JPH0341325Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a playback device that plays back optical discs such as compact discs and laser discs.

[Conventional technology]

As is well known, this type of disc playback device is
The disc is held by a turntable and rotated, and the optical pickup head, which is movable in the radial direction of the disc, reads signals recorded on the disc. Such a playback device naturally includes a drive for moving the optical pickup head.

The configuration of such a conventional drive device is shown in FIG.
An explanation will be given by taking the optical disc reproducing apparatus shown in FIG. 9 as an example.

In FIGS. 8 and 9, reference numeral 1 indicates a chassis, and this chassis 1 includes a disk drive motor 2.
and a drive motor 3 for moving the optical pickup head.
is attached. A turntable 4 is fixed to the rotating shaft of the motor 2, and an optical disk 5 is mounted on the turntable 4. The chassis 1 also includes a threaded rod 6 extending in a direction perpendicular to the rotational axis of the turntable 4.
A guide rod 7 is supported. Both ends of the threaded rod 6 are rotatably supported by the chassis 1, and both ends of the guide rod 7 are fixed to the chassis 1. An optical pick-up head 8 is supported on the threaded rod 6 and guide rod 7 so as to be movable in the directions of arrows P ₁ and P ₂ . That is, a female screw member 10 having a female screw hole 9 therein is fixed to the optical pickup head 8, and a guide hole 1 is formed on one side of the female screw member 10.
1 is fixed, the threaded rod 6 is screwed into the female screw hole 9, and the guide rod 7 is inserted into the guide hole 11. The threaded rod 6 is rotationally driven by the motor 3.

Thus, the above-described playback device rotates the screw rod 6 in the normal or reverse direction with the motor 3, and uses the screw rod 6 and the guide rod 7 as guides to move the optical pickup head 8 in the directions of arrows _P1 and _P2. By moving the optical pickup head 8 in this way, the signal recorded on the disk 5 is read by the signal reading section 12 of the optical pickup head 8.

Other drive devices include, for example, a metal head base 70 on which an optical pickup head (not shown) is mounted, as shown in FIG. 10, and a synthetic resin guide portion 71 and rack gear 72 attached to this. It is known that the head part has a head part like this. This head part has a head base 70.
A guide portion 71 and a rack gear 72 are separately attached to one side of the pinion gear 73 and the rack gear 72, which are rotated by a drive system consisting of a motor and gears (not shown). The mechanism allows the head base 70 to move while being guided by a guide rod (not shown) that passes through a guide hole 74 formed in the guide portion 71.

Here, the reason why the head base 70 is made of metal is that although it is preferable to make it made of synthetic resin from a cost standpoint, when considering overall miniaturization, the thickness of the head base 70 is made as thin as possible, and This is because since rigidity is required, it is best to use metal to satisfy both of these requirements.

[Problem that the invention attempts to solve]

By the way, in the optical disc playback apparatus shown in FIGS. 8 and 9 above, the female threaded member 10 having the female threaded hole 9 and the threaded rod 6 are used as a device for moving the optical pickup head 8. However, the disadvantage was that the structure was complicated and the equipment was expensive.

In addition, in the playback device having the optical pickup head shown in FIG.
Since the rack gear 72 and the guide portion 71 are separately attached to the 0, particularly high positional accuracy is required for each attachment, and therefore the precision of the dimensions and shapes of each component is required to be high.

In addition, the driving force from the pinion gear 73 is transmitted to the guide portion 71 via the rack gear 72 and the head base 70;
Since frictional resistance occurs between the guide rod and the guide rod,
When the head base 70 moves, a twisting phenomenon occurs between the rack gear 72 and the guide part 71 when the drive force is directly received from the pinion gear 73. Twisting force is applied to the two joints (attachment parts).

Since such torsional force is applied, fatigue due to use accelerates in the joint portion, and durability is impaired when used for a long time. That is, since the head base 70 is equipped with an optical pickup head, it is a part that requires highly accurate control in order to read signals. Therefore, if any part of the system consisting of the head base 70 is shaken, there is a risk that a fatal reading error will occur for the playback device.

This idea was made in view of the above circumstances, and aims to simplify and reduce the structure of the drive device for an optical pick-up head, and to improve its durability against rattling caused by long-term frictional resistance of the head. The purpose is to

[Means for solving problems]

The optical disk playback device of this invention has an optical pickup head mounted on a head base that is supported movably in the disk radial direction, a rack gear integrally formed on this head base, and a pinion gear meshed with the rack gear. The optical pickup head is moved by being rotationally driven by a drive source.

In this invention, the head base is made of metal, the rack gear is made of synthetic resin, and the head base and rack gear are integrated by outsert molding, thereby making it possible to easily form the rack gear on the head base.

With this idea, the structure for supporting the head base is such that the head base is provided with a guide portion having a guide hole formed integrally with the rack gear, and the guide portion is slidably inserted into the guide hole and is inserted approximately along the radial direction of the disk. It is desirable that the head base be guided by a guide rod that extends along the head base.

〔Example〕

1 to 7 are diagrams showing an embodiment of this invention, and are diagrams showing an embodiment in which this invention is applied to a compact disc player.

The optical disc playback device (compact disc player) described here consists of a disc cartridge case A that stores a disc (compact disc) and a device body B. The disc is stored inside the disc cartridge case A. The device is configured to load the disk together with the disk cartridge case A into the main body B of the device, and to reproduce the disk stored in the disk cartridge case A in its stored state.

Disk cartridge case A is disk 2
1 is rotatably stored, and as shown in FIGS. 2 and 3, a rack gear 22 is mounted on one side of
It has the following.

To explain the structure of the device main body B, in FIGS. 1 to 4, reference numeral 23 is a chassis, and a carrier 2 is mounted on the upper surface side of the chassis 23.
4, a holder 25, and a clamper 26 are arranged, and a head base 27 and an optical pickup head 28 are arranged on the lower surface side.

A disk drive motor 29 is attached to the lower surface of the chassis 23, and a turntable 30 is fixed to a rotating shaft of the motor 29 that projects upward from the chassis 23. Furthermore,
A feed loading motor 31 (power source) is attached to an end of the chassis 23 so that its rotating shaft projects downward. The carrier 24 is disposed on the upper surface of the chassis 23 so as to be movable in the directions of arrows P ₃ and P ₄ , and the holder 25 is disposed on the upper surface of the chassis 24 with the carrier 24 therebetween so as to be movable in the vertical direction. The holder 25 is attached to the chassis 23
It is always urged downward by springs 32, 32... stretched between the cams 32, 32..., and is at the upper limit position when the cam 33 formed on the lower surface is in contact with the upper surface of the carrier 24. When the cam 23 enters holes 34, 34 formed in the carrier 24, holes 35, 35, . . . formed in the chassis 23, it descends. A shaft 38 to which a loading pinion gear 36 and a carrier pinion gear 37 are fixed is rotatably supported by the holder 25, and the carrier pinion gear 37 meshes with a rack gear 39 formed on the carrier 24. The clamper 26 has a disk 21 at its front end.
The shaft portions 40, 40 are rotatably supported by the holder 25, and are always supported by a spring 41 in the direction of the arrow.
P Forced in _{the 5} direction.

In the above configuration, when the head base 27 is moved as described below, the carrier 24
It moves in the directions of arrows P ₃ and P ₄ in conjunction with the head base 27, thereby raising and lowering the holder 25 and rotating the loading pinion gear 36. Further, the holder 25 holds the disk cartridge case A containing the disk 21 and places the disk 21 on the turntable 30 when playing the disk. Further, the clamper 26 fixes the disc 21 placed on the turntable 30 to the turntable 30 with a steel ball 26a during disc playback. Also loading pinion gear 36
When the disk cartridge case A is loaded or ejected, it engages with the rack gear 22 of the disk cartridge case A to move the disk cartridge case A in the directions of arrows P ₃ and P ₄ .

Further, on the lower surface of the chassis 23, as shown in FIG.
44 is formed, and the guide rod attachment parts 43, 4 are formed.
Guide rods 45, 45 are attached between the guide rods 4, 43, and 44 so as to substantially follow the radial direction of the disk 21 placed on the turntable 30. The head base 27 is attached to the guide rods 45, 45 with the arrow P ₃ ,
The optical pickup head 28 is mounted on the head base 27 so as to be movable in _four directions.

Details of the head base 27 are shown in FIGS. 5-7. As shown in these figures, the plate part 46 of the head base 27 has a guide part 48 having guide holes 47, 47, 47 at both left and right ends thereof.
a, 48b, and 48c are formed, a wall portion 49 extending in one direction is formed on one side, and an engagement hook 50 is formed on the upper surface of one side. The wall portion 49 consists of a vertical portion 49a that projects downward and a horizontal portion 49b that projects outward from the vertical portion 49a.A cam 51 is formed on the outer surface of the vertical portion 49a, and the horizontal portion 49b A feed loading rack gear 52 is formed on the outer surface of the shaft. cam 51
is formed by forming notches 53, 54, 55 in a flat wall surface.Here, the plate part 46 is made of metal, and the guide parts 48a, 48b, 48c, the wall part 4
9. The engaging hook 50 is made of synthetic resin, and the metal plate portion 46 and other synthetic resin parts are integrated by outsert molding.
Further, in this case, the guide portions 48a, 48b and the wall portion 49 are particularly formed integrally.

The optical pickup head 28 is attached to the head base 27 with its signal reading section 28a facing upward.

The head base 27 to which the optical pickup head 28 is attached as described above has a guide portion 48.
One of the guide rods 45 is slidably inserted into the guide holes 47, 47 of the guide portions 48c and 48b.
The other guide rod 45 is slidably inserted into the guide hole 47 of the guide rod 45, 45.
is installed on. Therefore, head base 27
The feed loading rack gear 52 formed above is attached to extend substantially along the radial direction of the disk 21.

Further, on the lower surface of the chassis 23, as shown in FIG. 1, there is a feed loading pinion gear 57 that meshes with the feed loading rack gear 52 of the head base 27, and a feed loading pinion gear 57 that transmits the rotational force of the feed loading motor 31 to the pinion gear 57. The gear train 58 and its engaging portion 59a are connected to the cam 51.
An actuator 59 that comes into contact with the actuator 59 and a head position detection switch 60 that detects the position of the optical pickup head 28 based on the movement of the actuator 59 are attached.

Based on this configuration, the optical pick-up head 2
Reference numeral 8 denotes a head base 2 with a rack gear 52 meshing with the feed loading pinion gear 51 when the feed loading pinion gear 51 is driven to rotate.
7 moves in the directions of arrows P ₃ and P ₄ , it moves in the radial direction of the disk 21 placed on the turntable 30 directly below it. At this time, the carrier 24 described above has a carrier pin 61 formed thereon which is attached to the head base 27.
By engaging with the plate portion 46 or the engaging hook 50, it is possible to move in the directions of arrows P ₃ and P ₄ .

Next, the operation of the optical disc reproducing apparatus constructed as described above during disc reproducing will be described.

To play disk 21, press disk 21.
is stored inside the disk cartridge case A, and the disk cartridge case A is manually inserted into the holder 25 of the device body B. At this time, the operator inserts the disk cartridge case A in the direction of arrow _P3 , so that the tip of the rack gear 22 of this case A is connected to the loading pinion gear 36.
Insert until it engages. When this is done, a detection switch (not shown) detects this state and the feed loading motor 31 is turned on. When the motor 31 is turned on, the feed loading pinion gear 57 rotates via the gear train 58, and the head base 27, with which the feed loading rack gear 52 is meshed with the pinion gear 57, moves in the direction of arrow _P3 . In conjunction with this operation, the carrier 24 moves in the direction of arrow _P3 .
When the carrier 24 moves in the same direction, the carrier pinion gear 37 meshing with the carrier lug 39 rotates, and at the same time the loading pinion gear 36 rotates. The loading pinion gear 36 moves the disk cartridge case A in the direction of arrow _P3 by its rotation. When the disk cartridge case A is moved in this way and the disk 21 stored therein approaches the upper part of the turntable 30, the cams 33, 33 of the holder 25...
gradually enters the holes 34, 34 of the carrier 24, the holes 35, 35, . . . of the chassis 23, and the holder 25 is thereby lowered. Then, the disk 21 is placed on the turntable 30, and the clamper 2
6 is lowered, the steel ball 26a pushes the disk 21 downward through a part of the disk cartridge case A, and fixes the disk 21 to the turntable 30. At this time, the turntable 30 and the clamper 26 enter the case A through a hole (not shown) formed in the disk cartridge case A, and close the disk 21.
hold. Further, at this time, the loading pinion gear 36 stops rotating as the carrier pinion gear 37 comes off from the carrier lock gear 39.

Here, the head base 24 is connected to the guide rods 45, 4.
At this time, the engaging portion 59a of the actuator 59 engages with a predetermined notch 53 to 55 formed in the cam 51, whereby the head position detection switch 60 is activated. By switching and reversing the motor 31, the direction of arrow P ₄ is reversed.
Start moving in the direction. At this time, the head base 27 and the carrier 24 are disengaged, and the carrier 24 does not move in conjunction with the head base 27. When the head base 27 moves and the optical pickup head 28 reaches the lead-in position, the engaging portion 59 of the actuator 59 engages the cam 59.
This state is when the switch 60 is engaged with a predetermined notch.
is detected, the motor 31 is stopped, and the movement of the head base 27 is stopped.

At this point, the playback device is in a state where it can play the disc 21. When a play command is given to the apparatus, the disk drive motor 29 rotates and the disk 21 rotates together with the turntable 30. On the other hand, the feed loading motor 31 now becomes the power source for the feed operation, and begins to move the head base 27 in the direction of arrow _P3 by an appropriate amount in response to the above command, and the signal reading section of the optical pickup head 28 on the head base 27 is moved. 28
a indicates that the disk 2 is inserted through a laser beam introduction hole (not shown) formed in the disk cartridge case A.
The signal recorded on the disc 21 is read, and the disc 21 is thus reproduced. And disk 21
When the playback of the optical pickup head 28 has finished and the optical pickup head 28 has reached the lead-out position, this state is detected by the actuator 59 and the switch 60 in the same manner as described above, and thereby the disk drive motor 29, Feed loading motor 3
1 stops.

In addition, to eject the disk cartridge case A from this state, give an eject command to the device to rotate the feed loading motor 31, move the head base 27 in the direction of arrow _P3 , and move it to the guide rods 45, 45. reach the rear end of the When the head base 27 reaches this position,
The hook 50 engages with the carrier pin 61, the actuator 59 and the switch 60 detect this state, and the feed loading motor 31 is reversely rotated.
As a result, the head base 27 moves the carrier 24 in the direction of arrow _P4 while moving it in the same direction.
In this way, the disk cartridge case A moves in the reverse order of loading described above and returns to its original position.

According to this embodiment, the loading pinion gear 36 and the carrier pinion gear 37
The driving force is transmitted to the guide rod 45 via the rack gear 39 formed integrally with the guide portion 48c. Although force is applied to the head base 27 through the integrally molded body of the rack gear 39 and the guide portion 48c, no horizontal torsional force is applied to the head base 27. Looseness is reduced, and the wobbling of the optical disk 5 in the radial direction is reduced. Furthermore, the durability of the head portion for long-term use is improved.

[Effect of idea]

According to this invention, an optical pickup head is mounted on a head base, a rack gear is integrally formed on the head base, a pinion gear is meshed with the rack gear, and the pinion gear is rotationally driven by a drive source to drive the optical pickup head. As a result, the structure of the drive device for the optical pickup head is simplified, and the device can be provided at a low cost.

The driving force from the pinion gear is transmitted to the guide rod via the rack gear formed integrally with the guide part, so no torsional force is applied to the head base, so the integral molding of the rack gear of the guide part after long-term use. Looseness of the joints of the head base is reduced, and rattling in the disk radial direction is reduced. Furthermore, the durability of the head portion can be improved.

[Brief explanation of the drawing]

1 to 7 are views showing one embodiment of this invention, in which FIG. 1 is a bottom view of the playback device, FIG. 2 is a top view of the same, FIG. 3 is a side view of the same, and FIG. 5 is a plan view of the head base, FIG. 6 is a rear view of the head base, FIG. 7 is an enlarged view of the section viewed from arrow S in FIG. 5,
FIG. 8 is a plan view of a conventional reproducing apparatus, FIG. 9 is a side view of the same, and FIG. 10 is a front view showing a driving portion of another conventional reproducing apparatus. 21...Disk, 27...Head base, 2
8... Optical pick up head, 31... Power source (feed loading motor), 45... Guide rod, 47... Guide hole, 48a to 48c... Guide portion, 52... Rack gear (feed loading rack gear) , 57...pinion gear (feed loading pinion gear).

Claims (1)

[Scope of utility model registration request] In an optical disc playback device that reads signals recorded on the disc using an optical pickup head that is movable in the radial direction of the disc,
A head base supported movably in the radial direction of the disk, an optical pickup head mounted on the head base, and a rack gear formed on the head base substantially along the radial direction of the disk and meshing with a pinion gear rotationally driven by a power source. a guide portion formed integrally with the rack gear and having a guide hole into which a guide rod extending approximately in the radial direction of the disk is slidably inserted; the head base is made of metal; An optical disk reproducing device characterized in that the rack gear is made of synthetic resin.