JPH048496Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape running abnormality detecting device for a tape deck, and more particularly to a tape running abnormality detecting device suitable for use in an auto-reverse type tape deck capable of recording or playing back during reciprocal tape running.

For auto-reverse type tape decks,
It is equipped with a means for detecting the running state of the tape and generating a stop detection signal when the tape stops running, and assumes that the tape stops running as the end of the tape, and generates a direction switching signal based on the stop detection signal. This direction switching signal drives an electromagnetic means such as a solenoid to switch the running direction of the tape.

However, if the running direction of the tape does not reverse for some reason, or if the tape becomes unable to run due to it being wrapped around a pinch roller, capstan, etc. during running, the above direction switching signal will be generated. Furthermore, since the energized state of the direction switching solenoid is maintained, problems such as heat generation of the solenoid, burnout of the coil, and increase in power consumption occur, which is undesirable.

In order to solve this problem, the present applicant has proposed a tape running abnormality detection device as shown in FIG. The device is disclosed in the specification of Japanese Patent Application No. 135168/1982 (filed on September 29, 1982).
In the figure, reference numeral 1 denotes a tape running state detection means for detecting the running state of the tape and generating a stop detection signal when the tape stops running. This tape running state detection means 1, for example, generates a pulse train signal according to the running speed when the tape is running, and generates a low-level stop signal when the tape stops running, and rotates integrally with the tape reel. It is also possible to provide slits at regular intervals on the rotary plate and use the output of a photocoupler provided between the slits, or to detect the tape running state based on the noise between the brushes of the reel drive motor. You can also do that.

The output of the detection means 1 is supplied to a direction switching signal generation circuit 2 which generates a direction switching signal for switching the tape running direction. This circuit 2 has a pulse generator 21 that generates clock pulses and the output of the tape running state detection means 1 as clear inputs, and generates an output every time a predetermined number of clock pulses are counted when a low-level stop detection signal is applied. and a direction switching signal (Q output) set by the output of this counter 22.
and a second counter 24 which uses the Q output of this flip-flop 23 as a clear input and resets the flip-flop 23 when a predetermined number of clock pulses are counted when a direction switching signal is generated. The first counter 22 is used to set the time from when the stop detection signal is generated until when the direction switching signal is generated. This time is counter 22
In this example, the number of stages of the counter 22 is set to seven stages. The second counter 24 is used to set the generation time of the direction switching signal, and as described above, the generation time is determined by the number of stages and the period of the clock pulse. In this example, the number of stages of the counter 24 is two.

The direction switching signal serves as a drive signal for, for example, a solenoid for switching the direction in a mechanical section (not shown), and also serves as a clock input to the third counter 3 as a circuit for generating a running abnormality signal. The third counter 3 uses the output of the stop detection signal generating means 1 as a clear input, and generates a running abnormal signal when it counts a predetermined number of direction switching signals that are generated every predetermined time period when the stop detection signal is applied. do. That is, the running abnormality signal is generated after a predetermined period of time has elapsed from the generation of the stop detection signal, and this time is determined by the number of stages of the counter 3 and the generation cycle of the direction switching signal. In this example, the number of stages of the counter 3 is set to three.

In this configuration, when the tape is driven, the tape running state detecting means 1 generates a pulse train signal corresponding to the rotational speed of the reel motor, that is, the running speed of the tape. This pulse train signal becomes the clear input for counters 3 and 22, so counters 3 and 2
No. 2 performs no counting operation during tape running. When the tape reaches its end and tape running stops, the tape running state detection means 1 outputs a low-level stop detection signal as an end detection signal. Upon application of this stop detection signal, the counter 22 starts counting clock pulses and generates an output after counting seven clock pulses. In response to this output, flip-flop 23 enters the set state and generates a direction switching signal from the Q output. In response to this direction switching signal, a direction switching solenoid (not shown) of the mechanical section becomes energized to switch direction. At the same time, the direction switching signal also serves as a clock pulse for the counter 3, so the counter 3 counts up by "1". Then, the running direction of the tape is switched and the tape starts running in the opposite direction, and the pulse train signal is generated again from the tape running state detecting means 1, so that the contents of the counters 3 and 22 are all cleared.

Here, if the tape does not start running in the reverse direction due to some reason, such as the tape being wrapped around a pinch roller or capstan, the clock pulses are counted in response to the Q output of the flip-flop 23. Since the flip-flop 23 is reset by the _Q2 output of the counter 24, the direction switching signal temporarily disappears. Therefore, the excitation of the solenoid is also temporarily released. If the state in which the tape cannot run continues, the direction change signal is repeatedly generated at predetermined intervals because the counter 22 generates an output every time it counts seven clock pulses. In response to this, the direction switching solenoid is also repeatedly excited. If the tape does not start running even after the direction change signal is generated, for example, three times, the counter 3 generates a run abnormality signal when the direction change signal is counted up to _Q3 .

This running abnormality signal is used as a so-called shut-off signal in an open reel or cassette type tape deck to stop the tape driving operation by releasing the pressure contact between the tape and the capstan and stopping the reel motor.
Furthermore, in car stereos and the like, in addition to the above operations, it is also used as a command signal to eject the cassette half.

According to this circuit system, the third counter is always cleared by the rotation of the reel motor, resulting in the following inconvenience. That is, even if the tape actually wraps around a pinch roller, capstan, etc., when the tape running direction is reversed, the reel motor rarely remains completely stopped, and the third counter 3 is therefore cleared. In some cases, the above-mentioned functions may not work.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a tape running abnormality detection device that can detect a tape running failure condition early and reliably, generate a tape running abnormality signal, and ensure operations such as tape ejection. The purpose is

The tape running abnormality detection device for a tape deck according to the present invention includes means for generating a stop detection signal when the tape stops running, and generating a tape running direction switching signal at a predetermined period during the generation period of the stop detection signal. a counter that counts the number of tape running direction switching signals and generates a tape running abnormality signal when the counted value reaches a predetermined value;
It is characterized by comprising a reset means for resetting the counter at predetermined intervals.

The present invention will be explained below with reference to the drawings.

FIG. 2 is a circuit block diagram of an embodiment of the present invention, and parts equivalent to those in FIG. 1 are designated by the same reference numerals. If we talk about the parts that differ from Figure 1,
The configuration is such that the timer output of the timer circuit 4 is used as a clear signal for the third counter 3 for generating a tape running abnormality signal. This timer circuit 4
operates to periodically count a certain period of time asynchronously with the tape operation, and generates a clear signal for the counter 3 at each certain period of time,
The contents of this counter 3 are reset to the initial value.
Thus, for example, N
This carry output may be used as a clear output using a forward counter, but it is also possible to use other timer circuit configurations. The other configurations are the same as those shown in FIG. 1, and their explanation will be omitted.

By appropriately setting the set time of the timer circuit 4 and the predetermined value of the counter 3 that determines that there is a running abnormality due to the tape wrapping, the count contents of the counter 3 can be changed within a certain period of time set by the timer circuit 4. When a predetermined constant value is reached, a running abnormality detection signal is generated.On the other hand, if the counter contents do not reach the specified constant value within the specified period, the counter 3 is reset without generating an abnormality detection signal. Then, the timer circuit 4 again performs the counting operation of the counter 3 for a certain period of time.

By doing this, even if the tape moves slightly when the tape wraps around a capstan or the like and a tape running direction switching signal is generated to reverse the tape running, the counter 3 will not be affected by this. It is never reset.
Therefore, it becomes possible to detect tape running abnormalities before the tape is completely wrapped around the capstan or pinch roller, etc. and the running completely stops. This makes it possible to detect abnormalities earlier and more reliably, and to prevent the tape from moving between the capstan and the tape. Operations such as releasing pressure, stopping the motor, and ejecting the cassette half can be performed quickly, thereby reducing damage to the tape.

FIG. 3 is a schematic block diagram showing another embodiment of the present invention, in which a so-called microcomputer 30 such as a microcoprocessor performs the same function as the circuit block shown in FIG. 3
1 and 32 are two tape reel motors,
33 represents a tape, and 34 and 35 represent a capstan and a pinch roller, respectively. The rotational states of both reel motors 31 and 32 are controlled by a reel motor servo device 36, and a computer 30
Control signals are received and received via an I/O port 37 within the device. Further, tape running state detecting means 1 is provided with the same configuration as described in FIG. 1, and its output is inputted to computer 30 via I/O port 38. computer 3
0 has a built-in counter 3 and a timer circuit 4 for generating a running abnormality detection signal, and a pinch roller control device 40 is driven via an I/O port 39 to control the operation of the pinch roller 35. do.
Then, the cassette half-hold mechanism 42 is controlled via the I/O port 41 to perform hold and eject operations. Note that 43 indicates an operation section.

During normal tape running, a control signal is input from the computer 30 to the servo device 36 via the I/O port 37, thereby controlling the reel motor 31.
32 rotates, and the pinch roller control device 40 causes the pinch roller 35 to move to the capstan 34.
This keeps the tape 33 running in a stable state. Further, the computer 30 constantly determines whether the tape is running or stopped based on the signal from the reel motor rotation detection device 1. When it is determined that the tape is stopped, the counter 3 is caused to perform a counting operation, and after a certain period of time, a reel motor reversal command signal is generated to perform a reversal operation of tape running.

The timer circuit 4 always counts a certain fixed time, and when the timer circuit 4 detects that the certain fixed time has been reached, the computer 30 checks the contents of the counter 3, and if it exceeds a predetermined fixed value, the computer 30 checks the contents of the counter 3. , determines that the tape is wrapped, generates an abnormal tape running detection signal, forcibly stops tape running, turns off the cassette half-hold mechanism 42, and turns off the pinch roller control device 40. Similarly, the tape can be ejected by turning it off. If the value of the counter 3 is less than a predetermined value even after the timer circuit 4 reaches a certain period of time, the counter 3 is reset and the timer circuit 4 is newly set. Perform equivalent actions and effects.

It should be noted that the set time of the timer circuit 4 in each of the above embodiments and the set value of the counter 3 for determining that the tape is wound must be set to values that do not work during normal tape running operations. Of course.

Further, as shown in FIG. 3, if the system is configured by a microcomputer, the set values of the timer and counter can be easily varied by simply changing the constants of the program.

As mentioned above, according to the present invention, it is possible to recognize the occurrence of tape wrapping before the tape is completely wrapped around the capstan, pinch roller, etc., so it is possible to take early and reliable measures and prevent damage to the tape. can be achieved. In addition, even if the tape is completely wound, if there is a slight gap at the joint between the reel motor and the cassette half and the motor rotation detecting means cannot continuously detect the stopped state of the reel motor, the tape may be wound. can be recognized and treated. Therefore, it is suitable for use in, for example, car stereo equipment where the user cannot concentrate on operating the tape deck.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a tape running abnormality detection device currently proposed by the applicant, and FIGS.
The figures are circuit block diagrams of embodiments of the present invention. Explanation of symbols of main parts: 1...Tape running state detection means, 2...Direction switching signal generation circuit, 3...
Counter for generating driving abnormality detection signal, 4...Timer circuit.

Claims (1)

[Scope of utility model registration request] means for generating a stop detection signal when the tape stops running; means for generating a tape running direction switching signal at predetermined intervals during the generation period of the stop detection signal; and the number of occurrences of the tape running direction switching signal. Detection of tape running abnormality in a tape deck, characterized in that the tape deck is comprised of a counter that counts and generates a tape running abnormality signal when the counted value reaches a predetermined value, and a reset means that resets the counter at predetermined intervals. Device.