JP2011129236A - Optical pickup and optical disk drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To overcome the problem with an optical pickup that requires two back yokes for two magnets and a coil holder for holding the coil, and has a limit to shorten its length in the length direction. <P>SOLUTION: A lens holder 32 of a rectangular frame shape having four sides 32a-32d is configured such that coils 33a-33c and 33d-33f are arranged side by side on the surrounding wall surfaces facing one another, and magnets 41a-41c and 41d-41f are fixed in a line across a back yoke 42a within this frame, respectively, so that this frame is built in five layers composed of a line of coils 33a-33c, a line of magnets 41a-41c, a back yoke 42a, a line of magnets 41d-41f, and a line of coils 33d-33f. Thus, the required gaps are only two gaps, namely the gap between the coils 33a-33c and the magnets 41a-41c, and the gap between the magnets 41d-41f and the coils 33d-33f. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical pickup and an optical disc drive apparatus having the optical pickup, and more particularly to an optical pickup and an optical disc drive apparatus for guiding a light beam from a light source to a record carrier or from a record carrier to a photodetector.

An optical pickup used in an optical disc drive is configured to be elastically supported by a fixed member via a wire so that a movable member holding a lens can be displaced. The following techniques are known as such an optical pickup.
Patent Document 1 discloses, in particular, Claim 3 and paragraphs 0020 to 0025, a technique of disposing the back yoke 28 on the surface of the tilt coil that faces the tilt magnet.
Patent Document 2 discloses, in particular, paragraphs 0022 to 0025, a technique of disposing a back yoke 6c between the tracking drive mechanism 8 and the tilt mechanism 12.

Japanese Patent Laid-Open No. 2005-302161 JP 2005-235355 A

A portable type optical pickup is desired to be smaller than a stationary type. However, in the above-described conventional one, a back yoke and a magnet are paired, two back yokes are required for two magnets, and a coil holder for holding a coil is required independently of the lens holder. It was. For this reason, there is a limit to the reduction in the length direction of the fixed side member and the movable part side member.
The present invention reduces the size of the fixed side member and the movable part side member.

  The present invention is an optical pickup configured by elastically supporting a movable side member holding a coil and a lens with a fixed side member holding a magnet through a wire so as to be displaceable. The side member includes the lens, a lens holder that is formed in a substantially rectangular frame shape and supports the lens, and a coil that is held in the frame of the lens holder. A magnet that supplies a fixed-side magnetic field, a base that serves as a back yoke that supports the magnet so as to face the coil, a circuit board that supplies drive current to the coil, and a damper that supports the circuit board and the base A wire, and the wire connects the movable side member and the fixed side member with an elastic metal member so as to be displaceable, and the circuit board and the cooperating member. The magnet is disposed on both sides of the base while forming a plate-like back yoke so as to enter the frame of the lens holder at the base. It is set as the structure arrange | positioned so that it may support in the frame inner peripheral wall surface which opposes so that the same magnet may be faced in a frame.

  In the above configuration, the movable side member that holds the coil and the lens is elastically supported by the fixed side member that holds the magnet via the wire so that it can be displaced. Thus, the movable member can be driven to an appropriate position by the repulsive force or attractive force of the magnetic field that is appropriately formed. More specifically, the movable side member that holds the lens has a lens holder that holds a coil in the frame while being formed in a substantially rectangular frame shape, and the fixed side member has a back base. The coil is supported in the frame, and the magnet supplies a fixed-side magnetic field to the coil, and a drive current is supplied from the circuit board to the coil for driving. The circuit board and the base are supported by a damper box, and the wire is connected to the circuit board while movably connecting the movable side member and the fixed side member with an elastic metal member. The coil is electrically connected.

  Here, the back yoke is formed in a plate shape so as to enter the frame of the lens holder at the base, and the magnets are arranged on both surfaces thereof. Therefore, there is one back yoke that falls within the frame. Further, since the coil is directly supported by the opposed inner wall surfaces of the frame so as to face the magnet in the frame, a coil holder for supporting the coil becomes unnecessary. That is, the length in the frame can be narrowed by one back yoke and the coil holder.

Moreover, you may comprise the said magnet and the said coil so that it may face substantially parallel to the facing surface of the said fixed side member and the said movable side member.
When configured in this way, the length reduced by one back yoke and the coil holder can be reduced in the direction of the combined length of the fixed side member and the movable side member.
Further, three magnets are arranged in a row on each side of the back yoke and a total of six magnets are arranged, and three coils are arranged in a row facing the magnets, for a total of six coils. May be.
In this way, a sufficient driving force can be generated by facing the six coils and the magnet while saving space. Further, since the magnets are arranged one by one with the back yoke in between, there is little loss in generating the fixed-side magnetic field, and a strong magnetic field can be formed.

  In addition, as a specific example in which the above is integrated into a single product, an optical disk drive, a tuner, an input circuit unit that accepts operation input, and digital data expansion and compression are performed. A decompression / compression processing unit for writing and reading data, an A / D conversion unit for digitizing an input analog signal to the decompression / compression processing unit, and a D for analogizing an output digital signal from the decompression / compression processing unit An optical disc drive apparatus comprising: a / A conversion unit; reception by the tuner; reception of operation input by the input circuit unit; and control unit for controlling writing and reading of digital data by the expansion / compression processing unit Thus, the optical disk drive uses a wire so that the movable side member holding the lens can be displaced. An optical pickup configured to be elastically supported by a fixed-side member, and the movable-side member includes: the lens; a lens holder that is formed in a substantially rectangular frame shape and supports the lens; and A coil that is held in a frame, and the fixed-side member includes a magnet that supplies a fixed-side magnetic field to the coil, a base that serves as a back yoke that supports the magnet so as to face the coil, A circuit board for supplying a drive current to the coil; and a damper box for supporting the circuit board and the base. The wire is displaced by an elastic metal member between the movable side member and the fixed side member. The circuit board and the coil are electrically connected to each other while being connected, and a plate-like back yoke is installed at the base so as to enter the frame of the lens holder. The magnet is disposed on both sides of the coil, and the coil is disposed so as to be supported by opposing inner wall surfaces of the frame so as to face the magnet in the frame, and While the magnet and the coil face each other substantially parallel to the facing surfaces of the fixed side member and the movable side member, three magnets are arranged in a row on each side of the back yoke. The coils may be arranged such that a total of six coils are arranged side by side at a position facing each magnet.

  According to the present invention, compared with the shape of a conventional actuator, one coil holder, one back yoke, and a gap between components can be eliminated, so that the shape of the optical pickup can be reduced. In particular, the shape in the tangential direction combining the movable side member and the fixed side member can be reduced depending on the orientation direction.

It is a block diagram of the optical disk drive device which has an optical pick-up. It is a perspective view which shows schematic structure of an optical pick-up. It is a top view of an optical pick-up. It is a perspective view of a base, a back yoke, and a magnet. It is a perspective view of a base alone. It is a top view of the conventional optical pick-up.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the portable type optical pickup, the distance between the main axis and the sub axis is shorter than that of the stationary type (47.5 → 45 mm), so it is necessary to reduce the shape of the actuator in the tangential direction. First, the configuration of an optical disc drive apparatus to which an optical pickup is applied will be described.

FIG. 1 is a block diagram showing an optical disc drive apparatus having an optical pickup according to the present invention.
In the figure, a tuner unit 11 receives a commercial broadcast of a channel designated by a control unit 12 having a CPU, and receives an analog video signal (including an analog audio signal) that is an input analog signal obtained by reception. The data is output to the A / D converter 13. The A / D conversion unit 13 converts the analog video signal output from the tuner unit 11 into a digital video signal (including a digital audio signal) and converts it to a decompression / compression processing unit 14.

The D / A converter 15 converts a digital video signal (including a digital audio signal), which is an output digital signal output from the expansion / compression processor 14, into an analog video signal (including an analog audio signal). And output to the television receiver 19 provided outside.
The optical pickup 16a reads an optical disk (for example, DVD + R) that is rotationally driven by the spindle motor 16b, and outputs a signal obtained by the reading to the optical pickup processing unit 16c. The signal output from the optical pickup processing unit 16c is recorded on the optical disc.

  The optical pickup processing unit 16c forms an optical disk drive unit together with the spindle motor 16b and the optical pickup 16a. Therefore, the optical pickup processing unit 16c generates an RF signal from the signal output from the optical pickup 16a when reproducing data. Next, after demodulating digital data from the generated RF signal, a signal obtained by decoding is output to the decompression / compression processor 14. When recording data, the digital signal output from the decompression / compression processor 14 is encoded, and then the optical pickup 16a is driven using the encoded signal. That is, the decompression / compression processor 14 decompresses and compresses the digital data, and writes / reads the digital data to / from the optical disc drive unit via the optical pickup processor 16c.

  The decompression / compression processing unit 14 uses the encoding unit 14a to compress the video signal output from the A / D conversion unit 13 according to MPEG2 (AC3 or the like for an audio signal). Then, the compressed video signal is output to the optical pickup processing unit 16c. Further, by using the decoding unit 14b, the video signal output from the optical pickup processing unit 16c is expanded according to MPEG2 (AC3 or the like for the audio signal). Then, the digital video signal obtained by the decompression process is output to the D / A converter 15.

The input circuit unit 18 includes a key switch such as a power key provided on a front panel of the apparatus main body (not shown), a light receiving unit that receives an infrared signal transmitted from a remote controller (hereinafter referred to as a remote controller) 18a, and the like. When an instruction from the user is input, the input instruction (operation input) is received and output to the control unit 12.
The control unit 12 controls main operations as the optical disk drive device. That is, the channel received by the tuner unit 11 is controlled in accordance with a user instruction input to the remote controller 18a or the like. In addition, by controlling the optical pickup processing unit 16c and the expansion / compression processing unit 14, the program received by the tuner unit 11 is recorded on the optical disc. Also, the program recorded on the optical disc is reproduced and displayed on the television receiver 19.

The decompression / compression processing unit 14, the A / D conversion unit 13, the D / A conversion unit 15, and the control unit 12 correspond to a recording / reproduction control circuit.
FIG. 2 shows a schematic configuration of the optical pickup 16a in a perspective view, and FIG. 3 shows the optical pickup in a plan view.
The optical pickup 16a includes a movable side member 30 that holds a coil and a lens, a fixed side member 40 that holds a magnet, and a wire 50 that elastically supports the movable side member 30 so that the fixed side member 40 can be displaced. I have.

  The movable member 30 includes lenses 31a and 31b, a lens holder 32 that is formed in a substantially rectangular frame shape and supports the lenses 31a and 31b, and a coil 33 that is held in the frame of the lens holder 32. have. The lens holder 32 has four sides 32a to 32d, and supports the lenses 31a and 31b on the outer side of the one side 32a opposite to the fixed side member 40. Further, three coils 33 (coils 33a to 33c, coils 33d to 33f) are arranged and arranged directly on the inner peripheral wall surfaces 32a1 and 32c1 of the opposite sides 32a and 32c. Directly means that there is no separate member such as a coil holder other than the original coil 33 itself.

  The fixed member 40 includes a magnet 41 that supplies a fixed magnetic field to the coil 33 within the frame, and a base 42 that serves as a back yoke 42a that supports the magnet 41 so as to face the coil 33. And a circuit board 43 for supplying a driving current to the coil 33, and a damper box 44 for supporting the circuit board 43 and the base 42.

4 shows the base, the back yoke, and the magnet in a perspective view, and FIG. 5 shows the base alone in a perspective view.
As shown in FIGS. 4 and 5, the base 42 also serves as a back yoke 42a, and the magnet 41 is supported by the back yoke 42a. That is, by bending the metal plate material constituting the base 42 by 90 degrees, a horizontally long plate-like back yoke 42a capable of supporting the magnet 41 is formed, and the same magnets 41a to 41c and magnets 41d to 41d are formed on each surface thereof. 41f is aligned and affixed in a line.

  In a rectangular frame-shaped lens holder 32 having four sides 32a to 32d, coils 33a to 33c and coils 33d to 33f are arranged side by side on opposing circumferential wall surfaces, and a magnet 41a is sandwiched between the back yoke 42a in the frame. To 41c and magnets 41d to 41f are fixed in a line. Therefore, in the frame, one row of coils 33a to 33c, one row of magnets 41a to 41c, back yoke 42a, one row of magnets 41d to 41f, and one row of coils 33d to 33f face each other. positioned. If each member is called one layer for convenience, it will be five layers. Among these, as a gap for allowing the movable side member 30 to move relative to the fixed side member 40, a gap between the coils 33a to 33c and the magnets 41a to 41c, and a gap between the magnets 41d to 41f and the coils 33d to 33f. Two gaps are required, with a gap between the two.

FIG. 6 shows a plan view of a previous optical pickup by the applicant. Corresponding members have the same reference numerals for the sake of understanding.
As a member that does not exist in the present invention, a coil holder 34 that is fixed to the lens holder 32 while holding the coils 33a to 33c and the coils 33d to 33f on both sides is provided.
In the case of this optical pickup, the coil holder 34 is fixed so as to divide the inside of the frame into two parts in parallel with the two opposite sides 32a and 32c of the four sides 32a to 32d of the lens holder 32, and the two sides are arranged on the two sides. The coils 33a to 33c and the coils 33d to 33f are arranged side by side so as to face the peripheral wall surfaces of the sides 32a and 32c. On the other hand, in each of the two frame-shaped spaces, the magnets fixed to the back yoke 42a on the back side so as to face the coils 33a to 33c and the coils 33d to 33f and face the coils 33a to 33c. 41a to 41c and magnets 41d to 41f that are fixed to the back yoke 42a on the back side and face the coils 33d to 33f are arranged.

  In this case, in the frame, a back yoke 42a, a row of magnets 41a to 41c, a row of coils 33a to 33c, a coil holder 34, a row of coils 33d to 33f, a row of magnets 41d to 41f, The back yokes 42a are positioned so as to face each other. Similarly, if each member is referred to as a single layer for the sake of convenience, in the previous optical pickup example, there are seven layers. Among these, as a gap for allowing the movable side member 30 to move with respect to the fixed side member 40, a gap between the side 32a and the back yoke 42a, and between the magnets 41a to 41c and the coils 33a to 33c. A total of four gaps are required: a gap, a gap between the coils 33d to 33f and the magnets 41d to 41f, and a gap between the back yoke 42a and the one side 32c.

  As compared with the above, in the optical pickup 16a of the present invention, the length of one layer of the back yoke 42a as a member and one layer of the coil holder is reduced, and the two necessary gaps are provided. The gap will be reduced. In particular, since the surfaces of the coils 33a to 33f and the magnets 41a to 41f that face each other are substantially parallel to the faces that the movable member 30 and the fixed member 40 face, the movable member 30 is reduced. And the fixed side member 40, the purpose of reducing the shape of the actuator in the tangential direction required for the portable type optical pickup is met.

In the present invention, a pair of magnets 41a and 41d, a pair of magnets 41b and 41e, and a pair of magnets 41c and 41f are arranged in a straight line on both surfaces of one back yoke. For this reason, since the fixed side magnetic field is formed by a pair of magnets, the arrangement is such that a strong magnetic field can be efficiently formed.
In the fixed side member 40, the damper box 44 supports the circuit board 43 and the base 42, and the damper box 44 and the lens holder 32 are connected via the wire 50. Each of the wires 50 is formed of three metal wires, and is connected to the damper box 44 outside the remaining two sides 32b and 32d of the frame-shaped lens holder. Since the wire 50 is a metal member, the movable side member 30 is elastically supported with respect to the fixed side member 40. Moreover, since it is a metal member which is a conductive member, it also plays a role of electrically connecting the circuit board 43 and the coil 41. In the case of this embodiment, drive current for left tracking drive and right tracking drive is passed by two of each of the left and right three, and driving for vertical focusing drive is performed using each of the left and right ones. Current is flowing.

Needless to say, the present invention is not limited to the above embodiments. It goes without saying for those skilled in the art,
・ Applying mutually interchangeable members and configurations disclosed in the above embodiments by appropriately changing the combination thereof.− Although not disclosed in the above embodiments, it is a publicly known technique and the above embodiments. The members and configurations that can be mutually replaced with the members and configurations disclosed in the above are appropriately replaced, and the combination is changed and applied. It is an embodiment of the present invention that a person skilled in the art can appropriately replace the members and configurations that can be assumed as substitutes for the members and configurations disclosed in the above-described embodiments, and change the combinations and apply them. It is disclosed as.

DESCRIPTION OF SYMBOLS 11 ... Tuner part, 12 ... Control part, 13 ... A / D conversion part, 14 ... Decompression compression processing part, 14a ... Encoding part, 14b ... Decoding part, 15 ... D / A conversion part, 16a ... Optical pick-up, 16b ... Spindle motor, 16c ... optical pickup processing unit, 18 ... input circuit unit, 18a ... remote control, 19 ... TV receiver, 30 ... movable side member, 31a, 31b ... lens, 32 ... lens holder, 32a-32d ... side, 32a1 32c1 ... Frame inner peripheral wall surface 33 (33a-33f) ... Coil 34 ... Coil holder 40 ... Fixed side member 41 (41a-41f) ... Magnet 42 ... Base 42a ... Back yoke 43 ... Circuit board 44 ... Damper box, 50 ... Wire.

Claims (4)

An optical pickup constituted by elastically supporting a movable side member holding a coil and a lens with a fixed side member holding a magnet via a wire so as to be displaceable,
The movable member is
The lens,
A lens holder that is formed in a substantially rectangular frame shape and supports the lens;
A coil held in the frame of the lens holder,
The fixed side member is
A magnet for supplying a fixed-side magnetic field to the coil in the frame;
A base serving as a back yoke that supports the magnet so as to face the coil;
A circuit board for supplying a driving current to the coil;
The circuit board and a damper box for supporting the base,
The wire is
The circuit board and the coil are electrically connected while movably connecting the movable side member and the fixed side member with a metal member having elasticity,
While forming a plate-like back yoke so as to enter the frame of the lens holder at the base, the magnets are arranged on both sides thereof,
The optical pickup according to claim 1, wherein the coil is disposed so as to be supported by opposing inner wall surfaces of the frame so as to face the magnet in the frame. 2. The optical pickup according to claim 1, wherein the magnet and the coil face each other substantially parallel to a facing surface of the fixed side member and the movable side member. A total of six magnets are arranged in a row on each surface of the back yoke, and a total of six coils are arranged in a row facing the magnets. The optical pickup according to claim 1 or 2. An optical disk drive,
Tuner,
An input circuit unit for receiving operation inputs;
A decompression / compression processor that performs digital data decompression and compression, and writes and reads digital data to and from the optical disc drive;
An A / D converter for digitizing an analog signal input to the decompression / compression processor;
A D / A converter for analogizing the output digital signal from the decompression / compression processor;
An optical disc drive apparatus comprising: a control unit that controls reception by the tuner, reception of an operation input by the input circuit unit, and writing and reading of digital data by the decompression / compression processing unit;
The optical disc drive includes an optical pickup configured to be elastically supported by a fixed member via a wire so that a movable member holding a lens can be displaced,
The movable member is
The lens,
A lens holder that is formed in a substantially rectangular frame shape and supports the lens;
A coil held in the frame of the lens holder,
The fixed side member is
A magnet for supplying a fixed-side magnetic field to the coil;
A base serving as a back yoke that supports the magnet so as to face the coil;
A circuit board for supplying a driving current to the coil;
The circuit board and a damper box for supporting the base,
The wire is
The circuit board and the coil are electrically connected while movably connecting the movable side member and the fixed side member with a metal member having elasticity,
While forming a plate-like back yoke so as to enter the frame of the lens holder at the base, the magnets are arranged on both sides thereof,
The coil is disposed so as to be supported by opposing inner wall surfaces of the frame so as to face the magnet in the frame, and
The magnet and the coil face each other substantially parallel to the facing surfaces of the fixed side member and the movable side member, and three magnets are arranged in a row on each side of the back yoke. An optical disk drive device, wherein a total of six coils are arranged side by side at a position facing each magnet.

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