JPH081711B2 - Tape transfer device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape transfer device in a magnetic recording / reproducing device (hereinafter referred to as VTR).

2. Description of the Related Art In recent years, magnetic recording has been made more and more dense, and due to the thinning of tape, long-time recording of cassette tape has been remarkable. Therefore, the tape transfer device is required to have a high-speed access function for the tape, such as transferring the tape to a desired position or cueing. Therefore, even if the tape transfer speed is too high even if the tape transfer is stopped after the start and end of the tape (for example, transparent tape in VHS method VTR) is detected during the transfer of the tape, the start and end of the tape will be detected. It requires a large amount of tape to be transferred before stopping the tape, and the tape is transferred to the end before stopping the tape, giving abnormal tension to the tape (hereinafter, this situation is referred to as "tape rushes."".")
There was a danger. Therefore, the conventional tape transfer device detects that the remaining tape amount is low during the fast forward or rewind (FF / REW) mode execution, and reduces the tape transfer speed of FF / REW to reduce the remaining tape. Was being transferred. This is a function called near-end detection,
It was an indispensable function for tape protection in VTRs for commercial use and broadcasting, which had high tape transfer speed, large reel control winding diameter, and large inertia.

A conventional tape transfer device is disclosed, for example, in JP-A-54-161921.
It is shown in the publication.

FIG. 6 shows a block diagram of this conventional tape transfer device, 7 is a supply side reel (hereinafter referred to as S reel), 8 is a tape transfer speed detector called a timer roller, and 9 is a winding side. Reel (hereinafter referred to as T reel), 11 is a rotation cycle detector of the supply side reel, 12 is a rotation cycle detector of the timer roller, 13 is a rotation cycle detector of the take-up reel, 31 is an arithmetic processing circuit, 15 Is a motor control circuit, 16 is a reel motor for driving the T reel 9, and 17 and 18 are R
EW and FF signal terminals, and the tape T is transferred in the direction of the arrow with the tape transfer speed symbol v.

Here, since it is possible to think in the same way both in the case of fast-forwarding and in the case of rewinding, hereinafter, the case of fast-forwarding will be described. (That is, the S reel rotation cycle T _s is _equal to the T reel rotation cycle T _t
It becomes the time of rewinding when replaced with) where T _s = S reel rotation cycle T _r = timer roller rotation cycle R _s = S reel radius R _r = timer roller radius (= constant) v = tape transfer speed , The following formula is established.

v = 2πR _s / T _s = 2πR _r / T _r (1) Therefore, from the equation (1), R _s / R _r = T _s / T _r (2)

FIG. 7 shows the relationship between the S reel radius R _s and the ratio of the timer roller rotation period to the S reel rotation period (T _s / T _r ). If T _s / T _r is known, then R _s is Recognize. That is, if T _s / T _r can be measured, it is possible to know the remaining tape amount. Therefore, if the S reel rotation period T _s and the timer roller rotation period T _r are detected from the equation (2) and T _s / T _r is compared with a certain set threshold value K, the near-end end of the tape can be detected. .

FIG. 5 is a flowchart of the arithmetic processing for detecting the near start / end of the tape, which is performed by the arithmetic processing circuit 31 in FIG.

When the REW or FF mode is selected by the signals from the terminals 17 and 18, the S reel rotation cycle T _s obtained from the S reel rotation cycle detector 11 is read by the arithmetic processing circuit 31 in block 26, and in block 27. Similarly, the timer roller rotation cycle T _r
Is read. And at block 28 these ratio values
T _s / T _r is calculated. Then, in block 29, the value T _s / T _r of this ratio is compared with the threshold value K obtained in advance from the radius of the S reel corresponding to the beginning and end of the tape. T _s / T _r
When becomes smaller than K, the S reel radius becomes smaller than the S reel radius threshold R _sth shown in FIG.
The near end detection shown in block 30 is performed to reduce the tape transport speed.

Conventionally, the above-described method has been used to detect the near-end end of the tape and prevent damage to the tape during high-speed transfer of the tape.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-described configuration, the remaining tape amount at the time when the near-end end of the tape is detected is determined by measuring the remaining amount of the tape and detecting the near-end end. The time required for transfer at v (hereinafter referred to as remaining tape transfer time) t _th changes depending on the tape transfer speed v.

For VTRs for business and broadcasting, high-speed search, for example, 100
There are multiple tape transfer modes with different tape transfer speeds such as double speed, 50 times speed, 32 times speed, .... In such a case, in order to detect the end of the tape in these modes, the threshold K of the remaining tape amount must be set so that the tape rush that damages the tape does not occur when the tape transfer speed v is the maximum tape transfer speed v _MAX. However, when v is equal to or less than v _MAX , the near-end detection is performed with this threshold value, and there is too much room before the tape enters, and conversely it takes too much time to transfer the remaining tape. It had a problem that it was bad.

In view of the above points, the present invention provides a tape transfer device that improves the operability and responsiveness of a tape by detecting the near-end end of the tape at a position where the remaining tape transfer time t _th is constant regardless of the tape transfer speed v. The purpose is to do.

Means for Solving the Problems According to the present invention, a tape cassette type detecting means for detecting a type of a tape cassette to obtain values of a tape thickness e and a reel hub diameter R _h , and a timer roller that rotates as the tape runs. transporting a timer roller rotation period detecting means for detecting a rotational period T _r, the supply reel rotation period detecting means for detecting a rotational period T _s of the supply reel for supplying said tape, the remaining amount tape of said supply reel The remaining tape transfer time t _sth required for calculating the remaining tape transfer time is calculated by the following formula, and when the remaining tape transfer time becomes equal to or less than a predetermined threshold value, an arithmetic processing means for generating a near start / end detection signal, A reel motor that drives a take-up reel that winds the tape according to an end detection signal, and a motor control unit that reduces the speed of the tape from a high speed to a predetermined speed. A-flops transfer device.

t _sth = K ₁ · T _s ² / T _r −K ₂ · T _r where K ₁ = R _r / (2 ・ e) K ₂ = R _h ² / (R _r・ 2 ・ e) R _r : Timer Roller radius Further, according to the present invention, the tape cassette type detecting means for detecting the type of the tape cassette to obtain the values of the tape thickness e, the total length L of the tape and the reel hub diameter R _h , and the winding side reel for winding the tape. A winding-side reel rotation cycle detecting means for detecting a rotation cycle T _t of the supply reel, and a supply-side reel rotation cycle detecting means for detecting a rotation cycle T _s of a supply-side reel that supplies the tape,
The remaining tape transfer time t _sth required to transfer the remaining tape on the supply reel is calculated by the following formula, and when the remaining tape transfer time becomes equal to or less than a predetermined threshold value, a near start / end detection signal is _output. A tape having arithmetic processing means to be generated and motor control means for controlling the reel motor for driving the winding side reel by the near start / end detection signal to reduce the speed of the tape from a high speed to a predetermined speed. It is a transfer device.

t _sth = K ₁ · T _s ² / T _t −K ₂ · T _t where K ₁ = R _t / (2 · e) K ₂ = R _h ² / (R _t · 2 · e) R _t = ( (L · e / π + 2 · R _h ² ) / (1 + T _s ² / T _t ² )) ^1/2 R _t : Radius of reel on take-up side Since the tape transfer speed v is constant regardless of the tape transfer speed v, the lower the tape transfer speed v is, the smaller the remaining tape amount is, and the remaining tape winding time after the tape transfer speed is reduced is shortened. It is possible to improve responsiveness.

Second Embodiment FIG. 2 shows a block diagram of a main part of a tape transfer device according to a first embodiment of the present invention, in which 10 is a tape cassette type detector and 14 is an arithmetic processing circuit.

Here, q = remaining tape length e = tape thickness r = variable representing radius R _s = S reel radius R _h = reel hub radius (constant determined by tape cassette) t _sth = S reel remaining tape transfer time Then, the following equation holds.

If the remaining tape length q of the S reel and the tape transfer speed v are known, the time t _sth for transferring the remaining tape of the S reel can be obtained.

t _sth = q / v (4) From the equations (3) and (4) and the above equation (1), t _sth = (R _r · T _s ² / T _r −T _r · R _h ² / R _r ) / 2e (5)

From equation (5), if T _s and T _r are detected and R _h and e determined from the type of tape cassette are used, the remaining tape of the S reel can be determined at the tape transfer speed v currently being transferred. The time t _sth required for transfer can be known. Therefore, in the present invention, when this time becomes equal to or less than a certain threshold value t _th of the remaining tape transfer time, the near start / end detection is performed, and a near start / end detection signal is sent to the reel motor control circuit 15 so as to reduce the tape transfer speed v. generate.

 The present embodiment will be described below with reference to FIGS. 1 and 2.

In FIG. 2, the configuration is the same as in FIG. 6 except for the tape cassette type detector 10 and the arithmetic processing circuit 14, and the respective blocks are given the same numbers.

FIG. 1 is a flow chart of the arithmetic processing of the near start / end end detection of the tape performed by the arithmetic processing circuit 14 in FIG.

When the REW or FF mode is selected by the signals from the terminals 17 and 18, the tape cassette type detector 10 in block 1 is selected.
Information on the tape thickness e and the reel hub diameter R _h obtained by the above is input to the arithmetic processing circuit 14. Next, in blocks 2 and 3, S
The reel rotation cycle T _s and the timer roller rotation cycle T _r are obtained. Then, in block 4, the time t _sth required to transfer the remaining tape of the S reel is calculated by using the relational expression shown in the expression (5). In block 5, the calculated time t
_sth is a preset threshold for the remaining tape transfer time t _th
When t _sth becomes smaller than t _th , the near start / end detection signal is generated in block 6, and the tape transfer speed v
To prevent damage to the tape due to tape rushing during high-speed transfer of the tape.

As described above, according to the present embodiment, the near-end end detection of the tape is not judged based on the remaining tape amount but based on the remaining tape transfer time, so that the remaining tape transfer time is irrelevant to the tape transfer speed at that time. Therefore, the tape remaining amount becomes smaller as the tape transfer speed becomes lower, and the tape winding time after the tape transfer speed is reduced, that is, the tape responsiveness can be improved. .

In recent years, there are strong demands for smaller and lighter VTRs, and tape traveling systems that do not use timer rollers have also been proposed in order to simplify the tape traveling system. The second embodiment shows that the present invention can sufficiently cope with such a tape running system.

FIG. 4 is a block diagram of a main part of the tape transfer device according to the second embodiment of the present invention, and 25 is an arithmetic processing circuit.

Here, assuming that R _t = T reel radius L = total length of tape, the following two equations hold.

v = 2πR _s / T _s = 2πR _t / T _t (6) As in the first embodiment, from the equations (3) and (4) and the equation (6), t _sth = (R _t · T _s ² / T _t −T _t · R _h ² / R _t ) / 2e … (8)

At this time, the T reel radius R _t is calculated from the equations (6) and (7). Is.

(8), (9) from the equation, T _s, detects the T _t, the use R _h are determined from the type of the tape cassette, L, and e, At a tape transport speed v of the current during the transfer S The time t _sth required to transfer the remaining tape on the reel can be known. Therefore, in the present invention, similar to the first embodiment, when this time t _sth becomes less than or equal to a threshold value t _th of the remaining tape transfer time, the near start / end end is detected and the tape transfer speed v is reduced. A start / end detection signal is generated in the reel motor control circuit 15.

 The present embodiment will be described below with reference to FIGS. 3 and 4.

In FIG. 4, the configuration is the same as in FIG. 2 except for the timer roller 8, the timer roller rotation period detector 12 and the arithmetic processing circuit 25, and the respective blocks are given the same numbers.

FIG. 3 is a flow chart of the arithmetic processing for detecting the near start / end of the tape, which is performed by the arithmetic processing circuit 25 in FIG.

When the REW or FF mode is selected by the signals from the terminals 17 and 18, in block 19, the tape cassette type detector 10
Information on the tape thickness e and the reel hub diameter R _h obtained by the above is input to the arithmetic processing circuit 25. Next, in blocks 20 and 21, the S reel rotation cycle T _s and the T reel rotation cycle T _t are obtained. Then, in block 22, the time t _sth required to transfer the remaining tape of the S reel is calculated using the relational expressions shown in the expressions (8) and (9). Time calculated in block 23
Threshold t of the remaining tape transfer time that t _sth is set in advance
_When t _sth becomes smaller than t _{th in} comparison with _th , a near end detection signal is generated in block 24 to reduce the tape transfer speed v to _prevent damage to the tape due to tape rush during high speed transfer of the tape. Try to prevent it.

As described above, according to the present embodiment, even for a tape running system that does not use a timer roller, which simplifies the tape running system, the tape remaining amount is transferred without determining the near-end end detection of the tape based on the tape remaining amount. By judging by the time, the remaining tape transfer time is constant regardless of the tape transfer speed at that time. Therefore, the lower the tape transfer speed, the smaller the remaining tape amount, and the tape after tape transfer speed decrease It is possible to shorten the winding time, that is, improve the responsiveness of the tape.

Even if a control pulse is used instead of the timer roller in the first embodiment, the present invention can obtain the same effect.

That is, for example, in a VHS system VTR, there is a track for recording a head phase reference signal (hereinafter referred to as a control pulse) called a control track at the lower end of the tape, and the control pulse is recorded at a frequency of 30 Hz during tape recording. Has been done.

Therefore, it is possible to detect the tape transfer speed v at the time of tape reproduction by detecting this reproduction control cycle and comparing it with the cycle of the control pulse at the time of recording.

For example, if the reproduction control frequency is 300 Hz, it can be seen that the tape is being transferred at a speed 10 times that at the time of recording.

 Hereinafter, this example will be shown in the third embodiment.

FIG. 9 is a block diagram of a main part of a tape transfer device according to the third embodiment of the present invention, in which 38 is a control head, 39 is a control pulse period detector, and 40 is a control pulse period detector.
Is an arithmetic processing circuit.

Where T _c = cycle of control pulse detected by control head T _p = cycle of control pulse during recording (constant specified by standard) v ₀ = tape transfer speed during recording (specified by standard) Constant), the following equation holds.

v = 2πR _s / T _s = v ₀ · T _p / T _c (10) Similar to the first embodiment, from the equations (3) and (4) and the equation (10), t _sth = (v ₀ · T _p · T _s ² / 4π / T _c −π T _c · R _h ² / v ₀ / T _p ) / e (11)

From the equation (11), if T _s and T _c are detected and R _h and e determined from the type of tape cassette and T _p and v ₀ specified by the standard are used, the tape currently being transferred can be used. Time t required to transfer the remaining tape on the S reel at the transfer speed v
_You can know _sth .

Therefore, in the present invention, similarly to the first and second embodiments, when this time t _sth becomes less than or equal to a certain threshold t _th of the remaining tape transfer time, the near-end termination is detected and the tape transfer speed v is reduced. The reel motor control circuit 15
To generate.

 This embodiment will be described below with reference to FIGS. 8 and 9.

In FIG. 9, the configuration is the same as that of FIG. 2 except for the control head 38, the control pulse period detector 39, and the arithmetic processing circuit 40, and the respective blocks are given the same numbers.

FIG. 8 is a flowchart of the arithmetic processing for detecting the near start / end of the tape, which is performed by the arithmetic processing circuit 40 in FIG.

When the REW or FF mode is selected by the signals from the terminals 17 and 18, in block 32, the tape cassette type detector 10
Information on the tape thickness e and the reel hub diameter R _h obtained by the above is input to the arithmetic processing circuit 40. Next, in blocks 33 and 34, the S reel rotation period T _s and the control pulse period T _c detected by the control head are obtained. Then, in block 35, the period T _p of the control pulse at the time of recording, the tape transfer speed v ₀ at the time of recording, and the relational expression shown in the equation (11) are used to determine the remaining tape of the S reel. The time t _sth required for the transfer is calculated. In block 36, the calculated time t _sth is _compared with a preset threshold value t _th of the remaining tape transfer time, and when t _sth becomes smaller than t _th , a near start / end detection signal is sent in block 37. Then, the tape transfer speed v is reduced to prevent the tape from being damaged due to the tape rush during the high speed transfer of the tape.

As described above, according to the present embodiment, the same effect can be obtained by using the control pulse instead of the timer roller in the first embodiment, and the near-end end detection of the tape can be judged by the remaining tape amount. Instead, the remaining tape transfer time is made constant by determining the remaining tape transfer time regardless of the tape transfer speed at that time. It is possible to shorten the tape winding time after the transfer speed is lowered, that is, to improve the responsiveness of the tape.

Incidentally, in recent years, various computations, input / output control, time management, and the like have been remarkably spread to various electronic equipment devices of microcomputers, but in the present invention, the arithmetic processing circuits 14, 25, 31, 40 are microcomputers. Can be configured by replacing. When the tape transfer speed v at the time of high speed tape transfer is controlled to a preset tape transfer speed V _set , the remaining tape transfer time of the S reel
Since there is a one-to-one relationship between t _sth and the S reel rotation cycle T _s , a preset threshold t of the remaining tape transfer time t
_th and by previously created correspondence table of the threshold value T _th of reel rotation period corresponding to it (ROM table), without performing repetitive operations of remaining tape transport time t _sth the S reel T _s and T It is possible to obtain exactly the same effect at higher speed by repeatedly comparing _th .

EFFECTS OF THE INVENTION As described above, according to the present invention, even if the tape transfer speed v greatly changes to 100 times speed, 50 times speed, 32 times speed, ... By detecting the beginning and end of the tape with the threshold t _th of the remaining tape transfer time set in advance, the remaining tape transfer time is made constant regardless of the tape transfer speed at that time. The lower the speed becomes, the smaller the remaining tape amount becomes, and the shorter the tape winding time after the tape transfer speed is lowered, that is, the better the responsiveness of the tape, the greater the practical effect.

[Brief description of drawings]

FIG. 1 shows an arithmetic processing circuit 14 according to the first embodiment of the present invention.
Flowchart of arithmetic processing of near beginning and end detection of tape performed in
FIG. 2 is a block diagram of the main part of the tape transfer device according to the first embodiment of the present invention, and FIG. 3 is a block diagram of the near start / end detection of the tape performed by the arithmetic processing circuit 25 according to the second embodiment of the present invention. FIG. 4 is a flow chart of arithmetic processing, FIG. 4 is a block diagram of a main part of the tape transfer device in the second embodiment of the present invention, and FIG. 5 is a near-end termination of the tape performed by the arithmetic processing circuit 31 in the conventional tape transfer device. FIG. 6 is a block diagram of the main part of the conventional tape transfer device, and FIG. 7 is the S reel radius R _s and the ratio of the timer roller rotation cycle to the S reel rotation cycle (T _s / T). _r ), FIG. 8 is a flow chart of the arithmetic processing for detecting the beginning and end of the tape performed by the arithmetic processing circuit 40 in the third embodiment of the present invention, and FIG. 9 is the third embodiment of the present invention. 3 is a block diagram of a main part of the tape transfer device in the embodiment of FIG. 7 ... Supply reel, 8 ... Timer roller, 9 ... Take-up reel, 16 ... Reel motor for driving T reel 9, 17 ... Rewind signal terminal, 18 ... Fast forward signal terminal.

Claims (2)

[Claims] 1. A tape cassette type detection means for detecting a tape cassette type to obtain values of a tape thickness e and a reel hub diameter R _h , and a rotation period T _r of a timer roller which rotates as the tape runs. Timer roller rotation cycle detection means, supply side reel rotation cycle detection means for detecting the rotation cycle T _s of the supply side reel that supplies the tape, and the remaining amount of the supply side reel required to transfer the tape The tape transfer time t _sth is calculated by the following formula, and when the remaining tape transfer time becomes equal to or less than a predetermined threshold value, an arithmetic processing unit that generates a near start / end detection signal, and the tape according to the near start / end detection signal And a motor control means for controlling a reel motor for driving a take-up reel for winding the tape, and reducing the speed of the tape from a high speed to a predetermined speed. t _sth = K ₁ · T _s ² / T _r −K ₂ · T _r where K ₁ = R _r / (2 ・ e) K ₂ = R _h ² / (R _r・ 2 ・ e) R _r : Timer Roller radius 2. A tape cassette type detecting means for detecting a tape cassette type to obtain values of a tape thickness e, a total length L of the tape and a reel hub diameter R _h , and a rotation cycle T of a winding side reel for winding a tape. Winding-side reel rotation cycle detection means for detecting _t , supply-side reel rotation cycle detection means for detecting rotation cycle T _s of the supply-side reel that supplies the tape, and transfer the remaining tape on the supply-side reel The remaining tape transfer time t _sth required for calculating the remaining tape transfer time t _sth , when the remaining tape transfer time is equal to or less than a predetermined threshold, processing means for generating a near start / end detection signal; A tape transfer device, comprising: a motor control unit that controls a reel motor that drives the take-up reel according to a detection signal to reduce the speed of the tape from a high speed to a predetermined speed. t _sth = K ₁ · T _s ² / T _t −K ₂ · T _t where K ₁ = R _t / (2 · e) K ₂ = R _h ² / (R _t · 2 · e) R _t = ( (L ・ e / π + 2 ・ R _h ² ) / (1 + T _s ² / T _t ² )) ^1/2 R _t : Radius of winding reel