JP2000156053A - Optical pick up feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve left and right balance, to enable fine positioning and to reduce uneven wear of a sliding material by uniformly imparting a preload to two guide rails with one linear ultrasonic motor. SOLUTION: Guide rails are provided in order to transfer a traveling object parallel to the radial direction of a disk. A linear ultrasonic motor 5 is attached via a preload spring 8 to the underside of an optical pick up which is attached to the central part of the traveling object, and an elliptic motion is generated by applying a since wave voltage of 90 degrees phase to two pairs of piezoelectric elements. A sliding material 6 is pressurized to a base with the preload spring 8, and thrust is generated by utilizing the elliptic motion and force which pressurizes the base. Even if the preload spring is enlarged by setting up the linear ultrasonic motor to the central lower part of the traveling object and by setting up the optical pick up to the center of the traveling object in such a manner, since force is distributed into two guide rails, pressurizing force is enlarged and thrust is enlarged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pick feeder used for an information recording apparatus for recording and reproducing signals on an information recording medium.

[0002]

2. Description of the Related Art Conventionally, in an information recording apparatus using optics, a signal recording means for recording and reproducing a signal is moved to an arbitrary position in a radial direction of a disk to perform recording and reproduction. At this time, the signal recording means is incorporated into a coarse actuator and a light pick which convert the rotational movement of a DC motor or a stepping motor into a linear movement by using a rack and pinion method or the like and drive the signal means in parallel. And a fine actuator that moves to a precise position by a tracking mechanism.

In this system, since precise positioning is impossible due to positioning control of a DC motor or the like and backlash by a rack-and-pinion system, two types of actuators are used.

In recent years, the use of an ultrasonic motor as an actuator capable of fine positioning has been considered, and an optical pick feeder which is considered to be used for both coarse and fine is being studied. (JP-A-6-215496)

[0005]

The ultrasonic motor causes a piezo-electric element to expand and contract by applying a sine wave having a phase shift of 90 degrees to a plurality of arranged piezo-electric elements. The thrust is generated in the sliding part by utilizing the elliptical motion. This thrust is expressed by the product of the coefficient of friction between the sliding portion and the portion in contact with the sliding portion and the applied pressure applied therebetween. Therefore, in order to move the optical pick at high speed, a method of increasing the friction coefficient or increasing the applied pressure is considered. However, in this proposed method, as shown in FIGS. 9 and 10, the direction of the pressurizing force is given from the lateral direction of the guide rail, so that the balance is poor and not suitable for rapid acceleration / deceleration.

In Japanese Patent Application Laid-Open No. 10-64203, in which two guide rails are configured so that a preload is applied uniformly, two linear ultrasonic motors are used. It is difficult to avoid an increase in cost due to a complicated circuit for controlling the control.

[0007]

SUMMARY OF THE INVENTION In order to solve this problem, an optical pick feeder according to the present invention comprises a signal recording means for recording or reading information by an optical pick, and a signal recording means parallel to a disk and in a radial direction. Guide means comprising a moving guide rail; feed means for moving the signal recording means along the guide means by utilizing a piezoelectric effect below the signal recording means; and pressing the feed means downward. And a pressurizing means.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a signal recording means for recording or reading information by an optical pick, a guide means comprising a guide rail for moving the signal recording means in a direction parallel to a disk and in a radial direction, An optical pick-up comprising a feeding means for moving the signal recording means along the guide means using a piezoelectric effect below the recording means, and a pressurizing means for pressing the feeding means downward. It is a feed device, and the feed means can be stably moved because the feed means is pressed downward.

Further, the guide means includes two guide rails for moving the signal recording means in a direction parallel to the disk and in the radial direction. Feeding means for moving the signal recording means along the guide means using the piezoelectric effect may be arranged at the lower part.

Further, by providing the feeding means and the pressurizing means below the signal recording means on a line perpendicular to the center of gravity of the signal recording means and the disk, the feeding means can be supported in a well-balanced manner.

Further, the pressurizing means may be provided between the guide means and the signal recording means. Further, the pressurizing means may be formed by a U-shaped leaf spring.

Further, a roller may be provided between the pressurizing means and the guide means in contact with each other.

[0013]

(Embodiment 1) FIG. 1 is a top view of an optical pick feeder according to a first embodiment of the present invention, and FIG. 2 is a sectional view of FIG.

The optical pick 1 plays a role of writing or reading information on or from a disk, and requires accurate positioning accuracy. Therefore, a tracking and focusing mechanism driven by a magnetic circuit is incorporated.

The optical pick is attached to the center of a moving body 2 integrally formed by die casting of aluminum or the like, and is used as a coarse seek for accessing information on a disc at a target position of about 100.
Move to the range of μm. Thereafter, as a fine adjustment, a position adjustment is performed by a tracking mechanism in a range of about 1 μm. Since the characteristics of the information recording device are determined by the access time, it is necessary to have a very high speed and a large acceleration / deceleration.

The guide rails 3a and 3b are provided for moving the moving body 2 in parallel in the radial direction of the disk. One is held by a metal bearing and the other is held in a U-shape in order to allow accuracy in mounting to the disk.

A linear ultrasonic motor 5 is attached via a pressurizing spring 8 to the lower side of an optical pick attached to the center of the moving body 2. The linear ultrasonic motor includes a sliding member 6 and a piezoelectric element 7. Elliptical motion is generated by applying a 90-degree phase sine wave voltage to two pairs of piezoelectric elements.

The sliding member 6 is pressed against the base 4 by a pressurizing spring 8. A thrust is generated using the elliptical motion and the force pressing the base. The thrust is represented by the product of the pressing force and the friction coefficient between the sliding member and the base. Therefore, in order to increase the thrust, it is preferable to increase the pressing force and the friction coefficient. Normal pressing force is 1kg
In many cases, a ceramic material such as alumina is often used as the sliding material.

As described above, by installing the linear ultrasonic motor below the center of the moving body and the optical pick at the center of the moving body, even if the pressurizing spring is enlarged, the force is distributed to the two guide rails. Therefore, the pressing force can be increased, and the thrust can be increased. In addition, the balance of the center of gravity of the moving body is optimized, and imbalance due to high speed and high acceleration / deceleration is unlikely to occur.

It should be noted that such an optical pick feeding device is a CD.
It may be mounted on a player, DVD player, CD-ROM drive, DVD drive, MD player, MO drive.

With this configuration, it is possible to greatly improve the access time for reading and writing information, to reduce imbalance at high speed and high acceleration / deceleration, to reduce the thickness, and to reduce the sliding material. An optical pick feeder with reduced uneven wear can be configured.

(Embodiment 2) FIG. 3 is a top view of an optical pick feeder according to a second embodiment of the present invention.
FIG. 4 is a sectional view in FIG.

A linear ultrasonic motor 5 is attached via a pressurizing spring 8 to the lower side of the moving body on a line perpendicular to the position G of the center of gravity of the moving body 2 and the disk. The linear ultrasonic motor includes a sliding member 6 and a piezoelectric element 7.

As described above, by disposing the linear ultrasonic motor below the line perpendicular to the position of the center of gravity of the moving body and the disk, the force is distributed to the two guide rails even if the pressurizing spring is enlarged. Therefore, the pressing force can be increased, and the thrust can be increased. In addition, the balance of the center of gravity of the moving body is optimized, and imbalance due to high speed and high acceleration / deceleration is unlikely to occur.

(Embodiment 3) FIG. 5 is a top view of an optical pick feeder according to a third embodiment of the present invention.
FIG. 6 is a cross-sectional view in FIG.

The guide mechanism 11a is formed in a U-shape.
Reference numeral 11b is provided to translate the moving body 2 in the radial direction of the recording medium. Inside the guide mechanism, guide protrusions 12a and 12b provided on the movable body are provided so as to move the movable body along the guide mechanism. The pressurizing springs 8a and 8b are arranged in the guide protrusions, and are configured to apply pressure to the moving body.

The moving body 2a has a built-in linear ultrasonic motor 5 and is formed by integral molding by aluminum die casting or the like. The sliding member 6 is attached to the lower part of the integrally formed moving body while maintaining the degree of parallelism with respect to the length of the moving body.

By providing the pressurizing spring on the holding portion of the moving body, the moving body and the linear ultrasonic motor can be integrated. Therefore, imbalance due to high speed and high acceleration / deceleration is unlikely to occur, and it is possible to reduce the thickness due to the integrated structure, and it is possible to accurately configure the perpendicularity from the moving body to the linear ultrasonic motor, thereby preventing uneven wear of the sliding material. In addition, the linear ultrasonic motor can be driven smoothly.

(Embodiment 4) FIG. 7 is a diagram showing an optical pick feeder according to a fourth embodiment of the present invention.

In the third embodiment, the structure of the pressurizing spring 8 is formed in a U-shape, and the moving body 2 is held at a position formed in the U-shape.

It is possible to allow variations between the guide rails by increasing the angle of the U-shape, and it is possible to strengthen the holding of the guide rails by reducing the angle of the U-shape. . Usually, about 80 to 120 degrees is desirable.

By adopting such a configuration, it is possible to configure a pressurizing configuration that can tolerate variations between the guide rails at a very low cost.

Similar effects can be obtained by adjusting the radius of the semicircle and the length of one side of the polygon even when the shape of the pressurized spring is semicircular or polygonal. Further, the same applies to a combination of one with a U-shape and the other with a semicircle.

(Embodiment 5) FIG. 8 is a view showing an optical pick feeder according to a fifth embodiment of the present invention.

The roller 13 is arranged between the guide rail and the moving body so that the rotation axis of the roller intersects perpendicularly in a vector in which pressure is generated by the pressurizing spring as shown in the figure.

With this configuration, the mechanical loss of the holding portion can be greatly reduced, and the moving body can be moved smoothly.

A similar effect can be obtained by arranging two or more rollers on the lower side of the guide rail and on the lateral side toward the center so that the combined vector has a vector shape generated by pressing.

(Embodiment 6) In Embodiments 3 to 5, the position of the linear ultrasonic wave is formed integrally by aluminum die casting or the like so as to be below the center of gravity of the moving body.

By adopting such a structure, unbalance is less likely to occur even when the moving body is moved at high speed and high acceleration / deceleration, and it is possible to reduce the thickness of the moving body from the moving body to the linear ultrasonic motor. Since the squareness can be configured with high accuracy, uneven wear of the sliding member can be prevented, and the linear ultrasonic motor can be driven smoothly. Further, by forming the pressurizing spring in a V shape, the pressurizing structure can be made very inexpensive. In addition, the use of the roller in the holding portion can significantly reduce mechanical loss and smoothly drive the moving body.

[0040]

As described above, according to the present invention, a fine linear positioning is possible by applying a uniform pressing force to two guide rails with a single linear ultrasonic motor, so that the right and left balance is good. The tracking mechanism of the optical pick can be omitted, and the uneven wear of the sliding material can be reduced.
Since the thickness can be reduced, an advantageous effect that the access time of the information recording device can be significantly improved can be obtained.

[Brief description of the drawings]

FIG. 1 is a top view of an optical pick-up feeder showing a first embodiment of the present invention.

FIG. 2 is a sectional view of the same.

FIG. 3 is a top view of an optical pick-up feeder according to a second embodiment of the present invention.

FIG. 4 is a sectional view of the same.

FIG. 5 is a top view of an optical pick-up feeder showing a third embodiment of the present invention.

FIG. 6 is a sectional view of the same.

FIG. 7 is a shape diagram of a pressurized spring showing a fourth embodiment of the present invention.

FIG. 8 is a partial view of a moving body and guide roller holding members according to a fifth embodiment of the present invention.

FIG. 9 is a top view of an optical pick-up feeder showing a conventional example.

FIG. 10 is a sectional view of the same.

[Explanation of symbols]

 Reference Signs List 1 optical pickup 2, 2a moving body 3a, 3b guide rail 4 base 5 linear ultrasonic motor 6 sliding member 7 piezoelectric element 8, 8a pressurizing spring 9 spindle motor 10 stopper 11a, 11b guide mechanism 12a, 11b guide protrusion 13 roller

Claims (13)

[Claims] 1. A signal recording means for recording or reading information by an optical pick, a guide means comprising a guide rail for moving the signal recording means in a direction parallel to a disk and in a radial direction, and a piezoelectric element provided below the signal recording means. An optical pick-up feeder, comprising: feed means for moving the signal recording means along the guide means by utilizing the effect; and pressurizing means for pressing the feed means downward. 2. The guide means comprises two guide rails for moving the signal recording means in a direction parallel to the disk and in the radial direction. 2. The optical pick feeder according to claim 1, wherein a feeder for moving the signal recording means along the guide means by utilizing a piezoelectric effect is disposed at a lower portion. 3. The optical pick-up feeder according to claim 1, wherein a feeder and a pressurizer are provided below the signal recorder on a line perpendicular to the center of gravity of the signal recorder and the disk. 4. The optical pick feeder according to claim 1, wherein the pressurizing means is provided between the guide means and the signal recording means. 5. The optical pick feeder according to claim 4, wherein the pressurizing means is formed by a V-shaped leaf spring. 6. The optical pick feeder according to claim 1, wherein a roller is provided between the pressurizing means and the guide means. 7. The optical pick feeder according to claim 4, wherein the feeder is provided on a line perpendicular to the center of gravity of the signal recording means and the disk. 8. A CD player equipped with the optical pick feeder according to claim 1. 9. A DVD player comprising the optical pick feeder according to claim 1. 10. A CD-ROM drive equipped with the optical pick feeder according to claim 1. 11. A DVD drive equipped with the optical pick feeder according to claim 1. 12. An MD player equipped with the optical pick feeder according to claim 1. 13. An MO drive equipped with the optical pick feeder according to claim 1.