JPH02220253A - Tape running controller - Google Patents

Abstract

PURPOSE:To surely control deceleration of the tape speed by comparing tape position data from an operating means with stored changeover position data to read out speed data and sending it to a speed control means. CONSTITUTION:Pulse period detecting circuits 6 and 7 measure periods of reel pulses from frequency generators 21 and 22 based on a clock pulse CK, and a tape classification running and position detecting circuit 8 calculates tape classification data indicating the overall length of a magnetic tape 15 and tape position data based on an F/R signal indicating the rotation direction of a capstan motor and periods of reel pulses. A frequency divider 10 divides the frequency of a capstan pulse, whose frequency is proportional to the rotative speed of a motor 1, of a frequency generator 12 based on an FF/REW signal indicating the VTR operation mode, tape classification data, and tape running position data to generate a control pulse, and a speed control circuit 11 generates a speed control signal based on the control pulse sent from the frequency divider 10, the clock pulse CK, etc., and sends it to a mixing amplifier 13.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a magnetic recording and reproducing device for recording and reproducing signals on a magnetic tape, such as a VTR, and particularly in the process of tape fast forwarding and rewinding. , relates to a device for controlling tape running speed.

(Prior Art) Conventionally, in a tape recorder, when fast forwarding or rewinding a magnetic tape, the running speed of the magnetic tape is reduced from high speed to low speed before the tape reaches the end or start end. A device has been proposed to prevent excessive tape tension from occurring when the tape is stopped (Japanese Patent Laid-Open No. 59-92458 [G11B15746]).

(Problem to be Solved) However, in the conventional device described above, the rotational speeds of a pair of reel stands are detected, and the ratio of the rotational speeds of both reel stands is 1:1.
The reel motor is decelerated and the tape speed is switched to a low speed after a predetermined period of time has elapsed from the point at which the reel motor is decelerated and the tape speed is switched to a low speed. There was a problem in which normal operation could not be maintained when the return was started. In other words, since the timing start point of the predetermined period has already passed at the start of rewinding, the tape reaches the beginning without switching the tape speed to a lower speed, resulting in excessive tape tension. It is.

SUMMARY OF THE INVENTION An object of the present invention is to provide a tape running control device that can always reduce the tape speed near the end or start of the tape, regardless of the tape position at the start of rewinding or fast forwarding.

(Means for Solving the Problems) A tape running control device according to the present invention includes a speed control means for switching the tape running speed by controlling the rotational speed of a capstan motor (1), and both reel stands (19). ) (20) Calculating means for detecting the rotational speed and, based on the detection signal, calculating tape position data according to the distance of tape travel from the start end or the end end of the magnetic tape, and for each predetermined section of the magnetic tape. a data storage means in which speed data corresponding to the rotational speed of the capstan motor (1) to be set and tape position data (switching position data) representing a tape position at which the rotational speed of the capstan motor (1) should be switched; , the tape position data from the calculation means is compared with the switching position data of the data storage means, and speed data representing the rotational speed to be set for the capstan motor (1) is read from the data storage means to control the speed. and a switching determination means for sending the information to the switching means.

(Function) When a rewind command or a fast forward command is issued and the capstan motor (1) is driven to start running the magnetic tape at high speed, the calculating means calculates tape position data every moment.

The switching determination means determines the rotation of the capstan motor (1) to be set at that time based on the magnitude relationship between the tape position data sent from the calculation means and the switching position data stored in the tape storage means. Speed data corresponding to the speed is read from the data storage means and sent one after another to the speed control means.

As a result, the speed control means is the capstan motor (1)
The running speed of the magnetic tape is gradually reduced by changing the rotational speed of the magnetic tape when necessary.

(Effects of the Invention) According to the tape running control device of the present invention, regardless of the tape position at the start of rewinding or fast forwarding, the tape speed can always be controlled to decelerate near the end or start of the tape. This prevents excessive tape tension from occurring.

(Examples) The nine examples are for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing its scope.

FIG. 1 shows an example in which the present invention is applied to a VTR.
The mechanism of the tape running system is similar to that of a conventional VTR. That is, the capstan motor (1) that drives the magnetic tape (15) is connected to either the supply reel stand (19) or the take-up reel stand (20) via the well-known oscillating idler mechanism (14). The supply reel (2) and take-up reel (3) of the tape cassette are rotatably mounted on the zero-reel stands (19) and (26) selectively connected to the tape cassette, and a well-known tape loading mechanism (not shown) ), the magnetic tape (15) of the tape cassette is stretched on a predetermined tape running path, and signals are recorded and reproduced.

First and second frequency generators (21) and (22) that generate reel pulses with a frequency proportional to the rotational speed of each reel stand are arranged opposite to both reel stands (19) and (20),
The capstan motor (1) also has a third capstan pulse that generates a capstan pulse with a frequency proportional to the rotational speed of the motor.
A frequency generator (23) is provided.

The output ends of the first and second frequency generators (21, 22) are connected to pulse synchronization detection circuits (6, 7) via pulse amplifiers (4, 5), respectively. The detection circuit (6) (7)
is the period TL of the reel pulse based on the clock pulse CK sent from the clock input terminal (18).
, Ts.

The output ends of both lateral outputs 2g (6) and (7) are connected to a tape type/travel position detection circuit (8). The detection circuit (8) is connected to an input terminal (16) from a system controller (not shown).
) and the reel pulse cycles Tt and Ts, tape type data representing the total length of the magnetic tape is calculated, and tape type data representing the total length of the magnetic tape is calculated. Calculate tape position data according to the amount of tape travel from the end of the tape. These data are sent to a frequency divider (lO), which will be described later. still,
The calculation method will be described later.

The FF/REW signal indicating the VTR operating mode is sent from the system controller via the input terminal (17).
The signal is sent to a mode determining circuit (9), which determines whether the VTR is in fast forward mode, rewind mode, or normal playback mode.

The determination result is sent to the frequency divider (10).

Further, the output end of the third frequency generator (12) is connected to a frequency divider (10) via a pulse amplifier (12).

The frequency divider (10) divides the frequency of the capstan pulse from the third frequency generator (12) based on the operation mode of the VTR, tape type data, tape running position data, etc. It generates control pulses used for speed control. Details of this operation will be described later.

The clock pulse CK and the output of the frequency divider (10) are connected to a speed control circuit (11). The control circuit creates a speed control signal to be supplied to the capstan motor (1) based on control pulses, clock pulses CK, etc. sent from the frequency divider (10), and generates a speed control signal to be supplied to the capstan motor (1).
3).

The mixing amplifier (13) generates a motor control signal by combining the speed control signal and a phase control signal sent from a known phase control system (not shown), and generates a motor control signal. It is to be sent to.

In this embodiment, the tape type/running position detection circuit (
8) and the frequency divider (10) are configured by a microcomputer.

Calculation of tape type data by the tape type/running position detection circuit (8) is performed based on the well-known formula below.

K=Tt2+Ts2 Here, the longer the total length of the tape, the smaller the value of K, and the tape type can be determined by the value of K predefined according to the tape type. For example, the standard playback speed of the NTSC system ( In SP mode), the tape cassette for 2-hour needle drawing is 59.30<K≦75.8
In the case of a tape cassette for 30 minutes recording, the range is 80.45<K≦84.00.

Further, the calculation of the traveling position data is based on the F/R signal and the T
This is done by the ratio s/Tt. That is, in the process of running the magnetic tape from the starting end to the ending end, the periods Tt and Ts of the reel pulses change depending on the tape position as shown in FIG. Conversely, the tape position can be determined.

In this embodiment, the tape position data P is Ts/
Use the ratio of Tt. Therefore, for example, the tape position data P at the center of the tape is 1.0.

Next, an example of the operation of the microcomputer constituting the tape type/travel position detection circuit (8) and frequency divider (10) will be explained based on FIGS. 2 to 5.

FIG. 5 shows the relationship between the rotational speed of the capstan motor Me and the tape position at which rewinding is performed from halfway A near the end of the tape. When a 0 rewind command is issued, first t7 During the period, the Mc rotation speed is set to low speed VL.
(for example, the same speed as the standard playback speed), and for the next two periods, the speed is increased to an appropriate speed (for example, 2XVI).

After the ti period has passed, the Me rotation speed is increased to a higher speed V3 (
[M, for example, 10XV,) to perform most of the rewinding.

After the speed ■ is set, when the tape position reaches the position before the start end, that is, the tape position data P reaches Ll (for example, 2.6), the Me rotation speed is set to a low speed of V4 (for example, 3XV).
, ), and then, when P=L2 (for example, 2.9), the speed is lowered to a lower speed (for example, 1.5×V+), and the tape is wound up to the beginning of the tape.

The case of tape fast forwarding is the same as above, and the first t+,
Set the h period to ■1 and ■2, gradually increase the tape speed, and then increase the tape speed to position P= before the end of the tape at the speed of ■3.
When it reaches L,' (0,4), it decelerates to ■, and further decelerates to ■ at position P=L,' (0,3).

As mentioned above, 2, L8, L1', and L2' are stored in the memory of the microcomputer as switching position data, and 1 to 2 are speed data, respectively.

Below, the processing procedure of the microcomputer to realize the above operation will be explained.

When the VTR shifts from 5TOP mode to fast forward or rewind mode, the timer in the microcomputer is reset (25) as shown in Figure 2, and the rotational speed of the capstan motor (Mc) is changed as shown in Figure 5. Calculate the value of K based on the values of Tt and Ts of the 0th order (27) set to 1 (26), which is a low speed. The tape types T1, T2, and T are determined according to the value of K (steps (28) to (29> (30) (31)).

After that, as shown in Fig. 3, it is determined whether the rotation direction of the capstan motor is the normal feed direction (F) or the reverse feed direction (R) (32) <33) The 0 rotation direction is F, that is, fast forward. In the case of , after detecting Tt and Ts, calculate the tape position data P (34) L, and add the data P to the above L +
' Compare (35).

When P>L,', start the timer (36),
After the t1 period has elapsed, the Me rotation speed is set to 2, and after the t2 period has elapsed, the Me rotation speed is set to 2 (steps (37) to (38)).

After that, in step (35) it is determined that P≦L,',
When P>L,' is determined (39), Me rotation speed is
, decelerates to (40).

Further, when it is determined that P≦L2' (41), the Me rotational speed is decelerated to V (42) L, and then, when the tape end sensor is turned on, the capstan motor is stopped (43).

If it is determined in step (33) that the rotational direction of the capstan motor is R1, that is, rewinding, a series of operations shown in FIG. 4 are performed. The operation is performed in step (3) above.
Since the operations are the same as those in 4) to (43), the explanation will be omitted.

According to the above tape running control device, in rewinding and fast forwarding operations, the tape speed is not only always sufficiently reduced near the end or the beginning of the tape, regardless of the tape position at the start of tape running, but also At the start of tape running,
Because the tape speed is gradually increased, the magnetic tape is not damaged by excessive tape tension.

The drawings and the description of the above embodiments are for illustrating the present invention, and do not limit the invention described in the claims.
Nor should it be construed as limiting the scope.

Further, it goes without saying that the configuration of each part of the present invention is not limited to the above-mentioned embodiments, and various modifications can be made within the technical scope of the claims.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a tape running control device according to the present invention, FIGS. 2 to 4 are flowcharts showing the operation of the device, FIG. 5 is an explanatory diagram of tape rewinding operation,
FIG. 6 is a graph showing the relationship between tape position and reel pulse period. (1)...Capstan motor (19) (20)...Reel stand (21) (22) (23)...Frequency generator tape start end center tape end Figure 5 Procedure amendment (self-proposed) Heisei April 22, 1991 1. 2゜3゜ Indication Patent Application No. 1-411, Name of Invention Relationship with the Tape Travel Control Device Amended Case Patent applicant (188) Sanyo Electric Co., Ltd. 5゜ Invention of drawings and specification subject to amendment Corrected "Pulse synchronization detection" on page 7, line 7 of the specification to "Pulse period detection" in the detailed explanation column. that's all

Claims (1)

[Claims] (1) In a magnetic recording and reproducing device that runs a magnetic tape wound around a pair of reel stands by the drive of a capstan motor, during the process of fast forwarding and rewinding the magnetic tape, the tape moves to the beginning or end. A tape running control device that switches the tape running speed from high speed to low speed in multiple steps before reaching the speed of the tape, comprising: a) a speed control means that switches the tape running speed by controlling the rotational speed of a capstan motor; b) calculation means for detecting the rotational speed of both reel stands and calculating tape position data according to the amount of tape travel from the start or end of the magnetic tape based on the detection signal; and c) a predetermined position of the magnetic tape. data storage means storing speed data corresponding to the rotational speed of the capstan motor to be set for each section and tape position data (switching position data) representing the tape position at which the rotational speed of the capstan motor should be switched; d) Compare the tape position data from the calculation means with the switching position data of the data storage means, read out speed data representing the rotational speed to be set for the capstan motor from the data storage means, and control the speed control means. 1. A tape running control device comprising: switching determining means for sending data to a tape drive;