JPS63113852A - Magnetic tape driving controller - Google Patents

Abstract

PURPOSE:To execute a stable control extending from low speed to high speed by controlling the driving speed of a reel base through a control circuit, by the output of a speed detector provided with two converting elements for detecting the low speed and the high speed of a tape. CONSTITUTION:A speed detector 33 is provided with a first converting element 33a for detecting low speed running speed, consisting of a minute slit pattern 23a and a first photocoupler, and a second converting element 33b for detecting a high speed running speed, having a rough slit pattern. Their outputs are switched selectively by an electric switch 32b, and control the speed of one of driving devices 26, 28 of a winding reel base or a supply reel base through a control circuit 31. Accordingly, when a tape runs at low speed, a detection having high resolution can be executed, and when it runs at high speed, a wide and stable control extending from low speed to high speed can be executed without generating an output drop caused by the responsiveness.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic tape drive control device that can be used in rotary head type tape recorders and the like.

2. Description of the Related Art A conventional magnetic tape drive control device of this type is based on the configuration shown in, for example, Japanese Unexamined Patent Publication No. 58-122606, and one example of its application is a model shown in FIG. It is indicated by.

That is, the magnetic tape 3 (hereinafter referred to as tape) coming out of the tape cassette 2 held on the board 1 of the device is guided through a fixed tape guide 4a, first tape guides 5a, 5b, 5c, and 5.
d. A tape path is configured such that the tape returns to the tape cassette 2 while being guided by a tape guide drum 8 that includes a second tape guide 6, a fixed tape guide 4b, and rotating magnetic heads 7a and 7b (hereinafter referred to as heads). There is. During recording, the tape 3 is driven by a capstan 9 and a pinch roller 10, and is wound onto a take-up reel (not shown) by a take-up reel stand 12a driven by a take-up reel stand drive device 11. During fast forwarding, the take-up reel stand drive device 11 operates independently. The supply reel stand driving device 13 drives the supply reel stand 12b when rewinding the tape. On tracks recorded diagonally on the tape,
As is well known in the .81 video system, a recording pattern is determined to record a trunk detection signal for detecting tracking errors. Based on this recording pattern,
In the reproduction state of the apparatus, the track detection circuit 14 generates a head tracking error signal for a predetermined track based on the output signals of the heads 7a and 7b. Control circuit 1
5 uses this tracking error signal as an input signal to drive and control the capstan motor 16, so that the heads 7a,
7b controls the speed of the tape 3 so that it scans over a predetermined recording track.

In the recording state of the apparatus, the control circuit 15 operates to keep the rotational speed of the capstan motor 16 constant, thereby keeping the tape speed constant and the pitch of the trunk to be recorded constant. The cassette 2 is provided with tape guide posts 2a+2b and a recess 2c, and immediately after the cassette 2 is mounted on the board 1,
The tape is in the position shown in 3a, and the above-mentioned first tape guides 5a, 5b, 5c, 5ci and the second tape guide 6 are placed in the space surrounded by the tape 3a and the recess 2C.
and the pinch roller 10 are configured to fit in the positions indicated by broken lines. Then, by a drive device (not shown), these first tape guides 5a, sb, 5c, 5
A, the second tape guide 6, and the pinch roller 10 are respectively displaced from the positions shown by the broken lines to the positions shown by the solid lines, thereby bringing the apparatus into a state in which recording or reproduction is possible.

Problems to be Solved by the Invention However, in such a configuration, it is difficult to control the tape speed over a wide range from low to high speed. In other words, by keeping the rotational speed of the capstan motor 16 constant, it is possible to control low-speed running during tape recording, but when controlling high-speed running during fast forwarding or rewinding, it is possible to control the running speed of the tape during fast forwarding or rewinding. In order to control the tape speed and keep the tape speed constant in response to the ever-changing reel diameter, other means are required. Examples of alternative means include a combination of means for detecting the rotational speed of the reel stand and means for calculating based on this detection, or installing a separate tape speed detector, but either method is simple. This is not something that can be realized with a simple configuration, and is a problem with conventional examples.

Therefore, the present invention has been made in order to provide a simple device configuration that can control tape speed over a wide range from low speed to high speed.

Means for solving the problems and technical means of the present invention for solving the above problems are as follows:
A roller that rotates in contact with the magnetic tape, a tape speed detector that includes a conversion element that converts the rotational displacement of this roller into an electrical signal, and the rotational speed of the supply or take-up reel table is controlled according to the output of this detector. The tape speed detector further includes a first conversion element that detects a low tape running speed and a second conversion element that detects a high tape running speed, The output of the second conversion element is selected by an electric switch and inputted to the control circuit.

action The effect of this technical means is as follows.

That is, according to the configuration of the present invention, when the tape is run at a low speed and a signal is recorded on it, the control circuit controls the drive of the take-up reel base based on the output of the first conversion element. When the tape is running at high speed and the beginning of the tape is to be detected, the drive of the supply or take-up reel base can be controlled based on the output of the second conversion element (simply the above-mentioned Tape speed control from low to high speeds can be achieved simply by switching between the first and second conversion elements, and there is no need for conventional low-speed drive elements such as capstans and pinch rollers. This can be realized with a simple configuration.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings. FIG. 1 is a plan view showing a configuration model of an embodiment of the present invention, in which 17 is a board of the device, and a tape cassette 18
1 shows a state in which it is attached to a predetermined position on the board 17.

The tape 19 includes a fixed tape guide 20, first tape guides 21a, 21b, 21c, 21d, a second tape guide 22, a speed detector roller 23, and a rotating head 24. Tape guide drum 2 with built-in a and 24b
Guided by 5. A take-up reel stand 27 is rotationally driven by a take-up reel stand drive device 26 including a motor. A supply reel stand driving device 28 including a motor drives the supply reel stand 29 in the rewinding direction, and is activated when the rewinding state of the apparatus is selected by a mode selection device (not shown). The track detection circuit 30 includes the heads 24a and 2, as explained in the prior art section above.
4b is a circuit for reproducing the pilot signal and synchronization signal on the track recorded diagonally on the tape 19, and detecting the error between the trunk to be reproduced and the track being scanned by the head, that is, the tracking error. The details are a well-known technique in the R-DAT (rotating head digital audio tape recorder) currently under consideration at the DAT conference, so the explanation will be omitted. The control circuit 31 is an electric switch 32a.

32b selectively switches and inputs the output signal of this track detection circuit or the two output signals 33c and 33d of the speed detector 33 (detailed explanation in FIG. 2) including the roller 23, and depending on this input, the following This is a circuit for controlling the drive rotational speed of the reel stand drive device 26 or 28, as described in . That is, electric switches 32a, 32b
When is in the state shown in the figure, the device is in the recording state and the speed detector 3
The output 33c from the first photocoupler 33a for detecting the low running speed of No. 3 becomes an input to the control circuit 31, and the control circuit 31 adjusts the winding rule so that the output of the speed detector 33 including the roller 23 is constant. By controlling the drive speed of the stand drive device 26, the running speed of the tape 19 is kept constant. Further, when the electric switches 32a and 32b are in contact with the contacts on the upper side of the diagram, the device is in the reproducing state, and the control circuit 31 controls the take-up reel drive unit 26 so that the tracking error of the track detection circuit 30 is minimized. control the driving speed.

When the electrical switches 32a and 32b are in contact with the contacts on the lower side of the figure, the device is in a fast forward or rewind search state, and mode selection between fast forward and rewind is performed by the aforementioned mode selection device (not shown). . In this state,
The output 33d from the second photocoupler 33b for detecting the high speed running speed of the speed detector 33 is connected to the control circuit 31.
This control circuit 31 controls the drive speed of the take-up reel stand drive device 26 or the supply reel stand drive device 28 so that the output of the speed detector 33 is constant. In this search state, the control system operates to control the travel at a speed approximately 200 times faster than tape recording.

The cassette 18 is provided with tape guide posts 18a, 18b and a recess 18c. Immediately after the cassette 18 is mounted on the board 17, the tape is in the position shown at 19a, and the tape is placed in the space surrounded by the tape 19a and the recess 18c. , the above-mentioned tape guides 21a, 21b.

21C, 21d and 22 are configured to fit in the positions indicated by broken lines, respectively. These tape guides 21a
, 21 b, 21 c, 21 d and 22,
The explanation of the mechanism for displacing the device from the position indicated by the broken line in the figure to the position indicated by the solid line in the figure is a well-known structure, and the explanation will be omitted. Note that the first tape guides 21 a , 21 b , 21
c and 21d are guides for winding the tape around the tape guide drum 25 (90° in the embodiment), and the second tape guide 22 is a guide for winding the tape around the roller 23. The figure shows the beginning of winding the tape.
The supply tape roll 19b has the maximum diameter, and the take-up tape roll 19C has the minimum diameter, but when the tape has finished winding, the take-up tape roll has the maximum diameter 19d. The roller 23 ensures that the tape does not come into contact with the guide post l-18b in the tape cassette in any state in which the take-up tape roll reaches its maximum diameter from the minimum diameter.
Moreover, it is arranged so that its outer periphery is located in a so-called tape pass zone, at a position where it does not come into contact with the right wall 18d inside the tape cassette, thereby preventing unnecessary friction loss in the tape running system. Also, the second tape guide 2
2 has a sufficiently smaller diameter than a conventional vinyl roller, and the first tape guides 21 a , 21 b , 21
c, similar to 21d, tape 19a and recess 18c
The dimensions are such that it fits easily into a large space.

FIG. 2 is a perspective view showing the configuration of the speed detector 33 described in FIG.
3e, the peripheral surface of this roller is divided into two stages, and a fine slit pattern 23a (100 black and white slits in the example) is formed in the lower part.
A rough slit pattern 23b (10 white and 10 black slits in the embodiment) is formed on the upper part. A first photocoupler 33a including an LED, a phototransistor, and a lens is placed at a height facing the fine slit pattern 23a, and detects the rotational displacement of the roller 23 with high resolution. This first photocoupler 33a and the fine slit pattern 23a constitute a first conversion element for detecting the low running speed of the tape. Similarly, the second photocoupler 33b is placed at a height facing the rough slit pattern 23b, and detects the rotational displacement of the roller 23 with low resolution. This second photo coupler 33b
The rough slit pattern 23b constitutes a second conversion element for detecting the high running speed of the tape.

In this way, the first
By selectively using the conversion element 1 and the second conversion element for detecting high-speed running speed, speed control at low speeds can be achieved with high precision. A stable detection output can be obtained without causing a decrease in the detection output of the photocoupler due to an increase in speed, that is, a problem with the responsiveness of the photocoupler.

In FIG. 1, a speed detector roller 23 is provided at the cassette entrance, and the first tape guide 21c.

21d and this roller 23, the second tape guide 22
By providing this, there is no need for a fixed tape guide provided in the tape pass zone at the cassette entrance, and moreover, it is possible to provide the roller 23 with the necessary tape winding angle. Furthermore, by arranging the roller 23 so that it is located just before the tape enters the cassette 18, the distance between the roller 23 and the take-up reel stand 27 can be minimized, especially during recording. It is possible to prevent speed control from becoming unstable due to unnecessary elastic elongation.

With the above configuration, the tape speed is kept constant in the recording state of the device, and diagonal tracks recorded on the tape are
Each track pitch is maintained at a predetermined track pitch. In the reproduction state of the apparatus, the rotary head always operates to scan on a predetermined track. However, by directly driving the tape on the reel stand without using a capstan, tape wow occurs due to errors such as reel eccentricity and alignment error between the reel and reel stand, but the value of this is also 0. The RMS is about 5% RMS, and exhibits sufficient performance especially for digital audio chip recorders.

In addition, in the search state for fast forwarding or rewinding, the tape running speed is directly detected and controlled by the speed detector 33, so the control is simpler than the method in which control is performed while calculating the tape winding diameter of the reel, which changes from moment to moment. can.

Note that the configuration of the speed detector shown in Figure 2 is not limited to the configuration of this embodiment, and it is also possible to adopt a thin disk with radial slits as seen in rotary encoders. The ratio of resolution between the coarse slit pattern and the rough slit pattern can also be set as appropriate. .

Effects of the Invention As described above, the magnetic tape drive control device of the present invention has the following effects:
Using the output of a detector that detects the magnetic tape running speed as a control input, it can control everything from low-speed running of the magnetic tape in the recording state of the device to high-speed running control such as in the search state for fast forwarding or rewinding the magnetic tape. It is constructed so that magnetic tape speed control can be performed. Furthermore, this speed detector is configured to include a first conversion element for detecting a low running speed of the magnetic tape and a second conversion element for detecting a high running speed, so that when the magnetic tape is running at a low speed, This enables detection with high resolution, and enables stable speed detection by following the magnetic tape running at high speed without causing a drop in output due to responsiveness during high speed running. Therefore, according to the present invention, it is possible to provide such a device with a simple configuration, and it is possible to achieve the effects of realizing low cost and high reliability.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the overall configuration of one embodiment of the present invention, and FIG.
This figure is a perspective view showing the structure of a speed detector, and FIG. 3 is a plan view showing an example of a conventional magnetic tape drive control device. 18... Tape cassette, 19... Magnetic tape, 23... Speed detector roller, 25
...Tape guide drum, 26...Take-up reel stand drive device, 27...Take-up reel stand,
28... Supply reel stand drive device, 29...
... Supply reel stand, 31 ... Control circuit, 32a
, 32b... Electric switch, 33...
Speed detector, 23a, 33b...first conversion element, 23b, 33b...second conversion element. Name of agent: Patent attorney Toshio Nakao and one other person23-i
Rollers 23a, 33a -') r t conversion elements 23b, 3 of the degree product machine
3b-1 year 2 conversion element 33- Speed detector Fig. 2

Claims (1)

[Claims] A supply reel stand and a take-up reel stand that engage with the magnetic tape reel, a supply reel stand drive device that drives the supply reel stand in the rewinding direction, and a take-up reel that drives the take-up reel stand in the winding direction. A stand driving device, a roller that rotates in contact with the magnetic tape, and a speed detector that detects the running speed of the magnetic tape, which includes a conversion element that converts the rotational displacement of the roller into an electrical signal, and inputs the output of the speed detector. The speed detector includes a control circuit that controls the operation of the supply reel drive unit or the take-up reel drive unit to control the running speed of the magnetic tape, and the conversion element of the speed detector is configured to control the speed at which the magnetic tape is recorded. A first converting element for detecting a running speed and a second converting element for detecting a high running speed during fast forwarding or rewinding of the magnetic tape, and an output of the first or second converting element. A magnetic tape drive control device comprising: an electric switch for selectively switching and inputting the signal to the control circuit.