KR840001386B1 - Tape reel detector system - Google Patents

Abstract

A distinguishing device for a tape reel in a VTR detects and adds up the rotation numbers or periods of the supplying and receiving tape reels, which have the same diameters as the hubs. The added value is compared with the preset value, which is predetermined according to the type of the tape reel, having a different hub. This is useful for showing the actual remaining quantity of tape in the VTR when the customer uses a different tape reel beacause the circuit has previously detected the hub size.

Description

Tape rail discrimination method

1 is a block diagram illustrating an embodiment of the present invention scheme.

2 and 3 are diagrams showing the relationship between the tape usable time and the period of the two real disks in the NTSC system and the PAL system, respectively.

The present invention relates to a tape rail discrimination method, and provides a tape rail discrimination method that can easily check the type of tape rail used by adding the cycles or the number of rotations of the supply-side rail disk and the winding-side rail disk to a predetermined value. It aims to do it.

In addition, the present invention relates to a display method of remaining tape, and even if a tape rail having a different hub diameter is used by using the cycle or rotational speed of the supply-side rail disk and the tape rail hub diameter, the tape remaining amount of the supply-side rail disk corresponding to this is precisely determined. The purpose is to provide a way to display.

For video cassettes, as shown in the table below, the NTSC system is used for T-120 (the number of tapes available in minutes), T-90, T-60, T-30, T-20, and PAL system. There are many kinds of E-240, E-180, E-120, E-60, E-30, E-20 and so on. Meanwhile, there are two kinds of real hub diameters: 26 mm in diameter and 62 mm in diameter.

As the video cassette is different from the general audio cassette, a different hub diameter is used. Therefore, when displaying the remaining time of the tape, the cassette cannot be used in the same way as the remaining time of the audio tape recorder. It is convenient if the remaining amount is accurately displayed. In addition, the user may unknowingly use the cassette without examining the type of the real hub diameter of the cassette.

The present invention has been made in view of the above requirements, and an embodiment thereof will be described with reference to the accompanying drawings.

Since there are two types of rail diameters as described above, only the cycle of the supply side of the real disc or only the cycle of the reel side on the winding side is used. It is not possible to determine which hub diameter it is, but it is not possible to determine which hub diameter is on the supply side, but when the cycle between the supply cycle of the reel disk and the reel disk on the winding side is detected and it is determined whether it is large or small, Regardless of the diameter of the hub, the average cycle can be detected. The type of hub diameter can be determined, and the remaining tape time can be displayed using the calculator from the type of hub diameter and the cycle of the supply side disc. have.

Here you can actually use the formula to calculate the cycle and remaining tape time of the real disk,

Battlefield of Tape, LA

Tape length L wound on winding measurement day after t seconds

Remaining tape L 'on supply side day after t seconds

Tape Speed V

Tape thickness h

Tape outermost radius R with no tape drawn

of t seconds after the supply side reel tape winding radius R _S

Tape wound radius of winding measurement day after t seconds R _T

Period of supply side disc f _S

Cycle of wound winding disc f _T

Rail hub radius r

In terms of supply side work,

In this way,

Becomes Therefore, the sum F of the period f _S of the supply side disc and the period f _T of the winding side disc is

Becomes

On the other hand, when it comes to supply side

The remaining time t 'of the supply side

When the rail diameter r and the period f _S of the supply side disc are inserted, the remaining tape time t 'of the supply side rail can be calculated.

FIG. 1 shows a block system diagram for explaining one embodiment of the tape rail discrimination method according to the present invention, and shows a device capable of obtaining the above-described type of rail hub diameter r and the remaining tape time t 'of the supply side rail. In the figure, 1 is a rotation detector of the supply side rail, and 2 is a rotation detector of the winding side rail, respectively. For example, 48 pulses can be taken out for one rotation of the rail disc using a photo interrupter or the like. The pulses from the rotation detector 1 are supplied to the cycle counter 3, and the cycle counter 3 counts clock pulses of a constant frequency from the oscillator 4 until the number of pulses from the rotation detector 1 reaches a predetermined number. For example, if the clock pulses from oscillator 4 are counted until the number of pulses from detector 1 reaches 48, the count value is proportional to the time required for one revolution of the real disc. It becomes a signal corresponding to the period of. The signal from counter 3 is supplied to multiplier 5, where the constant corresponding to the tape normal running speed from tape speed setter 6 (33.35 mm / sec for NSTC system, 23.39 mm / sec for PAL system) The multiplier 5 thus extracts a signal having a level corresponding to the period f _S of the supply-side real disk at the time of normal drive of the tape (which can be regarded as the period f _S in practice).

On the other hand, the winding side real disc is exactly the same, and the output of the cycle counter 7 is multiplied by an integer corresponding to the running speed when the tape is normal as the multiplier 8, and the signal having a level corresponding to the cycle f _T of the winding side reel disc from multiplier 8 Can be regarded as a period f _T substantially). The period f _S from the multiplier 5 and the period f _T from the multiplier 8 are added by the adder 9 to form the period f _S + f _T to obtain the above formula (1).

The output of adder 9 (f _S + f _T ) is fed to comparator 10 where a value F = 12.1 sec (for NTSC systems) or a value F = 17.2 sec (preset) due to different cassette types of hub diameter. In comparison with the process of the PAL system, if it is below stationary, the T-90, T-120, and 3 (PAL system) in the cassette (FIG. 2 (NTSC system)) having a hub radius of r = 13 mm E-120, E-180, E-240), the cassette having a hub radius of r = 31 mm (T-20, T-30, T-60, This can be discriminated by E-20, E-30, and E-60 in Fig. 3. (PAL system) The predetermined signals are taken out by these two types of discrimination, and each cassette type is used as the cassette display 11. Is supplied to the remaining tape time calculator 12 as shown in the output f _S of the multiplier 5. In the remaining tape time calculator 12, the period f _S which is the output of the multiplier 5 and the comparator 10 An output (hub radius r) is obtained and the calculation according to the above expression (2) is performed.

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을 정수, f_S ²을 변수로 하여 연산이 행하여져 테이프잔량시간 t' 이 산출된다. 연산기 12의 출력은 표시기구동회로 13을 거쳐서 테이프잔량 시간표시기 14에 공급되어 테이프 잔량 시간이 표시된다.(2)

And

Is an integer and f _S ² is used as a variable to calculate the remaining tape time t '. The output of the calculator 12 is supplied to the tape remaining time indicator 14 via the display driving circuit 13 to display the remaining tape time.

In this way, the hub diameter of the used rail, that is, the type of cassette can be easily identified at a glance. Furthermore, even if other cassettes of the real hub diameter are used, the remaining tape amount corresponding to each cassette from the cycle of the hub diameter and the supply side rail The time can be displayed accurately.

The cycle counters 3 and 7 and the multipliers 5 and 8 are provided separately from the supply side winding and the winding side winding. However, the periodic counter and the multiplier are actually used by using a counter memory.

Instead of using the tape remaining time calculator 12, for example, the output of the multiplier 5 and the output of the comparator 10 are supplied using a comparison circuit equipped with a comparator group having a predetermined value level divided into 10 stages and a tape remaining time indicator. The levels may be compared in the comparator group of the comparison circuit to display the elements of the display in which the remaining tape time is divided into ten stages.

However, the display time of the display time is less than that shown in FIG.

Moreover, the present invention can be equally applied to an audio cassette or an open-rail type besides a video cassette.

The above embodiment is configured to detect the cycle of the real disk, but the inverse of the cycle, that is, the rotation speed, may be detected.

As described above, the tape rail discrimination method according to the present invention detects the cycle or the rotational speed of the supply side and the winding-side tape-free disk, respectively, and adds the cycle or the rotational speed of both real disks, and adds the added value of the tape rails having different hub diameters. The tape rails are used even if the user unconsciously attaches the tape rails, for example, without the user checking the type of tape rails, because the type of tape rails with different hub diameters are discriminated against the preset value according to the type. It is possible to easily check the type of and particularly difficult to discriminate from the outside, such as a video cassette, and to distinguish a cassette having a variety of tape rails having different hub diameters.

In addition, as described above, the remaining tape display method according to the present invention detects a signal corresponding to the cycle or rotational speed of the supply-side tape rail disk and selects the supply side rail from the signal corresponding to the hub diameter of the supply-side rail, which is determined in advance. Since the remaining amount of tape is displayed, for example, when different cassettes of different diameters such as video cassettes are used, the remaining amount of tape corresponding to the cassette in use can be displayed accurately, and the supply and winding side tape rail discs Detect the cycle diameter of the tape rail in use by detecting the cycle or rotation speed of each and adding the cycle or rotation speed of both real discs, and comparing the added value with the preset value according to the type of tape rail with different hub diameter. For example, the user can determine the type of tape rail Even if the tape rail is unknowingly installed, the remaining tape diameter can be automatically displayed by measuring the hub diameter, especially when using a cassette that is difficult to determine the hub diameter from the outside such as a video cassette. Alternatively, the remaining tape time is calculated using the variable of the rotation speed, the tape running speed, the tape thickness, and the hub diameter constant so that the remaining tape can be easily identified with the correct value.

Claims (1)

The cycle or number of revolutions of each of the real discs of the supply side tape rails having the same hub diameter rotated while the tape is running is detected, respectively, and the period or the number of rotations of the reel discs of the supply side tape rail and the take-up side tape rail are added to this sum, A tape rail discrimination method, characterized in that a type of tape rail having a different hub diameter is determined by comparing whether the teeth are larger or smaller than a predetermined value by different tape rail types having a hub diameter.

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