JPS5848253A - Retrieving system for tape position of tape recorder - Google Patents

Abstract

PURPOSE:To retrieve the target position of a tape in a stable and assured way, by producing a control signal for revolution of a reel motor in consideration of the distance between the target position of the tape and the present tape position. CONSTITUTION:The distance between the target position of a tape 3 and the present position of the tape is calculated by a computer 10 and then compared with the prescribed reference distance which is needed for the stoppage of tape. Then a reel motor revolution controlling signal is produced to move the tape toward the target position until coincidence is obtained between the above- calculated distance and the reference distance in case the reference distance is smaller than the calculated distance. When the reference distance is larger than the calculated distance, the present tape travelling speed is compared with the reference speed set previously. Then a reel motor revolution controlling signal is produced to lower the speed in case the present tape travelling speed is higher than the reference speed. The said control signal is produced to move the tape toward the target position in case the present travelling speed is lower than the reference speed. Then a control signal is produced to stop the revolution of the reel motor when the tape reaches the target position.

Description

[Detailed Description of the Invention] This paper is related to a tape position search method for a tape recorder.
By controlling the reel motor drive circuit by monitoring the tape running speed, tape running direction, and tape running position, it is possible to stably and reliably stop the tape at the target position and perform a position search. The purpose is to provide a tape position search method.

An embodiment of the method of the present invention will be described below.

2 Figure 1 Method of the present invention. -Example t, 'f-7''L/:l
-A schematic block system shown together with a front view of y is shown.

In the figure, 1 is the supply side reel, 2 is Volume II! The magnetic tape 3 unwound from the supply reel 1 is passed through a tension ball 4 m, a roller 5 attle, and then passes through the front gears of various heads including an erasing head, a recording head, and a reproducing head. - It is wound onto the winding reel 2 through the stage roller sh and the tension pole 4b, respectively. The magnetic tape 3 is held and driven by two sets of capstans and pinch rollers (not shown), but the pressure between the pinch rollers and the capstans is released during fast forward mode or rewind mode, which will be described later.

Also, 6.1 is the supply side and the winding @? Each reel motor is shown, and its rotational force causes the magnetic tape 3 to travel at high speed during fast forward mode or rewind mode. 8 indicates an i production button, and S indicates a tape position display device. The computer 10 is supplied with signals from the tape running speed and direction detecting device and the operation button 8, and from this computer 10, a rotation control signal for driving and controlling the motors L and T is used for tape position retrieval, which will be described later. -0 is output through the servo circuit 11.
The computer 10 also displays the tape position determined by counting the speed detection pulses on the tape position display device. Note that the servo circuit 11 is supplied with output detection signals from two sets of tape tension detection devices (not shown).

The above-mentioned tape tension detection device is a device that converts each moving position of the tension balls 4m and 4 into the magnitude of voltage and takes out the tension ball 4m.

4bK has a suspended spring and a tension ball of 4m.
, 4 correspond to the tape tension, so the tape tension is detected by detecting the rotational position of the tension ball 4m+41+. Further, the tape running speed and direction detecting device is configured to detect the magnetic tape 30.
It consists of a footage roller 5b that rotates as the magnetic tape 30 travels, a shielding plate connected to the footage roller sb, and a photointerrupter whose optical path is shielded by the shielding plate. The stage roller 5b and the shielding plate each rotate, and by utilizing the fact that the shielding period of the shielding plate, which intermittently blocks the optical path of the photointerrupter, changes, the photointerrupter can rotate the optical path according to the running speed of the magnetic tape. It outputs a detection pulse at a speed of ~, and two photo-interrupter light-receiving parts are provided in parallel, and the light received by these two light-receiving parts depends on which one is blocked by the Km shielding plate first. It is configured to detect the rotational direction of the footage roller sb and the shielding plate, that is, the running direction of the magnetic tape.

Calculation @1oVcm, the above target is such that the user can start braking before the tape position that the user intends to search (this is called the target position) and stop the tape running at the target position without excess or deficiency. The distance (tape length) Lφ from the position (this is referred to as the reference distance) is set in advance, and the tape running speed v8 is set to such an extent that the tape running can be stopped immediately based on the stop signal. A reference traveling speed Vmu is set. The operation of the method of the present invention will be explained below along with the processing operation of the computer 10.
.

FIG. 2 is a flowchart showing the processing procedure when the computer 10 performs a tape position search. First, when the user sets the target position and issues a search start command, the computer 10 After calculating the distance from the current tape position and the target position to the target position, it is determined whether the distance is longer or shorter than a predetermined reference distance Lφ. Now, as an example, as shown in FIG. 3(m), the magnetic tape 30 is running stopped at position 1, and this position! When searching for a target position located at a distance longer than the reference distance Lφ from L) Ld, the computer 10 calculates whether the current tap position is longer than the target position φ, as shown in FIG. Tape start end side (HOT side) Is there K? Tape end end 141 (HOT 11
), and in the former case, detects whether or not it is in fast-forward (PF) mode, and sets the fast-forward mode to fast-forward mode, and when it is not in fast-forward mode, K drives and controls the reel motor and 1 so that it is in fast-forward mode. On the other hand, in the latter case, the reel motor 6 and T detect whether or not the rewind mode is in effect, and if it is in the rewind mode, the rewind mode is set as is, and if it is not the rewind mode, the rewind mode is set. drive and control each. Third
In the example shown in FIG. is set to a rewind mode in which the supply side reel IK is rewinded.

In this rewinding mode, the rotation control signal for round rewinding which is taken out from the computer 1° shown in FIG. The reel motor 1 is rotated with a large torque so that the reel motor 1 rotates in this direction, and the reel motor 1 is rotated with a very small torque so that the take-up reel 2 rotates counterclockwise.

Therefore, since the torque of the reel motor 6 is sufficiently larger than that of the reel motor T, the take-up reel 2 is also pulled by the supply reel 1 due to the tensile force of the magnetic tape 3 pulled by the supply reel 1. The magnetic tape 3, which is rotated in the same clockwise direction, is wound onto the supply reel 1, and a constant pack tension is applied by the weak torque of the reel motor. As a result, the tape running speed gradually increases, and after reaching the steady running speed in the rewind mode, when the tape enters the reference distance Lφ at the tape position 22 as shown in FIG. As shown in Figure 2, the tape running speed V at that time
It is detected whether or not the running speed is faster than the reference running speed V, and if it is faster, then it is determined whether the running direction of the chip is the rewinding direction or the fast forwarding direction, and when the rewinding direction is 6, the mode is set to fast forwarding.1. In the fast forward direction, a signal for setting the rewind mode is output to the reel motors 6 and 7, respectively. Here, since the mode is rewind mode, the mode is set to fast forward mode. That is, the reel motor 1 is driven to rotate the take-up reel 2 counterclockwise with a large torque, and at the same time, the reel motor 6 is supplied with back tension to increase the stave tension. The side reel 1 is driven so as to rotate clockwise with a weak torque. However, before that, the supply reel 1 and the take-up reel 2i are rotated clockwise at high speed in the rewind mode, so even if the switch to the fast forward mode is made as described in 6 above, the supply reel 1 and the take-up reel 2i are rotated clockwise at high speed. The take-up reel 2 is connected to the reel motor 6 and T.
It continues to rotate clockwise due to inertia that is greater than the rotational torque. By controlling the rotation of the reel motors 6 and 70 in the above-described fast-forward mode, the clockwise rotational speeds of the supply reel 1 and the take-up reel 20 gradually decrease.

Although the magnetic tape 3 continues to be in the rewinding state as described above, even though the mode has been switched to the fast forward mode from the tape position -2, the computer 10 also displays the current tape position and the target position. Distance to position φ and reference distance Lφ
The current tape running speed V and the reference running speed vA are compared in terms of magnitude. Figure 3 (
As shown in FIG.
The tape running speed (also referred to as search speed) at a predetermined low speed at tape position 15 where the speed is lower than A vs. 4 stones.

The calculator 10 calculates that when the tape running speed VBK- is switched, the Ω tape position h' is 1. compared to the target position φ. Is it the IOT side?
If it is on the I/cΣOT side as shown in the example shown in Figure 3 (M)K, it is detected whether it is in rewind mode or not, and here it is in fast forward mode. So use rewind mode. As a result, the reel motors 6 and 7 are driven to switch to the rewind mode in which the magnetic tape 3 is wound onto the supply reel 1 at the tape running speed v8 at the tape position, but due to the inertia caused by the previous fast forward mode, the tape position 3, the tape running speed does not immediately reach the tape running speed VB, but gradually slows down, and after a delay of a predetermined distance, returns to the rewinding state at the running speed of vs. In this low speed VB rewinding mode, when the eye i position φ is reached, the computer 10
A stop signal is outputted to each of the reel motors e and IVc, and the reel motors 1 and 1 immediately stop rotating due to ζf1. In this way, the target position φ can be accurately set in a short time.
can be searched. .

The above position search can be started not only when the exhalation tape 30 stops running, but also in rewind mode or fast forward mode. This is possible even while the tape is running. For example, as shown in FIG. Assuming that the position search is started at tape position p4, which is within the distance Lφ, the computer 10
．． Since L<Lφ, as shown in FIG. 2, it is determined whether the - tape running speed V is faster or slower than the reference running speed Vm.

The tape running speed at this time is the high speed in the normal rewind mode and is faster than the V, so next, the computer controls the rotation of the reel motor group and T to prevent the running of the tape according to the running direction of the toFi tape. Let's do it. That is, since the machine is in the rewind mode, almost at the same time as starting the position search, the computer 10 rotates the take-up reel 2 shown in FIG. 1 counterclockwise with a large torque and applies back tension. Therefore, the reel motor 7.6 applies a driving voltage that rotates the supply reel 1 clockwise with a weak torque.
are supplied respectively to set the fast forward mode. However, the magnetic tape 3 is being wound onto the supply reel 1 at high speed at this time, and due to its inertia, the magnetic tape 3 is able to overcome the rotational speed of the reel motors 6 and T caused by the above-mentioned fast forward mode. The magnetic tape 3 is then wound onto the supply reel 1 and continues to be rewound, but its running speed gradually decreases until it reaches the reference running speed Vm. Since the tape position at this time is too far to the tape starting end side with respect to the target position φ, the computer 10 operates the reel motor 6 to enter a low-speed fast-forward mode in which the magnetic tape 3 is wound onto the take-up reel 2 at a low speed.
and TVc each output a very small drive voltage in the normal fast-forward mode. After switching to this low-speed fast forward #) i-mode, the magnetic tape 3 continues to be rewound due to inertia and moves further away from the target position φ, but the tape running speed V quickly drops to zero. Then, from the tape position at that time (shown as K-65 in Figure 3 (II)), the tape is wound onto the take-up reel 2 at a low speed in the low-speed fast-forward mode.
and approaches the target position φ. When the target position φ is reached, the computer 10 stops the rotation of the reel motors 6 and T, respectively. In this way, the target position φ is reached in the shortest time.
You can search for the location of.

next,! 3. The operation in case of @(C) will be explained.

FIG. 3(C) shows a normal fast-forward mode (normal F
At time F), the tape position is on the tape starting end side with respect to the target position φ, and the distance to the target position φ is within the reference distance Lφ! 6 shows the tape running speed and running direction when the position search is started at step 6. In this case, as is clear from Figure 2, the tape position! 6, the magnetic tape 3 continues to be wound onto the take-up reel 2, but its running speed gradually decreases until it reaches the reference running speed vA. This time, it is set to low-speed rewind mode, and eventually the tape position is reached! 7 and 4 The supply side is wound up at low speed. When the target position φ is reached, a rotation stop signal is generated from the calculation ate to immediately stop the reel motors 6 and T.

゛It should be noted that the present invention is not limited to the cases shown in Figs. 3(A) to <C> above, but also in other cases as well. It is clear that it can be searched. Alternatively, the detection can be performed by means for counting the number of pulses taken out by the tape position and tape running speed detecting means.

Note that the speed detection pulse taken out from the tape running speed and direction detecting device is converted to a voltage according to the tape running speed by passing through a frequency-voltage converter in the servo circuit 11.
The configuration is such that a constant low speed v8 can be obtained by feeding back to the reel motor 6 or T on the tape feeding side.

As mentioned above, the tape position search method of the tape recorder according to the present invention uses a computer to calculate the distance between the target position and the current tape position, and then calculates the distance between the target position and the current tape position and then calculates the distance between the target position and the current tape position. If the reference distance is shorter, a reel motor rotation control signal is generated to run the magnetic tape in the direction of the target position until it becomes longer; if the reference distance is longer, the current tape running speed is set in advance. Compare the current tape running speed with the standard running speed to set a low enough speed to immediately stop the tape running, and if the current tape running speed is faster, set the speed to lower the tape running speed =
If the current tape running speed is slower, it generates a reel motor rotation control signal that causes the magnetic tape to run at the lower speed in the direction of the target position, and then when the target position is reached. Since it is configured to generate a control signal to stop the rotation of the reel motor, it can be used reliably and stably without damaging the magnetic tape, no matter what state the magnetic tape is in (including stopping). Although the tape running speed varies depending on the tape winding diameter, since the magnetic tape is run at a low speed after becoming slower than the reference running speed, the distance from the target position is a predetermined value. It is possible to stop the tape running at the target position more accurately than when the tape running speed is reduced to a low speed after the tape running speed is below. Since the signal is used to drive and control the reel motor to run the magnetic tape in the opposite direction, the reel motor can be shared without the need for a dedicated electromagnetic brake or other braking means. Since the output speed detection pulse of the means is fed back to the reel Tanabata to maintain a constant speed, the tape running speed detection means can be shared, and the device can be simplified and constructed at low cost. It has certain characteristics.

[Brief explanation of the drawing]

FIG. 1 is a schematic block system diagram showing an embodiment of the method of the present invention together with a front view of a tape recorder, FIG. 2 is a flowchart showing the processing procedure of an embodiment of the method of the present invention, and FIG.
Figures 1) to (C) are diagrams showing the mode of the tape recorder, the tape running speed, and each side of the tape running direction when performing a position search according to the method of the present invention. 1... Supply side reel, 2... Winding side reel, 3...
...magnetic tape, 6. T...Reel motor, i...
Operation button, 10... Calculator. Quantity” (J5 Sea -

Claims (1)

[Claims] 1. Means for generating a speed detection pulse with a period corresponding to the tape running speed, means for detecting the tape running direction, an instruction signal for a target position on the tape to be searched, and a current tape position. It consists of a computer that generates a rotation control signal that controls the rotation of the reel motor by being supplied with the position signal, the speed detection pulse, and the tape running direction detection signal, respectively, and the computer calculates the target position and the current tape position. After calculating the distance, the distance is compared with a predetermined reference distance necessary for stopping the tape running, and if the reference distance is shorter, the reel motor rotation control signal causes the magnetic tape to run in the direction of the target position until it becomes longer. occurs, and if the reference distance is longer, the current tape running speed is compared with the reference running speed for setting a preset low-speed pulling that can immediately stop the tape running, and the current tape running speed is determined. If the current tape running speed is faster, a reel motor rotation control signal is generated to slow down the tape running speed, and if the current tape running speed is slower, the magnetic tape is moved toward the target position at the lower speed. A tape position monitoring system for a tape recorder, which is characterized in that after generating a reel motor rotation control signal to cause the reel motor to travel, a control signal for stopping the rotation of the reel motor when the target position is reached is generated. 2. The reel motor rotation control signal for slowing down the tape running speed is a signal that drives and controls the reel motor to run the magnetic tape in a direction opposite to the current tape row direction. A tape position search method for a tape recorder according to claim 1. 3. The tape position search method for a tape recorder according to claim 1, wherein the low speed is set to a constant speed by feeding back a low speed detection pulse to the reel motor.