JPH02306456A - Tape tension controller - Google Patents

Abstract

PURPOSE:To attain the economical control of tape tension with no use of a reel motor by performing the drive control of a brake means based on the control mode selected by a mode selection means. CONSTITUTION:A winding diameter deciding means 30 is used to decide the tape winding diameter information on one of two reels together with a mode selection means 32 which selects the control mode set previously based on the decided winding diameter information, a brake means 34 which applies the brakes to one of both reels, and a drive control means 32 which controls the drive of the means 34 based on the control mode selected by the means 32. Then the means 30 decides the winding diameter of either one of both reels, and a control mode is selected based on the decided winding diameter. Then the brakes are applied to the corresponding reel in accordance with the selected mode. Thus it is possible to attain the economical control of tape tension with no use of a reel motor.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a tape tension control device for a VTR, etc., and is particularly suitable for tension control during high-speed tape running such as REW search and FF search. This invention relates to a tape tension control device.

[Prior Art] As a tape supply/winding means, a direct drive (DD) reel motor is provided on each side for supply/take up, and a tape supply/take up means is provided. take u
There are various types of motors, such as one in which the idler gear is driven by a reel motor provided on both sides of p1, and one in which the idler gear is driven by a capstan motor using a belt or the like.

Among these, for those with a reel motor, the supply voltage to the reel motor (in the case of the DD, the motor on the winding side) is determined according to the tape winding diameter on the tape winding side, as shown in Table 1. It's changing.

Table 1 As shown in this table, the winding diameter is divided into 8 stages.
Supply voltage values are set in hexadecimal format according to each stage. The values in this table are D/A converted and become the drive voltage for the reel motor.

By controlling the supply voltage in this manner, tension control is performed so that the tape tension at the entrance and exit of the head drum is always at an optimal value.

Furthermore, even if the reel is driven by a capstan motor without a reel motor, an additional motor is provided only for reverse playback (REW search).
Some wind up the tape using this method. In this type of motor, the tape tension is controlled by controlling the voltage supplied to the motor, as in the case of the reel motor described above.

Furthermore, if there is no dedicated motor for driving the reel, the driving force is transmitted from the capstan motor to the reel using a rubber belt, a timing belt, or the like. In this type, a clutch is provided on the reel side, and control is performed using this clutch to generate an appropriate tape winding torque, that is, tape tension.

[Problems to be Solved by the Invention] However, the above conventional techniques have the following disadvantages.゛+l) Types that use a reel motor require a dedicated motor, which increases costs and is not suitable for widespread use.

(2) It is necessary to switch the voltage supplied to the reel motor in accordance with the tape speed of reverse playback. For this reason,
If the speed suddenly drops from high speed to low speed and the follow-up of the supply voltage is poor, the tape winding torque may be too large and the tape may be damaged. On the other hand, if the tape speed is suddenly increased from low to high, the winding of the tape may not be able to keep up with the speed, resulting in missing images. Therefore, switching the supply voltage requires careful timing control.

(3) On the other hand, in a type that does not have a dedicated motor and uses a clutch to control the tension, the reel torque generated by the clutch is applied at the beginning and end of the tape winding.
In other words, it is constant regardless of the winding diameter of the reel. Therefore, when the winding diameter is large, the tape tension is small,
When the winding diameter is small, the tape tension becomes large. For example, if the winding diameter ratio at the beginning and end of winding is about 3 times, the tape tension will also be about 3 times as much.

Therefore, if sufficient winding torque or tape tension is set to prevent image dropouts at the beginning of winding with a large diameter, the winding torque will be excessive at the end of winding with a small diameter, which will prevent tape damage. The margin becomes smaller.

The present invention has been made in view of these points, and one of its objects is to perform cost-effective tape tension control that does not use a reel motor.

Another purpose is to provide good tape tension control without requiring special timing control even when the tape speed changes rapidly.

Still another object is to perform tape tension control that can accommodate increased tape speeds and significantly shorten fast forward/rewind times.

[Means for Solving the Problems] The present invention provides a tape tension control device that performs tape tension control when supplying tape from a supply reel and winding the tape onto a take-up reel. A winding diameter determining means for determining tape winding diameter information, a mode selecting means for selecting a preset control mode based on the determined winding diameter information, and a braking means for applying a brake to at least one of the reels. and a drive control means for controlling the drive of the brake means based on the control mode selected by the mode selection means.

[Operation] According to the present invention, the winding diameter of any one of the reels is determined by the winding diameter determining means. Then, a control mode is selected according to the determined winding diameter, and a brake is applied to the corresponding reel according to this mode.

For example, in the case of reverse playback, a brake is applied to the take-up reel at the beginning of the tape winding operation.

[Examples] Examples of the present invention will be described below with reference to the accompanying drawings.

<Configuration of Embodiment> FIG. 1 shows an embodiment of a tape tension control device according to the present invention. In the same figure, tape 10
During reverse playback, the reel is supplied from the first reel 12 as shown by the arrow FA, travels as shown by the arrow FB, and is wound onto the second reel 14 as shown by the arrow FC. . A pinch roller 16 and a capstan 18 are provided in the tape running path.

Note that during normal playback, the tape running direction is reversed.
The second reel 14 is the supply side, and the first reel 12 is the take-up side.

Next, the first and second reels 12.14 are provided with Tv rotation detectors 20.22, respectively.

The detection output sides of these rotation detectors 20.22 are respectively connected to the input sides of the reel rotation signal detection section 24, so that the rotation signals of the first and second reels 12.14 are detected respectively. It has become.

Similarly, the capstan 18 capstan motor (not shown) is also provided with a rotation detector 26, which can be inspected and
The output value is connected to the input end of the capstan motor rotation signal detection section 28. These allow the rotation signal of the capstan motor to be detected.

Next, the output sides of the reel rotation signal detection section 24 and the capstan motor rotation signal detection section 28 described above are respectively connected to the input side of the tape winding diameter determination section 30. The tape winding diameter determination unit 30 determines the tape winding side reel winding diameter and tape supply side reel winding diameter based on the input signal, and the determination result is outputted to the mode motor drive unit 32. It has become.

The control signal output side of this mode motor drive section 32 is connected to the input end of a mode motor 36 that operates the take-up side reel brake 34.

In this embodiment, there are two operation modes: a mode in which the take-up side reel brake 34 is not applied to the second reel;
dl and a mode Mod2 in which the take-up side reel brake 34 is applied to the second reel. These mode determinations are performed by the mode motor drive unit 32 based on the determination results of the tape winding diameter determination unit 30.

It has become.

<Operation of the Embodiment> Next, the operation of the embodiment described above will be described using a case of reverse playback as an example. In this case, as mentioned above, the first
The reel 12 serves as a supply reel, the second reel 14 serves as a take-up reel, and the tape IO is wound from the first reel to the second reel.

At this time, the rotation signal of the first reel 12 is detected by the rotation detector 2.
−0 and detected by the reel rotation signal detection unit 24,
It is output to the tape winding diameter determination section 30. On the other hand, the rotation signal of the capstan motor is detected by the rotation detector 26 and the capstan motor rotation signal detection section 28,
Similarly, it is output to the tape winding diameter determining section 30.

In the tape winding diameter determination section 30, based on the manually input signal,
The number of rotation signals of the capstan motor included in one rotation of the tape supply side reel, that is, the first reel 12, is counted, and the winding diameter of the first reel 12 is determined based on this count value.

This determination result is output from the tape winding diameter determining section 30 to the mode motor driving section 32.

In the mode motor drive unit 32, the determined winding diameter value is compared with a predetermined threshold value, and the above-described mode determination is performed.

As a result, when the winding diameter value of the second reel 14 is larger than the threshold value and it is determined that the mode is Modl, the mode motor 36 is not driven by the mode motor drive unit 32. That is, the take-up side reel brake 34 does not act on the second reel 14.

On the other hand, when the winding diameter value of the second reel 14 is smaller than the threshold value and it is determined that the mode is Mod2, the mode motor 36 is driven by the mode motor drive unit 32. That is, the take-up side reel brake 34 acts on the second reel 14. In other words, when the tape tension at the end of winding is high, a predetermined brake is applied to the second reel 14, the winding torque is reduced, and the increased tape tension is reduced.

FIG. 2 shows the change in tape tension from the beginning of winding to the end of winding. In the figure, the tape tension when the mode is not switched as described above, that is, when the tape is operated only in mode Modl, draws a curve that gradually increases from the beginning of winding to the end of winding, as shown by graph LA. On the other hand, in this embodiment, the mode Modl and the mode Mod are set at the time point TP when the winding diameter exceeds the threshold value.
2 switching is performed, and in mode Mod2, the brake is applied. Therefore, the tape tension is L in the same figure.
As shown in B, it begins to decrease after reaching TP.

<Other Examples> Note that the present invention is not limited to the above embodiments. For example, in the above embodiment, the tape winding system was determined from the capstan/pinch roller system, but a specific calculation method in this case is disclosed in, for example, Japanese Utility Model Application No. 62-101188. In addition, as disclosed in Japanese Unexamined Patent Application Publication No. 53-6004, there is a method that calculates from the rotation period ratio of the supply side reel and the take-up side reel without detecting the rotation speed of the capstan motor. Any means may be used.

Next, in the above embodiment, the case of reverse playback (REW search) has been described as an example, but the invention can be similarly applied to the case of forward playback (FF search). It can also be applied to simple FF (fast forward)/REW (rewind) in full loading and half loading states.

In particular, when using a winding diameter determination means that calculates from the rotation period ratio of the supply side reel and the take-up side reel, not only the full loading and half loading conditions, but also the
Even when FF/REW is performed inside the cassette, it is possible to perform tension control even when the capstan is not used. That is,
If information about the tape diameter or remaining amount is required,
Regardless of the operating state, tape tension can be controlled by applying a brake to the take-up reel.

Next, in the above embodiment, tension control was performed in two modes, but it is also possible to set several more control modes, and even better tension control can be achieved. Tension can be further reduced.

Furthermore, when performing FF/REW with full loading, the axial load on the reel disk is reduced to reduce the tape winding load, but at this time,
When the reel diameter on the tape supply side is large, the tape tension decreases transiently, causing tape flapping and hunting.

The present invention can be applied to such cases, and if the brake is applied while the tape tension is small, the FF
/REW operation also enables image output. In addition, by doing this, the tape tension can be maintained at an appropriate value, making it possible to further increase the tape speed even in FF/REW operation, reducing the fast forward/rewind time between the beginning and end of the tape. It is possible to achieve a significant reduction in time.

In addition, in the above embodiment, the winding diameter of the take-up reel is detected, but since there is a certain relationship between the winding diameter of the take-up reel and the winding diameter of the supply reel, it is necessary to detect either of them. You may also do so.

Further, in the above embodiment, the mode motor drive unit 32° mode motor 36 is used as a means for applying the brake, but means such as a solenoid may also be used.

[Effects of the Invention] As explained above, the present invention has the following effects.

Since no reel motor is used, cost-effective tape tension control can be performed.

(2) Even when the tape speed changes rapidly, excellent tape tension control can be performed without special timing control.

(3) Can support higher tape speeds, allowing fast forwarding/
It is possible to significantly shorten the rewinding time.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a graph showing the operation of the embodiment. 10--tape, 12--first reel, 14...
2nd reel, 18...-capstan, 20.22°2
6... Rotation detector, 24... Reel rotation signal detection section, 28... Capstan motor rotation signal detection section, 30
---Tape winding diameter determining unit (winding diameter determining means), 32--
Mode motor drive unit (mode selection means, drive control means)
, 34--Reel brake on the winding side (braking means),
36...-mode motor. Patent applicant: Kunio Kakiki, representative of Victor Japan Co., Ltd.

Claims (1)

[Claims] In a tape tension control device that controls tape tension when supplying tape from a supply reel and winding the tape onto a take-up reel, the tape tension control device determines tape winding diameter information on any of the reels. a reel diameter determination means, a mode selection means for selecting a preset control mode based on the reel diameter information determined thereby, a brake means for applying a brake to at least one of the reels, and a mode selection means for applying a brake to at least one of the reels; A tape tension control device comprising: drive control means for controlling the drive of the brake means based on a selected control mode.