JP2008021357A - Pickup lens and optical pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pickup lens which can be attached accurately to a position of a specified angle, and an optical pickup device. <P>SOLUTION: The pickup lens 11 performs recording/reproducing of an optical disk, and is provided with an optical function part 111 having an optical function, and a flange part 112 provided to the outer periphery of the optical function part 111. The shape of the outer periphery of the flange part 112 in a plain view in almost parallel to the optical axis of the optical function part 111 is a polygonal shape. The optical pickup device has the pickup lens 11, and a lens holder to which the pickup lens 11 is attached, and the lens holder is provided with a housing part in which the flange part 112 of the pickup lens 11 is fitted and which houses the pickup lens 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pickup lens and an optical pickup device.

  In recent years, optical disk apparatuses that record and reproduce various information on optical recording media such as digital cameras, CDs, and DVDs have become widespread. For example, the optical disc apparatus includes an optical pickup device that records information on an optical recording medium and reads information recorded on the optical recording medium. The optical pickup device includes a pickup lens for condensing light from a light source onto an optical recording medium.

  The pickup lens is generally manufactured by molding various plastics or glass. A plastic pickup lens is manufactured by injection molding or transfer molding using a molding die. For example, in injection molding, a pickup lens is manufactured by pouring a resin from a gate into a cavity in a mold and cooling the resin (see, for example, Patent Document 1).

This kind of plastic lens is mass-produced in order to reduce the product unit price. Therefore, a plurality of lenses are manufactured simultaneously using a molding die having a plurality of cavities. For example, a molding die having eight cavities is used, and eight lenses are manufactured at the same time.
The pickup lens is generally formed in a circular shape or a substantially circular shape because it is easy to mold. With such a shape, astigmatism can be freely adjusted by rotating the lens around the optical axis, and the characteristics of the pickup can be optimized.

  FIG. 6 shows an example of an actuator of a conventional optical pickup device. In this actuator 900, a pickup lens 911 is attached to a lens holder 912, and the lens holder 912 is attached to the actuator 900 so as to be movable back and forth and right and left by a wire. The lens holder 912 includes a pedestal 913 and a holding rib, and the lens holder 912 is attached to the pedestal 913. The pedestal 913 is formed with a hole through which the light beam passes through the pickup lens 911. A holding rib for holding the pickup lens 911 is provided on the outer periphery of the base 913 and a hole formed in the base 913. A housing portion for housing the pickup lens 911 is formed by the holding rib.

In the lens holder 912, the pickup lens 911 can be freely rotated around the optical axis of the pick lens. Therefore, the degree of freedom of aberration adjustment can be increased, but the accuracy of the fixed position is lacking. Further, when the pickup lens 911 is attached, it is required to be attached at a designated angle. Since the tendency of the optical characteristics of the pickup lens is different for each cavity, an optimal mounting angle is set when mounting the lens to the lens holder.
JP 2002-122711 A

  Such a circular or substantially circular lens has a high degree of freedom in angle adjustment, but it is difficult to attach it at a position rotated to a specified angle. For example, when the convex portion on the lens holder is used as a guide, the specified angle is visually determined and attached using the marking provided on the pickup and the marking provided on the lens as a guide. In addition, the angle adjustment amount is originally different for each lens, but currently it cannot be changed for each cavity. For example, the same adjustment amount is used for the same cavity and the same molding lot. In this way, when the lens is circular or substantially circular, it can be freely rotated, but it is difficult to mount at an accurate angle, and the specified angle is not an angle such as 11 ° or 12 °, but is a guide for the angle. In many cases, an adjustment angle of about 45 ° is easily specified. However, since adjustment amounts become diversified and the correspondence becomes difficult when the number of cavities increases, adjustment amounts are grouped.

Further, when a circular or substantially circular lens is sandwiched and rotated by tweezers or the like, a delicate angle adjustment tends to cause a risk that the tweezers may cause the lens to repel and become defective. Furthermore, when the adhesive is applied to fix the lens, the angle of the lens is not stabilized due to the adhesive force of the adhesive, and the pickup characteristics become unstable.
The present invention has been made to solve such a problem, and an object thereof is to provide a pickup lens and an optical pickup device that can be accurately mounted at a specified angle position.

  A pickup lens according to the present invention is a pickup lens for recording / reproducing an optical disc, and includes an optical function part having an optical function, and a flange part provided on an outer periphery of the optical function part, The shape of the outer periphery of the flange portion viewed from above substantially parallel to the optical axis of the optical function portion is a polygonal shape. With such a configuration, it is possible to rotate and adjust the position of each corner, and it is possible to accurately attach to a specified angle position.

  Preferably, the shape of the outer periphery of the flange portion in plan view substantially parallel to the optical axis of the optical function portion is a substantially octagonal shape. As a result, the pickup lens can be rotated approximately 45 degrees to adjust the position, and can be accurately mounted at a specified angle position every approximately 45 degrees.

  The pickup lens according to the present invention is a plastic lens. Thereby, a pickup lens can be easily produced by injection molding.

  An optical pickup device according to the present invention is an optical pickup device having a pickup lens for recording / reproducing an optical disc and a lens holder to which the pickup lens is attached, and the pickup lens has an optical function. An optical function part; and a flange part provided on an outer periphery of the optical function part, wherein the lens holder includes a housing part into which the flange part of the pickup lens is fitted and accommodates the pickup lens, The shape of the outer periphery of the flange portion viewed from above substantially parallel to the optical axis of the functional portion is a polygonal shape. With such a configuration, each corner can be rotated and adjusted in position, and can be accurately and reliably attached to a specified angle position.

  Preferably, the outer peripheral shape of the flange portion when viewed in plan substantially parallel to the optical axis of the optical function portion is an approximately octagonal shape. As a result, the pickup lens can be rotated approximately 45 degrees to adjust the position, and can be accurately mounted at a specified angle position every approximately 45 degrees.

  The pickup lens is a plastic lens. Thereby, a pickup lens can be easily produced by injection molding.

  Furthermore, the pickup lens has a lens-side marking which serves as a positioning reference with respect to the lens holder. As a result, the pickup lens can be accurately attached at a specified angular position.

  Furthermore, the lens holder has a holder side marking for determining a relative position between the lens side marking and the lens holder. As a result, the pickup lens can be accurately attached at a specified angular position.

  Moreover, the said accommodating part is comprised from the some holding rib contact | abutted to the corner | angular part in the outer periphery of the polygonal flange part. Thereby, when manufacturing a lens holder, a holding rib can be easily manufactured simultaneously.

  Still further, the accommodating portion is composed of a plurality of holding pins that come into contact with side portions on the outer periphery of the polygonal flange portion. Thereby, when producing a lens holder, a holding pin can be easily produced simultaneously.

  ADVANTAGE OF THE INVENTION According to this invention, the pick-up lens and optical pick-up apparatus which can be correctly attached to the position of the designated angle can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

Embodiment 1 of the Invention
First, the configuration of the optical pickup device according to the present invention will be schematically described with reference to FIG. FIG. 1 is a perspective view showing a configuration example of an optical pickup device according to the present invention. As shown in FIG. 1, an optical pickup device 1 according to the present invention includes a pickup lens 11 and an actuator 13 provided with a lens holder 12. Hereinafter, these are abbreviated as a lens 11 and a holder 12.

  The lens 11 is a plastic lens that is injection-molded using a molding die, and the actuator 13 is a device for driving the lens 11 although the details thereof are not shown. The holder 12 of the actuator 13 is a holding member that holds the lens 11, and details thereof will be described later. The lens 11 is mounted on the actuator 13 of the optical pickup device 1 by being attached to the holder 12. The lens 11 is fixed by an adhesive while being fitted in the holder 12. The lens 11 is formed with a marking 110 for indicating a relative position with respect to the holder 12. The lens 11 is attached to the holder 12 while visually observing the marking 110 with a magnifying glass.

Next, the lens 11 according to the present invention will be specifically described with reference to FIG. FIG. 2 is a diagram showing a lens 11 according to the present invention, and FIG. 2 (a) is a top view. FIG. 2B is a side view and a sectional view, the right half of which is a side view and the left half is a sectional view.
As shown in FIG. 2, the lens 11 includes an optical function unit 111 and a flange unit 112, and the optical function unit 111 and the flange unit 112 are integrally formed in the lens 11.

  The optical function unit 111 is a part that functions optically, and is a lens in a narrow sense while the lens 11 is a lens in a broad sense. Specifically, the optical function unit 111 is a part that allows light having a convex or concave curved surface to pass through on the upper surface or the lower surface.

  The flange portion 112 is an outer peripheral portion of the optical function portion 111 of the lens 11 and has a flange upper surface 112a, a flange lower surface 112b, and a flange side surface 112c. The flange upper surface 112a is provided on the optical recording medium side in a state where the optical pickup device 1 is attached to the optical disk device and information is read from the optical recording medium. On the other hand, the flange lower surface 112b is disposed on the opposite side to the flange upper surface 112a, and is provided on the opposite side to the optical recording medium with the optical pickup device 1 attached.

  The flange side surface 112c is disposed on the outer peripheral portion of the flange portion 112, and the planar shape thereof is a polygonal shape when viewed in a plane substantially parallel to the optical axis of the lens 11, and more specifically, approximately 8 It is a square shape. That is, the shape of the outer peripheral portion of the flange portion 112 viewed in plan substantially parallel to the optical axis of the lens 11 is a polygonal shape, specifically, an approximately octagonal shape.

  Here, when the planar shape of the outer periphery of the flange portion 112 as viewed from the optical axis direction is a substantially octagonal shape, for example, by rotating the lens 11 counterclockwise, 45 °, such as 45 °, 90 °, etc. The lens 11 can be rotated in increments and attached to the holder 12 accurately. In addition, the rotation angle of the lens 11 with respect to the holder 12 can be reliably confirmed by the marking 110 from the relative angle of the marking 110.

  The planar shape of the inner peripheral portion of the flange portion 112, that is, the outer peripheral portion of the optical function portion 111, can be a complete circular shape. The gate position is provided on the flange side surface 112 c of the polygonal flange portion 112, and the upper surface of the corner portion becomes the reference position of the marking 110. The gate position can be provided between the corner portions of the polygonal flange portion 112, but is not limited thereto, and may be provided at the corner portions.

  In the present embodiment, the marking 110 is provided on the flange upper surface 112a, and is particularly disposed near a straight line connecting the corner portion and the center of the lens (optical axis). You may arrange | position between. The marking 110 is provided to identify, for example, a manufacturing tool such as a molding die, a cavity, and an injection molding apparatus. Further, the shape of the marking 110 can be an oval shape or a circular shape, and is not limited to one location, and may be provided at another plurality of locations.

Next, the actuator 13 according to the present invention will be specifically described with reference to FIG. FIG. 3 is a perspective view showing the actuator 13 according to the present invention.
As shown in FIG. 3, the actuator 13 has a main body 131 and a holder 12, and the main body 131 and the holder 12 are integrally formed in the actuator 13. The main body 131 is a portion that becomes the main body of the actuator 13, and the holder 12 is a portion that accommodates and holds the lens 11. The holder 12 is a cylindrical body having an accommodating portion 12a provided on the inside thereof, and the lens 11 is fitted into the accommodating portion 12a. The shape of the inner peripheral edge of the holder 12, that is, the shape of the bottom surface of the housing portion 12 a is the same shape as the outer periphery of the flange portion 112 of the lens 11, and specifically has a polygonal shape. More specifically, the shape of the bottom surface of the accommodating portion 12a is a substantially octagonal shape.

  The lens 11 is fitted into such a holder 12 as follows. The optical axis of the optical functional part 111 of the lens 11 and the longitudinal direction of the holder 12 (direction substantially perpendicular to the bottom surface of the accommodating part 12a) are aligned so that the accommodating part of the holder 12 is in this state. The lens 11 is fitted into 12a. At this time, the lens 11 is fitted into the accommodating portion 12 a surrounded by the inner wall of the holder 12 so that the side surface of the flange portion 112 of the lens 11 is along the inner wall of the holder 12. The flange portion 112 of the lens 11 is in contact with the inner wall of the housing portion 12a in this fitted state. That is, the flange portion 112 of the lens 11 is held by the inner wall of the housing portion 12a over the entire side surface. At this time, adhesive means such as an adhesive is applied to the side surface of the flange portion 112, and the side surface of the flange portion 112 is bonded and fixed to the inner wall of the housing portion 12a in a state of being fitted into the housing portion 12a.

  As described above, in the embodiment of the present invention, the shape of the flange portion 112 at the outer peripheral portion of the lens viewed in a plane substantially parallel to the optical axis of the optical function portion 111 is a polygonal shape. At the same time, the shape of the inner peripheral edge of the holder 12 into which the lens 11 is fitted, that is, the shape of the bottom surface of the housing portion 12 a surrounded by the inner wall of the holder 12 is the same polygonal shape as the planar shape of the flange portion 112. Thus, the lens 11 can be reliably and easily attached at an accurate angle without the lens 11 rotating within the housing portion 12 a of the holder 12. Therefore, the workability of the work of attaching the lens 11 to the holder 12 can be improved, and the stability of the pickup characteristics can be improved. In addition, compared to a conventional circular or substantially circular lens, although the mounting angle for adjusting the aberration is limited, a sufficient degree of mounting angle can be obtained by setting the adjusting angle to about 45 °. That is, the shape of the flange portion 112 of the lens 11 as viewed in plan substantially parallel to the optical axis of the optical function portion 111 and the bottom shape of the housing portion 12a surrounded by the inner wall of the holder 12 are substantially octagonal. Thus, the degree of freedom of the mounting angle can be realized.

Embodiment 2 of the Invention
In Embodiment 1, the shape of the accommodating portion 12a of the holder 12 is a cylindrical shape, but the structure of the lens holder is not limited to this, and can be configured using various attachment means.
FIG. 4 shows an example of a lens holder in the second embodiment. As shown in FIG. 4, the holder 32 does not hold the entire side surface of the flange portion 112 of the lens 11 like the holder 12 of the first embodiment, but holds the corner portion of the substantially octagonal lens 11. is doing. Specifically, the holder 32 has holding ribs 321, 322, 323, and 324, and the holding portion is configured by these holding ribs 321 to 324.

  The holding ribs 321 and 323 stand upright while facing each other at a substantially octagonal diagonal portion, and the holding ribs 322 and 324 stand upright while facing each other at a substantially octagonal diagonal portion. At this time, the space formed by the holding ribs 321 to 324 is opposed to the shape of the flange portion 112 of the lens 11 viewed in a plane substantially parallel to the optical axis of the optical function portion 111. In other words, the holding ribs 321 to 324 are arranged at corner portions along the outer periphery of the accommodating portion 12a of the holder 12 in the first embodiment.

  Such holding ribs 321 to 324 can hold corner portions of the flange portion 112 having a substantially octagonal shape. In addition, the lens 11 can be more reliably held by appropriately changing the elasticity of the holding ribs 321 to 324 or by narrowing the interval between the diagonally arranged ones. When the position of the lens 11 is regulated using the holding ribs 321 to 324 like the holder 32 of the second embodiment, the holder 32 can be reduced in weight compared to the holder 12 of the first embodiment. For this reason, it is possible to improve the load, improve the performance, and reduce the cost of the optical pickup device 1.

Embodiment 3 of the Invention
In the second embodiment, the holding rib is used to configure the housing portion. However, the present invention is not limited to this, and it is sufficient that the lens 11 can be held from the side surface. For example, as shown in FIG. 5, circular pins 421 to 424 can be used to configure the accommodating portion of the holder 42. At this time, the circular pins 421 to 424 hold the corner portions of the lens 11 in which the holding ribs 321 to 324 of the second embodiment are diagonally arranged, whereas the circular pins arranged diagonally are The side portion of the lens 11 is held.

As described above, the position of the lens 11 can be regulated using the circular pins 421 to 424. In this case, the weight can be further reduced compared to the holders 12 and 32 of the second embodiment. Furthermore, since the whole holder 42 can be formed by injection molding together with the circular pins 421 to 424, the manufacturing process including the molding die can be simplified.
The above description is for explaining the embodiment of the present invention, and the present invention is not limited to the above embodiment. Moreover, those skilled in the art can easily change, add, and convert each element of the above embodiment within the scope of the present invention.
In the embodiment of the invention described above, the shape of the outer peripheral portion of the flange portion 112 of the lens 11 when viewed in plan substantially parallel to the optical axis of the lens 11 is specifically an octagonal shape. The planar shape of the outer peripheral portion of the flange portion 112 of the lens 11 may be a polygon other than a substantially octagon. At this time, the shape of the bottom surface of the housing portion 12 a surrounded by the inner wall of the holder 12 corresponds to the shape of the outer peripheral portion of the flange portion 112 of the lens 11 viewed in a plane substantially parallel to the optical axis of the lens 11.
In the present invention, the substantially octagonal lens 11 has been described by taking the adjustment every approximately 45 degrees as an example. However, if approximately 60 degrees is required, it may be a substantially hexagonal shape, and the holder may be a corresponding shape. Good.

1 is a schematic perspective view showing an example of an optical pickup device according to the present invention. It is a schematic diagram which shows an example of the pickup lens which concerns on this invention. It is a perspective schematic diagram which shows an example of the lens holder which concerns on this invention. It is a perspective schematic diagram which shows another example of the optical pick-up apparatus which concerns on this invention. It is a perspective schematic diagram which shows another example of the optical pick-up apparatus which concerns on this invention. It is a perspective schematic diagram which shows an example of the conventional optical pick-up apparatus.

Explanation of symbols

1 Optical pickup device 11 Pickup lens (lens)
DESCRIPTION OF SYMBOLS 110 Marking 111 Optical function part 112 Flange part 112a Flange upper surface 112b Flange side surface 112c Flange lower surface 12 Lens holder (holder)
12a Housing part 13 Actuator 131 Body part 32 Lens holder (holder)
321 to 324 Retaining rib 42 Lens holder (holder)
421-424 circular pin

Claims (10)

A pickup lens for recording / reproducing an optical disc,
An optical function unit having an optical function;
A flange portion provided on the outer periphery of the optical function portion;
The pickup lens according to claim 1, wherein a shape of an outer periphery of the flange portion when viewed from above substantially parallel to an optical axis of the optical function portion is a polygonal shape.   2. The pickup lens according to claim 1, wherein a shape of an outer periphery of the flange portion in plan view substantially parallel to the optical axis of the optical function portion is a substantially octagonal shape.   The pickup lens according to claim 1, wherein the pickup lens is a plastic lens. An optical pickup device having a pickup lens for recording / reproducing an optical disc and a lens holder to which the pickup lens is attached,
The pickup lens includes an optical function part having an optical function, and a flange part provided on the outer periphery of the optical function part,
The lens holder includes a housing portion into which the flange portion of the pickup lens is fitted and the pickup lens is housed.
The optical pickup device according to claim 1, wherein a shape of an outer periphery of the flange portion when viewed from above substantially parallel to an optical axis of the optical function portion is a polygonal shape.   5. The optical pickup device according to claim 4, wherein a shape of an outer periphery of the flange portion in a plan view substantially parallel to the optical axis of the optical function portion is a substantially octagonal shape.   The optical pickup device according to claim 4, wherein the pickup lens is a plastic lens.   The optical pickup device according to claim 4, wherein the pickup lens has a lens-side marking serving as a reference for positioning with respect to the lens holder.   The optical pickup device according to claim 7, wherein the lens holder has a holder side marking for determining a relative position between the lens side marking and the lens holder.   The optical pickup device according to claim 4, wherein the housing portion includes a plurality of holding ribs that contact corner portions of the outer periphery of the polygonal flange portion.   The optical pickup device according to claim 4, wherein the housing portion is configured by a plurality of holding pins that abut on side portions on an outer periphery of the polygonal flange portion.

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