JPS6159670A - Optical pick-up driving method - Google Patents

Abstract

PURPOSE:To shorten access time by returning an output of a position detecting means to a motor for tracking at the time of seek, and driving and controlling an optical pick-up so that a relative displacement may be 0 for an optical pick-up carriage. CONSTITUTION:A carriage is shiftably installed in the R direction orthogonal to a track on an optical disk, and the carriage is shifted in the R direction by a motor 54 for seek. An optical pick-up 10 is relatively supported to the carriage in the R direction displaceably. At the time of seek, an output from a position detecting means 52 is fed back through a position compensating circuit 48 and a switch SwB to a motor 22 for tracking and the pick-up 10 is driven by the motor 22. The driving is executed to that a relative displacement in the R direction of the pick-up 10 for the carriage may be 0, a plate spring, etc., supporting the pick-up 10 will hardly deflect and vibration of the pick-up 10 becomes very small. Thus, access time can be shortened.

Description

[Detailed description of the invention] (Technical field) The present invention relates to a method for driving an original pick amplifier.

(Prior art) The original pickup writes information on tracks formed in a spiral or concentric form on the original disk.
It is also known as a device for reading information written on a track.

To write or read information using the original pickup, there is a soaking operation that brings the original pickup to a desired track position, a tracking operation that maintains the proper positional relationship between the original pickup and the track while writing or reading, and A focus song operation is required to focus the light from the original pickup onto the track.

The optical pickup is supported on a carriage, and the soaking operation is performed by moving the carriage.

A leaf spring is generally used to support the original pickup on the carriage, but this leaf spring causes the following problems. In other words, when a seek operation is performed, the leaf spring is bent due to the inertial force acting on the original pickup.
Even after the carriage stops at a predetermined position, the VC source pickup vibrates relative to the carriage due to the elastic force of the leaf spring, and until this vibration subsides, writing and reading cannot be performed, resulting in a long access time. One way to solve this problem is to use a locking mechanism using an lenoid or the like to fix the original pickup to the carriage during the seek operation, but the locking mechanism has a considerable KN. Therefore, there is a problem that the energy for the soak operation increases.

(Objective) The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to provide a novel source pickup driving method that effectively solves the above-mentioned vibration problem of the source pickup.

(composition) The present invention will be explained below.

The optical vinyl knob driving device to which the present invention is applied includes a base pickup, a carriage, a seek motor, a tracking motor, a position detection means, and a plurality of leaf springs.

The carriage is movable in a direction substantially perpendicular to the tracks on the original disk, which is called the R direction.

The optical pickup is supported on the carriage by a plurality of leaf springs, and is movable in the R direction relative to the carriage.

The /-travel motor is used to move the carriage in the R direction.

The tracking motor is mounted on the carriage and is used to displace the original pickup in the R direction relative to the carriage.

The position detection means is provided on the carriage and detects the displacement of the original pickup in the R direction relative to the carriage.

Now, one special advantage of the present invention is as follows. That is, at the time of seek, the output of the position detection means is fed back to the tracking motor to operate the tracking motor, and the optical pickup is driven and controlled so that the displacement relative to the carriage of the original pickup is zero.

By controlling the drive in this way, the displacement of the original big amplifier relative to the carriage during seek is effectively reduced, and the vibration of the original pickup when the carriage stops at the target position is significantly reduced. , this can be quickly attenuated.

The following is an explanation based on specific actual examples.

Figure 2 shows an example of a pickup drive device to which the present invention is applied.

An optical pickup 10 having a focus song function has an objective lens 12 and four leaf springs 14A, 14B, 1
4C114DKj"' (supported by 16 carriages,
By bending the leaf spring 14A and the like, it can be displaced in the R direction relative to the carriage 16.

22 tracking motors are mounted on the carriage 16 to displace the original pickup 10 in the R direction within the range of deflection of the leaf spring 14A and the like.

The tracking motor 22 is a linear motor, the magnet and yoke are fixed to the carriage 16, and the coil is fixed to the original pickup 10.

Further, a light shielding plate 24 fixed to the original pickup 10,
A sensor 26 fixed to the carriage 16 constitutes position detection means. This position detection means will be described in detail later.

The carriage 16 includes two rods 18A parallel to the R direction,
18B via linear bearings 20A and 20B, and is movable in the R direction.

A coil 28 is also fixed to the carriage 16, and this coil 28 passes through the yoke 30Kj in the R direction.

A yoke 32 is arranged parallel to the yoke 50, and a plate-shaped magnet 34 is fixed to the surface of the yoke 62 on the yoke 60 side.

The yokes 30, 32, the magnet 64, and the coil 28 constitute a seek motor. That is, the magnet 34 is magnetized in the thickness direction, and a uniform magnetic field is formed between the yoke 60 and the magnet 64. Coil 28 crosses this field, so passing current through coil 28 causes R
An electromagnetic force in the direction is generated, and the carriage is moved in the R direction.

A linear scale 66 is arranged parallel to the R direction, and a linear sensor 38 for reading the linear scale 16 is fixed to the carriage 16.

The position detection means will now be explained with reference to FIGS. 6 and 4.

In the previously mentioned j5K, the position detection means is composed of a light-shielding plate 24 and a sensor 26 fixed to the original pickup 10, and the sensor 26 is as shown in FIG.
Light emitting element 26A, light receiving element 26B, and slit plate 2
'6C.

The tip of the light shielding plate 24 is located at the tip when the original pickup 10 is at the reference position with respect to the carriage 16, in other words, when the original pickup 10 is not displaced in the R direction relative to the carriage 1B. , located at the center of the slit of the slit plate 16C.

In Figure 4, reference numeral 26C1 indicates the slit plate 26C. If the horizontal direction is the position of the tip of the light shielding plate 24, the light receiving element 2 is liquefied at this position.
The output of 6B changes as shown by curve F in Figure 274. Therefore, if the output of the position detection means, that is, the output of the light receiving element 26B is FO, at this time, the optical pickup 10 is at the reference position with respect to the carriage 16, and the carriage 1
The relative displacement amount in the R direction with respect to 6 is 0.

Figure 1 is a block diagram showing an example of a circuit for operating the original pickup drive device shown in Figure 2.

The signal obtained from the original pickup 10 is amplified by an amplifier (not shown) and then input to an analog calculation circuit 40. A focusing signal X, a tracking signal Y, and a data signal Z are outputted from the analog decoding circuit 40. Data signal 2 is input to control circuit 64.

A control circuit 64 controls the entire drive device.

Now, at the time of seek, the recontrol circuit 60 turns on the switch SwD and the switch SwB in response to a command from the control circuit 6d.

A signal A whose phase is shifted by 90 degrees is output from the linear sensor 68.
, B are generated, and these signals A and B are amplified by an amplifier (not shown) and sent to the control circuit 60 and the speed signal generation circuit 5.
The signal A is further applied to the phase compensation circuit 56. The speed signal generation circuit 58 applies a speed signal for moving the carriage downward to the seek motor 54 to the seek motor 54 via an amplifier (not shown).

The /-driving motor 54 has a coil 28, a yoke 30, 32. It is composed of a magnet 64.

On the other hand, control a-/L/circuit 6Q&t, signals A, BK
Therefore, the difference between the target position and the current position is detected, and data for speed determination is output to a D/A converter (not shown). The reference signal generation circuit 62 generates a speed adjustment signal in accordance with the output of the D/A converter.

This speed adjustment signal is added to the speed signal from speed signal generation circuit 58. The speed of the carriage is thus adjusted according to the speed adjustment signal.

When the carriage 16 reaches the target position, the control circuit turns off the switch SwD and at the same time turns off the switch SwE.
Turn on.

Note that during seek, the period until the switch SwD is turned off is called a seek mode, and the period after the switch SwE is turned on is called a positioning mode.

This positioning mode signal A from the linear sensor 38
It is carried out by That is, the signal A is input to the phase compensation circuit 56, and the seek motor 54 is driven by the output from the phase compensation circuit 56, and this driving is performed as if the output of the signal A was at a low level.

Now, at the time of seek, the output from the position detection means 52 is amplified by an amplifier (not shown), and then the phase compensation circuit 4
8. It is fed back to the truck blowfish motor 22 via the switch SwB and another amplifier not shown,
Light pink up 10 by tracking motor 22
to drive. This drive is performed by the position detection means 52 (light shielding plate 2
4 and sensor 26) is Fo
(Figure 4) In other words, carriage 1
This is done so that the relative displacement amount of the original pickup 10 in the R direction with respect to 6 becomes O. As a result of this control, during seek, there is almost no deflection in the leaf spring 14A, etc. that supports the optical pickup 10, and when the positioning of the carriage 16 is completed, the vibration of the original pickup 10 is extremely small. , this vibration quickly subsides.

When the vibration of the original pickup 10 subsides, the seek operation ends.

Then, the control circuit 60 switches the switches SWB, S
Turn off wE and switch SwA, Sw instead.
Turn on C to convert the mode to write or read mode.

In the write or read mode, the focusing signal X obtained from the analog calculation circuit 40 is fed through the phase compensation circuit 42 and an amplifier circuit (not shown) to the actuator for focusing the focus puffer movement (which is built in the original Pink Up 10). and a focusing operation is performed.

Anna again. The tracking signal Y obtained from the tracking calculation circuit 40 is fed back to the tracking motor 22 via the phase compensation circuit 46 and an amplifier (not shown), and a tracking operation is performed.

At this time, the output of the position detection means 52 is output from the phase compensation circuit 50.
and an amplifier (not shown), the seek motor 54
will be given feedback. In response to this, the seek motor 54 outputs the output signal F f Fo of the position detection means 52.
The carriage 16 is driven so as to

Therefore, the carriage 16 moves following the displacement of the original pickup 10 in the R direction due to the tracking operation. Therefore, during the tracking operation, the deflection of the leaf spring 14A etc. that supports the original pickup 10 is reduced,
The low frequency gain in tracking operation increases. In addition to this, tracking operations with large amplitudes caused by eccentricity of the original disk can also be easily performed.

(Effects) As described above, according to the present invention, a novel source pickup driving method can be provided.

In this driving method, when seeking, the amount of displacement of the optical big amplifier relative to the carriage is detected, and the tracking motor is operated to set the amount of displacement to 0.
Since the vibration of the original pickup due to the inertial force acting on the original pickup when the original pickup is accessed can be effectively prevented, the access time can be shortened. Furthermore, since the position detection means is a quantity, even if it is mounted on the carriage, the energy consumption of the seek motor will not be so great. Note that the position detection means may be constructed using a coder/coder and a decoder.

[Brief explanation of drawings]

Figure 1t-1 is a block diagram showing an example of a drive circuit system of an original big amplifier drive device in which the present invention is put into practice, and Figure 2 is a block diagram showing an example of an original pickup drive device in which the present invention is put into practice. The perspective view, Figures 2 and 6, and Figure 4 are diagrams for explaining the position detection means. 10... Original pickup, 14A, 14B,
14C, 14D... Leaf spring, 16... Carriage, 2
2... Tracking motor, 24... Light shielding plate,
26...sensor (constitutes position detection means together with light shielding plate 24)

Claims (1)

[Claims] A carriage movable in the R direction substantially perpendicular to the tracks on the optical disk, a seek motor for moving the carriage in the R direction, an optical pickup, and the optical pickup mounted on the carriage. a plurality of leaf springs supported on the carriage so as to be movable in the R direction relative to the carriage; and a tracking motor provided on the carriage for displacing the optical pickup in the R direction relative to the carriage. and a position detection means for detecting an amount of displacement in the R direction relative to the carriage of the optical pickup, the output of the position detection means being fed back to the tracking motor at the time of seek, 1. An optical pickup driving method, comprising driving and controlling an optical pickup so that the displacement relative to a carriage of the optical pickup is zero.