JPS5948470B2 - Tape amount calculation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that approximately calculates the amount of tape travel when a long tape wound around a reel is recorded or played back, and a display device thereof. It is something.

Calculating the amount of tape in this way can also be used when, for example, in a tape recording/playback device such as a power set tape recorder, the remaining amount of tape is to be displayed in secrecy during recording or playback. When recording or playing back, it is often necessary to know where on the tape the tape is currently being recorded and how much time is left for recording and playback.

In this case, it is necessary to know how much tape has been run so far. Conventionally, (1) a method of driving a mechanical counter by rotation of a reel shaft, (
2) A method in which electrical pulses are generated by rotating the reel shaft, and these pulses are counted and displayed electronically.
(3) Activate the timer in accordance with the running of the tape, count the electrical pulses generated by the timer,
Electronic display methods have been used. but,
Each of these methods has the following drawbacks and is not completely satisfactory. In other words, when displaying the number of rotations of the reel shaft in (1) and (2), there is a one-to-one correspondence between the displayed value and the position of the tape, but the number of rotations of the reel shaft depends on the length of the tape and the elapsed time. Since the numbers do not correspond to each other, the displayed values are unrelated to the length of the tape or the usage time. In addition, if the tape running time is displayed, if the tape is fast forwarded or rewound,
The value becomes completely unrelated to the length of the tape,
It becomes useless in the blink of an eye. The present invention measures the amount of tape travel itself, regardless of the speed at which the tape travels, such as normal travel, fast forwarding, rewinding, etc., and converts and displays this in time, thereby overcoming the drawbacks of conventional methods and devices. It's completely resolved.

In the case of force-setting tapes, the length of time the tape can be moved varies depending on the type of tape, such as C6O, C,O, Cl2O, etc.
By having a structure in which calculation conditions can be set in advance during the process of measuring the amount of travel, it is possible to perform a display that is suitable for various types of tape. The embodiment will be explained based on a force setting type recording/playback mechanism with reference to FIGS. 1 and 2.
1) is the supply reel on which the tape T is wound, and its radius is R.

It is. (2) is the take-up reel that winds the tape T;
This radius is also R. It is. Note that (3) is the traveling table T.
A magnetic head for recording or playing back music. At the beginning of winding the tape T (at the start), assuming that the entire amount of the tape T is wound on the supply reel (1) and the radius including the tape T is RO, as recording or playback progresses, , the tape T gradually reaches the reel on the winding side 2)
The diameter of the supply reel (1) including the tape gradually decreases. Let r be the changing radius, L1 be the total length of the tape, and t be the thickness of the tape. Here, on the winding side -
If the running distance (length) of the tape T when M2) rotates n times is l, then the following relationship exists between the number of rotations n of the take-up and rewinding M2) and the running length 2 of the tape T. Approximately true. The remaining time of the tape is given by the tape speed Slc, where RO is a constant standardized as a force setting standard, L.
is the total length of the tape), C6O, C, O, C, 2O is a constant determined by the type of equal force set, t is the thickness of the tape,
This is also a constant determined by the type of tape, and S is the speed of the tape. For example, in the case of force set, 4.75 cIrL/
It is a constant standardized as Sec.

The present invention is directed to the winding weir side. 2 (the number of revolutions n of the ω axis is counted, the above-mentioned constants are given, the used tape length 2 is calculated by the first calculation means, and this is displayed.

To explain specifically based on the block diagram in Figure 2,
A rotation detector 21 detects the rotation speed n of the take-up reel (2) of the tape T. This detector is composed of a combination of a light source and a photocell, or a magnet and a magnetically sensitive element. A pulse P corresponding to the rotation of is output.

22 is a direction detector that detects the rotating direction of the reel (2) or the running direction of the tape T; 23 is a pulse counter; for example, the direction detector detects the running direction of the tape;
When the table travels in the forward direction, the pulse P from the rotation detector 21 is added to the pulse counter disposed at the rear stage, and when it is in the reverse direction, the pulse P from the rotation detector 21 is subtracted. The data is inputted to the arithmetic unit 26 which is the arithmetic means.

These 21, 22, and 23 form a detection means 20 for detecting the rotation speed n of the reel. 24 is the keyboard, C6O
, C, O, Cl2O, etc., specify the tape to be used.

This is usually done by manipulating buttons, keys, etc. Further, this operation of the keyboard 24 inputs into the memory 25 a constant specific to the specified tape. These constants for force setting tapes may be as shown in the following table, for example:
This numerical value is stored in memory 25 in advance. These 24 and 25 form a condition setting means 30 that stores each constant. Reference numeral 26 is a first arithmetic unit, which receives constant data (T, L, rO, S) from the memory 25 and variable n from the pulse counter 23, and performs the calculation of equation (2).

Reference numeral 27 denotes a display connected to the first arithmetic unit 26. This indicator is composed of an LED, an LCD, etc., and displays the calculation result of the first arithmetic unit 26, that is, the used tape length 2, as appropriate.
Display in advanced numbers.

Note that the expression (2) is displayed in seconds. This may be displayed in minutes or seconds. FIG. 3 shows that using the calculation device for obtaining the tape running amount l of the present invention as described above,
This shows another embodiment for displaying the tape running amount 2, that is, the elapsed time of the used tape, and for convenience, parts equivalent to those in FIG. 2 are given the same reference numerals. This figure 3 r
The difference is that a second arithmetic unit 28 is provided and the first arithmetic unit 28 is provided.
The data on the tape running distance l outputted from the computing unit 26 is input to the computing unit 28 which is the second computing means, and the data on the tape speed s is read out from the condition setting means 30 and inputted. That is what we are doing. The second arithmetic unit 28 divides the input tape running amount l data by the tape speed s data, and provides the calculated output to the display 2T. As a result, indicator 2
7 displays the elapsed time of the used tape length. Fourth
The figure shows a further developed version of the calculation device of the present invention, and shows an embodiment for displaying the remaining length of the tape.

In FIG. 4, the same parts as those in FIG. This third arithmetic unit 29 is the first arithmetic unit 26
At the same time, the data on the tape running distance L output from the condition setting means 30 is inputted, and the data on the total tape length L is read out from the condition setting means 30 and inputted. The computing unit 29, which is the third computing means, subtracts the read tape total length L data by the input tape running length l, and provides the computed output, that is, the tape remaining length, to the display 2T. FIG. 5 shows another embodiment in which the present invention is further developed, and parts equivalent to those in FIG. 4 are given the same reference numerals for convenience.

Here, the difference from this Fig. 4 is that the device shown in Fig. 4 has a fourth
The point is that a computing unit 40 is provided as computing means. The fourth arithmetic unit 40 receives the arithmetic output output from the third arithmetic unit 29, that is, the data of the remaining tape length (L-l), and reads out and inputs the data of the tape speed s from the condition setting means 30. be done. The fourth arithmetic unit 40 divides the input tape remaining length (L-l) data by the read tape speed s data, and provides the calculated output to the display 2T. As a result, indicator 2
T displays the length of the remaining tape as the remaining tape time. It goes without saying that it is appropriate to use a microcomputer for these series of counting, storage, and calculations. The present invention as described above detects the number of rotations of a tape reel, and calculates the number of rotations in combination with various standards such as the thickness, overall length, and reel radius of the tape, and calculates the actual length of the tape. The feature is that the remaining amount of the tape is displayed as a time using calculations based on this method, so the time on the tape can be directly displayed, and when fast forwarding or rewinding the tape. However, it has great advantages in that the time is displayed accurately, and even if the type of tape changes, the time is displayed accordingly.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating an embodiment of the present invention, FIG. 2 is a block diagram of a main part of a calculation device of the present invention, and FIG. 3 is a block diagram of a main part showing an embodiment of a tape running time display device. , 4th
FIG. 5 is a block diagram of a main part showing an embodiment of a display device for displaying remaining tape length, and FIG. 5 is a block diagram of main parts showing a display device for displaying remaining tape time. 21... Rotation detector, 22... Direction detector, 23... Pulse counter, 24...
...Keyboard, 25...Memory, 26...
...First calculation means, 2T...Display device, 20
...Detection means, 30...Condition setting means, 28...Second calculation means, 29...
Third calculation means, 40...Fourth calculation means.

Claims (1)

[Scope of Claims] 1. A magnetic recording and reproducing device that selectively uses different types of tape cassettes in which tapes of different lengths are housed in the same cassette housing, (1) (2) detecting means for detecting the running direction of the tape and the number of rotations n of the reel and outputting it as binary digital data; thickness t
(3) condition setting means for outputting each binary coded digital data indicating the conditions of the radius r_0 of the reel and the total length L of the tape as necessary; and (3) the data of the rotation speed n is inputted from the detection means. , the thickness t of the tape from the condition setting means
Read the data of , reel radius r_0, set these as constants, and set the data of the input rotation speed n as a variable.
1. A tape amount calculation device comprising: first calculation means for calculating an approximate running length l of the tape using a square function of tn^2+(2πr_0+πt)n. 2. In a magnetic recording and reproducing device that selectively uses different types of tape cassettes in which tapes of different lengths are housed in the same cassette housing, (1) the running direction of the tape in the tape cassette; (2) detecting means for detecting the rotational speed n of the reel and outputting it as binary digital data; and (2) detecting the tape running speed S and the tape thickness t according to the type of the selected tape cassette.
, a condition setting means for outputting each binary coded digital data indicating the conditions of the reel radius r_0 and the tape total length L as necessary; (3) the data of the rotation speed n is inputted from the detection means; The data of the tape thickness t and the reel radius r_0 are read from the condition setting means, and these are set as constants, and the data of the input rotation speed n is set as a variable.
A first calculating means that calculates the approximate running length l of the tape using the square function of n^2+(2πr_0+πt)n, and (4) data of the tape running length l calculated by this first calculating means is input. and a second calculation means for reading data on the tape speed S from the condition setting means and dividing the data on the tape running length l by the tape speed S to calculate the elapsed time of the used tape. A tape amount calculation device characterized by: 3. In a magnetic recording and reproducing device that selectively uses different types of tape cassettes in which tapes of different lengths are housed in the same cassette housing, (1) the running direction of the tape in the tape cassette; (2) detecting means for detecting the rotational speed n of the reel and outputting it as binary digital data; and (2) detecting the tape running speed S and the tape thickness t according to the type of the selected tape cassette.
, a condition setting means for outputting each binary coded digital data indicating the conditions of the reel radius r_0 and the tape total length L as necessary; (3) the data of the rotation speed n is inputted from the detection means; The data of the tape thickness t and the reel radius r_0 are read from the condition setting means, and these are set as constants, and the data of the input rotation speed n is set as a variable.
A first calculating means that calculates the approximate running length l of the tape using the square function of n^2+(2πr_0+πt)n, and (4) data of the tape running length l calculated by this first calculating means is input. and a third calculating means for reading out the data of the tape total length L from the condition setting means and subtracting it with the data of the tape running length l to calculate the remaining length of the tape. Tape amount calculation device. 4. In a magnetic recording and reproducing device that selectively uses different types of tape cassettes in which tapes of different lengths are housed in the same cassette housing, (1) the running direction of the tape in the tape cassette; (2) detecting means for detecting the rotational speed n of the reel and outputting it as binary digital data; and (2) detecting the tape running speed S and the tape thickness t according to the type of the selected tape cassette.
, a condition setting means for outputting each binary coded digital data indicating the conditions of the reel radius r_0 and the tape total length L as necessary; (3) the data of the rotation speed n is inputted from the detection means; The data of the tape thickness t and the reel radius r_0 are read from the condition setting means, and these are set as constants, and the data of the input rotation speed n is set as a variable.
A first calculating means that calculates the approximate running length l of the tape using the square function of n^2+(2πr_0+πt)n, and (4) data of the tape running length l calculated by this first calculating means is input. (5) a third calculating means reads out data of the tape total length L from the condition setting means and subtracts it with data of the tape running length l to calculate the remaining length of the tape;
The data of the tape remaining length calculated by the third calculation means is input, the data of the tape speed S is read from the condition setting means, and the data of the tape remaining length is divided by the tape speed S. A tape amount calculation device comprising: fourth calculation means for calculating remaining tape amount time.