JPS6139253A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To avoid missing of a head of music or overlapping onto the end of the preceding music at music selection by correcting the position shift of a magnetic tape based on the slowness of the response speed of a device section. CONSTITUTION:An FMS detects music-inter-music-music at the music selection by forward running, the device is brought into an RMS state depending on the detection and the inter-music is detected at the RMS. The device is subjected to control to bring the mode into the PLAY mode depending on the detection of the inter-music and the amount of tape running from the point of time until the completion of preparation of the PLAY operation is measured by counting pulses. The measured value is counted down depending on the tape running after the PLAY state and the tape correction is finished when the value reaches zero. When muting is finished after a prescribed time, the muting during music selection is released.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a magnetic recording/reproducing device equipped with a music selection function. The device shown in the block diagram of Figure 5 is a device for selecting a desired song specified from the outside from among a large number of songs.

In the figure, a reproduced signal pinked up from a magnetic tape is inputted to an input terminal 1 by a magnetic head (not shown). This reproduced signal is amplified in the audio amplifier section 2 and then input to the music selection filter 3. The music selection filter 3 is for correcting the difference in the frequency characteristics of the reproduced signal due to the pressure contact state between the magnetic head and the magnetic tape and the difference in tape speed during music selection and playback, and is used to change the gain and cutoff frequency. is managed by a microcomputer (μmC0N) 4.

A signal as shown in FIG. 6(A) is sent to the output of the music selection filter 3, and is input to the music selection processing circuit 5. The music selection processing circuit 5 includes an amplification section that amplifies the signal from the music selection filter 3, a waveform shaping section that shapes the waveform of the amplified signal, and a logic section that logically processes the digital signal obtained by the waveform shaping. The logic section is logically designed to generate one pulse of a predetermined width as an inter-song detection pulse with a certain time delay, as shown in FIG. ing.

μmC0N4 monitors the pulse from the music selection processing circuit 5 during music selection, and when it confirms that the pulse has been input, causes the mechanism unit 6 to complete the music selection operation and move on to the playback operation (mechanism unit drive circuit 7 as the driving data
A reproduction command signal as shown in Figure (C) is output. The mechanism section 6 is provided with a state sensor that detects its state and sends out a state detection signal as shown in FIG. 6 ('D), and the signal from the state sensor is also monitored by μmC0N4. . By monitoring the state detection signal from the mechanism section 6, μmC0N4 determines whether the state of the mechanism section 6 is currently in a transition state transitioning from the song selection state to the playback state, or whether it is in the playback operation ready state, and starts the playback operation. Based on the determination that the preparation is complete, the reproduction command signal to the drive circuit 7 is stopped.

During the song selection operation, the μmC0N4 applies a mute signal to the audio amplifier 2 so as not to output unpleasant sounds due to the playback signal picked up by the magnetic head when transitioning from the song selection operation state to the playback operation state. As shown in FIG. 6(E), this mute signal is released after a certain period of time has elapsed after preparation for the reproduction operation is completed.

As is clear from the above explanatory power, μm
C0N4 determines that it is between songs and shifts to playback operation.

In this case, there is always a delay time based on the response speed of the mechanism section 6 until the reproducing operation reaches a steady state.

If this delay time is long, a large discrepancy occurs between the tape position determined to be between songs and the tape position determined to be ready for playback operation. For example, there is a 100 millisecond delay in releasing the reel stand double speed mechanism in the mechanism section 6, so if the tape speed at the time of song selection is 20 times the speed at playback, the σ tape speed at playback is actually 100 milliseconds. A positional deviation of seconds x 20 = 2 seconds occurs.

Therefore, when selecting a song while the tape is being transported in the forward direction (FMS), the beginning of the song is used as the starting point.
RMS) Sometimes it sneaks into the end of the previous song.

Now, the delay time for releasing the reel stand double speed mechanism is 100 millimeters.
J seconds, double the speed by 20 times, time required to detect between songs is 3 seconds (
FMS when tape speed is 4.5 am/sec (converted)
FIGS. 7(a) and 7(b) show the situation of tape position deviation at the time and RMS, respectively.

When the beginning of a song as described above occurs, the beginning of the playback sound of the song becomes unnatural, and when a drop occurs, the playback sound of the end of the previous song is generated before the playback sound of the song. arise, ru.

[Purpose of the invention]

The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional ones.14 By correcting the positional deviation of the magnetic tape due to the slow response speed of the mechanical part, it is possible to prevent the beginning of a song from being cut off during the song selection operation. It is an object of the present invention to provide a magnetic recording and reproducing device having a music selection function that can reliably and accurately locate the beginning of a music piece without having drawbacks such as creeping into the end of the previous music piece.

[Embodiments of the invention]

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows an embodiment of the present invention, in which a reproduction signal picked up from a magnetic tape by a magnetic head (not shown) is input to an input terminal 11. This reproduced signal is amplified in the audio amplifier section 12 and then input to the music selection filter 13. Music selection filter 1
3 is based on the pressure contact state of the magnetic head and magnetic tape and the difference in tape speed during song selection and playback (to compensate for the difference in frequency characteristics of the playback signal, the gain and cutoff frequency are adjusted by the control section). It is switched by a filter switching signal from the output port 14a of the microcomputer (μmC0N) 14.

A signal as shown in FIG. 2(A) is sent to the output of the music selection filter 13, and after being amplified by the amplifier 15, it is applied to the waveform shaping circuit 16. Waveform shaping circuit 1
6 shapes the input signal and outputs a pulse as shown in FIG. 2(B) with a duty rate of about 25%. This pulse is input to the input capacitor 14b of the μmCON 14, where it is scan-managed by a loop timer of 2 to 5 milliseconds.

The rotation sensors 17a and 17b are provided corresponding to the supply reel stand and the take-up reel stand, respectively, and each sensor is composed of a Hall element, a ball IC1 magnetoresistive element, a photocoupler, etc. attached near the reel stand, and generates an electrical signal with a frequency that corresponds to the rotation speed of the This electrical signal is shaped into a pulse by the waveform shaping circuits 18a and 18b, and then input to the input port 14c of the μmC0N14. For example, if the reel stand is magnetized to three pairs of N-3, three pulses will be generated per one rotation of the reel stand,
Six edge changes are obtained by rising and falling edges.

During normal operation, μmC0N14 uses the pulse applied to the input port 14c to determine the end of the tape,
If there is no change in the pulse within a certain period of about 2 seconds, it is determined that the tape has come to an end.

The mechanical sensor section 2o includes a head stand position sensor 2a and an FF
/RBW gear position sensor 20b, cassette half position sensor and metal switch 20c. The head stand position sensor 20a detects a brush B1 that moves in conjunction with the head stand, a common electrode T1 with which the brush B1 is always in contact within its movement range, the forward playback position, reverse playback position, and song selection of the head stand. It consists of detection electrodes NP, RP, M, SP, and EJP provided corresponding to the position and discharge position, respectively. The gear position sensor 2゜b for FF/REW is
The brush B2 moves in conjunction with the A, the common electrode T2 with which the brush B2 is always in contact within its movement range, and the position where the reel stand winds in the forward direction, winds in the reverse direction, and winds up due to the movement of the gear. It consists of detection electrodes C and R provided correspondingly to each other. The switch 20c is C5I, C52 for detecting the cassette half position and M for detecting the metal position a.
Consists of ETAL.

μmC0N14 is output port 1 in a series of mechanism drives.
4d sequentially sends a strobe signal to the mechanical sensor section 2o, and at this time, the mechanical sensor section 2o monitors the signal to the input port 14e, and the head stand position sensor 20a and the FF/REW gear position sensor 20b, which are linked to the mechanism section, The positions of the brushes B1 and B2 are detected, a judgment is made based on the detection results, and parallel outputs are sent out from the output boat 14f.

The parallel outputs are decoded by the decoder 22 and then applied to the driver 24. The driver 24 operates the actuator 26 to drive the mechanism 28 to a desired position.

In the above configuration, the music selection operation will be explained with reference to FIGS. 3 and 4. By the way, the gain and frequency characteristics of the reproduced signal at this time change due to changes in tape speed, so it is corrected by the music selection filter 13, amplified by the amplifier 15, and then waveform-shaped and sent as a music pulse to the input port 14b of the μmC0N 14. be taken in.

Then, the μmC0N 14 performs the music selection process shown in the flowchart of FIG. 3 based on the music pulse. First, in step s1, it is determined whether the music pulse has changed.

If the determination in this step is No, the next step S
2, a music selection timer is counted from 10.0 to 200 milliseconds. Thereafter, in the following step s3, it is determined whether the music selection timer has timed out. If the determination in step S3 is No, the process returns to step S1 and it is determined again whether or not there is a change in the music pulse.

When the music part on the magnetic tape is running in front of the magnetic head, the music pulse will change eventually, and the determination in step S1 will be YES, and the process will proceed to step S4. In step S4, O'' is written in the carry flag CF.In subsequent step S5, the contents of the 4-bit music selection shift register M are put into the accumulator Ac.

In the next step S6, the carry flag C is set to the least significant bit of the contents of M stored in the accumulator AC.
A rotation is performed to insert F, and the result is returned to M in the next step S7. The contents of the shift register M for music selection after the completion of step S7 are used to determine whether the current song is in progress, whether the song has entered an unrecorded part of the song, or whether the song has entered the middle of the song from between songs. be done.

If the determination in step S3 is YES, the process advances to step S8, where "1" is written in the carry flag CF, and thereafter steps 35 to S6 are performed to step S7.
leading to. After executing step s7, the process advances to step S9, where a music selection timer is set, and the process moves to the next task.

Currently, when performing music selection operation (FMS) by running in the forward direction, the lower bit of the music selection shift register M is "00".
→ The change from “01” to “10” is μmC0N14
When the R
MS) state is sent out from the output port 14f.

This parallel output is decoded by the decoder 22 and applied to the driver 24. The driver 24 supplies power to the actuator 26 in accordance with the decoded output to shift the mechanism to a music selection operation state by traveling in the reverse direction.

μmC0N14 also has the following characteristics when driving the above series of mechanical parts:
A strobe signal is sent to the mechanical sensor section 2° from the output port 14d, and the head stand position sensor 20a and FF/REW are sent.
The input boat 14c receives a position detection signal generated when the brush B L , 82 interlocked with the mechanism unit passes a predetermined position, and drives the actuator 26 based on this signal. Decide whether to continue or not.

The mechanism is in a steady state of music selection operation by running in the opposite direction.
-, μmC0N14 again monitors the lower two bits of the contents of the music selection shift register M based on the result of step s7 in the flowchart shown in FIG.
- When it changes to "01", it is determined that the song has entered an interval from the middle of the song, and a parallel output is sent from the output port 4f to put the mechanism into the playback state. Immediately after sending out this parallel output, the μmC0N 14 monitors the mechanical sensor unit 20, and transmits pulses generated based on the electrical signal from one of the rotation sensors 17a and 17b until the mechanical unit becomes ready for regeneration operation. Count.

Note that the regeneration operation preparation state means that the brush B1 of the head stand position sensor 20a is at the position of the electrode MSP in the positive direction, and the F
Assuming that the brush B2 of the F/REW gear position sensor 20b is located at the position of the electrode R, the brushes B1 and B
2 refers to the state in which movement from these positions to the positions of electrodes NP and C has been completed, respectively.

After the preparation for the playback operation is completed as described above, the magnetic tape, which had been running in the opposite direction, will now run in the forward direction. The count is counted down by a pulse based on an electric signal generated by one of the two. When the content of the count reaches zero due to this countdown, the correction for the magnetic tape that ran during the transition from the detection of the song interval to the completion of playback operation completion is completed, and after a predetermined length of time, when the mute time has elapsed, The mute operation that was interrupted during the song selection operation is canceled and the playback signal is now output.

The above operation can be summarized as shown in FIG. That is, when selecting a song while traveling in the forward direction, the FMS detects one song between songs, and in response to this detection, the mechanical section is brought into the RMS state. Song interval detection is performed during this RMS. At the same time, control is performed to put the mechanism into the PLAY state in accordance with this inter-musical detection;
The amount of tape travel until the LAY operation is ready is measured by counting pulses.

This measured value is counted down according to the running of the tape after entering the PLAY state, and tape correction ends when the value reaches zero. Thereafter, when the muting is completed after a certain period of time, the muting operation during the song selection operation is canceled.

The above explanation is about the song selection operation when the vehicle is traveling in the forward direction, but in the case of the song selection operation when the vehicle is traveling in the reverse direction, the explanation after switching from FMS to RMS in the above explanation applies as is. The explanation will be omitted.

In the above-described embodiment, a case has been described in which the tape position shift is corrected when the mechanical section is switched to the playback state in response to the detection of the song interval during the song selection operation by running in the reverse direction. However, the present invention generally This method can be applied to correction of tape position deviation due to delay in canceling the double speed mechanism, and examples thereof are as follows.

1) Correction when performing ATSC at double speed operation 2) FF/R
Tape slack correction when EW operation is canceled 3) FMS/RMS
Correction at the time of release of operation The present invention is equally applicable to the case where not audio signals but digital signals are recorded on the magnetic tape.

In addition, in the apparatus according to the present invention described above, since the tape position can be corrected, the need for a ratchet or the like of the reel stand braking mechanism is eliminated, and the number of parts in the mechanism section can be reduced.

〔Effect of the invention〕

As described above, according to the present invention, the positional deviation of the tape is detected based on the delay in the response speed of the mechanism (by measuring the tape length during the transient operation of the mechanism), and based on this, the tape position is detected. Since the positional deviation is corrected, for example, when applied to a device with a song selection mechanism, the conventional drawbacks such as cutting off the beginning of a song or falling in,9 are eliminated, and the beginning of a song can be found reliably and accurately. It becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the device according to the present invention, FIG. 2 is a waveform diagram showing waveforms at specific points in FIG. 1, and FIG. 3 shows the main part of the operation of the device in FIG. 4 is an explanatory diagram of the operation of the device shown in FIG. 1, FIG. 5 is a block diagram showing an example of the conventional device, FIG. 6 is a waveform diagram showing various states in FIG. FIG. 7 is an explanatory diagram of the operation of the apparatus shown in FIG. 5. 14...Microcomputer, 17a, 17b...
・Rotation sensor, 20... Mechanical sensor section, 20a...
Head stand position sensor, 20b... Gear position sensor for FF/REW. Figure 4) - Side

Claims (1)

[Claims] tape position detection means for detecting a predetermined position on the magnetic tape from a playback signal in a fast-forward state of the magnetic tape; and a tape position detection means for detecting a predetermined position on the magnetic tape from a playback signal when the magnetic tape is in a fast-forward state; and a tape position detection means for changing the running of the magnetic tape from the fast-forward state to a playback state in response to the detection of the predetermined position on the magnetic tape by the detection means. a state detecting means for detecting that the mechanism changes from a fast-forwarding state to a playback state due to switching by the switching means; 1. A magnetic recording and reproducing apparatus comprising: a tape running amount measuring means for measuring a tape running amount until a state is detected.