JPH08171736A - Disk reproducing device - Google Patents

Abstract

PURPOSE: To perform highly accurate skew adjusting while maintaining a distance constant between a recording medium disk and a pickup. CONSTITUTION: Pickup up and down movement mechanisms 18 and 18' for individually moving up and down both ends of a pickup 15 provided to be movable in the radial direction of a recording medium disk 33 in the moving direction are provided. By individually operating the pickup up and down movement mechanisms 18 and 18', the pickup is moved slantingly against the recording medium disk.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel disc reproducing apparatus. More specifically, it is an object of the present invention to provide a new disc reproducing apparatus capable of highly accurate skew adjustment while keeping the distance between the recording medium disc and the pickup constant.

[0002]

2. Description of the Related Art In recent years, in a disc reproducing apparatus, for example, an optical disc reproducing apparatus, in order to handle a high-definition still image or a high-quality moving image, the capacity of the disc has been increased by high density recording and the size of the device has been reduced. This is required, and as a technical method for achieving this, the wavelength of the laser light source in the optical pickup is shortened and the numerical aperture (NA Nu) of the objective lens is increased.
The miniaturization of the light spot diameter by raising the metallic aperture has been widely studied and developed.

However, when the light spot diameter is reduced and the track pitch is narrowed, the optical axis shifts (skew) with respect to the perpendicular to the disk as compared with the conventional system.
The mutual interference (crosstalk) of the signal with the adjacent track with respect to and the interference between the codes before and after increase, and it becomes difficult to accurately record / reproduce the signal.

As described above, in order to increase the density of the optical disc, it is necessary to keep the optical axis perpendicular to the optical disc with higher precision. Therefore, not only the flatness of the optical disc is sufficiently secured, but also the recording / reproducing apparatus side Therefore, it is desirable to have some kind of correction means.

Under the circumstances described above, conventionally, the mechanism shown in FIGS. 14 and 15 has been proposed and put into practical use.

A is a mechanical deck base, b is a spindle motor fixed to the mechanical deck base a,
A turntable c is fixed to the rotary shaft of the spindle motor b.

Reference numeral d denotes a movable unit, and the movable unit d is chucked on the turntable c by a swing base e, a guide shaft f on the swing base e, and a feed shaft g extending parallel to the guide shaft f. An optical pickup h that is moved in the radial direction of a not-shown optical disc that has been king is provided, and a swing base e is swingably supported by a mechanical deck base a by rotating shafts i and i.

Then, the mechanical deck base a is tilted by a tilting mechanism (not shown) to perform skew correction.

[0009]

By the way, for example, in recording / reproducing of a high-density optical disk, a highly reliable and low-cost skew servo mechanism capable of more accurate control is required.

However, in the mechanism shown in FIGS. 14 and 15, when the movable unit d is tilted, that is, when the skew adjustment is performed, the optical pickup h of the optical pickup h changes due to the difference in the recording / reproducing position on the optical disk. Since the amount of movement in the direction perpendicular to the optical disc is different, recording / reproduction cannot be performed while keeping the distance between the optical disc and the optical pickup h constant at all positions in the radial direction of the optical disc.

Therefore, the change is the optical pickup h
It will be corrected by the above focus actuator. In such a case, since the focus actuator is operated at a position away from its midpoint, the movable part itself of the focus actuator often tilts, and accurate control cannot be performed.

The optical disk recording / reproducing apparatus usually has a disk loading mechanism for inserting and ejecting an optical disk, but since it operates independently of the skew servo mechanism, the mechanism itself operates in two directions, a horizontal direction and a vertical direction. There was a problem that the device had to be complicated because the movement had to be realized.

[0013]

In order to solve the above-mentioned problems, the disk reproducing apparatus of the present invention vertically moves both ends in the moving direction of a pickup provided so as to be movable in the radial direction of a recording medium disk. A pickup vertical movement mechanism is provided, and the pickup vertical movement mechanism is operated separately to tilt the pickup with respect to the recording medium disk.

Another disc reproducing apparatus of the present invention is provided with a turntable vertical movement mechanism for vertically moving a turntable on which a recording medium disc is mounted by the vertical movement mechanism.

[0015]

Therefore, in the disc reproducing apparatus of the present invention,
Since both ends of the pickup in the moving direction can be moved up and down separately, the distance between the pickup and the recording medium disc can be increased regardless of the position of the pickup in the radial direction of the recording medium disc. The pickup can be tilted while always maintaining a constant value, and more accurate skew servo can be performed.

In another disc reproducing apparatus of the present invention, since the turntable can be moved up and down by utilizing the vertical movement mechanism of the pickup, a turntable vertical movement mechanism for loading the disc is provided. As compared with the case where the devices are separately provided, the device does not become complicated, and simplification and downsizing of the device can be easily realized.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the disk reproducing apparatus of the present invention will be described below with reference to the illustrated embodiments. In the illustrated embodiment, the present invention is applied to an optical disc recording / reproducing apparatus.

In the figure, 1 is a mechanical deck base, and 2 is a pickup base.

Reference numerals 3 and 3 denote guide walls which are erected on the mechanical deck base 1 and are arranged in parallel with each other while being separated from each other. A guide groove (not shown) extending in a substantially vertical direction is formed in the guide walls 3, 3, and guided pins 4, 4, ... Projected from a side edge of the pickup base 2 are formed in the guide groove. It is slidably engaged, which allows
The vertical movement of the pickup base 2 is guided.

Notches 5 and 5'are formed substantially at the centers of both ends of the pickup base 2, and sliding pins 6, 6, 6 ', and 6'are formed from opposite side edges of the notches 5 and 5'. Are projected so as to approach each other.

Reference numeral 7 denotes a rectangular cutout hole formed substantially in the center of the pickup base 2, and reference numeral 8 denotes a cutout hole formed at a position continuous with the one cutout 5 of the pickup base 2.

A ball screw 9 is rotatably supported on the pickup base 2 so as to cross the cutout hole 7, and a spur gear 10 is integrally provided at one end thereof.

Reference numeral 11 denotes a feed motor fixed on the pickup base 2, and a gear 12 fixed to the output shaft of the feed motor 11 has an intermediate gear 13 interposed between the spur gear 10 and the gear 12.
Is meshed with. Then, when the feed motor 11 is driven, the ball screw 9 is rotated.

Reference numeral 14 denotes a guide shaft, which is supported on the pickup base 2 so as to cross the cutout hole 7 and extend in parallel with the ball screw 9.

Reference numeral 15 is an optical pickup, which is a base 16
The pickup main body 17 is supported by the. Then, a nut (not shown) supported by the base 16 is screwed with the ball screw 9, and a guide bearing (not shown) also provided on the base 16 is slidably fitted on the guide shaft 14. Then, the nut is fed by the rotation of the ball screw 9, and the optical pickup 15 is guided and moved by the guide shaft 14 and the ball screw 9.

Reference numerals 18, 18 'denote cam drums rotatably supported on the mechanical deck base 1, and pickup cam grooves 19, 19, 19', 19 'are formed on the peripheral surface thereof. Each cam groove 19, 19 'is located at the lower end side and is continuous with one end of the preparatory portion 19a, 19'a whose height does not change and the preparatory portion 19a, 19'a, and the upward movement from there. It comprises parts 19b and 19'b. And
At the lower end of the cam drums 18 and 18 ', a gear portion 20,
20 'is integrally formed.

Reference numerals 21, 21 'are vertical movement motors, 22, 2'.
Reference numeral 2'denotes a worm fixed to the output shaft of the vertical movement motors 21, 21 ', and 23, 23' are rotatably supported on the mechanical deck base 1 and meshed with the worms 22, 22 '. The transmission gears 24, 24 'formed on the worm wheels 23, 23' are meshed with the gear portions 20, 20 'of the cam drums 18, 18'. Therefore, the vertical movement motors 21 and 21 'are
Is driven, the cam drums 18 and 18 'are rotated.

The sliding pins 6, 6 of the pickup base 2 are slidably engaged with the cam grooves 19, 19 of the cam drum 18, and the sliding pins 6 ', 6'are cams of the cam drum 18'. It is slidably engaged with the grooves 19 ', 19'. Therefore, the cam drums 18, 18 'are rotated and the cam grooves 19, 19, 1 of the sliding pins 6, 6, 6', 6'are rotated.
When the position where the sliding pins 9'and 19 'are engaged is changed, the height of the portion of the pickup base 2 where the sliding pins 6, 6, 6', 6'are provided changes.

25 is a spindle motor block,
A motor base 26, a spindle motor 27 fixed to the motor base 26, and a turntable 28 fixed to a rotation shaft of the spindle motor 27 are provided. One end of the motor base 26 is erected on the mechanical deck base 1. It is rotatably supported by the supported support members 29, 29. The sliding pin 3 is attached to the rotation end of the motor base 26.
0 is projected.

A turntable cam groove 31 is formed on the peripheral surface of one of the cam drums 18 and 18 '. The cam groove 31 is located on the upper end side and its height does not change.
Motion part 3 that continues at one end of the
It consists of 1. The sliding pin 30 of the spindle motor block 25 is slidably engaged with the cam groove 31.

When the cam drum 18 rotates and the position of the sliding pin 30 that engages with the cam groove 31 changes, the height of the rotating end of the spindle motor block 25 changes.

The phase relationship between the pickup cam groove 19 and the turntable cam groove 31 in the cam drum 18 is as shown in FIG. 3, and the pickup base 2 moves while the spindle motor block 25 is rotating. It is located at the lowermost part of the range, and the spindle motor block 25 is raised after it is in a substantially horizontal posture.

While the slide pins 6, 6 of the pickup base 2 are engaged with the operating portions 19b, 19b of the cam grooves 19, 19, the slide pin 30 of the spindle motor block 25 is in the cam groove 31. The spindle motor block 25 is engaged with the preparation portion 31a, and thus the spindle motor block 25 maintains a horizontal posture during this period.

Reference numeral 32 is a loading tray, which is supported by the guide walls 3 and 3 so as to be movable in the horizontal direction.

Next, the operation of the above-mentioned optical disk recording / reproducing apparatus will be described with reference to FIGS.

First, when the optical disc is mounted, the slide pins 6 and 6'are set in the preparation portions 19a and 19 'of the cam grooves 19 and 19'.
a is engaged with the end portions on the side of the reaction parts 19b and 19'b (position of 0 degree in FIGS. 3 and 4), and the sliding pin 3
0 is engaged with the lowermost end portion (position of 0 degree in FIG. 3) of the operating portion 31b of the cam groove 31.

Therefore, the pickup base 2 is located at the lowermost end of its moving range, and the spindle motor block 2
Reference numeral 5 is in a slanted state so that its rotating end side is located at the lowermost end. Then, the loading tray 32 is located at the pull-out position that projects outward.

Therefore, the optical disc 33 is inserted into the loading tray 32 which is projected outward, and the loading tray 32 is manually or automatically moved in the horizontal direction to be stopped at a predetermined retracted position shown in FIG.

Then, the cam drums 18 and 18 'are rotated in the same direction. As a result, the sliding pin 30 of the spindle motor block 25 is moved to the operating portion 31b of the cam groove 31.
Is moved from the lower end to the upper end, so that the rotation end of the spindle motor block 25 rises and the spindle motor block 25 becomes horizontal and chucks the optical disc 33 (see FIG. 7).

At this time, the slide pins 6, 6'of the pickup base 2 have the preparation portions 19a, 1'for the cam grooves 19, 19 '.
9'a is engaged, and thus remains at the lowermost position in the range of movement.

Further, when the cam drums 18 and 18 'are rotated in the same direction, the sliding pins 6 of the pickup base 2 are
6'becomes engaged with the operating portions 19b, 19'b of the cam grooves 19, 19 ', the pickup base 2 rises to a predetermined position (see FIG. 8), and the recording / reproducing operation starts in this state. .

During recording / reproduction, as shown in FIG. 13, the focus servo is turned on, and the DC component of the output of the skew sensor 34 and the drive signal 35 of the focus actuator for correcting the inclination and height errors. The cam drum 18 or 18 'is rotated so that both become 0. At this time, the height can be corrected by rotating the cam drums 18 and 18 'in the same direction, and the inclination can be corrected by rotating them in the opposite directions (see FIGS. 9 and 10).

As described above, even during recording / reproduction, the signal from the skew sensor 34 and the drive signal 3 from the focus actuator are generated.
The tilt and height of the optical pickup 15 can be kept constant by operating the cam drums 18 and 18 'according to the DC component of 5, so that the center of operation of the focus actuator during recording and reproduction and the neutral of the mechanical actuator. It is possible to make the points coincide with each other (usually, the inclination of the objective lens is adjusted to be the smallest), and highly accurate skew servo can be realized.

During recording / reproducing, the sliding pin 30 of the spindle motor block 25 has a preparatory portion 31 for the cam groove 31.
It is in a state of being engaged with a, and therefore maintains a horizontal posture.

Then, when recording / reproduction is completed and the optical disc is ejected, if the cam drums 18 and 18 'are rotated in the same direction in the opposite direction to the insertion, first the pickup base 2 is lowered to the lowermost end ( (See FIG. 11) Then, the rotation end of the spindle motor block 25 descends and tilts (see FIG. 12). After that, the loading tray 32 is horizontally moved to the pull-out position.

The limit switch shown in FIG.
For example, the cam drums 18 and 18 'are provided so as to detect the ends of the two rotation directions of the cam drums 18 and 18' to prevent runaway.

[0047]

As is apparent from the above description, in the disc reproducing apparatus of the present invention, both ends of the pickup, which is provided so as to be movable in the radial direction of the recording medium disc, in the moving direction are moved up and down separately. A pickup vertical movement mechanism is provided, and the pickup vertical movement mechanism is separately operated so that the pickup can be tilted with respect to the recording medium disk.

Another embodiment of the disc reproducing apparatus of the present invention is characterized in that a turntable on which a recording medium disc is mounted is moved up and down by the up-and-down moving mechanism.

Therefore, in the disc reproducing apparatus of the present invention, since both ends of the pickup in the moving direction can be moved up and down separately, the pickup is placed at any position in the radial direction of the recording medium disc. Even if the pickup is present, the pickup can be tilted while always keeping the distance between the pickup and the recording medium disk constant, and more accurate skew servo can be performed.

In another disc reproducing apparatus of the present invention, since the turntable can be moved up and down by using the vertical movement mechanism of the pickup, a turntable vertical movement mechanism for loading the disc is provided. As compared with the case where the devices are separately provided, the device does not become complicated, and simplification and downsizing of the device can be easily realized.

It should be noted that the shapes and structures of the respective parts shown in the above embodiments are merely examples of the embodiment when carrying out the present invention, and the technical scope of the present invention is limited thereby. Should not be construed in the open.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of an embodiment of a disc reproducing apparatus of the present invention together with FIGS. 2 to 13, and is a plan view showing a loading tray excluded.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a graph showing a phase relationship between a pickup cam groove and a turntable cam groove in one cam drum.

FIG. 4 is a graph showing a pickup cam groove in the other cam drum.

FIG. 5 is a side view showing the operation together with FIGS. 6 to 12, and this figure shows an initial state when a recording medium disc is loaded.

FIG. 6 shows a state following FIG.

FIG. 7 shows a state in which loading of a recording medium disc is completed.

FIG. 8 shows a state in which recording / reproduction is started.

FIG. 9 shows a state in which height correction is being performed.

FIG. 10 shows a state where inclination correction is being performed.

FIG. 11 shows an initial state of a recording medium disc ejection operation.

FIG. 12 shows a state following FIG. 11.

FIG. 13 is a control block diagram.

14 shows an example of a conventional disc reproducing apparatus together with FIG. 15, and this figure is a schematic plan view.

FIG. 15 is a schematic side view.

[Explanation of symbols]

 6, 6'sliding pin 15 optical pickup (pickup) 18, 18 'cam drum 19, 19' cam groove 26 motor base (supporting member) 28 turntable 30 sliding pin 31 cam groove 33 optical disk (recording medium disk)

Claims (4)

[Claims] 1. A pickup vertical movement mechanism for vertically moving both ends of the pickup movably provided in a radial direction of a recording medium disk in the moving direction is provided, and the pickup vertical movement mechanism is operated separately. A disc reproducing apparatus, wherein the pickup can be tilted with respect to the recording medium disc. 2. The pickup vertical movement mechanism comprises a cam drum having a cam groove on its peripheral surface, and a slide pin provided on the pickup and slidably engaged with the cam groove of the cam drum. The disc reproducing apparatus according to claim 1. 3. The disk reproducing apparatus according to claim 1, wherein a turntable on which a recording medium disk is placed is moved up and down by the up-and-down moving mechanism. 4. One end of a supporting member supporting a turntable is rotatably supported, and a sliding pin provided at the other end of the supporting member is provided around a cam drum of one of the pickup vertical moving mechanisms. A cam groove formed separately from a pickup cam groove on the surface is slidably engaged, and the other end of the turntable is vertically moved by rotation of the cam drum. Item 3. The disc reproducing apparatus according to Item 3.