JPS6051183B2 - Electronic tape counter device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic tape counter device that can reliably display the absolute position based on elapsed time even when a partially wound cassette tape is set.

Many kinds of recorded contents are arranged at different positions on a single magnetic tape, and if you want to quickly obtain these recorded contents, it is convenient to know the position on the magnetic tape in advance. be.

For this reason, general tape recorders are provided with a mechanical tape counter, and the position on the magnetic tape is confirmed by the count value of this tape counter, and the recorded contents are made to correspond to each other. However, conventional tape counters count the number of rotations of the reel, and since the winding diameter differs when the magnetic tape starts and finishes winding on the reel, the actual running distance of the magnetic tape and the tape counter value are different. The relationship with the count value is expressed nonlinearly. Therefore, there is a method of mechanically or electronically displaying an amount proportional to the rotation speed of the supply reel or take-up reel, or one of the supply reel or take-up reel, or the supply reel and take-up reel. The rotation period or rotation speed of both are detected, and a calculation circuit such as a microcomputer performs certain calculations.
A method of displaying the amount of tape running or remaining amount has been proposed. However, since the former method does not display a value proportional to the amount of tape travel, it can only be used as a guideline. Furthermore, if the cassette tape is reset midway, or if a cassette tape is loaded midway through, the absolute position of the tape may no longer be known. Furthermore, the latter method has the disadvantage that the mechanism for detecting the rotation of both reels is extremely complicated, making it impractical.

Furthermore, when the rotation of one reel is detected, if a cassette tape is loaded from the middle, the tape position from the start of the tape to when the cassette is loaded, that is, the absolute position relative to the tape, cannot be determined. have. In view of the above points, the present invention has been made to solve such problems and eliminate such drawbacks.The purpose of the present invention is to have a simple structure so that even when a cassette tape is loaded from the middle, the tape can be easily removed. It is possible to reliably determine the absolute position of the tape, and it is also possible to remeasure and recalculate as many times as desired at any timing during recording/playback, and to calculate the running time based on the unevenness of the number of tape turns N. If the deviation can be adjusted as desired, and the running time display before and after zero reset is the same, then
It is an object of the present invention to provide an electronic tape counter device that can confirm that an accurate running time is displayed and can also determine the running time from the beginning of the tape to the current position.

To achieve this purpose, the electronic! The tape counter device includes a measuring means for measuring the rotation period 1/R (rotation speed R) of the take-up reel of the cassette tape;
a counting means for counting the rotational pulses of the take-up reel of the cassette tape and outputting the number of tape turns n (n: an integer); a zero resetting means for resetting the force counting means to zero; and a zero resetting means for resetting the force counting means to zero. Using the information from the measuring means at the time of reset and predetermined constants A and B taken out depending on the type of cassette tape, the number of tape turns 4n on the take-up reel at the time of zero reset is calculated based on the formula: means for storing the number of tape rolls n calculated by the means in the counting means which has been reset to zero; and a calculation display means for calculating and displaying the running time t of the tape from the tape starting edge based on an arithmetic formula of is calculated and displayed.

Embodiments of the present invention will be described below based on the drawings. first,
Before describing the embodiments, in order to facilitate understanding of the present invention, detection of the traveling time of the cassette tape from the tape starting end and the number of tape windings will be described.

First, as shown in Figure 1, the radius of the hub is R.

, the thickness of the tape is d1 When the tape is wound n times on the take-up reel, the length f1 of the outer magnetic tape can be expressed by equation (1). Therefore, the total length l of the magnetic tape when it is wound n times can be expressed by equation (2).

Here, RO＞? Therefore, equation (2) can be expressed as equation (3).

Then, the magnetic tape moves at a constant speed V in the X direction.

When the vehicle is traveling at 1, the travel time t from the start of winding to the present can be expressed by equation (4). In this formula (4), A=7Td/■o (constant), B=2πRO/VO
(constant), this equation (4) can be expressed as equation (5).

Note that A is determined by the tape thickness d and tape speed VO, and B is the radius R of the hub.

and tape speed■. It is a constant determined by .

As an example, RO=11.0m1r1, V0=47.6
Order/S,B=1.452s,d(Pm) is C45 and C6O and *3 is 1F! F. 12 for C9O, Cl2O
So it's 9. Here, the constants A and B at the standard value
The calculated values are shown in Table 1 below. Therefore, since the constant B is constant regardless of the type of cassette tape, it is sufficient to store this value in advance. Further, the constant A is caused by the difference in the thickness dimension d of the tape depending on the type of cassette tape, and by specifying the type of cassette tape, the constant A for each cassette stored in advance can be read out. Alternatively, the tape thickness dimension d for each cassette type is stored in advance, and by specifying the cassette type, the corresponding dimension d is read out and the above-mentioned A=no? and calculate the constant A
can be found. Next, the rotational speed (R) of the take-up reel can be determined by differentiating n in Equation (4) with respect to t, as shown in Equation (6).

Therefore, if we install a partially wound cassette tape, operate it in steady running mode, that is, in recording or playback mode, and find the rotational speed ■R at the start of rotation of the take-up reel, then From the equation, the number n of tape windings on the take-up reel at that point can be determined as shown in equation (7).

Once the constants A, B and the number of turns n have been determined in this way, by substituting these values into Equation (5) and calculating them, it is possible to calculate It is possible to calculate the travel time up to the present moment.

Then, for subsequent tape runs, the (5th
) By calculating the equation, the running time corresponding to the absolute position of the cassette tape can be obtained, and even when the running state of the tape changes to rewinding, fast forwarding, etc., the running time corresponding to the absolute position of the cassette tape can be calculated. is determined accurately. Next, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram showing an embodiment of the electronic tape counter device according to the present invention.

In the same figure, 1 is a supply side reel, 2 is a take-up side reel,
3 is a magnetic tape, 4a and 4b are guides, 5 is a cassette tape, 6 is a reel rotating shaft on the take-up side, 7 is a rotating body 8 attached to this reel rotating shaft 6, and a mark on this rotating body 8 is magnetically set. A rotation detector consisting of a detection element 9 that detects optically or mechanically and outputs a rotation detection pulse and a rotation direction signal, and the period of this rotation detection pulse is directly proportional to the rotation period of the take-up reel 2. It is. 10 is a rotation period detection unit that detects the rotation period by inputting this rotation detection pulse, 11 is a counter unit that adds or subtracts this rotation detection pulse in accordance with the rotation direction signal, and 12 is operated when the magnetic tape 3 starts winding. and a count reset key for resetting the count value of the counter section 11; 13 is an arithmetic section for calculating the constant A and calculating the equation (5); 14;
is equipped with a movable contact 14a1'' and fixed contacts 14b1 and 14c, and when the movable contact 14a contacts the fixed contact 14b, the travel time is displayed, and when the movable contact 14a contacts the fixed contact 14c, the approximate travel distance is displayed. The key 15 is a display that displays the amount of travel or time of travel.

16 is a select switch that instructs the calculation unit 13 about the type of tape to be used; the movable contact 16a is connected to the fixed contact 1;
When connected to 6b, C6O is specified, when connected to fixed contact 16c, C9O is specified, and when connected to fixed contact 16d, Cl2O is specified.

Next, the operation of the circuit with the above configuration will be explained. First, the arithmetic unit 13 stores in advance the above-mentioned constant B1, that is, the value B=1.452 shown in Table 1, and the tape thickness dimension d for various cassette tapes.
is stored in advance, and by specifying the type of cassette tape with the select switch 16, the corresponding value d is read out and the constant A is calculated.

Next, when a partially wound C6O cassette tape is installed and the movable contact 16a of the select switch 16 is connected to the fixed contact 16b, the calculation section 13 calculates that A=te! is calculated, and this calculated constant A is held. Next, when the count reset key 12 is operated, the contents of the counter section 11 are reset to zero. Next, when the cassette tape is driven at a constant speed, that is, set to playback or recording mode, the rotating body 8 of the rotation detector 7 rotates in response to the rotation of the take-up reel 2 of the cassette tape 5. Along with this, the detection element 9 outputs a rotation detection signal and a rotation direction signal. On the other hand, the rotation period detection section 10 receives the rotation detection signal supplied from the detection element 9 as input, detects the rotation speed (period) (R) of the take-up reel 2, and outputs the detected rotation speed (period). When the arithmetic unit 13 receives the rotation speed signal 8 which is first output from the rotation period detection unit 10 after the reset operation, it reads out the pre-stored constant B and the previously calculated constant B, and calculates the By calculating equation (7), the number n of tapes wound around the take-up reel 2 at the start of running after the reset operation is calculated. The number of turns n thus calculated is set in the counter section 11. Then, when the cassette tape continues to run, this counter section 11 detects the amount of data supplied from the detection element 9. The detected rotation detection signals are sequentially added and subtracted in correspondence with the rotation direction signals.

Therefore, the counter section 11 is set to the number n of windings of the take-up reel 2, which is halfway wound, at the start of tape running after the reset operation, and thereafter corresponds to the running of the tape! The number of windings on the take-up reel 2 is sequentially added and subtracted, and accordingly, the counter section 11 represents the number n of windings on the take-up reel 2 from the start of the cassette tape. . Therefore, the movable contact 14a of the switching key 14 is connected to the fixed contact 1 as shown by the dotted line.
When connected to the cassette tape 4c side, the integrated value of the counter section 11 is displayed on the display 15 as a reference value corresponding to the running distance of the cassette tape from the start. Next, when the movable contact 14a of the switching key 14 is switched to the fixed contact 14b, the calculation section 13 is operated in conjunction with this operation.

Then, this calculation unit 13 stores a pre-stored constant B,
Using the previously calculated constant A and the current winding number n of the take-up reel 2, which is indicated by the integrated value of the counter section 11, the operation shown in equation (5) is performed to calculate the running time t,
The absolute value of the running time t for the cassette tape is displayed on the display 15. As is clear from the foregoing, the present invention enables re-measurement and re-calculation as many times as desired at any timing during recording and playback. This is done at the reset timing, and the tape counter is re-measured and re-calculated to re-set the number of tape windings, so any discrepancies in running time due to irregularities in the number of subsequent tape windings can be avoided. It can be corrected as desired, and if the running time display before and after the zero reset is the same, it can be confirmed that the accurate running time is displayed.

In addition, the running time from the tape start to the current position can be determined by adding the measured number of turns of the tape from the start of the tape to the specific position based on the measurement calculation. In the above embodiment, the case where the thickness dimension d of the corresponding tape is read out by specifying the type of cassette tape and the constant A is calculated using this value d was explained. Constant A corresponding to the type of tape
may be stored in advance, and the corresponding constant A may be directly read out in accordance with the designation of the type of cassette.

In addition, in the above explanation, the case where the value n calculated by the calculation unit 13 is set in the counter unit 11 was explained, but the calculated value n is stored in the memory and read out when calculating the travel time and used as a counter. The travel time may be calculated using the value added to the value after the reset operation in the section 11. However, in this case, the value of the counter section 11 represents the amount of tape travel after the reset operation. Furthermore, the M portion indicated by points in FIG. 2 can be replaced with a microcomputer. As is clear from the above description, according to the present invention,
With a simple configuration that detects the rotational speed (period) of the take-up reel without using complicated means, it can maintain a constant speed even if it is reset midway or a partially wound cassette tape is loaded. Once running, the absolute position of the cassette tape based on the elapsed time can be accurately displayed even if the running is changed such as fast forwarding or rewinding. It is possible to perform re-measurement and re-calculation at any time, and also to arbitrarily correct any discrepancies in running time due to irregularities in the number of tape wraps, and the running time display is the same before and after resetting to zero. If so, you can confirm that the accurate running time is displayed, and also add the actual number of tape wraps from the tape start to the current position to the number of tape wraps from the tape start to the specific position based on the measurement calculation. Since the running time can be determined, the practical effect is extremely large.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the relationship between a magnetic tape and a take-up reel, and FIG. 2 is a block diagram showing an embodiment of an electronic tape counter device according to the present invention. 1... Supply side reel, 2... Take-up side reel, 3... Magnetic tape, 4a and 4b...
...Guide, 5...Cassette tape, 6...
・Reel rotation axis, 7...Rotation detector, 8...
...Rotating body, 9...Detection element, 10...
...Rotation period detection section, 11... Counter section, 12
... Count reset key, 13 ... Calculation unit, 14 ... Switching key, 14a ... Movable contact, 14b and 14c ... Fixed contact, 1
5...Display section, 16...Select switch.

Claims (1)

[Claims] 1 Rotation period 1/V of the take-up reel of the cassette tape
a measuring means for measuring R (rotational speed V_R); a counting means for counting rotational pulses of the take-up reel of the cassette tape and outputting the number of tape turns n (n: integer);
a zero reset means for resetting the counting means to zero;
The number of tape turns n on the take-up reel at the time of the zero reset is determined by using the information from the measuring means and the predetermined constants A and B taken out depending on the type of cassette tape at the time of the zero reset of the zero reset means. 1/2A・(1/
V_R-B); means for storing the number of tape rolls n calculated by this means in the counting means reset to zero; and information from the counting means after being reset to zero. and the constants A and B, the running time t of the cassette tape from the tape starting end is calculated as t=An
and a calculation display means that calculates and displays the calculation based on the calculation formula ^2+B_n, and cooperates with the operation of the zero reset means to calculate and display the running time of the cassette tape from the beginning of the tape. An electronic tape counter device featuring: