed settles to V can be considered to be constant values.
Since the natural number n can also be arbitrarily selected, the delay time X is a function of only the tape moving distance Y and can be easily calculated from the count data of the counter 6.

As a result, the phase pull-in time after speed setting is shortened and the pull-in time can be made substantially constant. Further, even if the stop error amount varies due to the temperature characteristic or the like, since the delay time is calculated according to each stop error amount, the same operation accuracy can always be maintained.

As described above, according to this embodiment, the capstan motor (capstan motor 2) for driving and running the magnetic tape and the first pulse signal having a frequency proportional to the rotation speed of the capstan motor are output. Signal output means (FG signal output device 13), a counter (counter 6) for counting the pulse signal output from the first signal output means, and a rotary head (rotation) for recording and reproducing signals on the magnetic tape. Head 4), second signal output means (a head switching signal output device 14) for outputting a pulse signal according to the rotational position of the rotary head, and the second
Stop control means (stop control device 7) for stopping the capstan motor and starting the counting operation of the counter in synchronization with the pulse signal output by the signal output means of (a), and delay time data based on the count data of the counter. (Time data creation device 10) and start control means (start control device 8) for starting the capstan motor based on the delay time data, so that the phase pull-in time can be reduced with a simple configuration. Can be shortened and at the same time be constant.

In this embodiment, the delay time is calculated by calculating a plurality of delay time data in advance based on (Equation 2) and tabulating the data, and selecting the optimum delay time data according to the count data. Similar results can be obtained with the method.

[0031]

As described above, the present invention provides a counter for storing the number of pulses of a pulse signal having a frequency proportional to the rotation speed of a capstan motor, and a delay means for calculating delay time data based on the count data of the counter. Is newly provided, the phase pull-in time can be shortened and fixed with a simple configuration. Further, the operation accuracy can be maintained even when an external environment changes due to temperature characteristics or the like, and the practical effect is extremely large.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a magnetic recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a timing chart for explaining a stop operation and a start operation of the magnetic recording / reproducing apparatus in the embodiment.

FIG. 3 is a block diagram showing a configuration of a magnetic recording / reproducing apparatus in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic tape 2 Capstan motor 3 Pinch roller 4 Rotating head 6 Counter 7 Stop control device 8 Startup control device 10 Time data creation device 13 FG signal output device 14 Head switching signal output device

Claims (2)

(57) [Claims] 1. A capstan motor for driving and running a magnetic tape, first signal output means for outputting a pulse signal having a frequency proportional to a rotation speed of the capstan motor, and an output from the first signal output means. A counter for counting a pulse signal to be performed, a rotary head for recording and reproducing a signal on and from the magnetic tape, a second signal output unit for outputting a pulse signal according to a rotational position of the rotary head, and the second Stop control means for stopping the capstan motor and starting the count operation of the counter in synchronization with the pulse signal output by the signal output means; delay means for calculating delay time data based on the count data of the counter; Starting control means for starting the capstan motor based on the delay time data. Gas-recording and reproducing apparatus. 2. The delay means according to claim 1, wherein the delay time data is expressed by (Equation 1)
The magnetic recording / reproducing apparatus according to claim 1, wherein (Equation 1) X: delay time data (s) n: natural number T: cycle (s) of the pulse signal of the second signal output means Y: tape moving distance (m) calculated from count data of the counter V: fixed state L: The speed is V (m / m) since the capstan motor started.
s) The tape moving distance (m) until settling to (z) Z: The speed is V (m /
Time required to settle to s) (s)