JPS5954075A - Record disk reproducer - Google Patents

Abstract

PURPOSE:To correct the deflection angle of a tone arm in a simple and assured way, by using a stepping motor to drive the arm, detecting the deflection angle of the arm and driving a motor via a counter circuit to set the deflection angle at zero. CONSTITUTION:A tone arm 1 is displaced by a stepping motor 16, and a detector 15 for arm deflection angle consisting of a triangular cut part and a light emitting element is provided at the fulcrum of the arm 1. The signal corresponding to the deflection angle detected by the detector 15 is supplied to a system control circuit 18. Then a count indicating signal is supplied to a counter circuit 17 so as to set the arm deflection angle at zero. The circuit 17 adds and subtracts the count number and delivers a driving signal to drive the motor 16 via a driving circuit 19. Thus the arm 1 is displaced. Thus it is possible to correct the deflection angle of the arm 1 in a simple and assured way.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a record disc reproducing device, which drives a stepping motor with a drive signal of a phase corresponding to a count number, and is capable of reproducing a record disc with a simple configuration. The purpose is to provide.

FIG. 1 shows a block diagram of an example of a conventional record player. In the figure, reference numeral 1 is a Hoehn arm equipped with a pickup for reproducing signals recorded as sound grooves on a record disc 2. The Hoehn arm accepts operating conditions using a key switch, etc., and determines arm deflection angle, which will be described later. The record disc 2 is linearly displaced in the radial direction by a DC motor 5 rotated by the outputs of the supplied system control circuit 3 and drive circuit 4. The deflection angle of the tone arm 1 is fed back to the system control circuit 3, and a servo is applied so that the tone arm 1 follows the reproduction track. The signal reproduced by the pickup of the tone arm 1 is amplified by an amplifier circuit (not shown) and converted into an audio signal.

A shielding plate 8 is attached to the motor 5 via a pulley 6 and a worm gear 7 (it is pulled and is output according to the rotation of the motor 5)' A1 - The pulse from the interrupter 9 is sent to the counter 1 by the counting circuit 10. On the other hand, a reference position detector 11 is provided at the armrest position (reference position) of the tone arm 1, and the reset signal from the detector 11 output when the tone arm 1 reaches the armrest 1~ position is It is supplied to the counting circuit 10 to reset it. As shown in FIG. 2, the shielding plate 8 is provided with notches 8a at intervals of a pitch α, while the interrupter 9 is provided with (((
1//1. ) α-1-nα) Two sets of light-emitting/light-receiving elements 9a and 9b are provided at an interval of radians (n is an integer), and are taken out by rotation of the shielding plate 8 in the addition direction and the subtraction direction. The rotation direction of the motor 5 is detected by a combination of the output of the light emitting/light receiving element 9a shown in FIG. 3(A) and the output of the light emitting/light receiving element 9b shown in FIG. 3(B).

When playing, for example, by detecting whether or not light is blocked by a record placed on a turntable, a record size detection circuit 12 detects the size of the record. 2 is detected and supplied to the system control circuit 3, from which a count number corresponding to the lead-in position of the record 2 of that size is set in the target storage circuit 13. The counting circuit 10 counts the pulses from the photointerrupter 9, and the count is increased or decreased depending on the moving direction of the arm 1. A signal corresponding to the position of the arm 1 is extracted from the counting circuit 10 and supplied to the comparison circuit 14. be done. Comparison circuit 1/I compares the count number corresponding to the visible position of arm 1 from counting circuit 10 and the target count number from target value storage circuit 13, and this comparison error value is supplied to system control circuit 3. , the drive circuit 4 moves the arm 1 to the desired lead-in position so that the comparison error value becomes zero.

5- At the fulcrum of the arm 1, there is a triangular notch 1 as shown in Figure 4.
A shield 8i1a with a hole h is attached (J is attached, and an arm deflection angle detector 15 with a light emitting/light receiving element 15a provided on both sides is attached c) through the shield 8i1a.
According to the deflection in the direction of displacement and the direction perpendicular to the direction of displacement (that is, the direction tangential to the record groove), an output (FIG. 5) of a magnitude corresponding to the magnitude of the deflection is extracted.

In the performance state, a signal corresponding to one deflection angle of the arm 1 is taken out from the deflection angle detector 15 and supplied to the system control circuit 3, and the signal is outputted from the system control circuit 3 so that the deflection angle of the arm 1 is approximately equal to that of the arm 1. A drive control signal for displacing the record disc 1 is taken out and supplied to the motor 5, and the base of the arm 1 is displaced linearly in the radial direction of the record disc so that its pickup follows the playback track of the record disc 2. controlled. During the performance, pulses from the photointerrupter 9 are counted in the counting circuit 10, and the lead-out position or further inner position is determined according to this count and the size of the record being played, which is set in the target value storage circuit 13. When the count number of the circumferential position matches, the displacement of the base of the arm 1 in the linear direction is stopped. At this point, the arm 1 is raised by the arm lifter, or a repeat operation is performed.

However, this conventional record playback device is complicated because it requires a reduction mechanism such as a pulley 6 and a worm gear 7, and a pick-up position detection mechanism such as a shielding plate 8 and a photo interrupter 9. The installation of each component requires adjustment, which has the disadvantage that it cannot be constructed at low cost.

The present invention eliminates the above-mentioned drawbacks, and an embodiment thereof will be described with reference to FIG. 6 and subsequent figures.

FIG. 6 shows a block system diagram of an embodiment of the record disc reproducing apparatus according to the present invention, in which the same components as in FIG. 1 are given the same numbers. In the same figure, 16 is, for example, a hybrid type linear stepping motor;
A configuration driven by two sine wave signals a and b of an advanced phase shown in FIG. 8 (A) and a delayed phase shown in FIG. The positive rotation (■) and the negative rotation (◎) are determined by the combination of these signals a and b.

This linear stepping motor 16 has a two-phase drive configuration as shown in FIG. 9, and the magnetic field of the permanent magnet rotor (arm base) 16a is inputted with the magnetic field signals a and b, and the magnetic field is generated by the coil currents of the coils Ca and Cb. The relative position between the arm base 16a and the stator S is determined by the balance between the rear l\base 16a and the change in coil current.
The stator S and the stator S move relative to each other.

The counting circuit 17 has an addition mode and a subtraction mode determined by, for example, a 2-bit addition/subtraction drive instruction signal from the system control circuit 18, and in this determined mode, resets the signals from the reference position detector 11 to J. :
Start counting based on the point of reset,
Figure 8 (△), (1
3), while outputting the stepping motor drive signals a and b shown in FIG. In other words, as shown in FIG. 10, the time T
Then, the lap 1111to according to the count number.

The pulse signal C having H level at to, t, ... is integrated by the integrating circuit shown in FIG. 11, and the period to, to
.

A drive signal a having a level corresponding to tl...

b is taken out.

In this way, the counting circuit 17 is configured to be reset at the M1 position of the arm 1 and output an arm drive signal according to the count number, so the output count number depends on the displacement position of the arm base 16a. There is. Counting circuit 17
is updated to a drive signal corresponding to the count number every time the count number changes, and the count number corresponds to the position of the arm base 16a unless there is an abnormality.

Now, when record 2 is placed on the turntable,
As in the conventional example, the size of the record 2 is detected by the record size detection circuit 12, and the count numbers corresponding to the lead-in and lead-out positions of the record 2 are set in the target value storage circuit 13. Ru. The comparator circuit 14 compares the count number corresponding to the lead-in position from the target value storage circuit 13 and the count number corresponding to the position of the arm base 16a from the counting circuit 17.
The compared error value is supplied to the system control circuit 18, and a division instruction signal for making the error value zero is taken out.

The counting circuit 17 adds or subtracts the J runt number to this counting instruction signal, and a drive signal based on the calculation result is taken out and supplied to the drive circuit 19. The drive signal amplified by one drive circuit is supplied to the stepping motor 1G, and the arm base 16a is displaced to the desired lead-in position by the output of the stepping motor 16. When the arm 1 reaches the lead-in position, the arm lifter 20 is activated and the arm 1 is lowered onto the record.

On the other hand, a control signal d for rotating the turntable at a rotation speed corresponding to the record size is taken out from the system control circuit 18, thereby causing the record disc 2 to rotate at a predetermined rotation speed.

10- Next, during the performance, the arm 1 taken out from the deflection angle detector 15
A signal whose magnitude corresponds to the deflection angle is supplied to the system control circuit 18, and a counting instruction signal for changing the arm base 16a so as to make the deflection angle approximately zero is taken out from the system control circuit 18 and sent to the counting circuit. 17
supplied to

The counting circuit 17 adds or subtracts the count number according to the count instruction signal, and a drive signal corresponding to the calculated count number is taken out, and the arm base 16a is displaced so that the swing angle of the arm 1 is always approximately zero during the performance. be done.

Here, calculate the distance from the reference position of arm 1 during playback,
The amount of phase change (radian) of the drive signal of the counting circuit 17 from the reference position of arm 1 to the reproduction 1i2 position is φ, and the amount of phase change (radian) of the drive signal per count in the counting circuit 17 is Δφ 1 of the drive signal The displacement amount of the rotor 16a of the stepping motor 16 with respect to the period (one pitch of the stator S) is calculated by the count number of the P1 counting circuit 17 as N.
Then, φ−NΔφ L=((NΔφ)/2π)XP−(φ/2π)XP.

When the performance ends, the arm 1 is raised by the folding of the arm lifter 20, and the count corresponding to the armrest 1 position set in the target value storage circuit 13 and the count in the counting circuit 17 corresponding to the current arm base 16a position are The comparator circuit 14 compares the numbers with the numbers, and a count instruction signal is taken out from the system control circuit 18 so that the comparison error value becomes zero.

As a result, the stepping motor 16 is driven by the drive signal from the counting circuit 17, and the arm base 16a returns to the armrest position.

Note that the target value storage circuit 13 not only sets the count number according to the lead-in position and lead-out position of the arm 1 at the start position and end position of the record as described above, but also sets the count number according to the lead-in position and lead-out position of the arm 1 at the start position and end position of the record disc. The count number corresponding to the lead-in position and lead-out device is set at the beginning and end position of the song on the record being played, and the desired song is automatically started and ended. Even if you do it like that.

Further, as the stepping motor, a rotary stepping motor may be used in addition to the linear stepping motor as in the above embodiment.

As mentioned above, the record playback device according to the present invention includes 1 to 1.
- a stepping motor that displaces the base of the turn arm in the radial direction of the record; a counting means that is supplied with a counting instruction signal, adds and subtracts the counted number, and outputs a stepping motor drive signal with a phase corresponding to the counted number; Since the control means is supplied with a detection signal corresponding to the deflection angle of the tone arm and outputs a counting instruction signal to the counting means to make the deflection angle approximately zero, a conventional shielding plate is not required for detecting the position of the tone arm. There is no need to use a motor or photo interrupter, and since a stepping motor is used, a predetermined moving speed corresponding to the counting speed of the counting means can be easily obtained, and there is no need to use a conventional reduction mechanism such as a pulley or worm gear. There is no need to use 13-.As a result, the device can be configured more easily than conventional ones, and the installation of the above-mentioned parts does not require adjustment, so it can be configured at low cost. target value storage means for setting a target count number corresponding to the target position of the arm relative to the record; comparison means for comparing the target count number from the target value storage means with the count number from the counting means; A count instruction signal is supplied with a detection signal corresponding to the deflection angle to make the deflection angle approximately zero, and a count instruction signal is supplied with a comparison error signal from the comparing means to make the comparison error signal zero. Since it is equipped with a control means that outputs output to the counting means, when applied to a fully automatic player, etc., the first arm can be accurately lowered and raised to the lead-in position and lead-out position corresponding to the record size. It has features such as obtaining.

[Brief explanation of drawings]

FIG. 1 is a block system diagram of an example of a conventional device, and FIGS. 2 and 3 (Δ) and (B) are diagrams showing the positional relationship 14- between the shielding plate and the photo ink clubter used in the conventional device, respectively. 4 and 5 are respectively a schematic plan view of the arm deflection angle detector and its output characteristic diagram. FIG. 6 is a block system diagram of an embodiment of the device of the present invention. Figure 7 (A). (B) is a diagram showing the driving of a stepping motor by a rectangular wave, Figures 8 (A) and (B) are waveform diagrams of stepping motor drive signals, Figure 9 is a schematic diagram of a general linear stepping motor, and Figure 10. 11 is a pulse signal waveform diagram of a phase corresponding to the number of counts obtained in the counting circuit, and FIG. 11 is a circuit diagram of an integrating circuit in the counting circuit. 1...Tone arm, 2...Record, 13...
・Target value storage circuit, 14... Comparison circuit, 15... Deflection angle detector, 16... Linear stepping motor, I
Ga...Arm base, 17...Counting circuit, 18.
...System control circuit. Patent applicant: Representative of Victor Japan Co., Ltd. Patent attorney: Tadahiko Ito 1
5-

Claims (1)

[Claims] (1) Detect the deflection angle of the tone arm with respect to the tangential direction of the sound groove of the record being played, and use the detection signal to move the base of the tone arm in the radial direction of the record so that the deflection angle becomes approximately zero. A record playback device equipped with a mechanism for linearly displacing the tone arm includes a stepping motor that displaces the base of the tone arm in the radial direction of the record, and a stepping motor that is supplied with a counting instruction signal to add and subtract counts. a counting means for outputting a drive signal for the stepping motor with a phase corresponding to the count; and a counting instruction signal supplied with a detection signal corresponding to the deflection angle of the tone arm to make the deflection angle approximately zero. A record playback device comprising: a control means for outputting an output to the counting means. ■ i relative to the tangential direction of the sound groove of the record being played
A mechanism is provided for detecting the deflection angle of the tone arm and moving the base of the tone arm so that the deflection angle becomes approximately zero according to the detection signal. In the record playback device, a stepping motor displaces the base of the tone arm in the radial direction of the record, and a stepper motor that displaces the base of the tone arm in the radial direction of the record, and
a counting means that is reset from 1 to 1, is supplied with a counting instruction signal, adds and subtracts a count number, and outputs a drive signal for the stepping motor with a phase corresponding to the count number; and a target position of the tone arm with respect to the record disc. a target value storage means for setting a number, a comparison means for comparing a target count number from the target value storage means and a run number corresponding to the counting means, and a deflection of the tone arm. The counting instruction signal is supplied with a detection signal corresponding to the angle to make the deflection angle approximately zero, and the counting instruction signal is supplied with a comparison error signal from the comparing means to make the comparison error signal zero. A record playback device characterized by comprising a control means for outputting a signal to the counting means.