JPS58122659A - Intermusic detector for record player - Google Patents

Abstract

PURPOSE:To prevent malfunction due to noise, by operating a differential signal of an output of a pair of inter-recording sensors at the tip of a pickup arm, and searching the intermusic with a signal generated at the disc center from the center of intermusic. CONSTITUTION:The tip of the picup arm is provided with a light emitting element 49 and two photodetectors 50a, 50b closely to form the intermusic sensor 46. The output of the detectors 50a, 50b is amplified OP1, OP2 and differentially amplified 66. The circuit 66 has an operational amplifier OP3 taking two sensor outputs as an inverting and a non-inverting input, the two sensor outputs are differentially amplified to form the S-shaped intermusic signal as shown in Figure. This signal is inputted to an operational amplifier OP4 forming an intermusic comparator 68 taking a reference level as -VTH. Thus, the intermusic only is detected correctly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a song interval detection device, and more particularly to a song interval detection device for a record player equipped with a so-called automatic song selection function.

The object is to provide a song interval detection device that can distinguish between song gaps and lead-in and exit grooves, and reliably detect only search-time song gaps (including lead-in grooves).

The song interval detection device according to the present invention derives a differential signal of each output of a pair of song interval sensors provided near the tip of the pickup arm, and out of the differential signals between the song interval center and the disk center. The structure is such that an inter-song signal is generated based on a signal waveform generated on the side, and a search for an inter-song period is performed based on this inter-song signal.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic perspective view showing a record player according to the present invention, (a) is a closed state, (h
) indicates the oven (Copen) condition. As shown in FIG. 1, a record player l according to the present invention
Most have a so-called front-loading configuration in which a disc (not shown) can be set from the front of the main body. That is, operL//' provided on the operation section 2 on the front of the main body.
When the close key 2a is pressed, the slide base 4 on which the turntable 3 is mounted moves forward and protrudes to the front of the main body (open state), in this open state, after placing the disc on the turntable 3, it opens again.
By pressing the /close key 2a, the slide base 4 is moved back to the closed state and a disc is set. Further, in the closed state (a), fully automatic performance with automatic music selection is possible, and in the open state (6), performance can be performed by manual operation. Although the door to be provided on the front side of the main body is not shown, the door also opens and closes in conjunction with the slide base 4 during the oven/close operation.

The pickup arm 5 is located at the rear end of the slide base 4 in order to reduce the width of the slide base 4 and to facilitate setting of the disc on the turntable 3, and this position is used as a rest position. This pickup arm 5 has an area X shown in FIG.
It performs a lead-in operation by rotating in the opposite direction, and after reaching position B, which is slightly outside the outer edge of the 30 LP disc, it rotates in the T direction toward the pre-specified song interval. It is. The rotation range of the pickup arm 5 from the rest position A to the position B is controlled by two drive systems: a first drive system (hereinafter referred to as a mechanical drive system) that mechanically drives the pickup arm 5, and a first drive system that mechanically drives the pickup arm 5; is selectively driven by a second drive system (hereinafter referred to as DD drive system) that directly drives the DD drive system by electromagnetic force.

An arm stopper 1a is provided on the player housing side, and an arm stopper 4a is provided on the slide base 4 side. When the slide base 4 is stored in the housing, the pickup arm 5 is in contact with the arm stop collar l (2). (rest-in). At this time, as will be described later (in FIG. 3), the spring 30 is interposed between the binoquaso 7' plate 27 and the magnet holder 4, so
Fixed to the big up plate 27 and mechanical drive system 7
The pin member 12 driven by the pin member 12 resists the biasing force of the spring 30 and waits in a disabled state. When the slide base 4 moves forward, the arm stopper 1a and the pickup arm 5 are separated, so that the bottle member 12 is no longer pressed and the pickup arm 5 rotates backward until it comes into contact with the arm stop flange 4a. By doing so, the pickup arm 5 does not get in the way when the disc is attached or removed, and the space factor during storage is improved.

3 and 4 are a schematic plan view showing the drive mechanism of the pickup arm and a perspective view of each part before assembly. In FIGS. 3 and 4, the mechanical drive system 7 includes a rotary member 8 that has gears on its outer periphery and is rotatable and coaxially or concentrically with the rotation center axis of the pickup arm 5, and a drive source. a rotary motor 9; a power transmission unit io that is composed of a combination of gears and transmits the driving force of the rotary motor 9 to the rotating member 8;
The latch mechanism 11 selectively engages the bin member 12 that is interlocked with the pickup arm 5 in accordance with the rotation of the rotation member 8, thereby resting the pickup arm 5. It is driven in a first rotation range from position A to position C1 near the center of the tire. The latch mechanism 11 includes a swing arm 14 pivotably supported by a pin 13 implanted in the rotating member 8;
Guide pin 1 provided integrally with this swing arm 14
5 and a guide hole 16 formed in the rotating member 8 to guide the swinging arm 14 to the engagement position P or non-engagement position Q where the swinging arm 14 can be engaged with the bottle member 12 described above. When the swinging arm 14 is in the engagement position PK, it cooperates with a gripping member 18 provided on the rotating member 8 to grip the bottle member 12. The pickup arm 5 is rotated in accordance with the rotation, and when the pickup arm 5 reaches the position C, it is reversed to the disengaged position Q and disengaged from the bin member 12, thereby stopping the drive of the pickup arm 5. do.

On the other hand, the DD drive system 19 includes, for example, a movable magnet provided on the pickup arm side and a fixed coil provided on the arm stand side.
0 cm L The pickup arm 5 is driven in the second rotation range to position B slightly outside the outer edge of the P disk. The movable magnet y 20 is fixed to a rotating shaft (not shown) of a pickup arm 5 rotatably held by a bearing 22 of an arm stand 21 so as to face the yoke n at a predetermined distance from each other. , magnetized in the thickness direction so that magnetic poles different in the circumferential direction are arranged alternately in correspondence with drive coils and speed detection coils, which will be described later.

On the other hand, a board 24 is attached to the arm stand 21 so as to be located between the magnet 20 and the yoke 23, and this board has a pair of parts that cooperate with the magnet 20 to rotate the pickup arm 5 by electromagnetic force. drive coil 25 (Z, 25b and pickup arm 5
A speed detection coil 26 for detecting the rotational speed of is fixed. A pair of drive coils 25fZ and 25b are arranged with a positional relationship of approximately 180° around the rotation center axis of the pickup arm 5, and the speed detection coil opening drive coil 25a,
25b in a positional relationship of approximately 90 degrees. The pickup arm 5 is located at position D on the drive coils 25α and 25b.
(as shown in the third diagram), a drive current is supplied from the horizontal drive circuit described later, and when the position C is reached, the drive system is switched from the mechanical drive system 7 to the DD drive system 19, and the second rotation is started. Drive is performed by the DD drive system 19 in the range (position D to position B), and at the same time, the output of the speed detection coil 26 is fed back to the horizontal drive circuit to control the speed of the pickup arm 5. In addition, in order to ensure the switching from the mechanical drive system 7 to the DD drive system 19, an overramp portion (position D-C) is provided in the first and second rotation ranges.
has been established.

For example, a pickup arm 5 is located below the magnet 20.
A pickup plate 27 is provided rotatably with respect to the zero rotation axis, and this pickup plate 27 connects to the magnet holder 2 through a long hole 27a formed in the pickup plate 27.
The pickup arm 5 is
The magnet is attached to the holder 28 and rotates together with the pickup arm 5 so that the position can be adjusted in a horizontal plane relative to the pickup arm 5.

A spring 30 is interposed between the pickup plate 27 and the magnet holder, and the aforementioned pin member 12 is fixed to the pickup plate 27.

The pickup plate 27 has disk sizes of 17 cm, 25 cm, and 30 an, as shown in FIG.
The slits 31α, 31b and 3 corresponding to each lowering position of
1C and slits 31d and 31e for setting the tissue size determination zone are formed. The edge 31f of the pickup plate 27 is the turntable 3.
This corresponds to the position near the spindle (DD drive start position). A lowering position sensor 32 is provided to detect the absolute rotational position of the pickup arm 5 by being located on the rotation locus of these pick-up arms 7, and the lowering position sensor 32 is generated at the DD drive start position. 32 output from mechanical drive system 7 to DD drive system 19 during lead-in operation.
Switching to is carried out. Furthermore, a large number of slits, grooves 33 and holes 34 are formed on the Vinocqua tongue plate 27 to enable end detection.
On the rotation locus of this slit portion 33, end sensors 35a and 356 for human phase and B phase are located. This physiognomy,
End detection is performed based on the outputs of the B-phase end sensors 35a and 35b. These sensors 32,
35a and 35b are light-emitting and light-receiving elements disposed to face each other with the pickup plate 27 in between;
As shown in FIG. 4, it is housed in a holder mounted on an arm stand 21.

In FIGS. 3 and 4, the mechanical drive system 70 rotating member 8
1 is the elevation cam 37 of the pickup arm 5
On the elevation cam 37, one end of the elevation shaft held movably downward is in contact with the other end of the elevation shaft. is pickup arm 5 t-J
It is fixed to an elevation plate 39 holding a. A spring 50 is interposed between the arm stand 21 and one end of the elevation shaft to bias the elevation shaft in a downward direction. On the mechanical chassis 41 on which the mechanical drive system 7 is mounted, there are switches 42 and 43 for detecting the completion of raising and lowering the pickup arm 5 due to the elevation operation, and the rest position of the pickup arm 5 (the position shown in FIG. 3). A switch bias is provided to detect A). These switches are operated by being pressed by a cam portion 8a provided on the outer periphery of the rotating member 38. The ascent completion detection switch 42 is bi-quad during the lead-in operation.

It is also used to detect the position just before the pull arm 5 starts descending due to its elevation operation. That is, during the lead-in operation; the mechanical drive system 7 that precedes the rotation of the pickup arm 5 by the DD drive system 19 in the second rotation range after the drive operation of the pickup arm 5 is completed is activated by the ascent completion detection switch. 42, the robot is placed on standby just before the final stroke in which the elevation operation is performed in response to the output of the controller 42. The rotating member 8 of the mechanical drive system 7 starts rotating again in order to lower the pickup arm 5 in response to a lowering command issued when the pickup arm 5 reaches a desired song interval.

FIG. 6 shows a schematic perspective view of the pick-up arm assembly including the DD drive system 19 and the big door knob plate 27 mentioned above, and the head shell 45 attached to the tip of the pickup arm 5 is used to record discs. It is equipped with a song-to-song sensor at its tip that uses the difference in reflectance between the sound grooves and songs to distinguish between songs and sound grooves. As shown in FIG. 7, the song interval sensor 46 uses a single light emitting element 49 such as a light emitting diode located in a vertical plane including the tip of the cartridge 47 as a common light source. Two light-receiving elements 50 (Z.

50b, and are preferably arranged as close to the needle tip as possible. As shown in FIG. 8, the light-receiving element 5oa precedes the light-receiving element sob when the pink-up arm 5 rotates toward the outer circumference of the disk, and the light-receiving element 49
It receives the reflected light from the disk 6 based on the irradiated light from the disk 6, and generates an output according to the amount of the received light. On the other hand, the light receiving element 5
ob precedes the light-receiving element 50a when the pickup arm 5 rotates toward the inner circumference of the disk, and similarly, the light-emitting element 4
An output corresponding to the amount of light reflected from the disk 6 based on the irradiated light from the disk 9 is generated. And the light receiving element 50 (Z, s
ob generates outputs as shown in (α) and Cb) in FIG. 9, respectively, during the song interval 6α of the disc 6, and when the stylus tip 48 of the cartridge 47 is located above the center of the song interval, the output (a) and (6) have the relationship shown in FIG. 9 with respect to the center of the song.

FIG. 10 is a block diagram showing an example of the control section, and FIG. 11 is a circuit diagram showing a specific example of a portion of FIG.

In FIGS. 1O and 11, 51 is a system controller that centrally controls all the units in each block, and is, for example, a 4-pit microcomputer. This system controller 51 includes an operation section 2.
, various command signals from the switch section 52 , a signal indicating the operating state of the system from the switch section 52 , a position signal from the position sensor section 53 , a song interval signal from the song interval sensor section 54 , etc. are applied. In response to these signals, the system controller 51
sends a control signal to the DD drive system 19, the decoder circuit 58, and the like.

The operation section 2 is provided with all operation keys for automatic music selection, command keys for commanding various operations, and light emitting diodes for displaying the operations of these keys. The arm drive unit 56 is the system controller 51
This is an interface that drives the arm drive motor (rotary motor) 9 of the mechanical drive system 7 in response to the control signal from the lowering completion detection switch 43 and the output signal from the lowering completion detection switch 43. The loading drive unit 57 is an interface that drives the loading motor 6o for moving the slide base 4 (FIG. 1) in response to a control signal from the system controller 51. Synchro circuit 58 is an interface circuit for sending a recording synchro signal to a chip (not shown) that is selectively connected in response to a control signal from the system controller 51 when the cross switch 61 is turned on.

Here, the synchro output terminal 62 of this system is connected to the remote pause terminal of Chibuchitsuki, and the synchro output terminal 62 is set to the recording pause state, and the synchro switch 61 is
When turned on, the deck is not in the recording state while the player is playing, and the deck is in the pause state when the player is in the elevation state or while the arm is moving.

The key is designed to repeat Bose ← recording (pause release) every time one pulse is input to the pause terminal. The switch section 52 is provided with switches 42 and 44 for detecting the completion of raising of the big-up arm 5 and the rest position, as well as switches 63 and 64 for detecting the closed state and open state of the player body.

FIG. 12 is a circuit diagram showing a specific example of the inter-song sensor part 54 in FIG. 10. In this figure, the inter-track sensor 4
6 consists of a single light emitting element 49 and two light receiving elements 50a and 50h as explained in FIG.
0(Z, 50h) each receives reflected light from the disk 6 and generates an output according to the amount of received light.The two sensor outputs are amplified by an amplifier circuit 65 including operational amplifiers op, , and op2, and then differential It is supplied to the amplifier circuit 66.The two sensor outputs obtained at the output terminal of the amplifier circuit 65 have a waveform as shown in FIG. 13(a).
), (a) shows the song interval, (b) shows the lead-in groove, and (c) shows the lead-out groove. The differential amplifier circuit 66 is an operational amplifier O that uses the two sensor outputs as inverting and non-inverting inputs.
P3, and by differentially amplifying the two sensor outputs, an output waveform as shown in FIG. 13(b) is obtained. It is clear from FIG. 13(h) that the differential signal between songs has a substantially S-shaped curve.

The differential signal becomes the inverting input of the operational amplifier 0P40 that constitutes the inter-song comparator 68. The operational amplifier op has the reference level -vTH as a non-inverting input, and supplies its output to the system controller 51 as an inter-music signal. The reference level -vTH changes according to the sensitivity selected by the sensitivity changeover switch 70. Here, at the output terminal of the operational amplifier OP4, a positive high-level differential signal is obtained also in the lead-out groove as shown in FIG. 13(b), so the reference level is set to +vT.
If it is set to H, the groove derived at the time of searching between songs will also be determined to be between songs. Therefore, by setting the reference level to -vTH as in the present application, only the intervals between songs can be detected.

FIG. 14 is a circuit diagram showing a specific example of the DD drive system 19 in FIG. 10. The DD drive system 19 includes drive coils 25α and 25b connected in series, a horizontal drive circuit 73 that supplies drive current to the drive coils, a speed detection coil 26, and amplifies the minute detection voltage of this detection coil. It is composed of an amplifier circuit 74. The horizontal drive circuit 73 is
It is composed of a differential amplifier 75 consisting of an operational amplifier OP8 and an inverter 76 consisting of an operational amplifier OP8 and a gain of 1, and the band servo signal from the inter-track sensor part 54 is connected to the inverting input terminal of the operational amplifier OP. A speed servo signal from the speed detection coil 26 that has been amplified by the amplifier circuit 74 is applied to the input terminal, and the difference between the two with respect to the reference voltage is amplified and current is supplied to the drive coils 25α and 25b, thereby controlling the speed. The pickup arm 5 is driven. The band servo signal and the speed servo signal are supplied to the differential amplifier 75 as necessary by switch means 77 and 78 which are turned on and off under the control of the system controller 51, respectively. The amplifier circuit 74 is an operational amplifier OP.

The horizontal drive circuit 7
3 as a speed servo signal. In the amplifier circuit 74, VR is a volume for offset adjustment.

Here, the band servo operation will be explained.

As explained based on FIG. 13(h), the differential output of the differential amplification circuit 66 in the inter-song sensor portion 54 exhibits a figure-eight curve characteristic as shown in FIG. 15 for the inter-song period. The differential output becomes the band servo signal. Assuming that the needle tip/f 8 has now moved to the outer periphery by x [mm] with respect to the center of the song, then V (
v) band servo signal is generated. In response to this signal, the horizontal drive circuit 73 drives the drive coil 25a.

A current is supplied to 25b, and the needle tip 48 moves in the inner circumferential direction until it is located above the center of the song. Controlling the needle tip 48 in this way so that it is always positioned above the center of the song is called band servo. The band servo operation is controlled so that it starts when the pickup arm 5 reaches the top of the song interval during automatic song selection and ends when the down is completed.

When the pickup arm 5 is operated by the system controller 51 based on commands such as start/stop from the operating section 2 and other automatic music selection plays, the drive voltage generated by the drive voltage generation circuit 79 (FIG. 11) is It is applied to the inverting input terminal of the operational amplifier OP8, and is applied to the terminal 9 of the system controller 51 in the drive voltage generation circuit 79.
, 10 and 11, the moving speed and direction of the pickup arm 5 can be controlled by changing the value and polarity of the drive voltage with respect to the reference voltage based on control signals indicating outer circumferential direction, inner circumferential direction, and high-speed drive output from the pickup arm 5.

In FIG. 14, a cancellation coil 80 is integrally provided with the drive coil 25b and is connected in series with the speed detection coil 26. This canceling coil 80 cancels the noise component generated by the drive coils 25a and 25b, thereby reducing the S of the output of the speed detection coil 26.
This is to increase the /N and improve the stability of the speed servo. That is, when current is applied to drive coils 25a and 25b to drive pickup arm 5, magnetic flux is generated by this current, and alternating current flows to speed detection coil 26, creating a noise component. By placing it in series with the AC component, the alternating current component can be canceled. A variable resistor VFL2 is connected in parallel to the canceling coil 80, and this variable resistor VR
2, the amount of cancellation is variable.

FIG. 16 is a circuit diagram showing a specific example of the position sensor part 53 in FIG. 10, which includes a light emitting section 53A having three light emitting diodes and a light receiving section 53A having three phototransistors arranged opposite to these light emitting diodes. The lowering position sensor 32 and the A-phase and B-phase end sensors 35a and 35b are configured by the light emitting portion 53B.
The pink-up plate 27, which is interlocked with the pickup arm 5, rotates through the gap between A and the light receiving section 53B. Light receiving section 53
Each output from B is waveform-shaped by inverters 82 to 84 constituting a waveform shaping circuit 81, and is outputted to the disk 6 at the timing shown in FIG. 17 during the lead-in operation of the pickup arm 5. The lowering position signal (a) is sent to the terminal 4 of the system controller 51 as the A phase end signal (A
) is applied to the terminal 40, and the B-phase end signal (C) is applied to the terminal 39.

Next, the operation of the configuration described above will be explained.

Assuming that the disc 6 is already set, the player body is in the closed state, and the pickup arm 5 is in the rest position, and in this state, when the operating section 2 key is turned on, the terminal 26 of the system controller 51 becomes L level. , the rotary motor 9 of the mechanical drive system starts rotating in the arm lead-in direction, and auto lead-in starts.

At this time, the "start" light emitting diode (hereinafter abbreviated as LED) lights up, and at the same time, the terminal 36 becomes L level, so the turntable 3 rotates. When the pink-up arm 5 continues lead-in and the needle tip 48 comes near the center spindle, the output of the lowering position sensor 32 is input to the terminal 41 of the system controller 51 at a level (at this time, the A phase and B phase end Sensor 35 (Z, 35
In response to this, terminals 9 and 11 become L level, operating the DD drive system and entering the DD drive range.

1) After entering the D drive system, the mechanical drive system is released, and at this point the drive system of the pickup arm 5 is switched from the mechanical drive system to the DD drive system. Even after the latch is released, the mechanical drive system operates in the lead-in direction ahead of the DD drive system, and waits just before the start of the elevation down operation.

The lead-in operation by the DD drive system continues at high speed, and during this lead-in operation, the system controller 51 performs song interval detection based on the song interval signal from the song interval sensor part 54 inputted to the terminal 38. Then, the size of the disc is determined based on the lowering position signal from the lowering position sensor 32 inputted to the terminal 41 and the above-mentioned song interval signal.

Regarding size determination, first, a plurality of size determination zones corresponding to the disk size are set in the disk radial direction based on a drop position signal as shown in FIG. 17(a) obtained in response to the lead-in operation.

That is, in Fig. 17 (α), from the spindle position to point A is 17 crn%, from point A to point B is 25z, and from point B to point C (30 m
Corresponding to the position outside the outer edge of the disc) up to 30 cr
The size determination zone is n. As shown in the flowchart of Fig. 18, if the inter-track signal is input between the spindle position and the A point during lead-in, the disc size is set to 17 crn, and the inter-track signal is input between the spindle position and the A point. If there is, it will be set to 25 crn, and if there is a gap between the songs between points B and C, it will be set to 30 crn, and the final size will be determined when the pink up arm 5 reaches the C point, that is, outside the 30 crn board. If there is no disc, the size is not determined and the pickup arm 5 returns to the rest position. In the case of a 17crn disk, there is always a track interval (first track) between the spindle position and A, and since there is no track interval for A and -C disks, the final set size is 17crn. On the other hand, 30crn
In the case of a disc, there may be a gap between tracks between the spindle position and A, or between A and H, so the size may be 17C? It is set to F+ or 25cm, but since there is always a song interval (first song) between B and C, it is finally set to 30α.

When the pickup arm 5 reaches the C point, the output of the descending position sensor 32 changes to L level (A phase end sensor 35 (Z output goes to L level, B phase end sensor 35b
When the output of the system controller 5 becomes H level), the system controller 5
1 terminal 10 is L level, terminal 9 is H level (terminal 11
(remains at L level), and the drive direction of the DD drive system is reversed, whereby the pickup arm 5 moves at high speed toward the lowered position according to the disk size determined by the size determination.

In the case of a 30-accuracy disc, the DD drive system is stopped in response to the first fall of the output of the lowering position sensor 32 (at this time, the output of the A-phase end sensor 35a is at the ■] level).
Since overshoot occurs due to the high-speed movement of the pickup arm 5, after the DD drive system is stopped, the DD drive system is started again to drive the pickup arm 5 in the outer peripheral direction at a low speed, and the lowering position sensor 32 is activated. The pink amplifier arm 5 is stopped in response to the rise of the output. FIG. 19 shows the movement of the pickup arm 5 at this time. By making such a movement, the pickup arm 5 can be moved quickly and the accuracy of the lowering position can be improved.

The system controller 51 stops the DD drive system and at the same time operates the mechanical drive system that has been in a standby state until then to start the elevation down operation. When the cam portion 8α (shown in the third figure) of the rotating member 8 of the mechanical drive system turns on the lowering completion detection switch 43, the rotary motor 9 of the mechanical drive system stops and the down operation is completed. At the same time, the mute signal output from the system controller 51 terminal]2 disappears (becomes L level) simulating circuit 8
By turning off the transistor Q constituting 7, the muting relay 88 is turned off and the performance state is entered.

The end of the performance is detected by human face and B phase end sensor 35σ.

35b, but since such a method is well known, its details will be omitted.

When the end of the performance is detected, an H level mute signal is output from the terminal I2 of the system controller 51, and by turning on the transistor Q3, the muting relay 88 is turned on to cut off the audio signal system. is set to H level and the mechanical drive system is driven in the return direction to raise and return the pickup arm 5 to return to the rest position. When the terminal 36 returns to the rest position, the terminal 36 becomes the [I level] and the turntable 3
stops.

If the repeat key is on when the end of the performance is detected, the pickup arm 5 performs the auto lead-in operation described above. Also, the pickup arm can be returned to the rest position by pressing the stop key at any time during lead-in, elevation up or down, or during performance. At this time, repeat is forcibly canceled.

Next, we will discuss the automatic song selection function. The automatic song selection function is a function in which the pickup arm 5 leads into a desired song specified by the song selection key, and the song selection keys are "1" to "8".
There are 8 songs up to 8, and you can select up to the 8th song at will.

When the pickup arm 5 is in the rest position in the closed state, pressing the song selection key starts the lead-in operation in the same way as the auto lead-in, and as shown in FIG. 17th
After reaching point 1-C) in the figure (α), the pickup arm 5 moves at high speed in the direction of the inner circumference of the disc and heads toward the designated song. In FIG. 20, it is possible to change the designated song by pressing another music selection key again from the rest position to point (a), but it is impossible to change from (7) to (a).

When the designated song is the second or subsequent song, song interval detection and band servo are performed based on the song interval signal from the song interval sensor part 54. Between-song comparator 6 of the inter-song sensor part 54
8, since the operational amplifier OP4 has a reference level of -VTR for the differential signal (a) of the two inter-song sensor outputs shown in FIG. 21, the inter-song signal is detected at the timing shown in (b). Emitted. The stop position of the pickup arm 5 is controlled based on this inter-song signal (b), and the system controller 51 first responds to the falling edge (a) of the inter-song signal (b) input to the terminal 38. TeD
Stop the D drive system.

At this time, since the pickup arm 5 had been moving at high speed until then, it overshoots and stops.

Thereafter, the DD drive system is operated again to move the pickup arm 5 in the outer circumferential direction at high speed, and the moving speed is switched to low speed in response to the rising and falling signals (b) of the inter-song signal. In response to the falling edge (c) of (b), the DI drive system is stopped. At this time, the system controller 5I operates the mechanical drive system that has been in the standby state to start the elevation down operation, and at the same time, the terminal 35 goes to L level and the collector of transistor Q2 (shown in Figure 11) goes to H level. By doing so, the switch means 77 (shown in the 10th and 14th figures) is brought into conduction to turn on the band servo, and in response to the band servo signal (differential signal of the outputs of the two inter-musical sensors) from the inter-musical sensor part 54. Te DD
The pickup arm 5 is driven in a horizontal plane by a drive system. With this band servo, even if there is eccentricity of the disc, it is possible to follow the deviation between tracks as the disc rotates, and lower the needle tip 48 of the pickup arm 5 to position it at the center of the track. FIG. 21(C) shows the movement of the pickup arm 5 from the detection of a song interval to the elevation down. The operation after completion of elevation down is the same as during auto lead-in.

By pressing the music selection key during elevation up, down, or during performance, a so-called direct music selection operation is performed in which a designated music piece is lead-in. Also, when performing automatic song selection or direct song selection,
If repeat is on, after the performance ends, the pickup arm 5 again leads into the previously designated song and performs the performance repeatedly.

In automatic song selection or direct song selection, if more songs than the number of songs recorded on the disc are specified, for example, if the fifth song is specified on a disc containing four songs, the system controller 51 will move to the outermost position (in Fig. 20). (7)
17(h))
For example, if there is no designated song interval by the time a count of 5 is reached, the song selection operation is stopped, and during repeat performance, the repeat is canceled and the pink-up arm 5 is returned to the rest position.

Next, the auto-manual lead-in operation will be explained. When a disc is placed in the open state and the manual center key is then turned on, the pickup arm 5 performs lead-in from the rest position in the same manner as in the automatic lead-in operation. During this lead-in operation, the system controller 51 counts the fall of the descent position signal (α) from the descent position sensor 32 input to the terminal 41 as shown in FIG. 22, and the count value reaches 95N. At this point, the DD drive system is stopped. Since the mechanical drive system precedes the DD drive system from the middle of the lead-in and waits just before the start of elevation down, the pickup arm 5 stops in the up state. During this lead-in operation, the pink-up arm 5 may be held down by hand, for example, so if the pickup arm 5 does not come within the DD drive range even after a predetermined period of time has passed after the manual lead-in instruction, a manual cut operation is performed. If the count value does not reach 15' even though it is within the DD drive range, the pickup arm 5 stops in the amplifier state. The position sensor part 53 shown in FIG. 17 determines whether or not it is within the DD driving range.
The descent position signal (α) from
b), carried out based on (C).

Even during manual performance, the pickup arm 5 returns to the rest position through an elevation-up operation in response to end detection, as in the above-mentioned performance. In any case during manual lead-in, manual performance, manual up or down, the big amplifier arm 5 can be returned to the rest position by turning on the manual key. Also, with the manual key (when the pink-up arm 5 is within the DD drive range in the oven state), pressing the start key locates the pickup arm 5 in the inner circumferential direction, and pressing the stop key locates the pickup arm 5 in the outer circumferential direction. I can do it. At this time, the start J LED blinks while moving toward the inner circumference, and the stop J LED blinks while moving toward the outer circumference. still,
If the start or stop key is pressed before the elevation has been raised, the above operation will be performed after the elevation is raised to A.

In the above embodiment, the case where the present invention is applied to an offset arm has been described, but the present invention can also be applied to a linear tracking arm.

As described in detail above, in the present invention, a differential signal is derived from each output of a pair of track-interval sensors provided near the tip of the pickup arm, and of this differential signal, the center of the disc is more sensitive than the center of the track. If the signal waveform generated on the side, for example, the differential signal, is a waveform as shown in FIG. In order to reliably distinguish between tracks (including the lead-in groove) and lead-out grooves without erroneously detecting noise components generated near the lead-out groove, only the gaps between songs are searched. can be reliably detected.

[Brief explanation of the drawing]

1 is a schematic perspective view showing a record player according to the present invention, in which (a) shows the closed state and (b) shows the open state, FIG. 2 is a plan view showing the operating area of the pickup arm, and FIG. Figure 4 is a schematic plan view showing the drive mechanism of the pickup arm and a perspective view of each part before assembly, Figure 5 is a plan view showing the positional relationship between the pickup plate and a part of the position sensor, and Figure 6 is the pickup arm. FIG. 7 is a schematic perspective view showing the arm assembly; FIG. 7 is a schematic perspective view showing the herad shell; FIG. 8 is a diagram showing the positional relationship between the song sensor and the song gap; FIG. 9 is a diagram showing the positional relationship between the song sensor and the song gap. A diagram showing the output characteristics, FIG. 10 is a block diagram showing an example of the control section, FIG. 11 is a circuit diagram showing a specific example of a part of FIG. 10, and FIG. 12 is a specific example of a part of the inter-song sensor. circuit diagram,
Fig. 13 is a waveform diagram of each part in Fig. 12, Fig. 14 is a circuit diagram showing a specific example of the DD drive system, Fig. 15 is a diagram showing the relationship between song intervals and band servo signals in band servo, Fig. 16 The figure is a circuit diagram showing a specific example of a part of the position sensor, Fig. 17 is a timing chart showing the output of each sensor in Fig. 16, Fig. 18 is a flow chart for explaining the operation of size determination, and Fig. 19 20 is a diagram showing the arm movement during automatic lead-in, FIG. 20 is a diagram showing the arm movement during automatic song selection, and FIG. 21 is a diagram illustrating the operation when transitioning from song interval detection to band servo. , 22nd
The figure is a diagram for explaining the operation during auto-manual lead-in. Explanation of symbols of main parts 2... Operating unit 5... Pink up arm 7... Mechanical drive system 8... Rotating member 9... Rotating motor 11... Launch mechanism 19... DD drive System 20...Magnet 25 (Z, 25b
... Drive coil 26 ... Speed detection coil 27 ... Pickup plate 32 ... Lowering position sensor 35 (Z, 356 ... A phase, B phase end sensor 42 ... Ascent completion detection switch 43 ... ...Descent position completion detection switch 46...Song sensor 51...System controller 53...Position sensor part 60...Loading motor 70...Sensitivity switching switch 79...Drive voltage generation circuit 80 ... Cancellation coil 87 ... Muting circuit applicant Pioneer Co., Ltd. agent Patent attorney Motohiko Fujimura

Claims (1)

[Claims] a pair of inter-track sensors provided near the tip of the pickup arm; means for generating differential signals of respective outputs of the pair of inter-track sensors; What is claimed is: 1. A track interval detection device for a record player, comprising means for generating an inter-track signal based on a signal waveform generated by the record player, and searching for a track interval based on the inter-track signal.