JPH04103059A - Magnetic recording/reproducing device - Google Patents

Abstract

PURPOSE:To prevent the damage of a tape cassette by discriminating the winding diameter of the tape by comparing a counting ratio of outputs obtained from a supply reel pulse counter and a wind reel pulse counter, and a counting ratio of a reel pulse immediately after rewind or quick feed of the tape, and lowering a wind speed in the start and the end of the tape. CONSTITUTION:At the time of winding a tape cassette to the supply side or the wind reel side, a counting output ratio of supply reel pulse and wind reel pulse counters 12, 13 is calculated after a quick feed or rewind operation is started, held in a memory 15, and thereafter, one moror 1 or 2 is driven through a reel drive circuit 3 or 4. Subsequently, by comparing its ratio with a counting ratio held in the memory 15, an end point of a start point or an end point of the tape cassette is detected, and in the case of approaching this end part, the speed control is executed so that the sum of pulses obtained by a supply reel pulse generator 5 and a wind reel pulse generator 6 becomes constant, and the wind speed is lowered. In such a way, thrust-in of the end of the tape can be prevented, and damage of the tape cassette does not occur.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a magnetic recording/reproducing device, and particularly to a fast forwarding device.

The present invention relates to a magnetic recording/reproducing device that has characteristics in its operation during rewinding.

[Conventional technology]

2. Description of the Related Art Conventionally, video tape recorders and the like using tape cassettes use devices capable of fast forwarding and rewinding at high speed. The control of the reel control circuit of such a conventional magnetic recording and reproducing apparatus during fast forwarding and rewinding will be described with reference to FIG.

In this figure, the magnetic recording device has a supply reel motor 11 that rotationally drives a supply reel, and a take-up reel motor 2 that rotationally drives a take-up reel, and these reel motors are connected to a supply reel drive circuit 3 and a winding reel, respectively. It is driven by the reel drive circuit 4. The supply reel motor 1 includes a supply reel pulse generator 5 and a take-up reel motor 2.
A take-up reel pulse generator 6 is connected to. These reel pulse generators 5 and 6 generate reel pulses proportional to the rotation speeds of the supply reel motor 11 and the take-up reel motor 2, respectively, and their outputs are given to the reel speed control circuit 7. The reel speed control circuit 7 counts the sum when pulses are given from either of these at predetermined time intervals, and controls the supply reel drive circuit 3 or the take-up reel drive circuit 4 so that the sum of the pulses becomes a predetermined number. It controls the

Next, reel speed control of a conventional magnetic recording/reproducing device will be explained. First, during fast forwarding, the take-up reel motor 2 takes up the magnetic tape, and the supply reel motor 1 controls the back tension. At this time, the sum of the pulses proportional to the rotation of the supply reel motor 1 and the pulses proportional to the rotation of the take-up reel motor 2 is compared with a speed reference value in the reel speed control circuit 7 to control the take-up reel drive circuit 4. By doing this, the tape winding speed is kept constant regardless of the winding diameter of the magnetic tape. Similarly, during rewinding, the supply reel motor 1 winds up the magnetic tape, and the take-up reel motor 2 controls the hack tension. Then, the reel speed control circuit 7 controls the supply reel drive circuit 3 by comparing the sum of the given pulses with a speed standard, so as to keep the winding tape speed constant regardless of the winding diameter of the magnetic tape. I have to.

(Problem to be solved by the invention) However, in such a conventional magnetic recording/reproducing device,
Since the tape speed is constant during fast forwarding or rewinding, it is necessary to increase the winding speed in order to shorten the time from the start to the end of tape winding. However, since the winding tape speed is kept constant, the tape is wound at high speed at the beginning and end, which has the disadvantage that the tape cassette may be damaged.

The present invention has been made in view of the problems of the conventional magnetic recording and reproducing apparatus, and is capable of fast forwarding.

A technical problem is to determine the winding diameter of a tape during rewinding and to reduce the winding speed at the beginning and end of the tape.

[Means to solve the problem]

The present invention includes a supply reel motor connected to a supply reel of a tape cassette, a supply reel drive circuit that drives the supply reel motor, a supply reel pulse generator that generates pulses corresponding to rotation of the supply reel motor, and a supply reel motor connected to a supply reel of a tape cassette. A supply reel pulse counter that counts the pulses of the pulse generator, a take-up reel motor connected to the take-up reel of the tape cassette, a take-up reel drive circuit that drives the take-up reel motor, and a take-up reel motor connected to the take-up reel of the tape cassette. A take-up reel pulse generator that generates pulses corresponding to the rotation, a take-up reel pulse counter that counts the pulses of the take-up reel pulse generator, a supply reel pulse counter, and a take-up reel pulse counter. an arithmetic unit that calculates the count ratio of the output;
A memory that holds the output of the computing unit immediately after rewinding or fast forwarding the tape, a comparator that detects the end of the tape cassette by comparing the output obtained from the computing unit with the counting ratio held in the memory, and a supply reel. The drive circuit or the take-up reel drive circuit is selectively driven to control the tape winding speed at high speed, and after a matching output from the comparator is given, the supply reel pulse generator and the take-up reel pulse generator and a reel speed control circuit that controls the tape winding speed to a low speed based on the sum of the pulses.

[Effect]

According to the present invention having such features, when the tape cassette is transferred to the supply side or the take-up reel side, the count output of the supply reel pulse and take-up reel pulse counter is After calculating the ratio and storing it in memory, one motor is driven via the reel drive circuit.

Then, by comparing the ratio with the counting ratio held in memory, the end of the tape cassette's starting point or end point is detected, and when this end is approached, the supply reel pulse generator and the take-up reel pulse generator Speed control is performed to reduce the winding speed so that the sum of pulses obtained is constant.

〔Example〕

FIG. 1 is a block diagram showing the configuration of a magnetic recording/reproducing apparatus according to an embodiment of the present invention. In this figure, the same parts as those in the conventional example described above are given the same reference numerals, and detailed explanation will be omitted. In this embodiment as well, the magnetic recording and reproducing apparatus has a supply reel motor 19 that rotationally drives a supply reel (not shown) and a take-up reel motor 2 that rotationally drives a take-up reel. It is driven by a drive circuit 3 and a take-up reel drive circuit 4.

The supply reel motor 1 has a supply reel pulse generator 5, and the take-up reel motor 2 has a take-up reel pulse generator 6.
The connection is the same as in the conventional example described above. These reel pulse generators 5 and 6 generate reel pulses proportional to the rotation speeds of the supply reel motor 11 and the take-up reel motor 2, respectively, and their outputs are given to the reel speed control circuit 11. These pulses are also applied to a supply reel pulse counter 12 and a take-up reel pulse counter 13, respectively. The supply reel pulse counter 122 and the take-up reel pulse counter 13 count the number of pulses given at regular intervals, and their output is sent to the calculator 14.
given to. A computing unit 14 computes the counting ratio of these pulse counters, and its output is given to a memory 15 and a comparator 16. The memory 15 holds the count value from the arithmetic unit immediately after the start of winding or the start of supply, and its output is given to the comparator 16.

The comparator 16 compares these two inputs and provides a comparison output to the reel speed control circuit 11. The reel speed control circuit 11 is the first. It has a second speed reference value, and after the start of winding or supply, the sum of the outputs of the supply pulse generator 52 and the take-up reel pulse generator 6 is the first speed until the calculation output is given from the calculation unit 14. The supply reel drive circuit 3 or the take-up reel drive circuit 4 is controlled to reach the speed reference value, and then the supply reel motor or the take-up reel motor is driven at high speed using the first speed reference value, and the comparison output is The speed of the motor is reduced by performing control based on the first speed reference value again.

Next, the operation of this embodiment will be explained. First, in FIG. 1, when fast-forwarding from near the beginning of tape winding, the take-up reel motor 2 winds up the magnetic tape, and the supply reel motor 1 controls the back tension. At this time, the reel speed control circuit 11 compares the sum of pulses from the supply reel pulse generator 52 and the take-up reel pulse generator 6 with the first speed reference value, and controls the take-up reel drive circuit 4 to wind the wind. Keep the tape speed constant. Now, when winding is started from the beginning of winding as shown in FIG. 2, the ratio changes continuously. Line A in FIG. 2 is the first count ratio (supply reel pulse count/take-up reel pulse count) of the supply reel pulse counter 121 and take-up reel pulse counter 13, and line B is the second count ratio. ratio (take-up reel pulse count value/supply reel pulse count value). Then, a predetermined time after the start of winding, a calculated value obtained by the calculator 14 in response to a timing signal from the reel speed control circuit 11, for example, the counting ratio at point A1 in FIG. 2, is held in the memory 15. Then, the reel speed control circuit 11 changes the first speed reference value to the second speed reference value, increases the tape speed, and controls the speed of the take-up reel motor 2. Thereafter, the calculator 14 changes the speed of the take-up reel motor 2 from the first speed reference value to the second speed reference value. That is, the take-up reel pulse count value/supply reel pulse count value is calculated, and it is determined whether this matches the count ratio A1 held in the memory 15.

Then, as shown by straight line B in FIG. 2, when the tape approaches the end of winding, it reaches a point B1 where the counting ratios match.

In this way, the tape speed control circuit 11 switches to the original first speed reference value based on the comparison signal from the comparator 16, and controls the speed of the take-up reel motor 2. By doing so, the winding tape speed can be slowed near the end point, and it is possible to prevent the tape from running into the tape at the end. In addition, the fast-forwarding time from the beginning of winding to the end of winding can be shortened.

Also, when rewinding from the end of winding, the supply reel motor 1 winds up the magnetic tape, and the take-up reel motor 2 controls the back tension. The reel speed control circuit 11 then compares the sum of the pulses from the reel pulse generator 5.6 with a first speed reference value to keep the tape speed constant. Then, after a predetermined time, the second counting ratio B, that is, the calculated value of the take-up reel pulse count value/the supply reel pulse count value, is stored in the memo 1J15.0 For example, if the counting ratio at point B1 in FIG. Thereafter, the reel speed control circuit lIr1l is changed to the second speed reference value to increase the speed of the tape wound by the supply reel motor 1.

Then, when the counting ratio A becomes A1, which is equal to B1, the reel speed is controlled based on the original first speed reference value by the output from the comparator 16. In this way, the tape speed near the winding start end can be slowed down, and it is possible to prevent the end of the tape from sticking. The rewinding time from the end of tape winding to the beginning of winding can be shortened.

In this embodiment, during rewinding and fast forwarding, the tape running is controlled at high speed by comparing with the second speed reference value except near the start point and end point of the tape. It is also possible to run the tape at high speed without using the speed reference value.

〔Effect of the invention〕

As explained in detail above, according to the present invention, since the counting ratio of reel pulses is held in the memory and the speed is controlled based on it, it is possible to determine the vicinity of the tape end and start end. . Therefore, the tape running speed can be increased during rewinding and fast forwarding between them. Then, it becomes possible to reduce the winding speed when approaching the beginning or end of the tape.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a tape speed control section of a magnetic recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a graph showing the tape winding diameter and reel pulse count ratio, and FIG. FIG. 3 is a block diagram of a reel speed control section of the magnetic recording/reproducing device. 16--Comparator. Patent applicant Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] (1) a supply reel motor connected to a supply reel of a tape cassette; a supply reel drive circuit that drives the supply reel motor; and a supply reel pulse generator that generates pulses corresponding to rotation of the supply reel motor; a supply reel pulse counter that counts pulses of the supply reel pulse generator; a take-up reel motor connected to the take-up reel of the tape cassette; a take-up reel drive circuit that drives the take-up reel motor; a take-up reel pulse generator that generates pulses corresponding to the rotation of the take-up reel motor; a take-up reel pulse counter that counts pulses of the take-up reel pulse generator; the supply reel pulse counter and the take-up reel pulse generator; an arithmetic unit that calculates a counting ratio of outputs obtained from the reel pulse counter; a memory that holds the output of the arithmetic unit immediately after rewinding or fast forwarding the tape; a comparator that detects the end of the tape cassette by comparing the count ratio with the count ratio; and a comparator that selectively drives the supply reel drive circuit or the take-up reel drive circuit to control the tape winding speed at high speed; a reel speed control circuit that controls the tape winding speed to a low speed based on the sum of the pulses of the supply reel pulse generator and the take-up reel pulse generator after receiving a matching output from the comparator; A magnetic recording/reproducing device characterized by: