JP3538590B2 - Deceleration processing method at high speed running of magnetic tape - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for controlling a running state of a magnetic tape in a magnetic recording / reproducing apparatus such as a video tape recorder.
F) The present invention relates to an improvement in a travel control device that reduces the tape speed when a magnetic tape being fed or rewound at a high speed during rewinding (REW) approaches the end or start of the tape. .

[0002]

2. Description of the Related Art Running a magnetic tape to the end or the beginning of the tape while running at a high speed may damage the magnetic tape, and it is desired to reduce the tape speed when approaching the end or the vicinity of the beginning. .

When the deceleration point is set by using the area of the tape wound on a take-up reel or a supply reel, the area of the tape is determined by the number of tapes or the tape diameter and the tape thickness. When the thickness is different, there is a problem that an accurate deceleration point cannot be set.

[0004]

That is, although the tape thickness of a video tape is determined by a standard, when compared in a fixed area, the number of windings decreases as the tape thickness increases, so that the upper limit of the standard, that is, the tape Assuming a thick tape, the deceleration point was set to ensure deceleration.

[0005] In addition, air is involved during FF / REW,
Because some tapes have a thicker pseudo-thickness,
Further, it is necessary to provide a margin for the deceleration point, and these have been obstacles to speeding up in FF / REW. That is, when winding the tape at a high speed, the tape is wound, and at the same time, the air is also wound together with the tape. The amount of air is determined by the surface roughness of the tape surface and the tape cassette. If the surface of the tape is damaged, the amount of air increases, the winding state of the tape becomes loose, and the total area of the tape obtained before high-speed feeding may increase after high-speed feeding. is there.

In such a case, if the deceleration point is set with the total area obtained first, there is a problem that the deceleration cannot be completed, or if the deceleration point is set with a margin in consideration of the total area variation error, the deceleration is made earlier. Thus, there has been a problem that it takes time for high-speed feeding.

Therefore, an object of the present invention is to read the fluctuation of the winding area in a certain section during high-speed feeding, determine the winding state from the result, set the deceleration point optimally, and set a margin. The point is that the deceleration point can be set more accurately without taking the tape, and the speeding up of the tape running at the time of FF / REW can be safely achieved without fear of damaging the tape.

[0008]

In order to achieve the above object, in the present invention, in a certain section during high-speed feeding, the actual winding-side area is compared with the winding-side area of a tape having a standard thickness. Thus, the tape thickness is determined, and the deceleration point is set optimally in accordance with the determination.

That is, in the deceleration processing method at the time of high-speed running according to the present invention, the deceleration point having the most margin is set as an initial value in accordance with the total area and the winding side area obtained for the used tape, and the high-speed feeding is performed. The winding side area for starting the tape thickness discrimination processing and the rotation count number of the winding side reel are set according to the winding side area at the start, and the actual winding side area at the set rotation count number and the same rotation Compare the standard winding side area obtained for the standard tape thickness in the count number, and if the actual winding side area is larger than the standard winding side area, correct the deceleration point set as the initial value earlier. When the actual winding side area is small, the deceleration point is corrected later.

[0010] The standard winding side based on the standard winding thickness at the winding side for starting the tape thickness discrimination processing according to the winding side area at the start of high-speed feeding, the rotation count of the winding reel, and the standard tape thickness at the same rotation count. The deceleration point correction processing performed by comparing the area, the standard winding-side area with the actual winding-side area, and the like are calculated and executed based on a preset program.

According to the present invention, the high-speed feed mode (F
F / REW), a tape thickness discrimination processing program is executed, and when the tape thickness is thick, the deceleration point is set earlier than the initial setting, so that deceleration can be reliably performed. Since the setting is made later than the initial setting, the time required for FF / REW can be reduced.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS High-speed tape feeding operation, FF / R
Each section as shown in FIG. 2 is set from the start to the end of the EW operation. The following is a description of one example.

[Acceleration Section-A1] The capstan motor (tape feed motor) accelerates to a certain rotation.

[Acceleration Section-A2] When the number of revolutions of the capstan motor reaches a certain value, for example, 3400 rpm / sec, the capstan motor keeps rotating at a constant speed.

[Constant section of tape feed-TS] Next, the tape feed speed is a certain value, for example, 6,000 mm / sec.
When the above is reached, the capstan motor controls the tape feed speed to be constant to prevent the inertia on the winding side from becoming too large and to prevent damage to the tape when stopping from FF / REW. are doing.

[Supply Reel Rotation Speed Constant Section-RS] Thereafter, the supply reel rotation speed is a certain value, for example, 2500r.
When the speed reaches pm / sec, the capstan motor is controlled so that the number of revolutions on the supply reel side becomes constant, and the FF / REW
When the tape is stopped from the start, the slack of the tape on the supply reel side is suppressed.

[Deceleration point 1 section-D1] When the winding side area condition obtained by the "tape thickness determination processing" according to the present invention is reached, the capstan motor is driven under the first condition, for example, 1 rpm / 10 msec. After entering a one-step deceleration, a certain rotation speed, for example, 1200 rpm / sec
When it becomes, keep that speed.

[Deceleration point 2 section-D2] Further, when the winding side area condition obtained by the "tape thickness discriminating process" according to the present invention is reached, the capstan motor is driven under the second condition, for example, 1 rpm / 20 msec. Enter the stage of deceleration and further reduce the number of revolutions.

[Deceleration point 3 section-D3] When the rotation speed reaches a certain value, for example, 500 rpm / sec or less,
The capstan motor operates under the third condition, for example, 1 rpm / 2.
Entering the third stage deceleration by 0 msec, 160 rpm
The rotation speed is reduced to about / sec.

In the above-described high-speed feeding operation, the setting of the deceleration point will be described below. First, before entering the high-speed feeding operation, the total area of the tape, that is, "the area of each reel hub on the supply side / take-up side projected on a plane + the area of the tape" is obtained by a known method. Next, immediately after shifting to the high-speed feed mode (FF / REW), the area of the tape wound on each reel hub is obtained, and the various acceleration modes described above are entered in accordance with the state.

Hereinafter, the flow up to the setting of the deceleration point will be described with reference to the flowchart of FIG.
Note that, here, the take-up side refers to a take-up reel (take-up reel) at the time of FF, and a supply reel (supply-side reel) at the time of REW. 1. Initial value setting of the deceleration point First, the deceleration points 1 and 2 having the most allowance are set according to the values of the total area and the winding side area obtained for the used tape.
Is set as the initial value. 2. Start of tape thickness determination process 2-1. On the basis of the respective fixed values set in several steps in the numerical range to which the value of the area on the winding side when FF / REW is started, counting of the reel pulse on the winding side when the winding area is reached Is set based on a separately defined program to determine a count start point for starting the operation and a count (N rotations).

2-2. When the winding-side area reaches a set value, counting of the winding-side reel pulse is started, and when the counting of the winding-side reel pulse reaches a set value (N), the winding-side area at that time is obtained.

2-3. On the other hand, the standard take-up area is calculated by N rotations from the count start point of the take-up reel pulse at the standard tape thickness, and the tape is compared with the actual take-up area. Determine the thickness.

2-4. If the actual winding side area is large compared to the standard winding side area obtained, if the tape thickness is large or air is entangled and the winding state is loose,
If the actual winding side area is small, the tape thickness is in a thin state.
If the tape thickness is thin, a process of changing the deceleration point is performed later. 3. When the deceleration point determined above is reached, the first deceleration
The stage deceleration and the second stage deceleration are started, and finally, when the rotation speed of the capstan motor reaches 500 rpm / sec or less, the third stage deceleration is started.

The above 2. In the case where the area on the winding side does not correspond to any of the classes defined in the above program, the deceleration points 1 and 2 having the most margin set as the initial values are set.
Becomes effective as it is, and when the deceleration point is reached, deceleration is started.

Before the number of revolutions of the take-up reel reaches the set count, the supply-side area is monitored so as not to be less than a value set as an initial value. , Start deceleration.

[0027]

As described above, according to the deceleration processing method of the present invention when the magnetic tape is running at a high speed, the tape thickness discrimination processing program is executed in the high-speed feed mode (FF / REW), and when the tape thickness is large. Is to set the deceleration point earlier than the initial setting to enable reliable deceleration. If the tape thickness is thin, it is possible to shorten the time required for FF / REW by setting it later than the initial setting. it can. In other words, the optimal deceleration point can be set according to the state of the tape and the winding state,
The tape end is reached without deceleration, and the tape and mechanical parts are not seriously damaged.Furthermore, since the deceleration point is set based on the winding state, there is no need to take a large margin in setting the point, / REW time can be shortened, and fast and safe high-speed feeding is enabled.

[Brief description of the drawings]

FIG. 1 is a flowchart of a deceleration processing method during high-speed running of a magnetic tape according to the present invention.

FIG. 2 is an explanatory diagram of each section set from a start to an end in a high-speed feeding operation of a magnetic tape.

[Explanation of symbols]

D1 to D3 ... deceleration point

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 15/46

Claims (2)

(57) [Claims] 1. A deceleration processing method at the time of high-speed running of a magnetic tape for decelerating a magnetic tape wound around a supply-side reel and a winding-side reel and running at a high speed toward the winding-side reel, comprising: The initial value is the deceleration point that has the most margin according to the total area consisting of the hub area of each reel on the supply side / winding side and the area of the magnetic tape obtained for the used tape, and the winding side area obtained for the used tape. After setting the initial value of the deceleration point, a tape thickness determination process is performed to determine whether the tape thickness is thick or thin. Based on the setting of the winding-side area for starting the counting of the rotation of the winding-side reel according to the area, and the rotation count of the winding-side reel counted from the time when the winding-side area is reached. The actual winding-side area at the time when the set rotation count of the take-up reel is reached is determined, and the standard winding of the standard tape thickness at the set rotation count of the take-up reel is determined. By determining the take-up area, and comparing the obtained actual take-up area with the standard take-up area, if the actual take-up area is larger than the standard take-up area, the tape thickness Is determined to be thick, and if the actual winding side area is smaller than the standard winding side area, the tape thickness is determined to be thin.If the tape thickness determination processing determines that the tape thickness is large. The deceleration point determined as the initial value is corrected earlier, and if the tape thickness determination processing determines that the tape thickness is thin, the deceleration point determined as the initial value is delayed. Corrected to A deceleration processing method at the time of high-speed running of the magnetic tape. 2. A winding-side area for starting the counting of the rotation of the winding-side reel is set in several steps within a numerical range to which the value of the winding-side area at the start of the high-speed feeding belongs. 2. The method according to claim 1, wherein the magnetic tape is driven at a high speed.