WO2012060363A1

WO2012060363A1 - Protective cover and optical pickup device

Info

Publication number: WO2012060363A1
Application number: PCT/JP2011/075158
Authority: WO
Inventors: 智之村上
Original assignee: 三洋電機株式会社
Priority date: 2010-11-01
Filing date: 2011-11-01
Publication date: 2012-05-10
Also published as: JP2014013630A

Abstract

[Problem] To provide a protective cover which has improved strength and can be reduced in size, and to provide an optical pickup device provided with the protective cover. [Solution] A protective cover (40) comprises: a first opposing plate (41) which is formed by bending a single metal sheet and opposes the information recording face of an optical disc; a second opposing plate (42) which opposes a first elastic wire (34a) and is fixed to a base (36); and a third opposing plate (43) which opposes a second elastic wire (34b) and is fixed to the base (36). The first opposing plate (41) is provided with a first aperture (41a) which exposes object lenses (28a, 28b) and restricts movement of a holder (33) in a focusing direction (F) (+ side) towards the information recording face of the optical disc. The second opposing plate (42) faces more towards the outer circumference of the optical disc as the position of the first elastic wire (34a) approaches the position at which the holder (33) is supported. An optical pickup device (20) is provided with the protective cover (40).

Description

Protective cover, optical pickup device

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

For example, as shown in FIG. 6, a protective cover 10 to be attached to the optical pickup device 1 is known. The optical pickup device 1 is supported by

elastic wires

5 a and 5 b in a state in which a holder 4 that holds an objective lens 3 is separated from a base 2. Specifically, the elastic wire 5a supports the side surface of the holder 4 located on the inner peripheral side of the optical disc (not shown) with the substrate 6 as a fulcrum. The elastic wire 5b supports the side surface of the holder 4 located on the outer peripheral side of the optical disk with the substrate 6 as a fulcrum. The holder 4 is displaced by a predetermined distance in the focus direction F (first direction F) or the tracking direction Tr (second direction Tr) according to a signal input via the substrate 6 and the

elastic wires

5a and 5b. A spindle motor (not shown) for rotating the optical disk is disposed on the inner peripheral side of the optical disk of the optical pickup device 1. For this reason, an arcuate depression is formed on the side of the base 2 facing the spindle motor so as to avoid the spindle motor.

The protective cover 10 is formed by bending a single metal plate and fixed to the base 2. The protective cover 10 includes an upper plate 11 that faces the optical disc and

side plates

12a and 12b that face the

elastic wires

5a and 5b, respectively, when the protective cover 10 is fixed to the base 2. The upper plate 11 is formed with an opening 11a that exposes the objective lens 3 and restricts the holder 4 from moving beyond a predetermined distance in the focus direction F on the optical disc side. The opening 11a has a shape in which the protruding piece 11b protrudes toward the inside of the opening 11a. As described above, the movement of the holder 4 is restricted by the protrusion 11b coming into contact with the upper surface of the holder 4. On the side plate 12a on the spindle motor side of the protective cover 10 is formed a curved surface r that is curved in the same manner as the recess of the base 2 (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2008-90920 (first page, FIGS. 3 and 5)

In the protective cover 10 described above, a notch 13 must be provided between the upper plate 11 and the side plate 12a in order to bend a single metal plate to form the curved surface r on the side plate 12a. However, since the upper plate 11 of the protective cover 10 is provided with the notch 13, there is a possibility that sufficient strength cannot be secured to restrict the holder 4 from moving in the focus direction F on the optical disc side. Furthermore, for example, when a drop impact is applied to the optical pickup device 1 including the protective cover 10 and the protective cover 10 is deformed, it is difficult for the holder 4 to accurately move in the focus direction F and the tracking direction Tr. There is a risk of becoming.

Further, the protective cover 10 has the same length L1 on the substrate 6 side and the length L2 on the holder 4 side in the tracking direction Tr for the reason of forming a curved surface r by bending a single metal plate. There is a need to. For this reason, the protective cover 10 needs an extra length indicated by L3 in the third direction Tn, for example, only to ensure the length L2. As a result, a useless space is formed on the holder 4 side of the protective cover 10, and the optical pickup device 1 may be increased in size.

The main invention for solving the above-described problems is that the base, the objective lens, the holder for holding the objective lens, and the holder is displaced from the base in the focus direction and / or the tracking direction. A first elastic wire that supports one side of the holder located on the inner peripheral side of the optical disc and extends substantially parallel to the base; and the holder is separated from the base. A second elasticity that supports the other side surface portion of the holder located on the outer peripheral side of the optical disc and extends substantially parallel to the base so as to be displaced in the focus direction and / or the tracking direction. A protective cover for an optical pickup device including a wire, wherein the first opposing plate is formed by bending a single metal plate and facing the information recording surface of the optical disc. A second opposing plate that faces the first elastic wire and is fixed to the base, and a third opposing plate that faces the second elastic wire and is fixed to the base. The first counter plate has a first opening that restricts the objective lens from being exposed and the holder moving in the focus direction on the information recording surface side of the optical disc, and the second counter plate is In the protective cover, the position of the first elastic wire approaches the outer peripheral side of the optical disc as it approaches the position for supporting the holder.

The present invention also provides a base, an objective lens, a holder for holding the objective lens, and an optical disc so that the holder is displaced in the focus direction and / or the tracking direction in a state where the holder is separated from the base. A first elastic wire that supports one side surface of the holder located on the circumferential side and extends substantially parallel to the base; and the focus direction and the holder in a state where the holder is separated from the base. And / or a second elastic wire that supports the other side surface portion of the holder located on the outer peripheral side of the optical disc so as to be displaced in the tracking direction and extends substantially parallel to the base. A protective cover formed by bending a sheet of metal plate, the protective cover facing the information recording surface of the optical disc, and facing the first elastic wire , A second counter plate fixed to the base, and a third counter plate facing the second elastic wire and fixed to the base, the first counter plate being the objective lens And a first opening that restricts the holder from moving in the focus direction on the information recording surface side of the optical disc, and the second opposing plate has a position of the second elastic wire. The optical pickup device is directed toward the outer peripheral side of the optical disc as it approaches a position for supporting the holder.

The present invention also provides a protective cover for an optical pickup device including a first elastic wire and a second elastic wire, a first counter plate facing an information recording surface of an optical disc, and the first elastic wire A second counter plate that opposes the second elastic wire, and the third counter plate when the first counter plate is viewed in a substantially flat plate shape. The second cover plate is inclined with respect to the protective cover.

Also, the present invention is an optical pickup device comprising the protective cover.

Other features of the present invention will become apparent from the accompanying drawings and the description of the present specification.

According to the present invention, it is possible to provide a protective cover capable of increasing strength and miniaturizing, and an optical pickup device including the same.

(A) is a perspective view of the protective cover which concerns on this embodiment, (B) is the other perspective view of the protective cover shown to (A). FIG. 2 is a perspective view of the protective cover shown in FIG. 1 and the optical pickup device before the protective cover shown in FIG. 1 is attached. FIG. 3 is a perspective view of the optical pickup device shown in FIG. 2 to which the protective cover shown in FIG. 1 is attached. It is a figure explaining the optical path of the optical pick-up apparatus shown in FIG. It is a top view which compares the protective cover shown in FIG. 1 with the protective cover shown in FIG. It is a perspective view of an optical pick-up apparatus before a protective cover and a protective cover are mounted | worn.

At least the following matters will become clear from the description of this specification and the accompanying drawings.

=== Optical pickup device ===
<<< About the optical system >>>
The optical pickup device according to the present embodiment has a single-layer or multi-layer information recording surface such as a CD (Compact Disc), a DVD (Digital Vesatile Disc), and / or a Blu-ray (Blu-ray Disc) (registered trademark). Information is recorded and / or reproduced and / or erased by irradiating an optical disc (medium) having a signal layer) with a laser beam. Therefore, an example of an optical system of laser light emitted from the first laser light source 21a, the second laser light source 21b, and the third laser light source 21c of the optical pickup device 20 will be described with reference to FIG.

The first laser light source 21a emits laser light in an infrared wavelength band (765 nm to 840 nm) for irradiating the information recording surface of the CD when a control voltage is applied from a laser driver (not shown). The second laser light source 21b emits a laser beam in a red wavelength band (630 nm to 685 nm) for irradiating the information recording surface of the DVD when a control voltage is applied from a laser driver. The third laser light source 21c emits a laser beam in a blue-violet wavelength band (400 nm to 450 nm) for irradiating a Blu-ray information recording surface when a control voltage is applied from a laser driver. That is, when a CD standard first optical disk (not shown) is mounted on a turntable (not shown), the laser light L1a in the infrared wavelength band is emitted from the first laser light source 21a. When a DVD standard second optical disc (not shown) is mounted on the turntable, the red laser beam L1b is emitted from the second laser light source 21b. When a Blu-ray standard third optical disk (not shown) is mounted on the turntable, a blue-violet wavelength band laser beam L1c is emitted from the third laser light source 21c. The optical pickup device corresponds to an optical disc of at least one of the various types of optical discs.

<<< Optical system for the first optical disk >>>
The optical path (outward path) of the laser light L1a from the first laser light source 21a to the first optical disk will be described. The laser light L1a emitted from the first laser light source 21a is, in order, a coupling lens 22, a first diffraction grating 23a, a dichroic prism 24 (polarizing member), a flat plate beam splitter 25 (polarizing member), a fixed type / movable type first. After passing through the collimator lens 26a, the first rising mirror 27a, and the first objective lens 28a, the information recording surface of the first optical disk is irradiated.

The laser light L1a from the first laser light source 21a is enlarged light / diffused light, and its divergence angle is converted by the coupling lens 22. The laser beam L1a whose divergence angle is converted by the coupling lens 22 is split into 0th order light and ± 1st order diffracted light by the first diffraction grating 23a. The laser beam L1a dispersed by the first diffraction grating 23a is reflected by the dichroic prism 24 toward the flat beam splitter 25. The laser beam L1a incident on the flat beam splitter 25 is reflected toward the first collimator lens 26a and converted into substantially parallel light by the first collimator lens 26a. The laser light L1a converted into substantially parallel light by the first collimator lens 26a is reflected toward the first objective lens 28a by the first rising mirror 27a. The laser beam L1a incident on the first objective lens 28a is focused on the information recording surface of the first optical disc.

The optical path (return path) of the laser beam L2a reflected from the information recording surface of the first optical disc will be described. The laser light L2a passes through the first objective lens 28a, the first rising mirror 27a, the first collimator lens 26a, the plate beam splitter 25, and the first sensor lens 29a (first astigmatism element) in this order, and then the first light. The light is received by the detector 30a.

The laser light L2a from the first optical disk is converted into substantially parallel light by the first objective lens 28a. The laser light L2a converted into substantially parallel light by the first objective lens 28a is reflected toward the first collimator lens 26a by the first rising mirror 27a, and converted into convergent light by the first collimator lens 26a. The laser beam L2a converted into convergent light by the first collimator lens 26a is transmitted toward the first sensor lens 29a by the flat plate beam splitter 25. The laser beam L2a incident on the first sensor lens 29a is received by the first photodetector 30a after being given astigmatism to perform focusing control based on, for example, the differential astigmatism method.

The first photodetector 30a that has received the laser beam L2a generates an electrical signal that has undergone photoelectric conversion in accordance with the amount of zero-order light of the laser beam L2a, and outputs the electrical signal to a processing circuit (not shown). As a result, information reproduction from the information recording surface of the first optical disc is performed based on the electrical signal corresponding to the 0th-order light of the laser light L2a. In addition, the first photodetector 30a generates an electrical signal that is photoelectrically converted according to the light amount of the ± first-order diffracted light of the laser light L2a, and outputs the electrical signal to the processing circuit. As a result, a focus error signal, a tracking error signal, and the like are generated based on an electrical signal corresponding to the 0th order light and the ± 1st order diffracted light of the laser light L2a. Based on these signals, the holder 33 of the optical pickup device 20 is displaced in the focus direction F (first direction F), the tracking direction Tr (second direction Tr), etc., as will be described later.

<<< Optical system for the second optical disk >>>
The optical path (outward path) of the laser light L1b from the second laser light source 21b to the second optical disk will be described. The laser light L1b emitted from the first laser light source 21b sequentially passes through the second diffraction grating 23b, the dichroic prism 24, the flat plate beam splitter 25, the first collimator lens 26a, the first rising mirror 27a, and the first objective lens 28a. After that, the information recording surface of the second optical disk is irradiated.

The laser beam L1b from the second laser light source 21b is split into 0th order light and ± 1st order diffracted light by the second diffraction grating 23b. The laser beam L1b split by the second diffraction grating 23b is transmitted by the dichroic prism 24 toward the flat plate beam splitter 25. Similarly to the laser beam L1a, the laser beam L1b incident on the flat beam splitter 25 is reflected toward the first collimator lens 26a, converted into substantially parallel light by the first collimator lens 26a, and then first raised. The light is reflected toward the first objective lens 28a by the mirror 27a. The laser beam L1b incident on the first objective lens 28a is condensed on the information recording surface of the second optical disc.

The return path of the laser beam L2b reflected from the information recording surface of the second optical disk is the same as the return path of the laser beam L2a, in order, the first objective lens 28a, the first rising mirror 27a, the first collimator lens 26a, and the flat plate beam splitter. 25, the light is received by the first photodetector 30a after passing through the first sensor lens 29a. The first photodetector 30a that has received the laser beam L2b generates an electrical signal that is photoelectrically converted in accordance with the amount of zero-order light of the laser beam L2b, and outputs the electrical signal to the processing circuit. As a result, information reproduction from the information recording surface of the second optical disk is performed based on the electrical signal corresponding to the 0th-order light of the laser light L2b. In addition, the first photodetector 30a generates an electrical signal that is photoelectrically converted according to the light amount of the ± first-order diffracted light of the laser light L2b, and outputs the electrical signal to the processing circuit. As a result, a focus error signal, a tracking error signal, and the like are generated based on an electrical signal corresponding to the 0th order light and the ± 1st order diffracted light of the laser light L2b.

As shown in FIG. 4, the plate beam splitter 25, the first collimator lens 26a, the first rising mirror 27a, the first objective lens 28a, the first sensor lens 29a, and the first photodetector 30a are in the infrared wavelength band. This corresponds to two types of laser light L1a and L1b, that is, laser light L1a and red wavelength band laser light L1b.

<<< Optical system for third optical disk >>>
The optical path (outward path) of the laser light L1c from the third laser light source 21c to the third optical disk will be described. The laser light L1c emitted from the third laser light source 21c is in order of a third diffraction grating 23c, a beam splitter 31 (polarizing member), a fixed / movable second collimator lens 26b, a liquid crystal aberration correction element 32 (correction element), After passing through the second rising mirror 27b and the second objective lens 28b, the information recording surface of the third optical disk is irradiated.

The laser beam L1c from the third laser light source 21c is split into 0th order light and ± 1st order diffracted light by the third diffraction grating 23c. The laser beam L1c dispersed by the third diffraction grating 23c is transmitted toward the second collimator lens 26b by the beam splitter 31, and is converted into substantially parallel light by the second collimator lens 26b. The coma aberration of the laser light L1c converted into substantially parallel light by the second collimator lens 26b is corrected by the liquid crystal aberration correction element 32. The coma aberration is an aberration generated due to the inclination of the third optical disc with respect to the optical axis of the laser beam L1c. The laser beam L1c whose coma has been corrected by the liquid crystal aberration correction element 32 is reflected toward the second objective lens 28b by the second rising mirror 27b. The laser beam L1c incident on the second objective lens 28b is condensed on the information recording surface of the third optical disk.

The optical path (return path) of the laser beam L2c reflected from the information recording surface of the third optical disc will be described. The laser beam L2c passes through the second objective lens 28b, the second rising mirror 27b, the liquid crystal aberration correction element 32, the second collimator lens 26b, the beam splitter 31, and the second sensor lens 29b (second astigmatism element) in this order. After that, the light is received by the second photodetector 30b.

The laser beam L2c from the third optical disk is converted into substantially parallel light by the second objective lens 28b. The laser light L2c converted into substantially parallel light by the second objective lens 28b is reflected toward the liquid crystal aberration correction element 32 by the second rising mirror 27b. The laser light L2c incident on the liquid crystal aberration correction element 32 is transmitted toward the second collimator lens 26b and converted into convergent light by the second collimator lens 26b. The laser beam L2c converted into convergent light by the second collimator lens 26b is reflected by the beam splitter 31 toward the second sensor lens 29b. The laser beam L2c incident on the second sensor lens 29b is given astigmatism and is received by the second photodetector 30b.

The second photodetector 30b that has received the laser light L2c generates an electrical signal that is photoelectrically converted in accordance with the amount of 0th-order light of the laser light L2c, and outputs the electrical signal to the processing circuit. As a result, information reproduction from the information recording surface of the third optical disk is performed based on the electrical signal corresponding to the 0th-order light of the laser light L2c. In addition, the second photodetector 30b generates an electrical signal that is photoelectrically converted according to the light amount of the ± first-order diffracted light of the laser light L2c, and outputs the electrical signal to the processing circuit. As a result, a focus error signal, a tracking error signal, and the like are generated based on an electrical signal corresponding to the 0th order light and the ± 1st order diffracted light of the laser light L2c.

<<< Overall configuration >>>
The overall configuration of the optical pickup device 20 will be described with reference to FIGS. Hereinafter, the first to third optical disks are collectively referred to as optical disks, and the laser beams L1a to L1c and the laser beams L2a to L2c are collectively referred to as laser beams.

In the optical pickup device 20 and the protective cover 40 for the optical pickup device 20, the focus direction F (first direction F) is such that the laser light is transmitted through an objective lens such as the first objective lens 28a and / or the second objective lens 28b. The first direction F is the optical axis direction. The tracking direction Tr (second direction Tr) is, for example, orthogonal to the first direction F, which is the focus direction F, and is the second direction Tr, which is the radial direction of the optical disc. The second direction Tr is the moving direction of the optical pickup device 20 from the inner peripheral side to the outer peripheral side of the optical disc and / or the moving direction of the optical pickup device 20 from the outer peripheral side of the optical disc to the inner peripheral side. Yes. The tangential direction Tn is, for example, a substantially spiral / circumferential direction of the optical disc perpendicular to the first direction F, which is the focus direction F, and perpendicular to the second direction Tr, which is the radial direction of the optical disc. ing. The third direction Tn is, for example, orthogonal to the first direction F, which is the focus direction F, and also to a direction orthogonal to the radial direction of the optical disc and / or the second direction Tr, which is the moving direction of the optical pickup device 20. Has been. Here, for convenience, symbols such as the tangential direction Tn and the third direction Tn are used in common, but such a definition is, for example, a definition for convenience in this specification, and is limited to such a definition. It is not a thing.

When the optical pickup device 20 and the protective cover 40 for the optical pickup device 20 that are located in the vicinity of the optical disc and viewed from the side are used as a reference, the first objective lens 28a and / or the first objective lens 28a of the optical pickup device 20 is used with respect to the optical disc. The side on which the objective lens such as the 2 objective lens 28b approaches is the + side in the first direction F, and the side on which the objective lens moves away is the-side in the first direction F. In addition, when the optical pickup device 20 and the protective cover 40 for the optical pickup device 20 that are located in the vicinity of the optical disc and viewed in plan are used as a reference, the inner peripheral side of the optical disc is defined as the + side of the second direction Tr, and the optical disc The outer peripheral side is defined as the negative side of the second direction Tr. Further, when the optical pickup device 20 and the protective cover 40 for the optical pickup device 20 which are located in the vicinity of the optical disk and are viewed in plan are used as a reference, the one side plate 42 and the other side plate 43 of the protective cover 40 facing each other are used. The wide side is defined as the + side in the third direction Tn, and the narrow side of the one side plate 42 and the other side plate 43 of the protective cover 40 facing each other is defined as the − side in the third direction Tn.

Each direction and ± side of each direction in the present invention are each direction when viewing the optical disc with reference to the optical pickup device 20 and the protective cover 40 for the optical pickup device 20 and ± side of each direction. . In this specification, the definition of each direction and the ± side of each direction is a definition for convenience for describing the optical pickup device 20 and the protective cover 40 for the optical pickup device 20.

The optical pickup device 20 includes at least one objective lens 28a and / or 28b. The optical pickup device 20 includes at least a first elastic wire 34a and a second elastic wire 34b. Specifically, the optical pickup device 20 includes a first objective lens 28a, a second objective lens 28b, a holder 33, a first elastic wire 34a, a second elastic wire 34b, a substrate 35, and a base. 36, a magnet 37, and a protective cover 40.

The base 36 is supported by a rail (not shown) so as to face the information recording surface of the optical disk mounted on the turntable and move in the radial direction of the optical disk, that is, the tracking direction Tr. A drive spindle motor (not shown) that rotates the turntable is disposed on the + side of the tracking direction Tr of the base 36 (the inner peripheral side of the optical disk).

The holder 33 holds the first objective lens 28a and the second objective lens 28b so as to be substantially parallel to the information recording surface of the optical disc. Further, the holder 33 holds the first objective lens 28a and the second objective lens 28b so as to be aligned substantially in the radial direction of the optical disk, for example, along the tracking direction Tr here. Further, a focusing coil for displacing the holder 33 in the focus direction F or the like, or a tracking coil for displacing the holder 33 in the tracking direction Tr or the like is wound around the side surfaces of both ends of the holder 33 in the third direction Tn. Has been.

The magnet 37 is composed of a pair opposed to the focusing coil and the tracking coil on both ends in the third direction Tn of the holder 33, and is on a surface facing the information recording surface of the optical disk of the base 36 (hereinafter simply referred to as a facing surface). It is fixed to. At least two magnets 37 are installed on the base 36. For example, an even number of magnets 37 are mounted on the base 36.

The first elastic wire 34 a and the second elastic wire 34 b support the holder 33 so that the holder 33 is displaced in the focus direction F and / or the tracking direction Tr or the like in a state where the holder 33 is separated from the facing surface of the base 36. . Specifically, the first elastic wire 34 a extends substantially parallel to the opposing surface of the base 36 and the opposing surface of one side plate 42 (second opposing plate) of the protective cover 40, and serves as a fulcrum for the substrate 35. As described above, one (first) side surface side portion of the holder 33 positioned on the + side of the tracking direction Tr is supported. Note that the first elastic wire 34a reduces, for example, the contact area with one side surface of the holder 33 when the holder 33 moves substantially along the + side of the tracking direction Tr, thereby reducing the first elastic wire 34a in the tracking direction Tr. In order to smoothly move the holder 33 to the substantially + side, the holder 33 is moved away from one side surface portion of the holder 33 as it approaches the position on the substrate 35 side from the holder 33 side.

The second elastic wire 34b extends substantially parallel to the opposing surface of the base 36 and the opposing surface of the other side plate 43 (third opposing plate) of the protective cover 40, and has the substrate 35 as a fulcrum in the tracking direction Tr. The other (second) side surface side portion of the holder 33 located on the negative side (the outer peripheral side of the optical disk) is supported. Note that the second elastic wire 34b reduces or eliminates the contact area with the other side surface of the holder 33 when the holder 33 moves largely along the minus side of the tracking direction Tr. In order to move the holder 33 smoothly to the substantially negative side, it moves away from the other side surface of the holder 33 as it approaches the position on the substrate 35 side from the holder 33 side.

The first elastic wire 34a and the second elastic wire 34b electrically connect a driving circuit (not shown) for driving the holder 33 to the focusing coil and the tracking coil via the substrate 35. When a current corresponding to the focus error signal is supplied from the drive circuit to the focusing coil, the holder 33 is displaced in the focus direction F based on the relationship with the magnetic field of the magnet 37 (focus control). Further, when a current corresponding to the tracking error signal is supplied from the drive circuit to the tracking coil, the holder 33 is displaced in the tracking direction Tr based on the relationship with the magnetic field of the magnet 37 (tracking control).

The substantially flat substrate 35 is provided in the optical pickup device 20 substantially along a direction substantially orthogonal to the substantially flat base 36. For example, the substantially flat substrate 35 is fixed on the facing surface of the base 36, and the first elastic wire. 34a and the second elastic wire 34b are electrically connected to the drive circuit.

The protective cover 40 is formed by punching a single metal plate and then bending it, and is fixed to the base 36.

As shown in FIGS. 2 and 3, the first objective lens 28a, the second objective lens 28b, the holder 33, the first elastic wire 34a, the second elastic wire 34b, the focusing coil, and the tracking coil are The movable part of the actuator of the optical pickup device 20 is configured.

<Protective cover>
The details of the protective cover 40 for the optical pickup device will be described below with reference to FIG. The protective cover 40 is formed on a single metal plate (metal material) by performing press forming such as punching and bending. The protective cover 40 is formed by punching a single metal plate and then bending it, and includes an upper plate 41 (first counter plate), a side plate 42 (second counter plate), and a side plate 43 (third counter plate). It has.

The upper plate 41 has a first opening 41a that faces the information recording surface of the optical disc and exposes the first objective lens 28a and the second objective lens 28b. The first opening 41a restricts the holder 33 from moving in the + direction of the focus direction F (the focus direction on the information recording surface side of the optical disc), and protrudes toward the inside of the first opening 41a (stopper). ) Has a protruding shape. Specifically, the first opening 41a has a pair of (four in total) protruding pieces 41b on the same plane as the upper plate 41 so as to face each other toward the inside of the first opening 41a, for example. It is set as the shape which protrudes from the four corners of 1 opening part 41a. The projecting pieces 41b are in contact with, for example, approximately four corners of the surface (upper surface) of the holder 33 that faces the information recording surface of the optical disk. That is, the first opening 41a restricts the holder 33 from moving to the + side of the focus direction F at the position where the protruding piece 41b protrudes.

For example, in order to avoid contact between the spindle motor and the side plate 42, the side plate 42 faces the first elastic wire 34 a, and as the position of the first elastic wire 34 a approaches the position for supporting the holder 33, the third direction Tn Is inclined at an acute angle toward the outer peripheral side of the optical disc, which is the negative side in the second direction Tr.

For example, in order to avoid contact between the substantially cylindrical spindle motor and one of the substantially flat side plates 42 constituting the protective cover 40, the substantially flat upper plate 41 constituting the protective cover 40 is substantially flat. When the protective cover 40 is viewed in plan so that the other side plate 43 is substantially flat, the one side plate 42 having a substantially flat plate shape avoids interference with the substantially cylindrical spindle motor in plan view. It is inclined at a predetermined angle so as to be substantially linear.

Further, the side plate 43 faces the second elastic wire 34b, and as the position of the second elastic wire 34b approaches the position for supporting the holder 33, the + side of the second direction Tr with respect to the negative side of the third direction Tn. The optical disc is inclined at an acute angle toward the inner peripheral side of the optical disc.

When the protective cover 40 is viewed from above so that the substantially flat upper plate 41 constituting the protective cover 40 has a substantially flat plate shape, the substantially flat plate-like one side plate 42 and the substantially flat plate-like other side plate. 43 is arranged in, for example, a substantially “C” shape or a substantially “eight” shape.

Further, the protective cover 40 in plan view is formed in a trapezoidal shape having, for example, a substantially mountain shape, and the length of the upper base of the trapezoid is shorter than the length of the lower base of the trapezoid, The trapezoidal height is substantially equal.

When the optical pickup device 20 and the protective cover 40 for the optical pickup device 20 are viewed in plan, the optical pickup device 20 is substantially along the third direction Tn of the optical pickup device 20 and the protective cover 40 for the optical pickup device 20. Assuming that the virtual straight line substantially center line of the protective cover 40 for the optical pickup device 20 is drawn to the optical pickup device 20 and the protective cover 40 for the optical pickup device 20, the protective cover 40 viewed in plan is For example, one side plate 42 having a substantially flat plate shape and the other side plate 43 having a substantially flat plate shape are substantially trapezoidal, and the upper base of the trapezoid has a short length with respect to the virtual straight center line. As shown, both are inclined at a predetermined angle so as to be substantially linear in a plan view.

Specifically, the side plate 42 is bent from the side X to the focus direction F (first direction F) by bending the side X of the upper plate 41 positioned on the + side of the tracking direction Tr (second direction Tr). ) In the form of a flat plate toward the negative side. Then, the side plate 42 is arranged such that the direction from the end on the + side in the third direction Tn toward the end on the − side is an angle θ1 with respect to the third direction Tn, for example, on the − side in the tracking direction Tr. It is tilted at an acute angle. Note that θ1 can avoid contact between the + side surface of the tracking direction Tr of the side plate 42 and the spindle motor, and can avoid contact between the − side surface of the tracking direction Tr of the side plate 42 and the first elastic wire 34a. Thus, for example, the angle is such that the side plate 42 and the first elastic wire 34a are substantially parallel with a predetermined interval.

The side plate 42 is bent along a direction substantially orthogonal to the upper plate 41 to temporarily fix the protective cover 40 to the second opening 42 a that exposes the first elastic wire 34 a and the base 36. And a locking claw 42b (locking portion). The second opening 42a is formed continuously with the first opening 41a of the upper plate 41 so as to cut off between the + side and the − side of the side X in the third direction Tn. Note that the minus side in the third direction Tn from the second opening 42a of the side X is referred to as a side X1. The + side in the third direction Tn from the second opening 42a on the side X is referred to as a side X2. By forming the second opening 42 a in the side plate 42 and then bending the side X, the processing for forming the side plate 42 can be facilitated. Further, by forming the second opening 42 a in the side plate 42, the holder 33 can increase the distance that can be moved to the + side of the tracking direction Tr by the thickness of the side plate 42.

The locking claw 42b protrudes on the negative side of the tracking direction Tr on the negative side of the focusing direction F of the side plate 42. When the protective cover 40 is mounted on the base 36, the locking claw 42 b comes into contact with the surface opposite to the facing surface of the base 36 and temporarily fixes the side plate 42 and the base 36. After the locking claw 42b and the base 36 are temporarily fixed, the side plate 42 and the base 36 are fixed with an adhesive or the like, so that the optical pickup device 20 can be easily assembled.

The side plate 43 faces the second elastic wire 34b, and approaches the central axis of the optical disk as the position of the second elastic wire 34b approaches the position where the holder 33 is supported. Specifically, the side plate 43 extends in a flat plate shape from the side Y toward the − side in the focus direction F by bending the side Y of the upper plate 41 positioned on the − side in the tracking direction Tr in a straight line. is doing. The side plate 43 has a direction from the end on the + side in the third direction Tn toward the end on the − side such that the angle is θ2 with respect to the third direction Tn, for example, on the + side in the tracking direction Tr. It is tilted at an acute angle. For example, the side plate 43 and the second elastic wire 34b are substantially parallel with a predetermined interval so that the second elastic wire 34b does not come into contact with the + side surface of the tracking direction Tr of the side plate 43, for example. Is an angle.

The side plate 43 is formed by bending along a direction substantially orthogonal to the upper plate 41, and a third opening 43 a for facilitating the bending process of the side Y, and the protective cover 40 on the base 36. It has the latching claw 43b for temporarily fixing. The third opening 43a is formed continuously with the first opening 41a of the upper plate 41 so as to cut off between the + side and the − side of the side Y in the third direction Tn. Note that the minus side in the third direction Tn from the third opening 43a on the side Y is referred to as a side Y1. Further, the + side in the third direction Tn with respect to the third opening 43a on the side Y is referred to as a side Y2.

The locking claw 43b protrudes to the + side of the tracking direction Tr on the minus side of the focusing direction F of the side plate 43. When the protective cover 40 is mounted on the base 36, the locking claw 43 b comes into contact with the surface opposite to the facing surface of the base 36 and temporarily fixes the side plate 43 and the base 36. After the locking claw 43b and the base 36 are temporarily fixed, the side plate 43 and the base 36 are fixed with an adhesive or the like, so that the optical pickup device 20 can be easily assembled.

The protective cover 40 includes an upper plate 41 and a side plate 42 that are continuous via the sides X1 and X2, and an upper plate 41 and a side plate 43 that are continuous via the sides Y1 and Y2. For this reason, even if a drop impact is applied to the optical pickup device 20 including the protective cover 40, the strength of the protective cover 40 is improved, so that plastic deformation of the protective cover 40 can be prevented. Further, the strength for restricting the movement of the holder 33 toward the + side in the focus direction F (hereinafter simply referred to as movement) can be increased.

In the protective cover 40, the

side plates

42 and 43 approach the holder 33 as they approach the position from the + side to the − side in the third direction Tn. For this reason, for example, compared with the case where the

side plates

42 and 43 are formed in parallel with the third direction Tn, the distance between the projecting pieces 41b that contact the substantially four corners of the upper surface of the holder 33 and the sides X and Y of the upper plate 41. The distance can be reduced. As a result, the strength of the protective cover 40 is improved. Therefore, even when a drop impact is applied to the optical pickup device 20 including the protective cover 40, plastic deformation of the protective cover 40 can be prevented. Moreover, the intensity | strength for restricting the movement of the holder 33 can be raised with the protrusion 41b. Further, in the protective cover 40, for example, the length of the tracking direction Tr on the negative side of the third direction Tn in the protective cover 40 is shorter than when the

side plates

42 and 43 are formed in parallel with the third direction Tn. can do. Thereby, the strength of the protective cover 40 can be improved, and even when a drop impact is applied to the optical pickup device 20 including the protective cover 40, plastic deformation of the protective cover 40 can be prevented. Further, the strength for restricting the movement of the holder 33 can be increased.

For example, when an impact is applied to the optical pickup device 20 from the outside, the negative side in the third direction Tn of the holder 33 becomes a fulcrum of the first elastic wire 34a and the second elastic wire 34b that support the holder 33. The distance from the substrate 35 is longer than the positive side. For this reason, the distance that the holder 33 moves in the third direction Tn in response to the impact is relatively longer than the plus side. However, in the protective cover 40, the strength for restricting the movement of the holder 33 with respect to the protruding piece 41 b that contacts the upper surface of the negative side in the third direction Tn of the holder 33, in particular, is made closer to the sides X 1 and Y 1. Can be increased. Therefore, the protective cover 40 can particularly increase the strength of the protruding piece 41b that restricts the movement of the negative side of the holder 33 that has a long moving distance according to the impact, so that the drop impact is applied to the optical pickup device 20 including the protective cover 40. Even if is added, it is possible to further prevent the plastic deformation of the protruding piece 41b on the negative side in the third direction Tn in the protective cover 40. Further, the movement of the holder 33 can be more reliably regulated.

=== Comparison between protective covers ===
With reference to FIG. 5, the protective cover 40 which concerns on this embodiment compared with the protective cover 10 of FIG. 6 is demonstrated.

In the protective cover 40, the direction from the + side to the − side in the third direction Tn of the side plate 42 is inclined at an acute angle of θ1 toward the − side of the tracking direction Tr, which is the second direction Tr, with respect to the third direction Tn. Thus, contact between the spindle motor and the side plate 42 is avoided. For this reason, it is not necessary to form the curved surface r for avoiding a spindle motor in the side plate 12a like the protective cover 10 shown with a broken line in FIG. Thus, although the protective cover 40 is formed by bending a single metal plate, it is not necessary to form the notch 13 between the upper plate 41 and the side plate 42 unlike the protective cover 10. Further, the protective cover 40 has a direction in which the direction of the side plate 43 from the + side to the − side in the third direction Tn is an acute angle of θ2 toward the + side of the tracking direction Tr that is the second direction Tr with respect to the third direction Tn. Leaning on. For this reason, the protruding piece 41b can be formed at a position closer to each of the sides X and Y. Therefore, the protective cover 40 can increase the strength for restricting the movement of the holder 33.

In addition, a drop impact is applied to the optical pickup device 20 provided with the protective cover 40, and a large force is applied to the protective cover 40 at that time, the protective cover 40 is deformed, contacted with the holder 33, and the like. Since the protective cover 40 can be prevented from being deformed by this, the optical pickup device 20 can perform the focus control and tracking control of the holder 33 more reliably.

Further, since the protective cover 40 does not need to form the curved surface r on the side plate 42, the length in the tracking direction Tr does not need to be the same at both ends in the third direction Tn unlike the protective cover 10. For this reason, it is not necessary for the protective cover 40 to secure an extra length in the third direction Tn indicated by L3 of the protective cover 10. Further, since the

side plates

42 and 43 are inclined with respect to the tracking direction Tr, the protective cover 40 can make the length of the end portion on the third direction Tn− side in the tracking direction Tr shorter than that of the protective cover 10. Specifically, the length in the tracking direction Tr of the protective cover 40 can be made shorter than the protective cover 10 by the sum of the distance L4 between the side plate 42 and the side plate 12a and the distance L5 between the side plate 43 and the side plate 12b. . Therefore, the protective cover 40 can reduce a useless space formed between the side plate 42 and the first elastic wire 34a, between the side plate 43 and the second elastic wire 34b, and the like, and can be reduced in size as compared with the protective cover 10. .

In addition, since the base 36 to which the protective cover 40 is fixed can be reduced in accordance with the downsizing of the protective cover 40, the entire optical pickup device 20 can be downsized.

As described above, the protective cover 40 according to the present embodiment includes at least the base 36, the first objective lens 28a and the second objective lens 28b, and the holder 33 that holds the first objective lens 28a and the second objective lens 28b. When the holder 33 is separated from the base 36, it is positioned on the + side of the tracking direction Tr so as to be displaced in the focus direction F that is the first direction F and / or the tracking direction Tr that is the second direction Tr. The first elastic wire 34a that supports the first side surface portion of the holder 33 that extends and substantially parallel to the base 36, and the first direction F in the state where the holder 33 is separated from the base 36. The second side surface side of the holder 33 positioned on the negative side of the tracking direction Tr so as to be displaced in the focus direction F and / or the tracking direction Tr which is the second direction Tr. A protective cover 40 for the optical pickup device 20 that includes a second elastic wire 34b that extends substantially parallel to the base 36, and is formed by bending a single metal plate. An upper plate 41 facing the information recording surface of the optical disc, a side plate 42 facing the first elastic wire 34a and fixed to the base 36, and a side plate facing the second elastic wire 34b and fixed to the base 36 43, and the upper plate 41 has a first opening 41a that restricts the first objective lens 28a and the second objective lens 28b from being exposed and the holder 33 from moving to the + side in the focus direction F. The side plate 42 has − in the third direction Tn, which is a direction orthogonal to the first direction F and the second direction Tr, as the position of the first elastic wire 34a approaches the position where the holder 33 is supported. In the second direction Tr - it is sufficient that inclined at an acute angle toward the outer peripheral side of the optical disc to be the side.

Specifically, in order to avoid contact between the substantially cylindrical spindle motor and one of the substantially flat side plates 42 constituting the protective cover 40, the substantially flat upper plate 41 constituting the protective cover 40 is substantially the same. When the protective cover 40 is viewed in plan so as to have a flat plate shape, the substantially flat side plate 42 avoids interference with the substantially cylindrical spindle motor with respect to the other flat plate side plate 43. In other words, it may be inclined at a predetermined angle so as to be substantially linear in a plan view.

Further, the side plate 43 faces the second elastic wire 34b, and as the position of the second elastic wire 34b approaches the position for supporting the holder 33, the + side of the second direction Tr with respect to the negative side of the third direction Tn. It is preferable that the optical disc is inclined at an acute angle toward the inner peripheral side of the optical disc.

In addition, when the protective cover 40 is viewed in plan so that the substantially flat upper plate 41 constituting the protective cover 40 has a substantially flat plate shape, the substantially flat one side plate 42 and the substantially flat plate-like other side plate 42. The side plate 43 is preferably arranged in, for example, a substantially “C” shape or a substantially “eight” shape.

Further, the protective cover 40 in plan view is formed in a trapezoidal shape having, for example, a substantially mountain shape, and the length of the upper base of the trapezoid is shorter than the length of the lower base of the trapezoid, and the length of the lower base of the trapezoid It is preferable that the height of the trapezoid is substantially equal.

Further, when the optical pickup device 20 and the protective cover 40 for the optical pickup device 20 are viewed in plan, the optical pickup is substantially along the third direction Tn of the optical pickup device 20 and the protective cover 40 for the optical pickup device 20. When it is assumed that the virtual straight line substantially center line of the protective cover 40 for the device 20 and the optical pickup device 20 is drawn to the protective cover 40 for the optical pickup device 20 and the optical pickup device 20, the protective cover 40 in plan view. Is formed in a trapezoidal shape having a substantially chevron shape, for example, and one side plate 42 having a substantially flat plate shape and the other side plate 43 having a substantially flat plate shape have a length of a trapezoidal upper base with respect to a substantially linear center line. In order to shorten the length, it is preferable that both are inclined at a predetermined angle so as to be substantially linear in a plan view.

According to this protective cover 40, the side plate 42 is set to the negative side in the second direction Tr with respect to the negative side in the third direction Tn as the position of the first elastic wire 34a approaches the position where the holder 33 is supported. The optical disc is inclined at an acute angle toward the outer peripheral side of the optical disc. Thus, the protective cover 40 can be formed by bending a single metal plate so that the portion of the upper plate 41 excluding the first opening 41a and the portion of the side plate 42 excluding the second opening 42a are continuous. For this reason, even if a drop impact is applied to the optical pickup device 20 including the protective cover 40, the strength of the protective cover 40 is improved, so that plastic deformation of the protective cover 40 can be prevented. Further, the protective cover 40 can secure sufficient strength to restrict the movement of the holder 33 to the + side of the focus direction F. Moreover, the protective cover 40 can prevent deformation due to contact with the holder 33 or the like by ensuring sufficient strength to restrict the movement of the holder 33. Thereby, the optical pickup device 20 can perform the focus control and tracking control of the holder 33 more reliably. Further, the protective cover 40 can be reduced in size because a useless space formed between the side plate 42 and the first elastic wire 34a can be reduced. As a result, the entire optical pickup device 20 can be reduced in size.

Further, according to the protective cover 40, the side plate 43 faces the second elastic wire 34b, and with respect to the negative side in the third direction Tn as the position of the second elastic wire 34b approaches the position where the holder 33 is supported. The optical disc is inclined at an acute angle toward the inner peripheral side of the optical disc, which is the + side of the second direction Tr. Thus, the protective cover 40 can be formed by bending a single metal plate so that the portion of the upper plate 41 excluding the first opening 41a and the portion of the side plate 43 excluding the third opening 43a are continuous.

Thus, when the protective cover 40 is viewed from above so that the substantially flat plate-like upper plate 41 constituting the protective cover 40 has a substantially flat plate shape, the substantially flat one side plate 42 and the substantially flat plate shape are formed. The other side plate 43 is disposed in, for example, a substantially “C” shape or a substantially “eight” shape, so that the above-described effect is further exhibited.

In the protective cover 40 described above, the side plate 42 is formed by bending one side X of the upper plate 41 positioned on the + side of the tracking direction Tr, and the side plate 43 is positioned on the − side of the tracking direction Tr. The other side Y of the plate 41 is bent. The protective cover 40 is formed by bending the sides X and Y at both ends of the upper plate 41 in the tracking direction Tr. For this reason, the process which forms the protective cover 40 by bending one metal plate can be made easy.

In the protective cover 40 described above, the side plate 42 is formed by bending the side X of the upper plate 41 positioned on the + side of the tracking direction Tr in a straight line. In the protective cover 40, the side plate 42 is formed by bending the side X in a straight line. For this reason, the process which forms the protective cover 40 by bending one metal plate can be made easy.

Further, in the protective cover 40 described above, the side plate 42 has a second opening 42a through which the first elastic wire 34a is exposed. In this protective cover 40, since the second opening 42a is formed in the side plate 42, the side X can be easily bent, so that the protective cover 40 can be formed more easily.

In the protective cover 40 described above, the first opening 41a and the second opening 42a are formed continuously. In this protective cover 40, the side X can be easily bent by the continuous first opening 41 a and second opening 42 a, so that the protective cover 40 can be formed more easily.

Further, in the protective cover 40 described above, the first opening 41a has a shape in which the protruding piece 41b protrudes toward the inside of the first opening 41a, and the holder 33 is in the position where the protruding piece 41b protrudes. The movement to the + side of the focus direction F, which is the direction F, is restricted. The protective cover 40 can more reliably regulate the movement of the holder 33 because the projecting piece 41 b serving as a stopper contacts the upper surface of the holder 33. In the protective cover 40, the

side plates

42 and 43 approach the holder 33 as they approach the position from the + side to the − side in the third direction Tn. For this reason, the protruding piece 41b can be formed at a position close to each of the sides X and Y. Thereby, even if a drop impact is applied to the optical pickup device 20 including the protective cover 40, the strength of the protective cover 40 is improved, so that the plastic deformation of the protective cover 40 can be prevented. Further, the projecting piece 41 b can increase the strength for restricting the movement of the holder 33, and can be prevented from being deformed by contact with the holder 33. Since the deformation of the projecting piece 41b can be prevented, the holder 33 moves beyond the projecting piece 41b to the + side in the focus direction F, and the projecting piece 41b functioning as a stopper constitutes the movable portion of the actuator of the optical pickup device 20. It is possible to prevent the holder 33 from being caught. For this reason, the optical pickup device 20 can perform the focus control and tracking control of the holder 33 more reliably.

Further, according to this protective cover 40, when the protective cover 40 is viewed in plan so that the substantially flat plate-like upper plate 41 constituting the protective cover 40 has a substantially flat plate shape, the other substantially flat plate-like side plate is provided. With respect to 43, one side plate 42 having a substantially flat plate shape is formed so as to be inclined at a predetermined angle so as to be substantially linear in a plan view so as to avoid interference with a substantially cylindrical spindle motor. . When the protective cover 40 is viewed from above so that the substantially flat upper plate 41 constituting the protective cover 40 has a substantially flat plate shape, the substantially flat plate-like one side plate 42 and the substantially flat plate-like other side plate. 43 is, for example, a substantially “C” -shaped or substantially “eight” -shaped arrangement structure. The protective cover 40 in plan view is formed in, for example, a trapezoidal shape having a substantially mountain shape, and the length of the upper base of the trapezoid is shorter than the length of the lower base of the trapezoid. The height is approximately equal to the length. More specifically, when the optical pickup device 20 and the protective cover 40 for the optical pickup device 20 are viewed in plan, the optical pickup device 20 and the protective cover 40 for the optical pickup device 20 are substantially along the third direction Tn. Assuming that the virtual straight line substantially center line of the optical pickup device 20 and the protective cover 40 for the optical pickup device 20 is drawn to the protective cover 40 for the optical pickup device 20 and the optical pickup device 20, the plan view is obtained. The protective cover 40 is formed in, for example, a trapezoidal shape having a substantially chevron shape, and one side plate 42 having a substantially flat plate shape and the other side plate 43 having a substantially flat plate shape are formed on the upper base of the trapezoidal shape with respect to a substantially linear center line. Both are inclined at a predetermined angle so as to be substantially linear in plan view.

Thereby, it is possible to provide the protective cover 40 and the optical pickup device 20 capable of increasing the strength and reducing the size. Since the deformation of the protruding piece 41b constituting the protective cover 40 of the optical pickup device 20 can be prevented, the holder 33 moves beyond the protruding piece 41b to the + side in the focusing direction F, and the protruding piece 41b functioning as a stopper It is possible to prevent the holder 33 constituting the movable part of the actuator of the pickup device 20 from being caught. Further, it is possible to avoid contact between the substantially cylindrical spindle motor and the substantially flat side plate 42 constituting the protective cover 40.

=== Other Embodiments ===
The above-described embodiment is intended to facilitate understanding of the present invention, and is not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes equivalents thereof.

In the above-described protective cover 40, the side plate 42 faces the first elastic wire 34a, and as the position of the first elastic wire 34a approaches the position for supporting the holder 33, the second plate 42 moves toward the second side in the third direction Tn. Although it is assumed that it is inclined at an acute angle toward the outer peripheral side of the optical disk, which is the negative side of the direction Tr, for example, the side plate 42 faces the first elastic wire 34a, and the position of the first elastic wire 34a moves the holder 33 away from the holder 33. It may be formed so as to move away from the central axis of the optical disc as it approaches the supporting position.

Further, in the protective cover 40 described above, the first opening 41a has a shape in which the protruding pieces 41b that contact the substantially four corners of the upper surface of the holder 33 protrude toward the inside of the first opening 41a. . However, it is not particularly limited to this. For example, the first opening 41 a may not include the protruding piece 41 b, and the movement of the holder 33 may be restricted when both sides along the tracking direction Tr contact the upper surface of the holder 33. Further, the first opening 41 a may have a shape in which a projecting piece that contacts other than the approximately four corners of the upper surface of the holder 33 projects in addition to the projecting piece 41 b.

In the optical pickup device 20 described above, the holder 33 includes a first objective lens 28a that condenses the laser light on the first and second optical disks, and a second objective lens 28b that condenses the laser light on the third optical disk. For example, the optical disk is held in a state of being aligned substantially along the tracking direction Tr in the radial direction of the optical disk here, but is not particularly limited thereto. For example, the holder 33 includes a first objective lens 28a for condensing the laser light on the first and second optical discs, and a second objective lens 28b for condensing the laser light on the third optical disc, in the tangential direction Tn of the optical disc. You may hold | maintain in the state lined up substantially along. Further, the optical pickup device 20 may not include the optical system for the third optical disk, and the holder 33 may hold only the first objective lens 28a as the objective lens. The optical pickup device 20 may not include the optical systems for the first and second optical disks, and the holder 33 may hold only the second objective lens 28b as an objective lens. The optical pickup device 20 includes optical systems for the first, second, and third optical disks, and the holder 33 corresponds to the optical systems for the first, second, and third optical disks, and has an infrared wavelength band. One objective lens (not shown) corresponding to three types of laser light L1a, L1b, and L1c, that is, laser light L1a, laser light L1b in the red wavelength band, and laser light L1c in the blue-violet wavelength band may be held.

DESCRIPTION OF

SYMBOLS

1,20 ... Optical pick-up apparatus, 2,36 ... Base, 3 ... Objective lens, 4,33 ... Holder, 5a, 5b ... Elastic wire, 6,35 ... Substrate, 10, 40 ... Protective cover, 11, 41 ... Upper plate, 11a ... opening, 11b, 41b ... projecting piece, 12a, 12b, 42, 43 ... side plate, 13 ... notch, 21a ... first laser light source, 21b ... second laser light source, 21c ... third laser light source, DESCRIPTION OF SYMBOLS 22 ... Coupling lens, 23a ... 1st diffraction grating, 23b ... 2nd diffraction grating, 23c ... 3rd diffraction grating, 24 ... Dichroic prism, 25 ... Flat plate beam splitter, 26a ... 1st collimator lens, 26b ... 2nd collimator Lens 27a ... first rising mirror 27b ... second rising mirror 28a ... first objective lens 28b ... second objective lens 29a ... first sensor lens 29b ... second sensor Lens, 30a ... 1st photodetector, 30b ... 2nd photodetector, 31 ... Beam splitter, 32 ... Liquid crystal aberration correction element, 34a ... 1st elastic wire, 34b ... 2nd elastic wire, 37 ... Magnet, 41a ... 1st opening, 42a ... 2nd opening, 42b, 43b ... Locking claw, 43a ... 3rd opening, F ... Focus direction, L1, L2, L3 ... Length, L1a, L1b, L1c, L2a, L2b , L2c: Laser light, L4, L5: Distance, Tn: Tangential direction, Tr: Tracking direction, X, X1, X2, Y, Y1, Y2 ...

Claims

The base,
An objective lens;
A holder for holding the objective lens;
Supporting one side surface portion of the holder located on the inner peripheral side of the optical disc so that the holder is displaced in the focus direction and / or the tracking direction in a state where the holder is separated from the base, A first elastic wire extending substantially parallel;
Supporting the other side surface portion of the holder located on the outer peripheral side of the optical disc so that the holder is displaced in the focus direction and / or the tracking direction in a state where the holder is separated from the base, A second elastic wire extending substantially parallel to the wire;
A protective cover for an optical pickup device including
Formed by bending a single metal plate,
A first opposing plate facing the information recording surface of the optical disc;
A second opposing plate facing the first elastic wire and fixed to the base;
A third opposing plate facing the second elastic wire and fixed to the base,
The first counter plate has a first opening that restricts the objective lens from being exposed and the holder from moving in the focus direction on the information recording surface side of the optical disc;
The protective cover according to claim 1, wherein the second counter plate moves toward the outer peripheral side of the optical disc as the position of the first elastic wire approaches the position for supporting the holder.
The second counter plate is formed by bending one side of the first counter plate located on the inner peripheral side of the optical disc,
The protective cover according to claim 1, wherein the third counter plate is formed by bending the other side of the first counter plate located on the outer peripheral side of the optical disc.
The protective cover according to claim 2, wherein the second counter plate is formed by bending one side of the first counter plate in a straight line.
The protective cover according to any one of claims 1 to 3, wherein the second counter plate has a second opening through which the first elastic wire is exposed.
The protective cover according to claim 4, wherein the first opening and the second opening are formed continuously.
The first opening has a shape in which a protruding piece protrudes toward the inside of the first opening,
The protective cover according to claim 1, wherein the holder is restricted from moving in the focusing direction on the information recording surface side of the optical disc at a position where the protruding piece protrudes.
The base,
An objective lens;
A holder for holding the objective lens;
Supporting one side surface of the holder located on the inner peripheral side of the optical disc so that the holder is displaced in the focus direction and / or the tracking direction in a state where the holder is separated from the base, A first elastic wire extending substantially parallel;
The other side of the holder located on the outer peripheral side of the optical disc is supported so that the holder is displaced in the focus direction and / or the tracking direction in a state where the holder is separated from the base, A second elastic wire extending substantially parallel to the wire;
A protective cover formed by bending a single metal plate,
The protective cover is
A first opposing plate facing the information recording surface of the optical disc;
A second opposing plate facing the first elastic wire and fixed to the base;
A third opposing plate facing the second elastic wire and fixed to the base,
The first counter plate has a first opening that restricts the objective lens from being exposed and the holder from moving in the focus direction on the information recording surface side of the optical disc;
The optical pickup device, wherein the second counter plate moves toward the outer peripheral side of the optical disc as the position of the second elastic wire approaches the position for supporting the holder.
A first elastic wire;
A second elastic wire;
A protective cover for an optical pickup device including
A first opposing plate facing the information recording surface of the optical disc;
A second facing plate facing the first elastic wire;
A third opposing plate facing the second elastic wire,
The protective cover, wherein the second counter plate is tilted with respect to the third counter plate when the first counter plate is viewed in plan view in a substantially flat plate shape.
An optical pickup device comprising the protective cover according to claim 8.