JPS5827592B2 - Tape remaining amount display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape remaining amount display device for displaying the remaining amount of tape wound on a reel used in a tape recorder, etc., and particularly to a tape remaining amount display device for displaying the remaining amount of tape wound on a reel. The present invention relates to a tape remaining amount display device that can display the remaining amount of tape.

In tape recorders and the like, there are many cases where it is desired to accurately know the remaining amount of tape used.

For example, if you know the time of the source you are trying to record, it is important to know whether the partially used tape has enough remaining capacity to completely record the source. .

Conventionally, methods for checking the amount of tape include visual inspection and displaying the amount of travel using a tape counter, but neither of these methods is very suitable as a means of accurately recognizing the remaining amount of tape that has been used up to the point described above. Ta.

In addition, there are conventional devices that detect the rotational speed of the tape reel and display the remaining amount of tape by swinging a meter or other device based on that information, but they are not yet satisfactory in terms of accuracy. There wasn't.

Furthermore, by counting the number of reference pulses generated from the reference oscillator during one revolution of the reel shaft, the current absolute position of the tape can be determined, and the above-mentioned counting is performed every time the reel shaft rotates. This makes it possible to display the position according to the tape running.

However, such a method has the disadvantage that sequential display may not be possible due to errors such as uneven rotation of the reel shaft or variations in tape thickness, giving the user a sense of discomfort.

The present invention has been made in view of the above-mentioned points, and it is an object of the present invention to provide a digital tape remaining amount display device that can accurately display the remaining amount of tape.

In a tape recorder or the like, the rotation period of a tape reel changes depending on the amount of tape wound around the tape reel.

The rotation period t can be expressed as follows, where V is the playback speed of the tape and the winding diameter φ of the tape.

Also, the relationship with the diameter φ is Number of windings of remaining tape N and winding The diameter of the knoll is M, the thickness of the tape I'm H and I'm becomes.

Therefore, the number of turns N is given by the formula: Equation (1) and (2) becomes.

Also, the relationship between the length L of the remaining tape and the number of windings N is: Then, The relationship between the remaining time T and the number of windings N is becomes.

For example, for cassette tape recorder tape specified by C-60, H=20 (μm)
, M = 21.85 (mm), ■47.5 (mm),
Therefore, the number of remaining windings N and the remaining time T are N=378 (t-1,445), respectively.
・・・・・・(6) T=0.0013N2+1.444
2N・・・・・・・・・・・・(7)

Therefore, theoretically, if the rotation period t of the tape reel is known, the number of remaining turns N and the remaining time T can be calculated.

The present invention calculates the number of remaining windings N or the remaining time T based on the above-mentioned principle, and displays the calculated value.The present invention will be described below based on an embodiment with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, in which 1 is a pulse generation circuit for generating pulses according to the rotational speed of a tape reel around which tape is wound, and 2 is an output of the pulse generation circuit. A gate circuit for generating a gate signal from a signal, 3 an oscillator for generating a signal of a constant frequency, 4 performing initial value setting counting using the output signal of the gate circuit 2 and the output signal of the oscillator 3. and a counting circuit 5 that performs addition/subtraction counting using the output signal of the pulse generating circuit 1.
is a control circuit that generates a control signal for determining whether the counting circuit 4 performs initial value setting counting or addition/subtraction counting;
6 is a switching signal generation circuit for switching the counting circuit 4 to an addition state or a subtraction state, and 7 is a display circuit driven to 1 by the output signal of the counting circuit 4.

Therefore, to explain the details and operation of the circuit shown in FIG.
The pulse generating circuit 1 is for generating pulses at intervals corresponding to the rotation period of the tape reel, and includes a reed switch 8 which is opened and closed by a magnet fixed to the shaft of the tape reel, etc., as shown in FIG. , the AND circuit 9 and the inverter 10, and the monostable multivib break 11.

In the AND circuit 9, the output terminal X becomes the rLJ signal only when the rH1 signal is applied to both input terminals -FA and B. Normally, the signals at the input terminals A and B are both l'-
Hj, the signal at the output terminal X is "L", and the output of the inverter 10 is "H".

When the reed switch 8 is closed by the magnet, the input terminal A becomes an "L" signal and the output terminal output is “H”
This state continues until it reverses.

Therefore, the signal obtained at the output terminal of the inverter 10 is
It will look like Figure A.

The period during which the output signal of the inverter 10 is "L" is approximately 0.3 milliJ seconds.

The gate circuit 2 is for creating a gate signal using the output signal of the pulse generating circuit 1, and as shown in FIG. , and an OR circuit 15 to which the outputs of the bistable multi-bibreaks 13 and 14 are applied.

The first monostable multi-byte break 13 generates an output signal of rLJ at the moment when the output signal of the pulse generation circuit 1 becomes "■7", returns to rHJ after a predetermined period of time, and outputs the output signal of the second monostable multi-byte break 13. The break 14 generates an "L" output signal at the moment the output signal of the first monostable multi-bi break 13 becomes rHJ, and after a predetermined time elapses, it outputs an "L" output signal.
Return to J.

Therefore, the above-mentioned bistable multi-by-breaks 13 and 14
The output signal of the OR circuit 15 to which the output signal of is applied is, as shown at the beginning of Figure 2, the time of the rL1 part is constant and the "H" part A
The time becomes a rectangular wave that changes according to the rotation period t of the reel.

In the present invention, a gate circuit is used in which two monostable multi-by-breaks are used and their outputs are combined by an OR circuit.
■This is to keep the period of the "7" portion constant.

The oscillator 3 is for generating an output signal of a constant frequency. For example, when a C-60 tape is used, the frequency is 378 Hz based on equation 6.

By the way, when using C-90 tape, 567Hz,
When using C-120 tape, the frequency is 756 Hz.

The purpose of using such a frequency is to facilitate counting in the counting circuit in the subsequent stage.By setting the frequency as described above, the oscillator output signal during initial value setting counting in the counting circuit and the pulse generation during addition/subtraction counting It becomes possible to handle circuit output signals equally.

The output signal of the oscillator 3 is shown in FIG. 2C.

The control circuit 5 counts the output signal of the pulse generating circuit 1, generates rLJ as an output signal during the first few pulses, causes the counting circuit 4 to perform initial value setting counting, and thereafter outputs rHJ as an output signal. is generated to cause the counting circuit 4 to perform addition/subtraction counting.

Since the embodiment shown in FIG. 5 uses a quinary counter 16, it generates "L" as an output signal while counting the first four pulses, and generates rHJ after the end of the fourth pulse. being intimidated.

The control circuit 5 will be explained in more detail with reference to FIG.

The input terminal of the control circuit 5 is one input terminal A of the AND circuit 17, and the input terminal A is connected to the output terminal of the pulse generation circuit 1 via the mode changeover switch 18.

The mode switch 18 is provided based on the design concept of the present invention in which initial value counting is performed only during recording and playback, and is switched in conjunction with the operation button of the tape recorder.

Terminal E of the quinary counter 16 is a set terminal, and a reset signal is applied when the power is turned on or when the eject switch 19 is operated in conjunction with the operation of the eject button, and output terminal B is set to "■7" and output terminal C is set to "7". rLJ, keep the output terminal in the "H" state.

Next, the operation will be explained. When the mode selector switch 18 is in the position shown in the figure in the recording/playback state and the counter 16 is reset, the input terminal B of the AND circuit 17 is
Hl, input terminal A is also rHJ, output terminal 2 of control circuit 5
At 0, an "H" signal appears.

When the first pulse is applied, an "L" signal appears at the output terminal and D are rLlrLl and r, respectively.
It becomes Ll.

Therefore, the output signal of the AND circuit 21 is "H", the output signal of the inverter 22 is 1-HJ, and the output signal of the OR circuit 23 is "L".

Therefore, the counting circuit 4 at the subsequent stage enters the initial value setting counting state.

When the second pulse is applied, since both the input signals of the AND circuit 17 are "H", rLJ is applied to the input terminal of the counter 16, and the counter 16 steps forward, and the output terminal B of the counter 16 is incremented.

rHJrLj and "L" signals are derived at C and D,
The rH1 signal is sent to the output terminal of the AND circuit 21, and the rH1 signal is sent to the output terminal 2 of the AND circuit 21.
At 0, the rLJ signal appears.

When the third pulse is applied, the signals at the output terminals B, C and D of the counter 16 become rLJrHJ and rLJ, and the same <"L j signal is derived at the output terminal 20.

When the fourth pulse is applied, the signals at the output terminals B, C, and D of the counter 16 become rHJrHJ and rLJ, and the rLJ signal appears at the output terminal of the AND circuit 21 and the input terminal B of the AND circuit 17. The rHJ signal appears at the output terminal of the inverter 22, and the output signal of the OR circuit 23 is switched to "H".

For the fifth and subsequent pulse applications, the AND circuit 17
Since the signal at input terminal B of is r L J, the AND
Only the rHJ signal appears at the output terminal X of the circuit 17, which cannot serve as a step signal for the counter 16.
6 does not operate, and the output terminal 20 continues to receive the "I-(J" signal.

The output signal of the control circuit 5 is shown in FIG. 2, in which the counter 16 remains in the same state unless the power is turned off and then turned on again or reset by pressing the eject button.

Whether or not the output signal is kept at "L" from the beginning until the next pulse is arbitrarily set depending on the design of the circuit.

The counting circuit 4 performs initial value setting counting or addition/subtraction counting in accordance with the output signal of the control circuit 5.

Now, if the output signal of the control circuit 5 is "L", then
The counting circuit 4 performs initial value setting counting using the output signal of the gate circuit 2 and the output signal of the oscillator 3.

That is, the initial value is determined depending on whether a cycle of the oscillator output occurs during the gate period A at the beginning of FIG.

The frequency of the output signal of the oscillator 3 is determined by Equation 6, and is set so that the number of cycles entering the gate period A is equal to the number N of remaining turns.

Therefore, if the number of cycles is counted by the counting circuit 4 and displayed by the display circuit 7, the remaining number of turns N is displayed.

Further, if the output signal of the control circuit 5 is rHJ, the output signal of the pulse generation circuit 1 is used for addition/subtraction counting.

That is, by adding or subtracting pulses one by one from the count state counted by the initial value setting counter, the tape movement state after the initial value setting is transmitted to the counting circuit, and a display according to each state can be performed. I can do it.

Since the addition/subtraction counter simply counts the number of pulses and adds or subtracts them from the initial value, it is possible to count whether the tape recorder is in fast forward or rewind mode, and this is one of the features of the present invention. This is a characteristic point.

The counting circuit 4 includes a signal selection circuit as shown in FIG. 6 at its input section.

In FIG. 6, the first AND circuit 24 has three input terminals A, B and C, the input terminal A is connected to the oscillator 3, the input terminal B is connected to the gate circuit 2, and the input terminal C is connected to the impark 25. It is connected to the control circuit 5 via.

Further, the second AND circuit 26 connects the input terminal A to the control circuit 5,
The input terminal B is connected to the pulse generation circuit 1, and the first
The output terminals of the second AND circuits 24 and 26 are connected to input terminals A and B of an OR circuit 27.

The output terminal X of the OR circuit 27 is connected to a counter 28.

Therefore, if it is now the initial value setting counting state, the rHJ signal is applied from the control circuit 5 to the input terminal C of the first AND circuit 24 via the impark 25.

When the output signal of the gate circuit 2 becomes rHJ in this state,
According to the output signal of the oscillator 3, the first AND circuit 24 alternately derives the rHJ signal and the "L" signal.

On the other hand, since the input terminal A of the second AND circuit 26 is directly connected to the output terminal of the control circuit 5, the "■7" state is maintained, and the output terminal of the second AND circuit 26 is always "H".
A signal is derived.

Therefore, an "H" or rLl signal corresponding to the output signal of the oscillator 3 is derived from the output terminal of the OR circuit 27, and is applied to the counter 28, so that the counter 28 performs counting, and the remaining number of turns is N. Remember how many.

While the output signal of the control circuit 5 is rLl, the gate signal is applied to the input terminal H of the three-fine LAND circuit 24.

Therefore, initial value setting counting is performed three times, and accurate counting can be performed.

Next, addition/subtraction counting will be explained.

If it is in the addition/subtraction counting state, the output signal of the control circuit 5 will be "H", and the input terminal C of the first AND circuit 24 will be "H".
The rH signal is input to the input terminal A of the second AND circuit 26.
J signal is applied.

Therefore, the output signal of the first AND circuit 24 is always rHl, and the second AND circuit 26 generates an "L" signal when the output signal from the pulse generation circuit 1 is applied.

Therefore, the output signal of the OR circuit 27 becomes rHJ only when there is an output from the pulse generating circuit 1, and the counter 28 is incremented.

The counter 28 may be of a general type, and it can count up in 1 or 1 by applying one pulse.
It counts down.

Whether the counter 28 is in an up-counting state or a down-counting state is set by an output signal from a switching signal generating circuit 6, which will be described later.

The output signal of the OR circuit 27 is shown in FIG.

The switching signal generating circuit 6 is connected to the counter 28 of the counting circuit 4.
is set to an up-counting state during initial value setting counting and when the tape recorder is in a rewinding state, and is set to a down-counting state when the output signal of the control circuit 5 is rHJ in the recording/playback state and when the tape recorder is in a fast forward state. This is for setting the state.

As shown in FIG.
It consists of an R circuit 29 and a switch 30 that is linked to a rewind button, and the input terminal A of the OR circuit 29 is connected to the output terminal of the control circuit 5, and the input terminal B is grounded via the switch 30. At the same time, it is connected to a power source via a resistor 31.

Further, the output terminal B of the OR circuit 29 is connected to the up/down control terminal (U/D) of the counter 28 of the counting circuit 4.

The control terminal (U/D) of the counter 28 is set to count up when the rH1 signal is applied and to count down when the rLJ signal is applied.

If the counting circuit 4 is currently performing initial value setting counting, the output signal of the control circuit 5 is rLJ, so the rLJ signal is input to the input terminal A of the OR circuit 29, and the rH signal is input to the input terminal B from the power supply.
J signal is applied.

Therefore, the output signal of the OR circuit 29 becomes "H", and the counter 28 is set to an up-counting state.

Next, if rewinding is in progress, the output signal of the control circuit 5 is "H", so the input terminal A of the OR circuit 29 is "H".
Since the switch 30 is closed, the "H" signal is applied to the input terminal B, and the "L" signal is applied to the input terminal B, the output signal of the OR circuit 29 becomes "H", and the counter 28 is set to an up-counting state.

Also, if it is in the recording and playback state after initial value counting is completed, O
An "H" signal is input to the input terminal A of the R circuit 29, and an "H" signal is input to the input terminal B of the R circuit 29.
An "H" signal is also applied to the OR circuit 29, the output signal of the OR circuit 29 becomes "L", and the counter 28 is set to a down-counting state.

Furthermore, if fast forwarding is in progress, the rHJ signal is similarly applied to both input terminals AB of the OR circuit 29, and the counter 28
is set to a down count state.

The output signal of the switching signal generating circuit 6 is shown in FIG.

Finally, the display circuit 7 will be explained.

As described above, the necessary signals have been obtained and the necessary information has been accumulated in the counter 28 of the counting circuit 4, but this must be transmitted to a display element (for example, a neon tube or a light emitting diode) for display. .

The information stored in the counter 28 of the counting circuit 4 is as follows:
The remaining number of turns is N, and when displayed, the remaining number of turns is N.
Directly displaying the number of remaining turns N as the remaining time Tl
There is a method to convert this and then display it.

First, a case where the remaining number of turns N is directly displayed will be explained.

For example, in the case of tapes for tape recorders, C-60 is approximately 742 times, C-90 is approximately 1113 times, and C-120 is approximately 1 time.
It is wound 484 times.

Therefore, the display circuit 7 and the counting circuit 4 are required for four digits.

FIG. 8 shows an example of displaying the remaining number of turns N, and shows elements for counting 32, 33, 34, 10's, and 1's digits.

35 is the 1000's digit and the 100's digit of the counter 28, and 36 is a first conversion circuit that converts the signal of the element 32 for counting the 1000's digit into an input signal of the display element 37 indicating the 1000's digit; 38 Similarly, numeral 39 is a converting circuit for the 100's digit, 40 is a converting circuit for the 1's digit, and the elements 36, 38, 39 and 4 of the power wand 28 are connected to each other.
Display elements 37, 41, and 4 output 4 bits of 0, respectively.
Convert to 7 output signals suitable for 2 and 43.

As shown in FIG. 8, if the remaining number of turns N is to be displayed, the output of the counter 28 can be used as is, so the display can be done very easily.

If a conversion table of the number of remaining windings N to the remaining time T is provided separately, the remaining time T can be displayed accurately.

Further, by using the present invention, it is also possible to directly display the remaining time instead of displaying the remaining number of windings N.

The remaining number of turns N and the remaining time T have a relationship as shown in Equation 7, so they do not correspond linearly.

Therefore, by dividing the whole into multiple parts and linearly approximating each part, the number of remaining turns N and the remaining time T
It is possible to make them correspond.

That is, as shown in Fig. 9, for curve A shown in equation 7, range A is approximated by a straight line, range B is approximated by a straight line, range C is approximated by a straight line 2, and range 1 is approximated by a straight line H. Accordingly, the remaining time can be displayed on the display element of the display circuit 7.

Specifically, the signal counted by the counting circuit 4 in FIG. 1 may be divided into 6 or 3 parts and applied to the remaining time display circuit in units of 10 seconds.

Table 1 shows the relationship between the number of remaining turns N and the remaining time T in each range shown in FIG.

Based on Table 1, when the actual circuit was set and displayed, the time errors were all within 1 minute, so it can be said that the display function is sufficient for practical use.

Table 1 above is for the tape recorder tape C-60, and if similar linear approximation is performed for C-90 and C-120, the remaining time can be displayed very accurately.

The circuit for displaying the remaining time is shown in a block diagram as shown in FIG.

In FIG. 10, 44 is a divider which outputs one pulse for every plurality of manual pulses.

The divider 44 can be switched into four stages: 6 divisions, 5 divisions, 4 divisions, and 3 divisions.

Further, 45 is a counter for 10 seconds, 46 is a counter for 1 minute, and 47 is a counter for 10 minutes, with counting elements 48, 40 and 50 and display elements 51, 52 and 53, respectively.
has.

The division ratio of the divider 44 is switched by control signals obtained from the one-minute counter 46 and tenths-place counter 47, and the division ratio is changed depending on the number of remaining turns N as shown in Table 1. Can be switched.

As described above, the tape remaining amount display device according to the present invention includes:
The remaining amount of tape can be displayed accurately digitally.
This is very effective when checking the remaining capacity of a partially used tape.

Furthermore, by using the tape remaining amount display device according to the present invention and also using a preset device and an automatic stop device, it is possible to stop the running of the tape at a desired position, and it can be used for various purposes such as cueing. It is.

In particular, the tape remaining amount display device according to the present invention is excellent in that it can perform counting even during fast forwarding and reversing, which is an unprecedented function.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the tape remaining amount display device according to the present invention, FIG. 2 is a characteristic diagram showing waveforms of each part thereof, and FIG. 3 is a circuit diagram showing an example of a pulse generation circuit. Fourth
The figure is a circuit diagram showing an example of a gate signal generation circuit, Fig. 5 is a circuit diagram showing an example of a control circuit, Fig. 6 is a circuit diagram showing an example of an input stage of a counting circuit, and Fig. 7 is an example of a switching circuit. 8 is a circuit diagram showing an example of a display circuit, FIG. 9 is a characteristic diagram showing the relationship between the number of remaining turns N and the remaining time T, and FIG. 10 is a circuit diagram showing an example of a display circuit. It is a block diagram. Explanation of main drawing numbers, 1...Pulse generation circuit, 2.
...Gate circuit, 3...Oscillation circuit, 4.
... Counting circuit, 5 ... Control circuit, 6 ...
...Switching signal generation circuit, 7...Display circuit.

Claims (1)

[Claims] 1. A panus generation circuit that generates pulses at intervals corresponding to the rotation period of the tape reel around which the tape is wound, a gate circuit that generates a gate signal by shaping the output signal of the pulse generation circuit, and a constant frequency pulse generation circuit. an oscillator that generates a signal; a control circuit that generates a control signal; and a control circuit that generates a control signal;
state, initial value setting counting is performed using the output signal of the gate circuit and the output signal of the oscillator, and the control signal is
a counting circuit that performs addition/subtraction counting using the output signal of the pulse generating circuit when in the state, a switching circuit that switches the counting circuit to an addition state or a subtraction state, and a display circuit that is driven by the output signal of the counting circuit. A tape remaining amount display device comprising: