JPS62239453A - Tape middle point detector - Google Patents

Abstract

PURPOSE:To quickly fast forward and rewind a tape by obtaining extents of rotations from certain points to another points of a tape supply reel and a take-up reel and detecting the middle point of the tape in accordance with these extents of rotation. CONSTITUTION:When the tape is rewound from the tape end, the diameter of winding of a supply reel 1 is about zero and that of a take-up reel 2 is maximum, and they are in the unbalanced state. When rewinding is started in this state, the extent of rotation of the supply reel 1 is larger than that of the take-up reel 2 and when the unbalanced winding diameter state is inverted between two reels and the diameters of winding of both reels are changed to each other, the integral extents of rotation from the start of rewinding of both reels coincide with each other. Since the tape top or the tape end does not exist until the extents of rotation of the supply reel 1 and the take-up reel 2 are equal to each other after the start of tape running, the tape can be transported at high speed then, and the tape speed can be accurately reduced a certain time before the extents of rotation of both reels coincide with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tape intermediate detection device that detects a tape intermediate position where there is no tape top or tape end between a certain tape position and a certain tape position.

[Summary of the invention]

In the case of a cassette tape, for example, when the supply reel and take-up reel have the same wheel hub diameter and the tape winding diameters of both are unbalanced, when the tape is rotated for the first time, the supply reel and take-up reel are This system uses the fact that there is no tape top or tape end until the cumulative rotation amount of the reel and take-up reel are the same to detect that the tape is in the middle. Since there is no tape, the tape has the characteristic that high-speed fast forwarding or rewinding can be performed in the middle of the tape.

[Conventional technology]

When performing fast forwarding or rewinding in a tape recorder such as V'r'R, the problem is how to control tape running at the end or top end of the tape.

For example, in the case of an open reel, if you do not stop the tape at the end or top end of the tape, all the tape will be wound onto one reel and the tape will be loaded through the running system between the supply reel and take-up reel. If the correction is not made, recording and playback will no longer be possible.

In addition, in the case of cassette tapes, the ends of the tape are fixed to the hubs of the supply reel and take-up reel, so if the tape is not stopped at these ends especially when fast forwarding or rewinding the tape at high speed, There is a drawback that when the inertia of the reel is large, the tape may break or the guide bin of the traveling system may be damaged.

Therefore, normally fast forwarding and rewinding are controlled to decelerate near the top or end of the tape, and the tape is stopped at the end of the tape to control the running of the tape so as to avoid the above-mentioned drawbacks.

The top and end of the tape can be detected using a photosensor, etc., but even if you try to stop the tape after detecting the end or top end, if the speed of fast forwarding or rewinding is fast, the inertia It will now be too late.

In other words, it is necessary to predict the top and end of the tape. Conventionally, the tape winding diameter of the supply reel and take-up reel is measured, the top or the vicinity of the end is found from these measured values, and the tape speed is decelerated from this point. Once the tape speed has reached such a level that the end of the tape can be detected by a photosensor, etc. and stopped immediately, the tape is then fed at that speed, and once the top or end of the tape is detected by the photosensor, the tape is controlled to stop. Is going.

[Problem that the invention seeks to solve]

When Togoro predicts the tape top or end from the tape winding diameter of the tape supply reel and take-up reel and tries to stop the tape running at the tape top or end, the V5 diameter measurement generally has a measurement error. is relatively large, and it is necessary to decelerate from the front to account for this measurement error, and the time it takes to run at a predetermined slow speed that allows the tape to be stopped immediately is relatively long. There was a drawback.

As a result, there is a drawback that time is taken when reaching the top or end of the tape by fast-forwarding and rewinding the tape.

By the way, when a tape is run from a certain point to a certain point, if it is known that there is no tape end in between, the tape can be fed at high speed during that time. and,
It is conceivable to use such a tape intermediate detection output to send the tape to the tape end or tape top at high speed.

The present invention aims to provide a tape intermediate detection device suitable for use in such cases.

[Means for solving problems]

In this invention, the supply reel (11) and the take-up reel (
2) first and second rotation amount detection means (21) (22[E') (22T) for storing rotation amount information from each arbitrary tape position to another arbitrary tape position;
(28) and (31) (32E) (32T
) (3B), and when the arbitrary tape position is in a state where the tape winding diameters of the supply reel (1) and the take-up reel (2) are unbalanced, the information of the first and second rotation amount detection means is detected. By comparison, the point where both pieces of information match is considered to be the middle of the tape, and 'ζ is detected.

[Effect]

For example, when rewinding from the tape end, the winding diameter of the supply reel (1) is approximately zero, and the winding diameter of the take-up reel (2) is the maximum diameter, resulting in an unbalanced state.

When rewinding is started from this state, the amount of rotation on the supply reel (1) side is larger than the amount of rotation on the take-up reel (2) side.
When the unbalanced winding diameter state is reversed on the two reels and the winding diameters become completely opposite, the cumulative rotation amounts of both reels from the start of rewinding match.

Therefore, after starting tape running, the supply reel ([)
Since the tape top (or end) does not exist until the rotation amount of the take-up reel (2) and the rotation amount of the take-up reel (2) are equal,
It is possible to feed the tape at high speed during that period, and it is also possible to accurately decelerate the tape from a certain time before the rotation amounts match.

〔Example〕

Figure 2 shows a reel drive circuit using this invention device.
This is an example. In this example, tape running control is performed by a microcomputer (IO).

And in this example, fl) is the supply reel, (2)
(3) is the supply reel drive motor, (4) is the take-up reel, (3) is the supply reel drive motor, (4)
) is the take-up reel drive motor.

Both reel motors (3) and (4) are equipped with frequency generators (
311) and (411) are provided, from which two-phase frequency signals with a phase difference of 90° are obtained,
This is supplied to the microcomputer (10), and information indicating the number of rotations and the direction of rotation of the reel motors (3) and (4) is given to the microcomputer (10).

In addition, (5) and (6) are a tape end sensor and a tape top sensor, which are LEDs (5a),
(6a) and phototransistor (5b), (6
For example, a sensor consisting of b) is used. The detection outputs of these photosensors (5) and (6) are supplied to a microcomputer (10) and are used as tape end or tape top detection information.

The microcomputer (10) supplies signals to the reel motors (3) and (4) to control tape running during fast forwarding and rewinding.

In this invention, tape intermediate detection is basically performed using the following idea.

That is, as shown in FIG. 3A, at the tape top,
Consider a case where the tape is stopped and the tape is fast-forwarded from this point. In this case, the supply reel (1
) is assumed to be the same as the hub (2A) of the take-up reel (2).

In this case, the rotational speeds of the supply reel (11) and take-up reel (2) are larger in the state shown in Fig. 3A, and the tape winding diameters of both reels +i> and (2) are equal. When it becomes the same, as shown in Figure 3B, the take-up reel (
In case of 2), when the winding diameter becomes larger, the rotational speed of this take-up reel (2) becomes larger.

Therefore, reel (1) and (
The cumulative rotations 9NS and NT in 2) are NS < NT from the state shown in Figure 3 A to the state shown in Figure 3 B, and Ns ≧
It can be seen that there is no tape end until the number Nth.

Therefore, it can be seen that the tape is in the middle from the state shown in FIG. 3A to the state shown in FIG.

Although not shown in this example, a means for measuring the tape winding diameter of the supply reel (1) and take-up reel (2) is provided, and the value of the winding diameter from this winding diameter measuring means is read by a microcomputer. (10).

Tape feeding control during fast forwarding and rewinding is performed using the above-mentioned tape intermediate information and this winding diameter information.

Next, the tape middle detection operation will be described below.

First, in this example, it is detected that the tape is in the middle,
The intermediate end of the tape is the end or top of the tape so that fast forwarding or rewinding is performed at high speed.

In this case, first memorize the star I/point for fast forwarding or rewinding, and start from that starting point on the supply reel (1
) and the amount of rotation of the take-up reel (2) and until the integrated values match, it is known that there is no end of the tape and the tape is in the middle, so this is used.

Figure 1 shows that when detecting a point from a certain point to a certain point as the middle of the tape, the certain points can be made to be the tape end and tape top, and the operation of the microcomputer (1o) that controls the tape feed is controlled. It is a diagram shown in a functional block diagram.

That is, in the case of this example, the up/down counter (21) and ( 31) is provided.

In this case, the means for determining the cumulative rotation amount of reel (11) and reel (2) have exactly the same configuration for both reels f1) (2), so the reel (1) side is in the 20s, and the reel (2) is in the 20s.
) side is numbered (30), and below, reel (1
) side will be explained.

That is, the two-phase frequency signal FGx from the frequency generator (311) attached to the reel motor (3),
FG2 is supplied to the detection circuit (20), which generates a pulse RP with a frequency corresponding to the rotation speed and a signal D indicating the rotation direction.
R is obtained, a pulse RP corresponding to the rotational speed is supplied to the clock terminal of an up/down counter (21), and a signal DR indicating the direction of one rotation is supplied to the up/down control terminal of this up/down counter (21).

Therefore, the amplifier down counter (21) stores an integrated amount corresponding to the direction and amount of rotation of the reel (11).

The count value output of this counter (21) is supplied to an end launch circuit (22E) and a tape top latch circuit (22T), as well as a comparison circuit (23E).
) and (23T).

Further, the direction signal DR from the detection circuit (20) is supplied to the latch circuit (VB<22T) and the inverter (24)
The signal is supplied to the enable terminal of the latch circuit (221E) via the latch circuit (221E). The launch circuit (22E) can be latched when the supply reel fil rotates in the forward direction, while the launch circuit (22T) can be latched when the supply reel fil rotates in the reverse direction so that the tape is wound on the supply reel (11 side). Lunch will be available.

Also, the lunch clock pulse CLK is set to an AND gate (
Latch circuit (22E) through 25[E] and (25T)
) and (22T).

On the other hand, when loading the tape, the launch pulse LP passes through the OR gates (26E) and (26T) to this latch circuit (
22[E] and (22T'I).

In the initial state, when the cassette tape is loaded, the count value of the counter (21) at that time is latched in the latch circuit <22E'I and (22T), and information on the starting point is stored. Then, the count value of the latch circuit (22B) and the output count value of the counter (21) are compared in the comparator circuit (23E), and the supply reel (1) rotates further in the direction of feeding out the tape, since the tape is not yet at the end. Therefore, when the count value of the counter (21) becomes larger than the value of the launch circuit C228), an output of "1" is obtained from this comparator circuit (23H), which causes the ant game-1-(25E) to open. Then, the clock CLK is supplied to the latch circuit (22B), and the value of the counter (21) at that time is latched.

When the content of the launch circuit (22E') is not the value for each tape end, the counter (21) is turned in the direction where the tape end is 1'.
The launch value of the latch circuit (22E) is rewritten to its end value.

Similarly, the output count value of the counter (21) and the latch value of the latch circuit (22T) are compared in the comparator circuit (23T), the reel (1) rotates in the rewinding direction, and the counter (
21) is counted down and the latch circuit (22T)
When the output becomes smaller than the launch value of 1, an output of ``1'' is obtained from this comparison circuit (23T), and as a result, ant game 1- (25'f') is opened, and 17 solenoid CLK is latched. The signal is supplied to the circuit (22T), and the launch value of this launch circuit (22T) is rewritten to the tape top value.

Therefore, "ζ, launch circuit (22E) and (22T
), the cassette tape loading m&, once the tape has been sent to the tape end or tape top, the counter at that time (
The end value and top value which are the values of 21) are latched,
Nothing will change after that.

Then, the count value output of the C1-1 block down counter (21) is supplied to the subtraction circuit (28). On the other hand, the outputs of the latch circuits (22B) and (22T) are supplied to the selector (22T).
7) and the direction signal DR from the detection circuit (20).
This selector (27) is controlled by the selector (27), and the output from the latch circuit (22T) during fast forwarding and the output from the launch circuit (221E) during rewinding are taken out from this selector (27). (28), and the difference from the count value from the counter (21) is determined.

Therefore, during fast forwarding, this subtraction circuit (28) calculates the difference between the predetermined rotation amount position output from the launch circuit (22T) and the cumulative rotation amount up to the current position from the counter (21).
During rewinding, if the difference between the predetermined rotation amount position output from the launch circuit (22E) and the cumulative rotation amount up to the current position of the counter (21), that is, the value of the launch circuit (22T) is the top value, If the value of the latch circuit (22E) is the end value, the rotation amount from the end of the tape to the current position is the rotation amount from the tape end to the current position. Rotation M up to, respectively? ? It will be done.

Similarly, on the take-up reel (2) side, the subtraction circuit (3
8), the degree of rotation from the point determined by the values of the latch circuits (32E) and (32T) to the current location can be obtained.

In this way, the amount of rotation of the supply reel (1) between two points can be obtained from the subtraction circuit (28), and the amount of rotation of the take-up reel (2) between two points can be obtained from the subtraction circuit (38).

The outputs of these subtraction circuits (28) and (38) are supplied to an arithmetic circuit (40), and the difference between them is calculated. Both reels (1) and (
2) is supplied to the reel motor drive control circuit (41).

On the other hand, the measured winding diameter value from the tape winding diameter measuring means of the supply reel (11) and the measured winding i flea value from the tape winding diameter measuring means of the take-up reel (2) are determined by the control circuit (4).
1).

Then, the tape speed is adjusted as follows so that the tape stops correctly at the tape end or top, and the tape intermediate detection output is calculated based on the rotation amount values of the supply reel ([) and take-up reel (2). It is executed as follows by using

That is, in the case of subtraction port II! 3 (28) and (38
) until the outputs match, it will not be the end or top of the tape. And the latch circuit (
22E ) (22T ) and (32E ) (3
Whether the value of 2T') is the end value or the top value can be known from the measured value of the tape diameter a.

Therefore, from this tape winding diameter measurement value, for example, it can be detected that the tape is near the end.

At this time, if the output of the arithmetic circuit (40) indicates that the tape has not yet reached the end, this arithmetic circuit (40)
The reel motor drive control circuit (4) starts decelerating the tape feed speed from the point before the tape end by the time from when it starts decelerating the tape feed speed to the desired stop position based on the output value of (0).
1) Start tape speed deceleration.

In this way, the speed can be made low enough to stop the tape in the shortest amount of time until the end of the tape is reached, and the time required to run at low speed until the photosensor detects the end of the tape and stops the tape is minimized. It can be done.

In the above example, the reel hub diameters of the supply reel (1) and the take-up reel (2) are the same.

If you want to rewind the tape and stop it at the top of the tape, you can do it in exactly the same way.

From the winding diameter measurement value, launch circuit (22E) (22T
) and (32E) (327) are inside the tape top or tape end. Can be returned.

Even in this case, high-speed feeding can be carried out with peace of mind because there is no tape end or tape top from the time when tape fast forwarding or tape rewinding is started until the cumulative rotations of the supply reel (1) and take-up reel (2) match.

However, even if the tape is loaded in an intermediate position other than the tape end or tape top, the tape will run due to playback, recording, etc., and once it has traveled to the tape end or tape top, it will latch. The launch count values of the circuits (22E) (22T) and (32B) (32T) will be the end value and top value of the tape unless the tape is replaced, and thereafter forwarding and rewinding will be performed based on these values. This makes it possible.

Please note that the reel hub diameters of the supply reel and take-up reel are the same.
It is assumed in the above case that a! +4 difference is the approach pressure to the end or top 11
This can be handled by taking into consideration the difference in tape hub diameter in advance.

Further, as long as the tape hub diameters of the supply reel and the take-up reel are the same, there is no limitation to the size of the hub diameter. Therefore, various reel hub diameters have been proposed depending on the size of the cassette tape, and the present invention is applicable to all of these cassette tapes.

As mentioned above, in this example, when fast forwarding from the tape top to the tape end or rewinding from the tape end to the tape top, ``ζ'' is executed in conjunction with the winding diameter measurement data. When it falls within the error range, it is possible to control the running of the tape based on the tape top or end mark (direction) according to the present invention, so it can move between the tape top and tape end at a higher speed than the conventional one. It is possible to fast forward and rewind.

For this reason, the tape running time is minimized at the slow speed at the end of the tape, at the end of the tape, and at the 7th step, unlike in the past.

The approach distance near the tape end or tape top, that is, the point at which tape deceleration is to be performed, can be determined from the tape end winding diameter, that is, the hub diameter, and the remaining reel rotation speed until the tape top or end. Since it is possible, you can also shift the end point to the inside of the actual point to be safe. You can also easily set a speed limit to reduce the speed of the remaining end.

〔Effect of the invention〕

According to this invention, the amount of rotation of the tape supply reel and take-up reel from a certain point to a certain point is determined, and by detecting that the tape is in the middle from the amount of rotation, this tape intermediate detection output is detected. During this time, when fast forwarding or rewinding, high-speed forwarding can be performed with peace of mind as there is no tape end or tape top.

If the starting point for the amount of rotation of the reel is the tape top or tape end, the tape can be fed at high speed from the tape top to the tape end or from the tape end to the tape top, increasing the speed of fast forwarding and rewinding. It is possible to achieve this goal.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram of an example of the main parts of the device of this invention.
FIG. 2 is a block diagram of an example of a reel drive circuit to which this invention is applied, and FIG. 3 is a diagram for explaining the invention in detail. (1) is the supply reel, (2) is the take-up reel, (21) and (31) are up-down counters for integrating the amount of reel rotation, and (40) is the difference in the amount of rotation between the supply reel and the take-up reel. The arithmetic circuit (41) is a reel motor drive control circuit.

Claims (1)

[Claims] A first storage unit that stores rotation amount information from an arbitrary tape position to another arbitrary tape position on each of the supply reel and the take-up reel.
and a second rotation amount detection means, and compares the information of the first and second rotation amount detection means when the arbitrary tape position is in a state where the tape winding diameters of the supply reel and the take-up reel are unbalanced. A tape intermediate detection device detects the tape as being in the middle until the two pieces of information match.