JPH0633582Y2 - Head feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a head feeding device provided in a recording and / or reproducing device such as an optical pickup in a compact disc player.

[Outline of device]

In the present invention, a gear close to the final stage gear of a reduction mechanism that reduces and transmits the driving force from a drive source to a rack for feeding a head is attached in a direction that always meshes with a gear that meshes with this gear. With the structure that biases the gears, rattling due to backlash between gears is prevented, the driving force is accurately transmitted to the rack, and the head feed servo is stabilized.
It is intended to improve vibration resistance.

[Conventional technology]

Conventionally, a head feeding device provided in a recording and / or reproducing apparatus, for example, an optical pickup feeding device of a compact disc player is roughly classified into a screw feeding mechanism, a spur gear reduction mechanism, and a linear motor drive. There is one that uses a mechanism.

That is, as shown in FIG. 4, the one using the screw feed mechanism has one side portion of the movable base (2) having the optical pickup (1) mounted on the frame (3) and laterally in the direction of the disc table (4). It is slidably engaged with the mounted guide shaft (5), and the frame (3) is attached to the other side of the movable base (2).
A screw block (7) screwed onto a screw shaft (6) that is rotatably supported in parallel with the guide shaft (5) is fixed to the screw shaft (6), and the screw shaft (6) is fed by a feed motor (8) to a reduction gear mechanism ( It is configured to be rotationally driven via 9). When the screw block (7) is moved by the rotation drive of the screw shaft (6), the movable base (2) is moved along the guide shaft (5) with respect to the disc table (4) in the contact / separation direction so as to be optically movable. The pickup (1) is mounted on the disc table (4) and moved in the radial direction of the rotating disc.

In addition, as shown in FIG. 5, a guide member having a rack (13) on the side surface is provided on one side of a movable base (12) to which an optical pickup (11) is attached, as shown in FIG. (14) is fixed, and the guide member (14) is slidably engaged with the plate-shaped frame (15) by the guide shaft (17) which is laid horizontally in the disc table (16) direction. On the surface of (15), there is provided a spur gear group (19) as a reduction mechanism that meshes with the rack (13) of the guide member (14) and decelerates and transmits the drive of the feed motor (18). ing. The movable base (12) is driven by the spur gear group (19) rotated by the feed motor (18) through the rack (13) and along the guide shaft (17) with respect to the disc table (16). The optical pickup (11) is moved in the contact / separation direction in the radial direction of the disc on the disc table (16).

Further, in the case of using the linear motor drive mechanism, a linear motor (25) is arranged on the frame (23) in the direction of the disc table (24) as shown in FIG. 6, and a guide is provided in parallel with the linear motor (25). A movable base (22) having a shaft (26) mounted horizontally and an optical pickup (21) attached thereto is slidably engaged with the linear motor (25) in a straddled state. Then, by applying an electric current to the linear motor (25), the movable base (22) is moved along the guide shaft (26) toward and away from the disc table (24) to move the optical pickup (21) to the disc table ( 24) Move in the radial direction of the upper disc.

[Problems to be solved by the invention]

The conventional optical pickup feed device configured as described above, which uses the screw feed mechanism shown in FIG. 4, can be downsized and thinned and consumes less power, but the screw shaft manufactured with high precision, etc. However, since the spur gear shown in FIG. 5 uses the reduction gear mechanism, the spur gear can be manufactured relatively easily, which is advantageous in terms of cost and consumes less power. Since the gear has a large diameter due to the reduction ratio, it is impossible to miniaturize the device.Moreover, since the spur gears are simply meshed with each other, the rattle between the gears causes rattling when transmitting the driving force. There is a problem that the optical pickup is not smooth.

Further, the one using the linear motor drive mechanism shown in FIG. 6 can drive at high speed, but the configuration of the linear motor is complicated and the shape is large, so that the cost is extremely high and the entire apparatus is large, and the potable disc is large. There is a problem that it cannot be used for players and consumes a large amount of power. As described above, the conventional optical pickup feeders have their respective advantages, but have many drawbacks depending on the purpose of use.

In view of this point, the present invention has an object to provide a head feeding device such as an optical pickup which can be made small and thin, consumes less power, and can be manufactured at low cost.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a feed motor (40) as a drive source used for feeding an optical pickup (31) as a head, a rack (36) for feeding the head, and a rack (36) for feeding the head. 36) is provided with a reduction mechanism (38) for reducing and transmitting the driving force from the feed motor (40), and the reduction mechanism (38) includes a final stage gear (45) meshing with the rack (36). , A third gear (44) for transmitting the rotational driving force from the feed motor (40) to the gear (45) at the final stage
An intermediate gear (46) provided between the final stage gear (45) and the third gear (44), a gear base (39) on which each gear is mounted, and an intermediate gear (46). The gear holder (47) to which the shaft (48) to be mounted is attached and is movable on the gear base (39), the intermediate gear (46) and the final stage gear (45) and the third gear.
And a wire spring (49) as an elastic member for urging the gear (44) in the direction in which the gear (44) is always meshed.

[Action]

According to the present invention configured as described above, the intermediate gear (46) is rotatably supported by the gear holder (47) moved with respect to the gear base (39), and the wire spring (4) as an elastic member is provided.
6) and the final stage gear (4) of the reduction mechanism (38).
5) and the third gear (44) close to the gear (45) are meshed with each other, so that the final gear (45) and the third gear (4)
4) Stable and reliable meshing between the gears on the final stage side of the reduction mechanism, that is, the final stage gear (45) and intermediate gear (4
6), the backlash is removed between the third gears (44) and rattling is prevented, the feed drive force can be reliably transmitted to the rack, and the head feed servo is stabilized,
The vibration resistance will be improved.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3, and a case where the present invention is applied to a feeding device for an optical pickup as in the case of the conventional example described above will be described.

In the figure, (31) is an optical pickup, which is attached to a movable base (32), and the movable base (32) is attached to a guide shaft (35) horizontally extended in the plate table (33) in the direction of the disc table (34). A rack (36) that is slidably engaged on one side and has the required length on the outer side on the other side.
A guide member (37) provided with is fixed, and the guide member (37) is slidably engaged with the inner edge of the frame (33).

Further, in the frame (33), a drive mechanism and a speed reduction mechanism (38) are provided at a portion corresponding to the rack (36) side of the guide member (37).
Is installed. That is, the gear base (39) is fixed to the frame (33), the feed motor (40) as a drive source is fixed to the lower surface side of the gear base (39), and the drive shaft (40a) of the motor is upper surface side. The motor gear (4
1) is press-fitted. On the other hand, on the upper surface side of the gear base (39), a group of spur gears constituting the reduction gear mechanism (38) is arranged, and the first gear (42) of this group of spur gears has a large diameter tooth portion (42).
a) and a small diameter tooth portion (42b), the large diameter tooth portion (42a) is meshed with the motor gear (41), and the small diameter tooth portion (42b) is the second
Is meshed with the large diameter tooth portion (43a) of the gear (43). The second gear (43) is meshed with the large diameter tooth portion (44a) of the third gear (44), and the final gear (45) is attached to the rack (36) of the guide member (37). It is meshed. The small diameter tooth portion (44b) of the third gear (44) and the final stage gear (4
An intermediate gear (46) meshes with 5) to form a speed reduction mechanism (38), and the driving force of the feed motor (40) is decelerated and transmitted to the rack (36).

In the reduction gear mechanism (38) configured as described above, the intermediate gear (46) meshed with the third gear (44) and the final gear (45) is a gear movably engaged with the gear base (39). The holder (47) is rotatably supported by a shaft (48) which is integrally formed on the holder (47). The gear holder (47) includes a wire spring (49) and a third gear (44) and a final gear (45). ), And the intermediate gear (46) is driven by both gears (44) and (45).
It is configured to be pressed and meshed with.

That is, the gear base (39) is provided with a gear holder (4) in an intermediate direction between both shaft support portions of the third gear (44) and the final gear (45).
A rectangular engagement hole (50) for moving and engaging with (7) is provided, and a lower surface side concave step (50) is provided at a front edge of the engagement hole (50).
a), and the upper edge concave step (50b) is formed at the trailing edge. On the other hand, the gear holder (47) has a cross section Shape, that is, a concave step portion (5) on the lower surface of the front edge of the engagement hole portion (50) sandwiching the intermediate vertical surface portion (47a) that is inserted into the engagement hole portion (50).
0a) slides on the front surface (47b) and the rear edge upper surface concave step (50
a rear surface portion (47c) that is in sliding contact with b), and a shaft (48) is erected on the upper surface of the intermediate portion. The gear holder (47) is inserted into the engagement hole (50) of the gear base (39) at the vertical surface portion (47a), and the front surface portion (47b) is slid on the front edge lower surface side concave step portion (50a). The rear surface portion is brought into sliding contact with the rear edge upper surface concave step portion (50b) and engaged. In this state, the intermediate gear (46) is attached to the shaft (48), and both ends of the rear side of the shaft (48) are engaged with both sides of the gear base (39) to elastically cross the wire spring. (49) is brought into contact with the gear holder (47) to urge it forward, and the intermediate gear (46) is pushed onto the small diameter tooth portion (44b) of the third gear (44) and the final gear (45). It is meshed so as to attach.

In the head feeding device of this example configured as described above, the driving torque of the feed motor (40) is from the motor gear (41) press-fitted into the drive shaft (40a) to the first gear (42) → the second gear. (43) → the third gear (44) → the intermediate gear (46) is sequentially decelerated and transmitted, and the final stage gear (45) of the reduction mechanism (38).
Is rotated at a predetermined speed.

Then, the rotational force of the gear (45) at the final stage of the speed reduction mechanism (38) is transmitted to the rack (36) with which it meshes, and the movable base (32) to which the optical pickup (31) as a head is attached is a rack ( The optical pickup (31) is driven by a guide member (37) provided with a guide shaft (36) and is moved along the guide shaft (35) toward and away from the disc table (34), so that the optical pickup (31) is moved to the disc table (34). It will be moved in the radial direction of the upper disc.

In the above operation, of the gear group of the reduction mechanism (38),
The intermediate gear (46) is the third gear (44) and the last gear (4
Since the gears are engaged with each other with a constant urging force against 5), the backlash between these gears is removed and rattling does not occur and the drive force is reliably transmitted to the rack (36). (31) is moved accurately and stably.

Further, since the shaft (48) that pivotally supports the intermediate gear (46) is pressed from the rear side by the wire spring (49) to urge the intermediate gear (46), the gear holder (47) is provided at the rear portion. When the gear holder (47) is pushed down, a rotational moment that rotates backward is generated. The rear surface portion (47c) comes into contact with the portion (50a) and the rear edge upper surface side concave step portion (50b) so that rotation is blocked and the horizontal state is maintained. As a result, the shaft (48) always supports the intermediate gear (46) in a vertical state, and the intermediate gear (46) meshes with the third gear (44) and the final stage gear (45) in the normal position. ,
The driving force can be reliably transmitted.

As described above, the speed reducing mechanism of the head feeding device of the present embodiment is configured to remove the backlash by urging the intermediate gear at the final stage of the gear group, so that a gear having a large diameter is obtained in order to obtain a predetermined reduction ratio. Instead, even if a large number of small-diameter gears are used, the driving force can be reliably transmitted to the rack of the head movable base without rattling.

Further, the amount of rattling caused by the temperature change of the gear portion of the reduction gear mechanism can be absorbed by the urging of the intermediate gear, and the head feed can be always performed accurately, and the reduction gear mechanism can be configured by a spur gear having a small diameter. Therefore, it is possible to make it smaller and thinner.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, a tension coil spring, a compression coil spring, or the like can be used as the biasing means of the intermediate gear without being limited to the wire spring. Further, the intermediate gear may be biased only in the final gear direction, that is, the backlash due to the bias of the gear in the reduction mechanism is removed on the side closer to the driven part so that the drive transmission may be delayed. Is prevented.

[Effect of device]

As described above, according to the present invention, the intermediate gear meshing with the gear at the final stage of the reduction mechanism for decelerating and transmitting the driving force from the drive source to the rack for feeding the head and the third gear close to this gear The gear is rotatably supported by a shaft on a gear holder that is movable in the intermediate direction between the gear at the final stage and the third gear with respect to the gear base, and the gear is urged by an elastic member to move the intermediate gear to the final stage. Since it is configured to mesh with the gear No. 3 and the third gear No. 3, backlash between the gears at the final stage of the reduction mechanism is removed and rattling is prevented,
Also, the intermediate gear is indirectly biased in the meshing direction by the elastic member via the gear holder, so that it does not interfere with this rotation and is always smoothly rotated to drive the rack. Can be reliably transmitted, and the head can be constantly and stably fed and moved, so that the feed servo is stabilized and vibration resistance is improved. In addition, the reduction mechanism can be configured with many small diameter spur gears by eliminating the backlash between the gears at the final stage, so it can be made smaller and thinner, and the overall size of the feeder can be reduced. It is possible to reduce the cost, and in particular, the effect is great when applied to a feeding device of an optical pickup of a disc player.

[Brief description of drawings]

FIG. 1 is a partially exploded perspective view of a head feeding device according to the present invention, FIG. 2 is a plan view thereof, FIG. 3 is an enlarged sectional view of a part thereof, and FIGS. It is a perspective view of a head feeding device. In the figure, (31) is a head (optical pickup), (32) is a movable base, (36) is a rack, (38) is a reduction mechanism, (40) is a feed motor, (44) is a third gear, and (45). )
Is a final stage gear, (46) is an intermediate gear, (47) is a gear holder, (48) is a shaft, and (49) is a wire spring.

Claims (1)

[Scope of utility model registration request] 1. A drive source used for feeding a head, a rack for feeding the head, and a reduction mechanism for decelerating and transmitting a driving force from the drive source to the rack. , A final stage gear meshing with the rack,
A third gear that transmits the rotational driving force from the drive source to the final stage gear, an intermediate gear provided between the final stage gear and the third gear, and a gear base on which each gear is mounted. When,
A gear holder on which a shaft for pivotally mounting the intermediate gear is mounted, and which is movable in the intermediate direction between the final gear and the third gear on the gear base; and the gear holder,
The head feeding device, wherein the intermediate gear includes the final gear and an elastic member that biases the third gear in a direction in which the intermediate gear is always meshed.