JP2009070529A - Optical pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an optical pickup device in which a wire supporting a movable body with an objective lens can be easily and electrically connected to terminals of a focusing coil and a tracking coil without any interference. <P>SOLUTION: A movable object 20 having an objective lens 40, a focusing coil 22 and a tracking coil 24 have a circuit board 30 integrally. The circuit board 30 has a wire coupling part 33 coupling tip parts of a plurality of wires 19 supported by a supporting object 13 and a soldering land 34 of coil terminals. The movable object 20 has a guiding part 36 for guiding terminals of respective coils to the soldering land 34 of the circuit board 30 and a projection 38 for entangling terminals of respective coils. The coil terminal is guided by the guiding part 36, entangled by the projection 38, soldered to the soldering land 34. The wire coupling part 33 is connected to the soldering land 34 with a wiring pattern 35. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical pickup device used for reading or writing information recorded on an optical disc.

  Currently, information media such as compact discs (hereinafter referred to as “CD”) and digital versatile discs (hereinafter referred to as “DVD”) are mainly used as information signal recording media. The CD is mainly used as an information recording medium for music, and the DVD is used as an information recording medium for video music and movies. An optical disc has a large recording area capable of recording music together with video, and since the housing and the medium are non-contact, there is an advantage that the quality of music and video does not deteriorate. In order to increase the recording capacity of the optical disc more than before, it is necessary to increase the recording density. Along with this, a high-performance optical pickup device is required to read information on a medium having a high recording density.

  2. Description of the Related Art Conventionally, an optical disk device that reads and writes information recorded on an optical disk such as a CD or a DVD is known. In order to read information recorded on an optical disk, the optical disk device rotates the optical disk by placing the optical disk on a table that is rotatable in the horizontal direction. A rotating optical disc is irradiated with a laser emitted from an optical pickup device, and reflected light from the optical disc is received by a light detection element provided in the pickup. In order to receive the accurate reflected light from the optical disk, it is a precondition that the light is emitted to an accurate position with respect to the optical disk.

  At the same time that optical disk devices are becoming more widespread, more manufacturers are working to reduce product prices. One of the factors necessary to realize a low price is to reduce manufacturing costs. In producing an optical disc device, the product structure is simplified to such an extent that the quality is not deteriorated, whereby the manufacturing time is shortened and the manufacturing cost is reduced. If the manufacturing cost is reduced, the price of the product can be reduced.

  A conventional optical pickup device will be described. Most of the structures of optical pickup devices that are generally known are a coil movable type. The coil movable type includes a movable body having an objective lens and a support body that houses the movable body. The movable body includes a coil that is movable in a focusing direction and a tracking direction. Includes a magnet for moving the movable body in the focusing direction and the tracking direction. The movable body is moved to an accurate pickup position by an electromagnetic force generated between the focusing coil, the tracking coil, and the magnet. An optical pickup device having a structure in which a coil is provided on a movable body as described above is called a coil movable type. The coil movable type has an advantage that the movable body can be made lighter by providing a coil instead of a magnet on the movable body side. However, this coil movable type has the following problems.

  Patent Document 1 is an invention that focuses on the problem of the coil movable type. The outline of Patent Document 1 will be described below. The movable body is driven by an electromagnetic force of a magnetic field line formed by a corresponding magnet by applying a current to a coil provided in the movable body. When a current is applied to the coil for a long time, heat is generated by electric resistance. If this heat continues to rise, the power resistance value of the coil increases and the sensitivity to the amount of power supplied decreases. When the sensitivity is lowered, a vicious circle action in which the power resistance value further increases occurs. At present, the movable structure of a voltage-driven optical pickup is generally the mainstream, and an increase in resistance due to coil heat generation becomes a system instability factor as a direct fluctuation component. In order to solve the above problem, an invention is known that suppresses fluctuations in voltage sensitivity due to an increase in coil temperature. This document describes the soldering of the tracking coil, the focusing coil, and the wire spring (hereinafter also referred to as “wire”), but does not pay attention to the ease of soldering work in the manufacturing process.

  Further, Patent Document 2 describes an invention related to focus control, tracking control, and radiant tilt correction control. As an actuator used for active control, a movable mechanism that reduces lost motion due to nonlinearity or the like as much as possible is adopted. In the present invention, an example of soldering is given as a method for fixing a metal wire spring. There is a description that it is not possible to cope with the heat during soldering unless it is a linear spring having an arbitrary material and an arbitrary cross-sectional shape, but there is no description of a method for solving this. Moreover, the present invention is different from the intention of the present invention.

  The invention described in each of the above patent documents relates to a technique for improving productivity of a coil terminal and a wire that supports a movable body with respect to a focusing coil, a tracking coil, or a radiant tilt coil. There is no. The points to be noted in the coil soldering operation process are the heat resistance of the target material, the productivity aimed at simplifying the operation process, and the reproducibility of the damaged member damaged in the operation.

  There are many prior arts related to optical pickup devices as described in the following patent documents. However, there is no one that solves this by focusing on the technical problem taken up by the present invention.

JP 2003-281748 A JP 2003-345368 A JP 2001-344776 A JP 2002-8256 A JP 2002-133680 A JP 2002-237068 A

  In the movable body that supports the objective lens, the wire that supports the movable body and the terminals of the focusing coil and the tracking coil can be easily and electrically connected without interference. To provide an optical pickup device capable of simplifying the electrical connection work by allowing the wire and the coil terminal to be electrically connected to each other through a circuit board in another place. It is an object.

  The present invention includes a support, a focusing magnet fixed to the support, a tracking magnet fixed to the support, a plurality of wires cantilevered on the support, and a tip of each wire A movable body supported by the movable portion, a focusing coil fixed to the movable body and facing the focusing magnet, a tracking coil fixed to the movable body and opposed to the tracking magnet, and an objective lens supported by the movable body The movable body integrally includes a circuit board, and the circuit board includes a wire coupling portion that couples the wires, a terminal of the focusing coil, and a terminal of the tracking coil. The movable body has a soldering land, and the movable body guides the end of each coil to the soldering land of the circuit board. , Having a protrusion for binding the terminal of each coil, the terminal of the focusing coil and the tracking coil are guided to the guide part, entangled with the protrusion and soldered to the soldering land, The most important feature is that the wire connecting portion and the soldering land are connected by a wiring pattern.

  The ends of the focusing coil and the tracking coil are guided to the guide portion, pass through the soldering land on the circuit board, are entangled with the protrusions, are positioned, and are soldered to the soldering land. Since the soldering land and the wire connecting portion are separated from each other on the circuit board and connected by a wiring pattern, the wire and the end of the coil can be soldered at different positions on the circuit board. it can. For this reason, it is possible to individually perform the wire connecting operation to the circuit board and the soldering operation of the coil terminal, and it is possible to facilitate these operations. In addition, since the interference between the end of each coil and the wire can be avoided, the wire connecting work to the circuit board and the soldering work of the coil end can be facilitated from this point, and the failure rate of the soldering work can be reduced. Can also be reduced.

Embodiments of an optical pickup device according to the present invention will be described below with reference to the drawings.
1 and 2 show the overall configuration of the optical pickup device viewed from each angle. 1 and 2, reference numeral 10 indicates a yoke made of a magnetic material, and reference numeral 20 indicates a movable body (hereinafter also referred to as “lens holder”). The yoke 10 is formed in a lateral U-shape by bending a plate having a rectangular window hole in the center along two parallel lines crossing the window hole, and the upper and lower sides are opposed to each other. The space formed between the two is a space for storing the movable body 20. Magnets are fixed to surfaces where the upper side and the lower side of the yoke 10 face each other, that is, the lower surface of the upper side and the upper surface of the lower side. The upper and lower magnets are each composed of a focusing magnet 16 and a tracking magnet 17, and the window hole formed in the yoke 10 divides the fixed area of the focusing magnet 16 and the fixed area of the tracking magnet 17. The yoke 10 functions as a back yoke for each magnet.

  In FIG. 1, a block-like support 13 is fixed to the lower surface of the yoke 10. A circuit board 15 is fixed to the lower surface of the support 13. The support 15 has a shape close to a rectangular parallelepiped, and a plurality of holes are formed at equal intervals in the short direction (vertical direction in FIG. 2) at both ends in the longitudinal direction. One end of each wire 19 is inserted into each of these holes, and one end of each wire 19 penetrates the circuit board 15 in the thickness direction and is soldered to a predetermined soldering land of the circuit board 15. The wire 19 is cantilevered to the circuit board 15. In the illustrated embodiment, three wires 19 are arranged at both ends in the longitudinal direction of the support 13. Each wire 19 extending from both ends of the support 13 passes through the side of the yoke 10, and the tip of each wire 19 is fixed to the side surface of the movable body 20 as will be described in detail later. The movable body 20 is supported by being soldered to the wire connecting portion.

  In FIG. 3, the movable body 20 has a shape close to a horizontally long rectangular parallelepiped, and a circular objective lens 40 is provided in the center of the front. Vertical window holes 20A are formed at both ends in the longitudinal direction of the movable body 20, and cut and raised portions 10A formed on both sides of the yoke 10 enter the window holes 20A with a space. . The movable body 20 is manufactured by integral molding of resin, for example. On the upper and lower surfaces of the movable body 20, protrusions 29-1 and 29-2 with hooks that function as bobbins for winding the focus coil and the tracking coil are integrally formed at both ends in the longitudinal direction. Yes. A focusing coil 22 is wound around the protrusion 29-1, and a tracking coil 24 is wound around the protrusion 29-2. 3 and 7, the focusing coil 22 is disposed on the upper right side and the lower surface left side of the movable body 20, and the tracking coil 24 is disposed on the upper surface left side and the lower surface right side of the movable body 20. These focusing coils 22 are opposed to the focusing magnet 16 with a predetermined gap, and the tracking coils 24 are opposed to the tracking magnet 17 with an appropriate gap.

  4 and 5, reference numeral 30 indicates a circuit board that is integrally fixed to both end surfaces in the longitudinal direction of the movable body 20. Each circuit board 30 includes three circuit pattern sets each including a wire coupling portion 33, a coil terminal solder land 34, and a wiring pattern 35 that electrically connects the wire coupling portion 33 and the coil terminal solder land 34. . Each circuit pattern set is electrically isolated from each other. In order to electrically isolate each circuit pattern set from each other, in the illustrated embodiment, a slit is formed from the side where the coil terminal solder land 34 is formed. Each wiring pattern 35 extends from each coil terminal solder land 34 in the horizontal direction (vertical direction in FIGS. 1, 2, 4, etc.). Each wire coupling portion 33 is on the extension line of the slit, and therefore, the wire coupling portion 33 is located on the side of the extension line along the wiring pattern 35 of the coil terminal solder land 34. An end portion of the wiring pattern 35 on the wire coupling portion 33 side is bent toward the wire coupling portion 33 and is electrically connected to the wire coupling portion 33. The wire coupling portion 33 is substantially the same as the soldering land. The circuit boards 30 fixed to both end faces of the movable body 20 are formed symmetrically with the movable body 20 in between.

  Both ends in the longitudinal direction of the movable body 20 to which the circuit board 30 is fixed are configured as follows. 5 and 6, planar circuit board fixing portions 31 are formed on both end surfaces in the longitudinal direction of the movable body 20, and the back surface of the circuit board 30 is fixed to each circuit board fixing portion 31. In the movable body 20, three sets of guide portions 36 and a binding portion 38 are formed at positions where the circuit board 30 fixed to the circuit board fixing portion 31 is sandwiched. The guide portion 36 is a columnar protrusion, and is used to guide the end of the focusing coil 22 or the tracking coil 24 to the soldering land 34 of the circuit board 30. The binding portion 38 is a quadrangular columnar projection, and is used to stabilize the coil terminal by binding the coil terminal led to the guide portion 36 to the soldering land 34 before soldering the coil terminal. Is. In other words, the coil terminal is soldered to the soldering land 34 after being bound to the binding part 38. A soldering land 34 and a wiring pattern 35 of the circuit board 30 are arranged along a virtual line connecting the center of each guide part 36 and the center of the binding part 38 corresponding thereto, and a wire coupling part is formed on the side of the virtual line. 33 is located. By being configured as described above, the coil terminal is spanned across the circuit board 30 between the pair of guide portions 36 and the binding portion 38. The base portions of the guide portion 36 and the binding portion 38 are stepped so that an appropriate interval is generated between the coil terminal and the surface of the circuit board 30.

The positions of the guide portions 36 and the binding portions 38 formed on each end face of the movable body 20 are alternately reversed for each set. That is, the guide part 36 in the vertical direction in FIGS. 5 and 6, and the center part in the horizontal direction in FIGS. 1 and 2 is on the soldering land 34 side of the circuit board 30, and the binding part 38 is on the wire coupling part 33 side of the circuit board 30. In contrast, the guide portions 36 on both sides are on the wire coupling portion 33 side of the circuit board 30, and the binding portion 38 is on the soldering land 34 side of the circuit board 30. The coil terminal is wound around the guide part 36 and the binding part 38 that form a pair, but the number of turns around the guide part 36 may be one or less, and it may be enough to determine the position of the coil terminal. The binding portion 38 is appropriately wound a number of times in order to stabilize the coil terminal. As shown in FIGS. 12 to 14, the winding direction of the coil terminal with respect to the guide portion 36 and the winding direction with respect to the binding portion 38 are opposite to each other, as shown in FIG. 12 to FIG. 14. Coil terminals are slanted over a virtual line connecting the centers. In this way, the coil terminal is slanted over, so that the coil terminal can be moved away from the wire coupling portion 33 so that the coil terminal does not become an obstacle during the soldering operation of the wire 19 described later. Has been taken into account.
The guide portion 36 may not be a protrusion. For example, it may be a groove into which a coil wire fits, or may be in the form of a hook.

  One end is fixed to the circuit board 15 fixed to the lower surface of the support 13, and a circuit board 30 attached to the movable body 20 near the tip of the wire 19 extending to the side of the movable body 20. These are coupled to the wire coupling portion 33 by soldering. Three wires 19 extend on both sides of the movable body 20, and the ends of the wires 19 are coupled to the wire coupling portion 33, and the wires 19 are parallel to each other to support the movable body 20. Yes. Each wire 19 is an electric conductor and made of an elastic material. By applying an external force, each wire 19 can be translated while maintaining a predetermined posture while bending each wire 19. ing. Each wire 19 extends parallel to an imaginary line connecting the pair of guide portions 36 and the center of the binding portion 38. Therefore, the direction of each wire 19 and the direction of each coil terminal spanned between the guide part 36 and the binding part 38 as described above are non-parallel.

  An assembling procedure of the main part of the optical pickup device according to the embodiment described above will be schematically described. First, the circuit board 30 is fixed to the circuit board fixing portions 31 on both sides in the longitudinal direction of the movable body 20 by bonding or other appropriate means. Next, the focusing coil 22 and the tracking coil 24 are wound around the protrusions 29-1 and 29-2 with hooks of the movable body 20 automatically or manually, respectively. Each coil terminal is hung on a predetermined guide portion 36, straddled across the circuit board 30, tied around the binding portion 38, and further soldered to the soldering land 34. Finally, the objective lens 40 is attached to the movable body 20. 11 to 14 show a state where each coil terminal is processed as described above. Thereby, the movable body 20 substantially constitutes an objective lens holder unit.

Next, as shown in FIGS. 15 to 17, the tip end of the wire 19 is soldered to each wire coupling portion 33 of each circuit board 30. In soldering the wire 19, the direction of the wire 19 and the direction of the circuit board 30 and the relative positional relationship are determined accurately by using a jig or the like.
On the other hand, the support body 13 and the yoke 10 are coupled in advance, and the circuit board 15 is fixed to the lower surface of the support body 13. While inserting one end portion of each wire 19 into each predetermined hole of the support body 13, in a space formed between the focusing magnet 16 and the tracking magnet 17 fixed to the upper side and the lower side of the yoke 10, respectively. The movable body 20 is inserted and positioned at a predetermined position. Since one end portion of each wire 19 further penetrates a predetermined hole of the circuit board 15, the wire 19 is fixed by soldering to a soldering land formed around the through hole. In this way, the movable body 20 is supported by the support body 13 via the wire 19. As described above, when an external force is applied, the movable body 20 can move in parallel while maintaining a predetermined posture by bending the wires 19 in parallel with each other.

  Each wire 19 is an elastic body that supports the movable body 20, is made of a conductive material, and is also used as a wire for flowing a control current from the circuit board 15 on the support body 13 side to each focusing coil 22 and tracking coil 24. Function. When a control current flows through the focusing coil 22, the movable body 20 is driven in the optical axis direction of the objective lens 40 by the electromagnetic force generated between the magnetic field formed by the focusing magnet 16 and focusing control is performed. When a control current flows through the tracking coil 24, the movable body 20 is in a direction perpendicular to the optical axis of the objective lens 40 due to an electromagnetic force generated between the magnetic field formed by the tracking magnet 17 and is recorded on an optical disc (not shown). Driven in the direction crossing the track, tracking control is performed.

  According to the embodiment described above, the ends of the focusing coil 22 and the tracking coil 24 are guided to the guide portion 36, pass through the soldering land 34 on the circuit board 30, and entangled with the binding portion 38 made of a protrusion. Are positioned and soldered to the soldering land 34. Since the soldering land 34 and the wire coupling portion 33 are located on the circuit board 30 and are electrically connected by the wiring pattern 35, the wire 19 and the end of the coil are connected on the circuit board 30. It can be soldered at another position. For this reason, it is possible to individually perform the operation of connecting the wire 19 to the circuit board 30 and the operation of soldering the coil terminal, and it is possible to facilitate these operations. In addition, since the interference between the end of each coil and the wire 19 can be avoided, the connection work of the wire 19 to the circuit board 30 and the soldering work of the coil terminal can be facilitated from this point as well. The scrap rate can also be reduced.

  In addition, according to the illustrated embodiment, each coil terminal is led to the guide portion 36 and straddles the circuit board 30, and is entangled with the tie portion 38 made of a protrusion, and is soldered to each soldering land 34. In addition, the direction in which each coil terminal is hung on the guide part 36 and the direction in which the coil terminal is wound on the binding part 38 are opposite to each other, and the wire direction and each coil terminal direction are not parallel to each other. Therefore, the operation of connecting the wire 19 to the circuit board 30 and the operation of soldering the coil terminal are further facilitated, and the yield can be further increased. The illustrated embodiment assumes a slim pickup type, and since the height of the movable body is reduced, the wire direction and each coil terminal direction are not parallel as described above. If the movable body has a margin in the vertical direction, each coil terminal can be run parallel to the wire direction so as not to be buffered by the wire, and a soldering land can be provided in the middle. Moreover, the wire 19 and the terminal of each coil are guided to the guide part 36, and each is soldered on the circuit board 30, thereby realizing an accurate conductive connection without interfering with each other. In addition, since the circuit board 30 includes the soldering land portions of the wire 19 and each coil terminal, the wire 19 and each coil terminal can be soldered at an accurate position.

  The circuit board 30 and the movable body 20 may be integrated in the assembly process. For example, the circuit board 30 is made of a heat-treated material, and the movable body 20 is made of a material that emphasizes light weight. It is possible to achieve a purposeful design while reducing unnecessary costs. In the illustrated embodiment, the optical axis of the objective lens 40 is depicted as being oriented in the horizontal direction, and the description has been made accordingly. However, the optical axis of the objective lens 40 is oriented in the vertical direction, or at an appropriate angle. The optical pickup according to the present invention may be used in any posture because it may be used in a tilted posture.

It is a perspective view which shows the Example of the optical pick-up apparatus concerning this invention. It is the perspective view which looked at the said Example from another angle. It is a front view which shows the Example of the optical pick-up apparatus concerning this invention. It is a right view which shows the Example of the optical pick-up apparatus concerning this invention. It is a disassembled perspective view which shows the movable body and circuit board in the said Example. It is the perspective view which looked at the above-mentioned movable body and circuit board from the bottom side. It is a front view which shows the said movable body and circuit board. It is a right view which shows the said movable body and circuit board. It is the perspective view which looked at the above-mentioned movable body and circuit board from the upper surface side. It is the perspective view which looked at the above-mentioned movable body and circuit board from the bottom side. It is a front view which shows the movable body in the state which performed the coil terminal process in the said Example. It is a right view which shows the movable body in the state which performed the coil terminal process in the said Example. It is the perspective view which looked at the movable body of the state which performed the said coil terminal process from the upper surface side. It is the perspective view which looked at the movable body of the state which performed the said coil terminal process from the lower surface side. It is a front view which shows the state which mounted the wire in the movable body of the state which performed the said coil terminal process. It is a right view of the movable body which mounted the said wire. It is the perspective view which looked at the movable body which mounted the said wire from diagonally upward.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Yoke 13 Support body 15 Circuit board 16 Focusing magnet 17 Tracking magnet 19 Wire 20 Movable body 40 Objective lens 22 Focusing coil 24 Tracking coil 29-1 Protrusion 29-2 Protrusion 30 Circuit board 33 Wire coupling part 34 Soldering land 35 Wiring pattern 36 Guide part 38 Tying part 40 Objective lens

Claims (7)

A support, a focusing magnet fixed to the support, a tracking magnet fixed to the support, a plurality of wires supported in a cantilever manner on the support, and a tip of each wire. A movable body, a focusing coil fixed to the movable body and opposed to the focusing magnet, a tracking coil fixed to the movable body and opposed to the tracking magnet, and an objective lens supported by the movable body. An optical pickup device,
The movable body has a circuit board integrally,
The circuit board has a wire coupling portion for coupling the wire, a soldering land of a terminal of a focusing coil and a terminal of a tracking coil,
The movable body has a guide portion for guiding the terminal of each coil to a soldering land of the circuit board, and a protrusion for binding the terminal of each coil,
The terminals of the focusing coil and tracking coil are guided to the guide part, entangled with the protrusions and soldered to the soldering land,
An optical pickup device, wherein the wire connecting portion and the soldering land are connected by a wiring pattern. 2. The optical pickup device according to claim 1, wherein the wire coupling portion and the soldering land of the circuit board are located at one end and the other end of the circuit board. The optical pickup device according to claim 1, wherein a wire coupling portion is provided at a side of an imaginary line connecting the center of the guide portion of the movable body and the center of the protrusion. The optical pickup device according to claim 1, wherein the circuit board includes a plurality of sets of wire coupling portions and soldering lands in parallel. 2. The optical pickup device according to claim 1, wherein each of the coil terminals is led to a guide portion, straddles the circuit board, is entangled with a protrusion, and is soldered to a soldering land. 6. The optical pickup device according to claim 5, wherein a direction in which each coil terminal is hung on the guide portion and a direction in which the coil terminal is entangled with each other are opposite to each other, and the wire direction and each coil terminal direction are non-parallel. The optical pickup device according to claim 1, wherein the wire is coupled to the wire coupling portion by soldering.

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