JP3219484B2 - Tape wrap detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape deck such as an audio tape deck and a video deck.

[0002]

2. Description of the Related Art FIG. 10A shows a state in which a tape on a tape deck is running normally. In the normal running state, the tape 13 runs in the direction of the arrow shown in the drawing,
Take-up reel 12, capstan 14, pinch roller 15
Rotate in the directions indicated by the arrows. On the other hand, the tape 13 is moved to the capstan 1 by the action of static electricity or the like.
4 and the capstan 14 as shown in FIG.
May be caught in. If you leave this state,
Eventually, an abnormality occurs in the mechanical operation, and the tape stops running. However, the tape 13 remains wound around the capstan 14, and it becomes difficult to discharge the tape from the deck.

When the tape is wound, the tape is not supplied to the take-up reel 12, and the tape is pulled out from the take-up reel 12. On the other hand, FIGS. As apparent from the comparison, the rotation direction of the take-up reel 12 is opposite to that in the normal operation. The present inventor has previously proposed a tape wrap detecting device that can detect the wrap of the tape at an early stage by utilizing this phenomenon. One example will be described with reference to FIGS. In a conventional example, as shown in FIG. 11, a reflection plate 1 is mounted on a reel base of a take-up reel, and one sensor 3 composed of a photo reflector is arranged to face the reflection plate 1. And on the reflection plate 1,
White and black patterns are printed, each of which is painted in large, medium, and small patterns.

When the reflector 1 rotates as the tape runs and the reel rotates, and the white portion of the surface of the reflector 1 passes through the sensor 3, the output signal a becomes H. When the black portion passes, the output signal a becomes H. L. As the reflection plate 1 continues to rotate in the direction indicated by the arrow, the output signal a from the sensor 3 changes in the order shown in (1) of the time chart of FIG. When the reflection plate 1 is reversed, the order is reversed. Then, the output signal a is not generating a pattern as shown in FIG. 12 (2), the reflecting plate 1 and entrainment of the tape occurs at time t ₁ is the reverse, from this point, the pattern of change The order is reversed. When the reverse rotation occurs at time t ₁ (the output signal a has the large pattern H), the L pattern following the H state becomes large. On the other hand, if the normal rotation is continued, the pattern of L should be small as is apparent from the waveform of (1). Is detected, and it can be detected that the entanglement has occurred.

[0005]

[SUMMARY OF THE INVENTION] However, in the above conventional example, when the reversed 12 time t ₁ the worst case, as shown by (2) occurs, can not determine the time t _2, time t _Only when the number becomes ₃ , the difference between the L patterns is determined. Therefore, tape wrapping occurs and 2
There is a problem that the discrimination is made after the pattern, and the winding of the tape proceeds during that time. In order to shorten the detection time, the pattern may be made finer, but since the resolution of the sensor is limited, it is not possible to make the pattern finer and shorten the detection time. SUMMARY OF THE INVENTION It is an object of the present invention to reduce the time from when tape winding occurs to when it is detected in a tape deck.

[0006]

In order to achieve the above object, two sensors are provided on each of two reel portions of a tape deck, and each sensor processes a signal corresponding to a rotation position of the reel. A sensor that is arranged in a positional relationship such that a phase difference appears in the signals, and uses the output signal of one sensor as a reference signal and the output signal of the other sensor as a comparison signal; and the reference signal in the output signal of the sensor. Discriminating means for discriminating the rotation direction of the reel based on the status of the comparison signal when the edge of the reel is input, and when the rotation direction of the two reels discriminated by the discrimination means is different, the tape winding has occurred. In the tape wrapping detecting device having a judging means for judging, the timing at which the next edge is inputted is estimated from the inversion cycle of the reference sensor signal so far. , An input allowable period allow a period before and after that timing provided, providing a means to perform discrimination of the direction of rotation only in the allowable input period means for determining the direction of rotation of the reel. Alternatively, instead of the above, the majority of the status of the comparison signal when the edge of the reference signal is input and the status of the comparison signal at the sampling time prior to the input of the edge may be used to determine when the edge is input. A means for determining whether or not the status of the comparison signal is a normal signal.

[0007]

The fact that the winding of the tape has occurred and the take-up reel has rotated in the reverse direction to feed the tape can be detected by examining the state of the comparison signal at the rising or falling of the reference signal after the reverse rotation. The winding of the tape can be detected as early as within a half cycle of the signal.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
This will be described with reference to FIG. In the drawings, components having the same function are denoted by the same reference numerals, and redundant description will be omitted. Figure 1 assumes technique [premise ART winding detecting apparatus of the present invention will be described with reference to FIG. In FIG. 1, 1 is a reflector attached to a reel base of a tape take-up reel, 2 is a reflector attached to a reel base of a supply reel, and each reflector 1 and 2 has a white portion and a black portion. Printed at equal intervals. The direction of the arrow in the figure is the normal rotation direction of the reflection plates 1 and 2.

Each of the reflection plates 1 and 2 is provided with two sensors 3 and 4 and 5 and 6 facing each other, and each sensor is constituted by a photo reflector. When the tape runs and the reels rotate to rotate the reflectors 1 and 2, the sensors 3 to 6 alternately detect white and black portions, and output signals a to d thereof.
As shown in FIG. 2, when the white portions of the reflectors 1 and 2 are detected, the state becomes H, and when the black parts are detected, the state becomes L. The sensors 3 and 4 and 5 and 6 provided on the same reflection plate are arranged in a positional relationship such that the phase difference between their output signals a and b and c and d is shifted from each other. 7,8
Is a flip-flop. Output signals a and c of the sensors 3 and 5 are input to a D terminal of each flip-flop, and output signals b and d are input to a CK terminal. Output signals e and f from the Q terminals of the flip-flops 7 and 8 are input to an EOR circuit (exclusive OR circuit) 9. And this EO
The output signal g of the R circuit 9 becomes the winding detection signal.

Next, the operation of the circuit of FIG. 1 will be described with reference to the time chart of FIG. First, the operation of the circuit from the reflector 1 to the flip-flop 7 will be described. Since the sensors 3 and 4 are displaced from each other as described above, their output signals a and b are out of phase, and the output signal a of the sensor 3 is out of phase with the output signal b of the sensor 4 during normal rotation. Is progressing. In contrast, when the reflecting plate 1 and the take-up reel winding the tape occurs at time t _a is reversed, the output signal b of the sensor 4 is the phase difference is advanced than the output signal a of the sensor 3, the reflecting plate 1 The phase difference between the output signals a and b is reversed between the forward rotation and the reverse rotation. This phase difference, checks the status of the output signal a at the time t ₁ ~t ₄ rising edges of the signal b, it is determined that the signal a is advanced i.e. forward when it is H, status is L Time signal b
Advances, that is, reverse rotation.

The rotation direction is determined by flip-flop 7
It is performed by Flip-flop 7, the status of the D terminal is output as the signal e at time t ₁ ~t ₄ rising edges of the signal b inputted to the CK terminal. Therefore, the output signal e is at the time of forward rotation of the reflector 1 becomes the status of H, and the reflecting plate 1 changes from forward rotation to reverse rotation at time t _a, the output signal e becomes status of L. The above operation is performed similarly in the other of the reflector 2 to the flip-flop 8, the reflecting plate 2 is the direction of rotation even winding of the tape is generated at time t _a is not changed, the reflecting plate 2 continues to forward from time t ₆ to t _8, the output signal f of the flip-flop 8 continues the state of the H (forward).

Accordingly, the time t _a at the time of normal operation of the take-up reel and the supply reel is rotating and reflecting plate 1 and 2 have the normal rotation together in the same direction previously, the flip-flop 7,
8 are both H, the output signal g of the EOR circuit 9 is L, and no entrainment detection signal is output. If inclusion of the tape occurs at next time t _a, the take-up reel is rotating in a direction for feeding the tape by the reverse rotation, the reflecting plate 1 along with it is a reversal edge of the signal b following the time point t _a flip-flop 7 at the time t ₃ of
Is L. On the other hand, the other reflector 2
Continues the normal rotation, and the output signal f of the flip-flop 8 remains at H, so that the output signal g of the EOR circuit 9
Becomes H, and it is detected that the entrapment has occurred. In this example, when the winding of the tape occurs, the detection is performed at the rising time of the output signal of the sensor immediately after the occurrence of the winding of the tape, and the detection can be performed within a half cycle of the output signal of the sensor. Further, since all the reflection plate patterns can be made as small as the detection limit of the sensor, the time required for detecting the tape winding can be reduced.

In an auto-reverse tape deck, the tape runs in the reverse direction during the reverse operation, the take-up reel and the supply reel are switched, and both the reflection plates 1 and 2 are reversed. Entanglement detection is performed in the same manner as described above. That is, during the normal operation of the reverse operation, the output signals e and f of the two flip-flops 7 and 8 both become L, so that the output signal g of the EOR circuit 9 becomes L and the winding detection signal is not output. Also,
When the entanglement occurs, the output signal e changes from H to L while the output signal e remains at H, so that the output signal g changes to H and the entanglement detection signal is output. Although an example in which photoreflectors are used as the sensors 3 to 6 has been described, a photointerrupter or a magnetic sensor or the like may be used as the sensor.

[Embodiment] In the base technology described above, if there are dirt 16 and print unevenness 17 on the printed surfaces of the reflectors 1 and 2 as shown in FIG. 3, the sensors 3 and 4 pick up these as signals. As shown in the time chart of FIG. 4, the dirt 16 appears as the L status during the H status of the signals a and b, and the printing unevenness 1
7 appears as an H status in an L status.
Now, if during reflector 1 time t ₁ ~t ₁₄ is continued forward rotation, the signal a at the time point t ₁ ~t ₁₃ of the rising edge of the signal b is detected status of H, falling Although the time t ₂ ~t ₁₄ the signal a of edges are status of L must be detected, dirt 16, for printing unevenness 17, at time t ₅ ~t ₇ or t ₁₀ ~t _12, status signals a When the relationship between H and L is detected in the opposite direction, the reflection plate 1 is erroneously determined to have rotated in the forward direction but in the reverse direction.

An example of a tape wrapping detecting apparatus provided with means for preventing erroneous detection due to the stain 16 or uneven printing 17 will be described as a second embodiment with reference to FIGS. In this example, as shown in FIG.
The output signals a and b of 4 are input to the microcomputer 10 and processed as described below to obtain a rotation direction signal. Although the description is omitted, the same applies to the other reflection plate 2.

FIG. 6 is a flow chart for explaining the operation of the present embodiment.
Time t _3, the signal error is generated at t _4, the time t ₁₀ to the signal b, the
It will be described when a signal error occurs in the t _11. Step 61 is started by interruption every sampling period Δt. In step 62, t is increased by Δt. In step 63, the statuses of the output signals a and b of the sensors 3 and 4 are sampled and a _{0 and} b ₀ are sampled.
And In the subscripts ₀ , ₁ , and ₂ of a and b, 0 represents the present time, 1 represents the _immediately preceding sampling time,
2 represents the previous sampling time point. In step 64, the current sampling value b ₀ is set to
Determine if it is equal to ₁ . b ₀ ≠ b ₁ unless since it is no edge in the signal b, the process proceeds to step 66, putting the value of b ₀ to b _1, the a ₁ to a _2, a ₀ to a ₁
And enters the WAIT of step 67.

If b ₀ ≠ b ₁ in step 64, it means that the signal b has an edge, and the process proceeds to step 65.
In step 65, it is determined whether or not t is in the window of FIG. 7 between t _min and t _max . This window is provided for estimating the timing at which the next edge is input from the inversion cycle of the past signal b, and assuming that the edge that arrived during the input allowable period with a margin before and after that is regarded as a normal edge. This is set in step 68 described later. Now, as in the time t _10, t _11, also the edge of the signal b is detected by the printing unevenness, since the t _10, t ₁₁ is out of the window, the signal b at this time t _10, t ₁₁ The edge is regarded as an erroneous signal, and the process proceeds to steps 66 and 67 without detecting the status of the signal a, and the WA
Enter IT. In step 65, the time t ₇ ~t _9, signals t ₁₂ a
Is determined to be within the window, such as the edge of
In step 68, a window is set in preparation for the next sampling. That is, _tmax and _tmin are obtained by giving a margin of α to the current inversion period t obtained in step 62, and a window is set as an input allowable period of the next edge of the signal b. Then, t is reset to zero.

Next, after step 69, a majority circuit is constructed. Falling edge of the signal b is obtained at time t ₉ in a window, before and after the time point t ₃ of the time t _9, t ₄
If there is an erroneous signal in the signal a during that time, the signal a becomes H at the falling edge of the signal b, and it is determined that the signal a has reversed. Errors in the determination of the rotation direction are eliminated by the majority circuit. In step 69, F is set to 0. In step 70, the signal a ₀ at the present time and the signal a at the previous sampling time are
₁ is equal (ie, the status of signal a is
It is determined whether or not it is continuous with the immediately preceding time), and YES
If it is, the value of F is increased by 1 in step 71, and if NO, the process proceeds to step 72. In step 72, it is determined whether or not the current sampling value a ₀ is equal to the immediately preceding sampling value a _2. If YES, the value of F is increased by 1 in step 73; Proceed to.

In step 74, it is determined whether or not F is 2 or more. If F is 2 or more, it is determined that a normal signal has been obtained since the same status has been continued for three cycles.
Employing the contents of the sampling values a ₀ as a rotational direction signal. If F is less than 2, the false signal detection and determines and enters the WAIT step 77 as the rotation direction signal is inverted the contents of the sampling values a _0. By the above steps,
Erroneous signals in the signals a and b are eliminated, and the rotation direction of the reel is reliably detected. The signal of the rotation direction obtained here is
Processing is performed in the same manner as in the first embodiment.
Detected reliably.

The tape wrap detecting apparatus of the present invention has been described above. Next, a wrap releasing operation after the tape wrap is detected will be described. In the auto-reverse deck, when the running direction is switched, the capstan that has been driving the tape is pinched off and the capstan in the opposite direction is pinched on. As a result, the tape that has been wound on the capstan or pinch roller, which has been driving the tape, can be wound on the reel. Also,
In the case of a deck without the auto-reverse function, after detecting the winding, the capstan that had been driving the tape is pinched off, FF (fast forward) and / or REW (rewind) is performed, and the capstan is driven by the reel drive. ,
The tape wound on the pinch roller is wound on a reel.

While the above-described wrapping release operation is being performed, the fact that the reel on the tape supply side has rotated (or rotated in the normal direction) is detected from the output of the reel sensor, so that the tape deck operates normally. It can be confirmed that the status has been restored. Also, while the wrapping is detected and the wrapping is released, if the user feels abnormal and presses the play button, the tape will be rewound again, and if the eject button is further pressed, the cassette will remain with the tape wrapped. It will be pulled out and will damage the tape. Therefore, during this time, it is necessary to inform the user of the fact that the entanglement releasing operation is being performed by an indicator or the like, and to prohibit the switch operation.

One example of the unwinding operation after the detection of the unwinding will be described with reference to FIGS. 8 and 9. FIG. FIG. 8 is a flowchart in the case where the running direction is reversed by the auto-reverse deck after the detection of the winding, and after the detection of the end of the tape in the normal deck control program and the steps 81 and 82 for reversing the running direction, the detection of the winding and thereafter. Is released. If tape wrapping is detected in step 83, step 84
Reverses the running direction. In step 85, it is determined whether or not the supply reel has started to rotate. If the supply reel starts to rotate, the winding has been released, and the routine returns to the normal deck control program. The rotation of the supply reel is determined based on whether or not the signal period detected by the sensor is longer than a reference time. This reference time is obtained by multiplying the reel sensor cycle under the condition that the reel rotates at the slowest speed by a coefficient exceeding 1 for preventing malfunction.

In a deck without the auto-reverse function, the operation of releasing the winding after the detection of the winding is performed by adding the flow of FIG. 9 to the deck control program. Step 9
If the entrapment is detected in step 1, the process proceeds to step 92, where the MU
The TE and the indicator are turned on to indicate that the user is involved and that button operations and the like should not be performed.
Next, in step 93, FF (fast-forward) is performed for an appropriate time t (s), and in step 94, R is output for an appropriate time t (s).
Perform EW (rewind). When the tape thus wound is wound on a reel, the process returns to PLAY at step 95, returns the MUTE and indicator turned on at step 96 to OFF, and thereafter returns to the normal deck control program.

[0024]

According to the present invention, in the tape deck, the time from when the tape is wound to when it is detected is shortened, so that the tape can be wound while the amount of the tape wound into the capstan is small. Release operation, etc.
Unwinding can be reliably performed, and damage to the deck and the tape can be reduced.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a base technology of the present invention.

FIG. 2 is a time chart illustrating the operation of the circuit in FIG. 1;

FIG. 3 is a plan view of a reflector that causes erroneous detection.

FIG. 4 is a time chart for explaining the reason why the reflection plate of FIG. 3 causes erroneous detection.

FIG. 5 is a circuit diagram of an embodiment of the present invention.

FIG. 6 is a flowchart illustrating the operation of the circuit in FIG. 5;

FIG. 7 is a time chart illustrating the operation of the circuit in FIG. 5;

FIG. 8 is a flowchart of an automatic reverse deck entanglement release operation.

FIG. 9 is a flowchart of the operation for releasing the entanglement of a deck without an auto-reverse function.

FIG. 10 is a plan view showing a tape running state of the tape deck.

FIG. 11 is a plan view of a conventional reflector used for detecting winding of a tape.

FIG. 12 is a time chart for explaining the operation of FIG. 11;

[Explanation of symbols]

 1, 2, ... reflector 3, 4, 5, 6 ... sensor 7, 8 ... flip-flop circuit 9 ... EOR circuit 10 ... microcomputer 11 ... supply reel 12 ... take-up reel 13 ... tape 14 ... capstan 15 ... pinch roller 16 … Dirt 17… Print unevenness

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-29102 (JP, A) JP-A-3-9215 (JP, A) JP-A-4-112649 (JP, A) 179640 (JP, U) Japanese Utility Model 2-101330 (JP, U) Japanese Utility Model 57-45050 (JP, U) Japanese Utility Model Utility Model 60-98128 (JP, U)

Claims (2)

(57) [Claims] 1. A sensor which is provided two on each of two reel portions of a tape deck and processes a signal corresponding to a rotation position of a reel, and has a positional relationship such that a phase difference appears in an output signal thereof. A sensor that is disposed and uses an output signal of one sensor as a reference signal and an output signal of the other sensor as a comparison signal; and the comparison signal when an edge of the reference signal in the output signal of the sensor is input. Detecting means for determining the rotation direction of the reel based on the status of the tape reel; and determining means for determining that tape winding has occurred when the rotation directions of the two reels determined by the determination means are different. The device estimates the timing of input of the next edge from the inversion cycle of the reference sensor signal so far, and has a margin before and after that timing. A tape wrap detecting device, further comprising: an input permissible period provided; and means for discriminating the rotation direction of the reel provided with means for determining the rotation direction only during the input permissible period. 2. A sensor which is provided two on each of two reel portions of a tape deck and processes a signal corresponding to a rotation position of the reel, and has a positional relationship such that a phase difference appears in an output signal thereof. A sensor that is disposed and uses an output signal of one sensor as a reference signal and an output signal of the other sensor as a comparison signal; and the comparison signal when an edge of the reference signal in the output signal of the sensor is input. Detecting means for determining the direction of rotation of the reel based on the status of the tape reel; In the apparatus, the status of the comparison signal when the edge of the reference signal is input and the comparison signal at the sampling time before the edge is input. A means for judging whether or not the status of the comparison signal at the time of edge input is a normal signal based on a majority decision with the status of the signal.