JPH0240137A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To stably perform a focus drawing operation by operating both focus driving device and track driving device and driving a focus drawing means accordingly. CONSTITUTION:The focus driving device 5b, a focus actuator driving circuit 16 and a focus drawing device 17 are operated to move an objective lens 5 in the direction of A. At this time, a signal (e) is inputted from a control circuit 21 via a changeover switch 51 to a tracking initial operation device 50 in order to move the objective lens 5 in the direction of B (or B') at the first stage of the focus drawing operation time, and a tracking actuator driving circuit 20 is impressed with an output voltage, so as to operate the track driving device 5a. Then, a holder 26 and a sleeve 27 are also rotated together with the objective lens 5 around a shaft 28, where resultant driving force 54 of driving force 52 caused by the focus driving device 5b and driving force 53 caused by the track driving device 5a is acted. By this method, the focus drawing operation of the objective lens is smoothly performed.

Description

[Detailed Description of the Invention] [Industrial Application] This invention is an optical information recording/reproducing device, in particular, a focus servo means for autofocusing a disk surface of a compact disk, a video disk, etc., within a control area. This invention relates to an autofocus initial retraction device for retraction.

[Conventional technology]

6 to 11 show the schematic configuration of the main parts of a conventional optical information reproducing device, and FIG. 6 shows the schematic configuration of the optical system/drive system and the drive system of the optical information recording/reproducing device A configuration explanatory diagram showing circuit blocks to be operated; FIG. 7 is a plan view showing an example of the configuration of part 0 in FIG. 6;
The figure is a sectional view of the center side from the direction of arrow C in FIG. 7, FIG. 9 is an explanatory diagram illustrating the change in reflected light from the disk on the photodetector section in FIG. 6, and FIG. 10 is the diagram as shown in FIG. FIG. 11 is an explanatory diagram of the waveform obtained by converting the reflected light in the focus error signal detector into an electric signal, and FIG. 11 is an explanatory diagram of the waveform applied to the focus actuator drive circuit in FIG.

In Fig. 6, 1 is a light source, 2 is a collimating lens, and 3 is a light source.
The half mirror 14 is a light beam emitted from the light source 1. The light beam 4 passes through the collimating lens 2 and becomes a parallel beam.

5 is an objective lens, 5a is a track drive device, and 5b is a focus drive device, and arrows B, B', and A respectively.
, A'' direction of the objective lens 5.

Reference numeral 6 denotes a disk serving as an information recording carrier, which is rotationally driven by a rotational drive source 7 .

8 is an information bit, and the information content is expressed by the presence or absence of a recess or the length.

9 is the reflected light from the disk 6; 10 is a photodetector for photoelectrically converting the reflected light; 11 is a light bulb for illuminating the disk B; 112 is a lens barrel; and 13 is an outer wall of the lens barrel. 100 is an optical pickup main body. L is the distance between the objective lens 5 and the disk 6. 14 is a focus error signal detection unit, 15 is a focus control device, 1B is a focus actuator drive circuit, 17 is a focus retraction device, 18 is a tracking error signal detector, 19 is a tracking control device, 20 is a tracking actuator drive circuit, 21 is a The control circuit 22 is a changeover switch. In FIGS. 7 and 8, 23a, 24a
, 25a are a track coil, a track magnet, and a track yoke that constitute the tracking drive device 5a in FIG.

26 is a holder that holds the objective lens 5 and the track coil 23a, 27 is a sleeve integrally formed with the holder 26, and 28 is the holder 26 shown in the arrow A-A'' in the figure.
, a shaft for sliding and rotation when moving in the B-B' direction, 2
9 is an explosive material, 30 is a substrate, and 31a, 32a, 33a are focus drive devices in FIG. 6! These are a focus yoke, a focus coil, and a focus magnet that constitute the lens 15b.

9 shows changes in the shape of the reflected light 9 on the photodetector 10 when the distance between the objective lens 5 and the disk 6 in FIG. 6 changes, and FIG. 10 shows the focus error signal detection W
14 shows changes in the focus error signal due to changes in the distance described above. FIG. 11 shows the focus initial pull-in device 17.
shows the voltage applied to the focus actuator drive circuit 1B.

Next, the operation will be explained.

In FIG. 6, the disk 6 is picked up by the optical pickup body 10.
In order to record and reproduce data at 0, it is necessary to maintain the distance between the disk 6 and the objective lens 5 to match a known optical focal length. Normally, when recording or reproducing on or from the disc 6, after the disc 6 is mounted on the rotary drive source 7, the focus drive device 5b is operated so that the distance of the objective lens 5 matches a predetermined optical focal length. (hereinafter referred to as focus pull-in) In the focus pull-in operation, signal a from the control circuit 21 activates the focus pull-in device 17 via the changeover switch 22, and the focus actuator drive circuit 1
When the voltage shown in FIG. 11 is applied to 6, the focus drive device 5b is activated to move the objective lens 5 in the direction of arrow A shown in FIG. While the objective lens 5 is moving in the direction of arrow A, the reflected light 9 on the photodetector w10 exhibits a shape change as shown in FIG. 9 as the distance $L between the disk 8 and the objective lens 5 changes, and a focus error signal is generated. Detection If! At step 14, changes in the focus error signal shown in FIG. 10 are monitored. When the distance $L between the objective lens 5 and the disk 6 reaches a state where the focus error signal shown in FIG. 10 indicates the level of the focus range shown in the figure, the control circuit 21
generates a switching signal and switches the changeover switch 22.

From the control cycle #821, the signal C operates the focus control device Wt15, and the distance between the objective lens 5 and the disk 6 is maintained at the optically focused position. After that, the tracking II is controlled by the signal d from the control circuit 21.
I! The control device 19 operates and the tracking actuator drive amount! The track drive device 5a is operated via 820 to move the objective lens 5 so that the light spot 11 is located on the pit 8 on the disk 6. By controlling the objective lens 15 in the focus direction and the track direction, even if the disk 8 rotates and moves in the arrow A-A' and arrow B-B'' directions with the rotation of the rotational drive source 7, the disk A light spot 11 is accurately irradiated onto the upper pit 8 to control the recording and reproduction of information.

In FIGS. 7 and 8, the focus drive device 5b that controls the focus pull-in operation is a focus yoke 31.
a, a focus coil 32a, and a focus magnet 33a. Further, when the objective lens 5 moves in the directions of arrows A, A', B, and B', the sleeve 27 on the holder 26 moves on the shaft 28.

[Problem that the invention attempts to solve]

Since the conventional optical information recording/reproducing device is configured as described above, the sleeve 2 is closed during the focus pull-in operation.
7 and the shaft 28 will affect the focus pull-in operation, and if scratches, dust, etc. adhere to the inside of the sleeve 27 and the shaft 28, even if the focus drive device is activated,
If the applied voltage is low due to static friction, the sleeve 27 will not operate, but if the applied voltage exceeds a certain level, it will operate, but the operating speed is high and the objective lens 5 will pass through the focus pull-in range. As a result, there were problems such as the inability to perform a focus pull-in operation.

This invention is as described above! It is an object of the present invention to provide an optical information recording/reproducing device capable of smoothly pulling in the focus of an objective lens.

[Means to solve the problem]

The optical information recording/reproducing apparatus according to the present invention applies magnetic energy to the electromagnetic actuator to the focus control means and the track 1tI! which is necessary to bring the irradiation light of the objective lens to the focal position where it converges on the information plane. This is obtained from both control means.

Further, the optical information recording/reproducing device according to the present invention has a focus 111I! One means is provided with an inverter for inverting the electrical energy applied to the electromagnetic actuator during application.

[Effect]

Optical information ik in this invention! During the focus pull-in operation of the objective lens, the η regeneration device activates the focus drive device and the track drive device to move the objective lens in the track direction at the beginning of the focus pull-in operation, thereby starting the focus pull-in operation tangentially and smoothly. can be done.

Further, in the optical information recording/reproducing device of the present invention, during the focus retraction operation of the objective lens, the inverter provided between the focus retraction valve device and the focus actuator drive circuit allows the objective lens and the disk to be aligned at the initial stage of the operation. Since the objective lens is moved once in the direction opposite to the focal point position and then moved in the direction of the focal point position, the focusing operation can be started smoothly.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

Fig. 1 is an explanatory diagram showing the schematic structure of the optical system and drive system of the optical information recording/reproducing device according to the present invention and the circuit blocks for operating the drive system, and Fig. 2 shows the output voltage pattern from the tracking initial operation device. FIG. 3 is an explanatory diagram showing the operating force on the axis of the sleeve. In FIG. 1, 50 is a tracking initial operation device, 51 is a changeover switch, in FIG. 3, 52 is a driving force by a focus drive device, 53 is a driving force by a track drive device, and 54 is a composite drive of driving forces 52 and 53. It is power. In addition,
In the figure, other components are the same as the conventional example.

Next, the operation will be explained.

When performing a focus pull-in operation between the objective lens 5 and the disk 6, the objective lens 5 is moved in the direction of arrow A by operating the focus drive device 5b, focus actuator drive circuit 16, and focus pull-in device, as in the conventional example. . At this time, a signal e is input from the control circuit 21 to the tracking initial operation device 50 via the changeover switch 51 so as to move the objective lens 5 in the direction of arrow B (or B') at the beginning of the focus pull-in operation.
The output voltage shown in FIG. 2 is applied to the tracking actuator drive circuit 20 to operate the track drive device 5a. At this time, the holder 26 and the sleeve 27 also rotate along the axis 28 in the B (or B') direction together with the objective lens 5. In FIG. 3, between the sleeve 27 and the shaft 28,
A combined driving force 54 of the driving force 52 by the focus driving device 5b and the driving force 53 by the track driving bag w5a acts. Note that the output voltage pattern from the tracking initial operation device 50 (FIG. 2) is output only at the initial stage of focus pull-in, and before the output from the focus error signal detector 14 shown in FIG. 10 reaches the focus pull-in range. The initial tracking operation is completed.

FIG. 4 is a configuration explanatory diagram showing a schematic configuration of the optical system/drive system of an optical recording/reproducing apparatus according to another embodiment of the present invention and a circuit block for operating the drive system, and FIG. 5 is a configuration explanatory diagram showing the output voltage from the inverter. It is an explanatory view showing a pattern. In FIG. 4, 5S is an inverter, and the other components are the same as in the conventional example.

In FIGS. 4 and 5, when performing a focus pull-in operation between the objective lens 5 and the disk 6, the objective lens 5 is operated by the focus drive device 5b.

The focus actuator drive circuit 1B and the focus retracting device [17 are operated, but the focus retracting device 17
Since the reversing plate 55 is interposed between the focus actuator drive circuit 1B and the focus actuator drive circuit 1B,
The output signal a from the inverter 55 becomes the signal a,
The signal line shows the output voltage pattern shown in FIG. As a result, the objective lens 5 first moves in the direction of arrow A' in the figure via the focus actuator drive circuit 16 and the focus drive device 5b, and then moves in the direction of arrow A. The subsequent operations are the same as in the conventional example.

=11 [Effects of the Invention] As described above, according to the present invention, the focus retracting means of the optical information recording and reproducing device is configured to operate both the focus drive device and the track drive device, so that the drive force of both is used. Since a rotational resultant force can be obtained, and the rotational resultant force is larger than the driving force of the focus drive device alone, the focus retraction operation can be performed stably against changes in static friction between the sleeve and the shaft. 1. Against scratches and dust inside the sleeve and on the shaft. This has the effect of providing stable operation.

In addition, since the focus retracting means is made to operate in the opposite direction to the normal operation direction in the initial state, and starts operating in the normal direction from a certain point, the reaction force is used as the driving force (plus This has the effect that the focus pull-in operation can be performed stably against changes in static friction between the sleeve and the shaft, and stable operation can be obtained against scratches and dust inside the sleeve and on the shaft.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing a schematic configuration of an optical system/drive system of an optical information recording/reproducing apparatus according to an embodiment of the present invention and circuit blocks for operating the drive system, and FIG. An explanatory diagram showing the output voltage pattern, Figure 3 is an explanatory diagram showing the operating force on the axis of the sleeve,
FIG. 4 is a configuration explanatory diagram showing a schematic configuration of the optical system and drive system of an optical information recording and reproducing apparatus according to another embodiment of the present invention, and a circuit block for operating the drive system, and FIG. 5 is an illustration of the output from the inverter. FIG. 6 is an explanatory diagram showing the voltage pattern. FIG. 8 is a sectional view of the central side taken from the direction of arrow C in FIG. 7, and FIG. 9 is a top view of the photodetector of the reflected light from the disk in FIG. 6. FIG. 10 is an explanatory diagram of the waveform obtained by converting the reflected light in FIG. 6 into an electrical signal by a focus error signal detector. FIG. 11 is an explanatory diagram of the focus actuator drive circuit in FIG. 6. FIG. 2 is an explanatory diagram of waveforms applied during initial focus pull-in. 5 is an objective lens, 5a is a track drive device, 5b is a focus drive device, and 6 is a de. 'Suffix, 8 is the information l/rack, 9 is the reflected light, 11 is the light beam, 15 is the focus control device, 17 is the fu, the scum retracting device, 1st is the dragging full J equipment, 26 is the holder, 27 is a sleeve,
28 is an axis, 50 is a tracking initial operating device, and 55 is an inversion I#. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Agent Masuo Oiwa (2 others)

Claims (2)

[Claims] (1) An objective lens that converges and irradiates a light beam onto an information track of an optical information recording medium and receives reflected light from the optical information recording medium, a holder and a sleeve integrally fixed to the objective lens, and the sleeve an electromagnetic actuator that moves the objective lens, holder, and sleeve; and electric energy applied to the electromagnetic actuator to control the movement of the objective lens, holder, and sleeve, and irradiate the information surface. In an optical information recording/reproducing apparatus equipped with a focus control means and a track control means for converging light, the electromagnetic An optical information recording/reproducing device characterized in that electric energy applied to the actuator is obtained from both the focus control means and the track control means. (2) The optical information recording/reproducing apparatus according to claim 1, wherein the focus control means is provided with an inverter for inverting the electric energy applied to the electromagnetic actuator during application.