Winding – tensioning – or guiding – Unwinding and rewinding a machine convertible information... – Carrier speed or tension control
Reexamination Certificate
1999-08-20
2001-05-08
Nguyen, John Q. (Department: 3653)
Winding, tensioning, or guiding
Unwinding and rewinding a machine convertible information...
Carrier speed or tension control
C242S336000, C360S073010, C360S094000
Reexamination Certificate
active
06227476
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an information recording/reproducing apparatus having a high speed take-up mode in addition to a normal take-up mode, and more particularly to a take-up control device for a loaded tape cassette in the information recording/reproducing apparatus wherein a discrimination of a loaded tape cassette can be conducted by only one reel-cycle measurement circuit.
A recent type of take-up control device is provided with a high speed take-up mode in addition to a normal take-up mode in order to perform take up of the tape more speedy.
The high speed take-up mode is such a mode that a tape-up speed at a fast feeding time (FF time) and a rewinding time (REW time) can be varied in a plurality of steps according to a type of the tape cassette (i.e. a diameter of a reel hub). For example, a tape of 120 min can be wound up from the beginning to the end in about 1 minute.
There are a thick hub type of 62 mm and a thin hub type of 26 mm in diameter of the reel hub. Tapes of 30 min and 60 min are classified as the thick hub type, while tapes of 90 min and 120 min are classified as the thin hub type.
In the high speed take-up mode, the method of controlling the take-up speed varies depending on a difference between the diameters of the hubs (the thick hub type and the thin hub type). Therefore, it is necessary to discriminate the diameter of the reel hub, at a moment when the tape cassette is loaded in the apparatus and the first take-up mode is carried out.
Conventionally, the discrimination of the reel hub has been conducted on the basis of a calculated value A in the following calculation formula (1):
(4
Tt
)
2
+(4
Ts
)
2
=A
(a constant value) (1)
In the formula, Tt is a reel pulse cycle of a take-up reel, and Ts is a reel pulse cycle of a supply reel.
In the above formula (1), each of the reel pulse cycles Tt and Ts is multiplied by 4. This is because 4 pulses of reel pulses are output on each one rotation of the reel. By multiplying each reel pulse by 4, a cycle of one rotation of the supply reel and a cycle of one rotation of the take-up reel can be obtained. Therefore, the formula (1) is a calculation formula for obtaining a sum of a square of the one rotation of the supply reel and a square of the one rotation of the take-up reel.
The value A is a proper value to be determined by the type of the tape cassette (the thick hub type and the thin hub type), and the tape cassette can be discriminated whether it is of the thick hub type or the thin hub type by means of the value A.
In the meantime, after the discrimination of the reel hub diameter is finished, a switching control of the tape speed in the take-up mode must be conducted in such a speed mode as corresponding to the discriminated reel hub diameter.
The switching of the tape speed in the take-up mode will be conducted by estimating an amount of the tape remaining in the supply reel (or the take-up reel). As one of methods for estimating the remaining amount of the tape, a ratio between the reel pulse cycle Ts of the supply reel and the reel pulse cycle Tt of the take-up reel (the following formulae (2) and (3)) is employed to determine a value N, and the tape speed will be changed by means of the value N.
N=Tt/Ts
(FF mode) (2)
N=Ts/Tt
(REW mode) (3)
As another method for estimating the remaining amount of the tape, as is disclosed in Japanese Patent Publication No. 58-27592B, number of remaining turns in the tape and remaining time can be calculated from a thickness of the tape, a diameter of the reel, reproduction speed of the tape and a rotation cycle of the reel.
As described, the related take-up control device is so constructed that the speed is controlled by estimating the remaining amount of the tape employing the reel pulse cycle Tt of the take-up reel and the reel pulse cycle Ts of the supply reel. The conventional device has a drawback that it requires a number of components and a complicated circuit structure, because two circuits are necessary for measuring the reel cycles respectively for the take-up reel and the supply reel.
SUMMARY OF THE INVENTION
The present invention has been made in order to overcome the above mentioned problem, and it is an object of the invention to provide a take-up control device for a tape cassette in an information recording/reproducing apparatus which allows the loaded tape cassette to be discriminated by means of a single reel-cycle measurement circuit.
In order to achive the above object, there is provided a take-up control device for a loaded tape cassette in an information recording/reproducing apparatus having a high speed take-up mode in addition to a normal take-up mode, comprising: means for measuring a rotation cycle of a reel acting as a supplying side of the tape cassette; means for calculating a changing rate of the rotation cycle measured by the measuring means; first discriminating means for discriminating whether the tape cassette is of a thick hub type or a thin hub type on the basis of the rotation cycle measured by the measuring means, and for discriminating, when the tape cassette has been discriminated as the thin hub type, whether the tape cassette is of the thin hub type or out of standard, on the basis of the changing rate calculated by the calculating means; and means for conducting a high speed take-up mode suitable for the type of the loaded tape cassette discriminated by the first discriminating means. Therefore, the tape cassette can be discriminated by means of the rotation cycle of the reel acting as the supplying side only, and requires only one circuit for measuring the rotation cycle. The number of the components can be thus decreased, whereby the products can be supplied at a low cost.
In the device, the first discriminating means discriminates the tape cassette as the thin hub type when the measured rotation cycle is longer than a predetermined first standard cycle, while as the thick hub type when it is at or shorter than the first standard cycle, and discriminates the loaded tape cassette as the thin hub type when the calculated changing rate is above a predetermined standard rate, while as out of the standard when it is at or below the standard rate. By introducing the new concept of the changing rate, the tape cassette can be discriminated by means of the rotation cycle of the reel acting as the supplying side only.
In the device, in case where the loaded tape cassette has been discriminated as the thin hub type by the first discriminating means, the high speed take-up conducting means shifts the high speed take-up mode to the normal take-up mode at least one of when the measured rotation cycle has become at or below a predetermined second standard cycle shorter than the first standard cycle, or when the calculated changing rate has become at or below the standard rate. In this way, even though the high speed take-up mode is conducted, the winding speed of the tape of the thin hub type or out of the standard can be reliably decreased just before completion of the rewinding.
The device further comprises: means for accumulating a recording time or a reproducing time since the tape cassette has been loaded; and second discriminating means for discriminating that the loaded tape cassette is of the thin hub type, when the time accumulated by the accumulating means is above the time capable of recording or reproducing in the tape cassette of the thick hub type. Since there is provided means for discriminating only the thin hub type apart from the means for discriminating the type of tape cassette, the thin hub type can be reliably discriminated from the tape out of the standard. Further, in case where the loaded tape cassette has been already discriminated as the thin hub type by the second discriminating means, no further discrimination by the first discriminating means will be necessary. The discrimination process can be thus simplified.
In the device, the tape cassette out of the standard includes a VHS-C tape cassette. Therefore, the VHS
Funai Electric Co. Ltd.
Lackenbach Siegel Marzullo Aronson & Greenspan
Nguyen John Q.
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