JPH0229964A - Tape speed controller for magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent an overspeed of a tape at its beginning and end parts and to quicken the startup of the tape by performing the startup with an orderly increase of the reel speed when the tape length is unknown and starting it up directly with a set reel speed when the tape length is known. CONSTITUTION:Cycles are measured by cycle measuring means 5 and 6 for take-up and supply reels respectively with pulse signals generated by the reels 3 and 4, and the tape length is calculated by a tape length calculating means 17. Then, at the time of commencing a high speed tape travel in the case of a known tape length, cycle sum data corresponding to the tape length are set in a data setting means 8, so as to carry out the startup directly with a set reel speed. And, in the case of an unknown tape length, the startup is performed by increasing the reel speed in order so as to decide whether or not the cycle sum becomes correspondent to the reel speed. By this method, the reel speed at its beginning and end parts is prevented from becoming a higher speed, and the startup speed in the case of the known tape length is quickened.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides tape speed control for a magnetic recording/reproducing device that prevents the reel speed at the beginning or end of the tape from becoming too high during high-speed tape running such as during high-speed search. Regarding equipment.

[Conventional technology]

A conventional tape speed control device of this type is shown in FIG.

In the figure, 1 is a rotating drum, 2 is a tape cassette, and a tape 2a pulled out from the tape cassette is wound around the rotating drum 1 at a desired angle. 3 is a supply reel, 4 is a take-up reel, and 3ap4a is the supply reel 3
, a supply reel FC (frequency generator) that generates a pulse C when the take-up reel 4 rotates, and a take-up reel FC.
It is.

5.6 is a supply reel period measuring means and a take-up reel period measuring means for measuring the rotation period of the supply reel 3 and the take-up reel 4 based on the reels FG3a and 4a; 7 is the supply reel period measuring means 5, and the winding reel period measuring means 5; An adder for adding the period from the reel period measuring means 6; 8 is a data setting means for setting reel servo data for a control means 9 to be described later based on reel speed information from a microcomputer (not shown); 9 is the adder. This reel speed control means controls the reel speed so that the sum of the periods of both reels from 7 and the sum of periods determined based on the data from the data setting means 8 are the same.

10 is a low-pass filter that converts the speed control output from the reel speed control means B 9 into a control voltage; 11;
is a motor drive circuit that drives a motor 12 that serves both as a reel drive and a capstan drive based on the output from the low-pass filter 10.

13 is a pinch roller, 14 is a capstan shaft, and 14a is a capstan FC that generates a pulse when the capstan shaft 14 rotates.

Next, the operation of the conventional example described above will be explained. When the microcomputer issues an instruction to run the tape at a constant speed, the data setting means 8 sets tape speed data in the reel speed control means 8.

The reel speed control means 9 includes a capstan FG14 that generates pulses by detecting the rotation of the capstan shaft 14.
a, and the capstan FG, which is the standard according to the tape speed.
Servo information such that the servo information becomes the same is supplied to the capstan axis control means. That is, the capstan drive motor 12, which also serves as a reel drive, is controlled via the low-pass filter 10 and the motor drive circuit 11 so that the rotational speed of the capstan shaft 14 is constant.

Further, when an instruction to run the tape at high speed is issued from a microcomputer (not shown), the data setting means 8 sets reel servo data in the reel speed control means 9. on the other hand,
The reel period is measured by the reel period setting means 5, 6 from the outputs generated from the reels FG3a, 4a. The measured reel periods are added by an adder 7, and the result is supplied to the reel speed control means 9. Then, the reel speed control means 9 uses the reel servo data to compare the reference period sum determined based on the reel servo data with the sum of both reel periods from the adder 7, and calculates the comparison error by the pulse width. The reel drive motor 12, which also serves as a capstan drive motor, is outputted as a modulation signal and controlled by being supplied via the motor drive circuit 11 with a control voltage converted by a low-pass filter IO so that the sum of the rotation periods of both reels is constant. .

Assuming that high-speed tape running is now performed at a tape speed of 200 times, the data setting means 8 sets the period sum data that is 200 times the tape length at a tape length of 120 minutes in the reel speed control means 9, and the tape speed is increased by 200 times. It will be run.

[Problem to be solved by the invention]

By the way, in the conventional tape speed control device described above, when detecting the tape start and end, the start and end of the tape are detected at one rotation period during high-speed tape running, so the start and end of the tape are detected. The reel rotation period on one side near the (supply reel during fast forwarding, take-up reel during rewinding) changes depending on the reel speed. Therefore, when detecting the beginning and end of the tape, the reel speed cannot be detected unless the reel speed has completely reached the set reel speed.

Therefore, if high-speed tape running is performed near the beginning or end of the tape, for example, if the reel speed is 200 times, the beginning or end of the tape will not be detected until the reel speed reaches 200 times. There was a problem in that the light reached the beginning and end of the tape at a magnification of 200 times, causing damage to the tape, magnetic head, and mechanism.

[Purpose of the invention]

The present invention aims to solve the above-mentioned problems, and its purpose is to prevent the reel speed from reaching high speeds at the beginning and end of the tape, thereby reducing the influence on the tape, magnetic head, and mechanism. An object of the present invention is to provide a tape speed control device for a magnetic recording/reproducing device that prevents the above problems.

[Summary of the invention]

In order to achieve the above object, the present invention prevents the reel speed from becoming high at the beginning and end of the tape by changing the way the reel speed rises when the tape length is known and when it is unknown. Another gist of the present invention is that when the tape length is known, the reel speed can be increased quickly.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. Note that the same reference numerals as in FIG. 3 above indicate the same circuits, and a description thereof will be omitted.

15 is a tape remaining amount time calculating means for calculating the remaining amount of tape based on the output from the supply reel period measuring means 5;
Reference numeral 16 denotes tape running time calculating means for calculating the running time of the tape based on the output from the take-up reel period measuring means;
Reference numeral 7 denotes a tape length calculation means for calculating the tape length based on the outputs from the tape remaining time calculation means 15 and the tape running time calculation means 16, whereby the tape length is determined and the reel cycle sum data corresponding to the tape length is calculated. is configured to be set in the data setting means.

Next, to explain the operation based on the above configuration, when a play or record instruction is given from a microcomputer (not shown), a pulse signal is generated by the reels FG3a and 4a of the supply reel 3 and the take-up reel 4. is output to the supply reel cycle measuring means 5 and the take-up reel cycle measuring means 6, and the cycle is measured. Then, this output is supplied to the tape remaining amount time calculation means 15 and tape running time calculation means 16, and the tape remaining amount time and tape running time are calculated, so that the tape length calculation means 17 calculates the tape length.

Next, the high-speed tape running operation in high-speed search etc. will be explained with reference to the flowchart of FIG.

Note that the operations in the flowchart are performed by a microcomputer (not shown).

First, the microcomputer determines whether or not the tape is running at high speed (step S1). If it determines that the tape is running at high speed, it then determines whether the tape length is known (step S2). If the result is known from the above-mentioned tape playback and recording operations, the cycle sum data corresponding to the tape length, that is, the cycle sum data corresponding to the reel speed and reel length is directly set in step S3.
), the reel speed starts up faster and the operation ends.

On the other hand, if the tape length is not known, the tape length is 120.
Initial period sum data is set such that the reel speed is 100 times (compared to during normal playback) in minutes (step S4), and the microcomputer determines whether the reel servo is locked (step S5). That is, it is determined whether the reel speed has reached the set speed or not. When the reel servo is unlocked, the reel servo is monitored until it is locked, and when the reel servo is locked, it is checked whether the period sum data corresponds to the reel speed set by the data setting means 8. A judgment is made (step S6). In this judgment, if it is judged that the set period sum data is reached, the reel speed is increased and the operation is completed.

On the other hand, if it is determined in step S6 that the set cycle sum data is not set, the cycle sum data with a 1.1 rank higher reel speed is set (step S7), and the reel speed is set to be faster than the reel speed in step S4 (step S5).
This operation is repeated until the set cycle sum data is reached.

In the above embodiments, the reel servo controls the reel rotation speed so that the sum of the rotation periods of the supply reel and the take-up reel is constant. Even if the servo is controlled so that the sum of squares is constant, the same operation as in the embodiment described above is performed.

〔Effect of the invention〕

As described above, in the present invention, when the tape length is unknown, the reel speed does not reach a high speed state when starting at the beginning or end 53i of the tape, so it is possible to prevent the tape, magnetic head, and mechanism from being affected. Furthermore, when the tape length is known, the reel speed rises quickly, so tape searches can be performed quickly.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart showing the same operation, and FIG. 3 is a block diagram showing a conventional example. DESCRIPTION OF SYMBOLS 1... Rotating drum, 8... Reel servo data setting means, 9... Reel speed control means, 15... Tape remaining amount time calculating means, 16... Tape running time calculating means, 17...・Tape length calculation means. Patent applicant: Pioneer Corporation Figure 2

Claims (1)

[Scope of Claims] A magnetic recording and reproducing device having a reel servo that controls the rotational speed of a reel that winds a tape, and a capstan servo that controls the rotational speed of a capstan shaft that runs the tape at a constant speed. The tape speed control device includes data setting means for supplying reel speed information to the reel servo, and tape length calculation means for calculating the tape length of the tape when the capstan shaft is running at a constant speed, and the tape length calculation means is configured to calculate the tape length when the high speed tape starts running. When the tape length is unknown, a reel start-up operation is performed to sequentially increase the reel speed, and when the tape length is known, the reel speed is directly started up to the reel speed set by the data setting means. A tape speed control device for a magnetic recording/reproducing device, characterized in that: