JPS6161181B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotational state detection device for detecting the rotational state of an electronic device having a rotating body, such as a magnetic recording/playback device.

[Technical background]

To detect the end of a tape in a magnetic recording/playback device such as a cassette tape recorder, the reel shaft in the running direction is moved by the pulling force at the end of the tape. This is done by operating switching means. However, it is not desirable to provide such a complicated mechanism only for detecting the end of the tape, and such a mechanical means not only has a complicated structure but also requires difficult adjustment. Moreover, it is complicated and has a high failure rate due to aging, etc., and there is a risk of various problems such as accidents such as tape cutting or dropouts due to physical stretching of the tape.

In order to solve this drawback, a pulse generating means is provided that generates pulses as the rotating body rotates, and the pulse interval output from this pulse generating means is counted, and this counted value is set to a preset value. On the other hand, a rotational state detection device has been proposed that detects the rotational state of a rotating body by detecting a coincidence or an increase in the number of rotational states.

1 to 3 show an example in which this conventional detection device is applied to a cassette tape recorder.

Reference numeral 1 in FIG. 1 is a cassette tape, and this cassette tape 1 is mounted on a mounting section 2, and a pinch roller 42 and a pinch roller ₄₂ are rotatably pressed against a capstan shaft 41 that follows the rotation of a motor 3 by an interlocking mechanism to be described later. It is driven to travel by reel shafts 5 ₁ and 5 ₂ .
That is, the motor shaft of the motor 3 is provided with a first pulley 6 that is directly connected to the motor shaft.
This first pulley 6 transmits its rotational force via a belt 7 to a second pulley 9 which is coaxial with the flywheel 8 and the capstan shaft ₄₁ and has an integral structure. Further, an idler 10 is rotatably pressed against the flywheel 8, and a take-up reel 111, which is coaxial with the reel shaft ₅₁ and has an integral structure, is rotatably pressed against the idler ₁₀ . The rotation of the flywheel 8 is caused by the rotation of the reel shaft 5.
₁ has also been transmitted. Note that the take-up reel ₁₁₂ , which is provided coaxially with the reel shaft ₅₂ , is rotated in the opposite direction to the reel shaft ₅₁ by a mechanism that is substantially similar to the interlocking mechanism described above, although it is not particularly shown. ing. On the other hand, a third pulley 13 for rotationally driving a pulse generator 12, which will be described _later , is coaxially provided on the take-up reel 111.
4 to a fourth pulley 15 provided in the pulse generator 12. The pulse generator 12 is composed of a disc-shaped electrode 16 that is integrally constructed with the fourth pulley 15, and a detector 17 that elastically contacts the periphery of the disc-shaped electrode 16. . The disc-shaped electrode 16 has an insulating portion provided on a portion 16a of its periphery, and at least its periphery is conductive, and this conductive portion is grounded via the rotating shaft. There is. On the other hand, since the detector 17 is pulled up to a potential of +V (volts) via the resistor 18, the rotation of the disc-shaped electrode 16 causes the detector 17 to relatively slide on its periphery. Logic “1” (+
V) and logic "0" (ground) outputs are obtained. That is, this output is the insulation part 1 of the disc-shaped electrode 16.
It becomes "0" when the peripheral edge other than 6a (conductive) and the detector 17 are in contact with each other, and becomes "1" when the insulating part 16a and the detector 17 are in contact with each other. The output signal obtained from this detector 17 is input to a one-shot circuit 19 that detects a fall from logic "1" to "0" and generates a one-shot trigger pulse, and its output is clocked by the basic clock. The signal is input to a delayed flip-flop (hereinafter simply abbreviated as F/F) 21 which is read and controlled by the clock signal φ _B output from the generator 20. The F/F 21 holds its output for a period of one cycle of a counter 24, which will be described later, and its output is inputted to one input terminal of an AND gate 23 via an inverter 22.
This opening and closing is controlled. On the other hand, 24 counts the pulse interval output from the one-shot circuit 19, and includes a register 25 with "m-1" digits, and a "+1" circuit 26 with a delay time corresponding to one digit.
The output of register 25 is “+
The basic clock generator 2 is connected to one input of the ``1'' circuit 26 and to the other input of the ``+1'' circuit 26.
A clock signal φ _A output from 0 is applied. Therefore, the output of the counter 24, that is, "+
1'' circuit 26 is inputted again to the input terminal of the counter 24 (input terminal of the register 25) via the AND gate 23, and also inputted to one input terminal of the comparator circuit 27. The other input terminal of this comparison circuit 27 is given an output from a code generator 28 which outputs preset detection data in synchronization with the output timing of the counter 24. The counted value is compared with the data output from the code generator 28, and when it is detected that they match or the counted value of the counter 24 is larger, the output is outputted to R.
-S flip-flop (hereinafter simply abbreviated as R-SF/F) 29 is applied to the set terminal S. R-
An operation start signal output when the tape starts running is applied to the reset terminal R of the SF/F 29, and is set to the initial state. The output of the R-SF/F 29 is applied as a stop signal to the display processing circuit 30, and is also applied as a motor stop signal to the motor drive circuit 31. On the other hand, in addition to the stop signal, the display processing circuit 30 receives various information from an operation unit (not shown) and a travel distance counter (not shown) that counts the travel distance, and these signals and A numerical display that converts information into a display code as appropriate to display the amount of tape travel, etc., a running direction indicator mark "" that displays the running direction, a "STOP" mark that displays the stopped state,
Display device 3 such as a liquid crystal display device provided with various indicators such as a “REC” mark to display the recording status
It is sent to 2. In addition, motor drive circuit 3
1, in addition to the stop signal, high-speed/low-speed instruction signals such as play or fast forward instructed by the operation section are input, and the rotation, stop, speed, etc. of the motor 3 are controlled based on these signals. It's in control.

Next, the operation of the above configuration will be explained with reference to the time chart of FIG. 2. First, there is an instruction to run the tape from the operation section, and when the motor drive circuit 31 responds and drives the motor 3 as shown in FIG. 2a, an operation start signal is output as shown in FIG. As shown in Figure d, R-
SF/F29 is reset. On the other hand, the pulse generator 12 outputs a pulse synchronized with the rotation of the reel shaft ₅₁ at time T1 shown in FIG. ₂ , and the one-shot circuit 19 outputs a one-shot pulse as shown in FIG. 2b. Ru. The output of this one-shot circuit 19 is read into the F/F 21, and the output is applied to the AND circuit 23 via the inverter 22, so that the contents of the register 25 are cleared in the first cycle, and the next Every time the clock signal φ _A is output from the period, “+
The counter 24 performs an operation of counting in increments of 1, and the count contents are sent to the successive approximation circuit 27. The other input terminal of the comparator circuit 27 is also connected to the code signal output from the code generator 28 (currently,
This code signal is assumed to be "200") is applied, and the count value of the counter 24 is "200".
A comparison circuit 27 compares whether or not the value has been reached. Therefore, the counted value of the interval between the first pulse outputted from the one-shot circuit 19 at time _T1 and the second pulse outputted at time _T2 is "160" as shown in FIG. 2e. In this case, since the count value does not exceed "200", the comparison circuit 27 does not output and the R-SF/F 29 is not set as shown in FIG. 2d. Then, the register 25 of the counter 24
is reset by applying the output of the one-shot circuit 19 at time _T2 to the AND gate 23 via the F/F 21 and the inverter 22, and counting starts again from "0". In this way, at subsequent times T ₂ to T ₅ , the counter 24 is
As shown in FIG. 2b, a new count is started every time a one-shot pulse is output from the one-shot circuit 19, and the count contents are "0" to "120" and "0".
~ “100” and “0” ~ “100” are sent to the successive approximation circuit 27 and compared with the code “200” output from the code generator 28, but in both of these comparisons, the count of the counter 24 is Since the numerical value is smaller, there is no output from the comparison circuit 27 and the R-SF/F 29 is not set as shown in FIG. 2d. Now, suppose that the operator operates the stop button or pause button on the operation section to stop the rotation of the reel shaft ₅₁ at _T6 , then the reel shaft ₅₁ stops rotating.
The rotation of the pulse generator 12, which is interlocked with the rotation of the pulse generator 12, also stops, and no output can be obtained from the one-shot circuit 19 thereafter. Therefore, the count value of the counter 24 which started counting from time T ₆ reaches "200" as shown in FIG. 2e, and the count value "200" of the counter 24 and the code "200'' is detected by the comparator circuit 27 and R-
SF/F 29 is set as shown in FIG. 2e. Then, by applying the output of this R-SF/F29 to the display processing circuit 32 and the motor drive circuit 31, the display device 32
The "STOP" mark is displayed as shown in Figure 2, and the motor 3 is connected to the motor drive circuit 31 as shown in Figure 2a.
It is controlled to stop. It is assumed that the count value of the tape running amount counter at this time is "80". In addition, in the above example, the case where the stop is caused by the operator's operation is described, but in this case, the rotation period of the reel shaft ₅₁ becomes slow due to some kind of load fluctuation or a drop in the power supply potential, and the count value of the counter 24 becomes " Exactly the same behavior occurs when the value exceeds 200.

In addition, Fig. 3 shows an example of using a preset type counter, and in Fig. 3, F/F2
The output of 1 is applied directly and via the inverter 33 to one input terminal of AND gates 34 and 35, and the code (detection data) from the code generator 36 is applied to the other input terminal of the AND gate 34. The outputs of the counters 38 are applied to the other input terminals of the AND gates 35, respectively. The outputs of these AND gates 34 and 35 are input to a counter 38 via an OR gate 37. The counter 38 is connected to the register 39 and "-1"
The circuits 40 are connected in series, and one input terminal of the "-1" circuit 40 receives the output of the register 39.
A clock signal _φ A output from a basic clock generator (not shown) similar to that of the above embodiment is input to the other input terminal. On the other hand, counter 3
The output of 8 is also applied to a "0" detection circuit 41 that detects when the count value of this counter reaches "0", and this "0" detection circuit 41 detects that the count value of this counter reaches "0". The configuration is such that when detected, R-SF/F29 is set. Therefore, in this example, from T ₁ to T ₅ in FIG. do)
is preset and R-SF/F29 is not set. That is, in this example, when the output from the one-shot circuit 19 is output via the F/F 21, the AND gate 34 is opened in the first cycle and the code "200" output from the code generator 36 is preset. In the second cycle, the F/F 21 stops outputting, and the AND gate 35 is opened, and the "-1" circuit 40 causes the "-1" circuit to output "-" in one cycle.
1" operation is performed. Therefore, at times T ₁ to _{T 5} shown in the above example, the count value is "0".
Before that, there is an output from the one-shot circuit 19, and "200" is newly preset. However, in the counting after time T ₆ shown in the above example, since the pulse generator 12 is stopped, the counter 38 continues counting until its count value reaches "0", and the "0" state changes to "0'' is detected by the detection circuit 41, the R-SF/F 29 is set, and the same operation as in the example shown in FIG. 1 is performed.

[Purpose of the invention]

The present invention is a further improvement of the conventional rotation state detection device shown in FIGS. 1 to 3, and an object of the present invention is to provide a rotation state detection device capable of detecting a plurality of rotation states.

[Summary of the invention]

That is, in the present invention, a plurality of detection data, for example, data for detecting defective operation, data for stopping operation, and power supply control, are set in advance, and the pulse interval count value of the pulses accompanying the rotation of the rotary body is set in advance. A plurality of rotational states are detected by comparing the rotational speed and the plurality of detection data.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. In FIG. 4, the F/F 21, inverter 22, AND gate 23, and counter 24 are the same as those in _{FIG .} ), and a plurality of R-SF/F29s (29 ₁ to 29 _o ) are provided corresponding to each R-SF/F29. That is, in this embodiment, the comparison circuits 27 ₁ to 27
The output of the _counter 24 is applied to one input terminal of each of the code generators 28, and a plurality of different code signals C ₁ , C _{2 . .} . This is what is entered in _o . Therefore, by using the output code of the code generator 28, for example, for detecting defective operation, stopping operation, or controlling the power supply, each comparison circuit 27
R-SF/F29 provided corresponding to ₁ to 27 _o
In the set state of ₁ to 29 _o , operations such as the above-mentioned malfunction, operation stop, power supply control, etc. can be performed.

In other words, in this embodiment, for example, by setting the defective operation detection code to ``180'', the operation stop code to ``250'', and the power supply control code to ``300'', the code shown in FIG. At times _T1 to _T5 , none of R-SF/ _F291 to _F29o is set, but when the rotation of the pulse generator 12 stops from time _T6 onward, the motor 3 stops as in FIG. 1 described above. , a “STOP” mark is displayed on the display device 32. Although the operation will not stop, the count value of the counter 24 may be between "180" and "250" due to the tape being wrapped around the capstan shaft, some kind of load fluctuation, or a drop in power supply potential. If this is the case, it is set by the output of any one of the comparison circuits 27 ₁ to 27 _o that detects this defective operation, and the output of any one of the R-SF/Fs 29 ₁ to 29 _o detects a defect in the display device 32, for example. An operation indicator (not shown) or the like is displayed. Therefore, the user can use this malfunction indicator to know that some kind of abnormality has occurred in the tape running, and by pressing the button to stop the tape running immediately, the user can prevent unforeseen situations such as tape cutting. becomes possible. Furthermore, after a predetermined period of time has elapsed after the pulse generator 12 stops rotating, the count value of the counter 24 reaches the same value as the power control code " _{300 "} . R due to the output of
- SF/F29 ₁ to 29 _o will be set. Power consumption can be reduced by controlling the power supply to each circuit to be stopped using this set output.

Note that in the above embodiment, a plurality of comparison circuits 27
Although an example using ₁ to 27 _o has been described, it goes without saying that this can be reduced to one by time-division control using appropriate means.

〔Effect of the invention〕

As explained above, the rotation state detection device according to the present invention is provided with a pulse generation means that generates pulses as the rotating body rotates, and also counts the pulse interval output from the pulse generation means, and calculates the pulse interval between the pulses outputted from the pulse generation means and the counted value. By comparing each of the plurality of detection data set in advance, it is possible to detect the rotational state of the rotating body corresponding to each of the plurality of detection data. The circuit can detect multiple rotational states of the rotating body. In particular, since it is possible to detect malfunctions of the rotating body, such as abnormal tape wrapping, etc., before the operation stops, this is very useful for maintenance of the equipment. Furthermore, with the present invention, the same circuit can detect whether the stop is caused by an instruction from the stop button or the pause button, or when the tape ends, so there is no need for such input from the operation unit. It has various advantages such as being able to be realized without increasing the number of terminals even when integrated.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a conventional rotation state detection device, Fig. 2 is a time chart for explaining the operation in Fig. 1, and Fig. 3 is a main part block diagram showing another example of the conventional device. , and FIG. 4 are essential block diagrams showing one embodiment of the present invention. 3...Motor, 4 ₁ ...Capstan shaft, 5
_{1,5 2} ...Reel axis, 12...Pulse generator,
19... One shot circuit, 24, 38... Counter, 27, 27 ₁ to 27 _o ... Comparison circuit, 2
8, 36...Code generator, 29, 29 ₁ to 29
_o ...R-SF/F, 41..."0" detection circuit.

Claims (1)

[Scope of Claims] 1. A rotating body driven by a motor, a pulse generating means for generating pulses as the rotating body rotates, and a counting means for counting pulse intervals output from the pulse generating means. Detecting the rotational state of the rotating body corresponding to each of the plurality of detection data by comparing each of the plurality of preset detection data with the current count counted by the counting means. What is claimed is: 1. A rotational state detection device comprising: a detection means for detecting a rotation state; 2. In claim 1, the plurality of detection data are data for detecting defective operation, data for stopping operation, and power control, and the detection means detects each of these states. Characteristic rotation state detection device.