JP2014235765A - Half mirror fixation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a half mirror fixation device with sufficient fixation accuracy of a half mirror.SOLUTION: An optical pickup device 10 includes a variety of optical elements incorporated in a housing 12. A half mirror fixation device 50 provided to the housing 12 includes: a half mirror storage portion 51; three mirror fixation reference walls 52, 53, and 54 of which wall surfaces are in contact with the half mirror 32; and a fixation member 56 of elastic material. The half mirror is stored in the half mirror storage portion and is linearly pressed by the fixation member so as to be fixed to the mirror fixation reference walls. Accordingly, fixation accuracy of the half mirror is improved.

Description

  The present invention relates to a half mirror fixing device incorporated in an optical pickup device.

  The configuration of a conventional optical pickup device will be described. In an optical pickup device, a plurality of optical elements are housed in a housing in which a resin material or the like is molded into a predetermined shape. An actuator for holding a substrate, a connector, and an objective lens is disposed on the upper surface of the housing. An optical pickup device irradiates an optical disk with laser light emitted from a light emitting element incorporated in a housing, and reads the laser light reflected by the optical disk with a light receiving element, thereby reading information from the optical disk. Read or write.

  The half mirror reflects the laser light emitted from the light emitting element in the direction of the objective lens and transmits the laser light reflected by the optical disc in the direction of the light receiving element. Therefore, the optical pickup device is required to fix the half mirror with high accuracy. Conventional fixing of the half mirror includes a configuration in which the half mirror is housed in a holding stand and fixed with an adhesive or a metal spring. As shown in FIG. 5, in the half mirror 100, a laser beam reflecting surface 100a is supported by a holding base 101, and a supporting surface 100b opposite to the reflecting surface is pressed and fixed by a metal spring 102 (Patent Document 1). ).

JP 2000-057618 A

  The quality of the optical pickup device depends greatly on the fixing accuracy of the half mirror, so that a mounting configuration in which no aberration occurs in the half mirror is required.

  However, in the configuration in which the half mirror is fixed by the metal spring, the half mirror is inserted into the holding table, the reflecting surface 100a of the half mirror is brought close to one wall surface of the holding table, and the support surface 100b of the half mirror and the other of the holding table are A gap is provided between the wall surface and temporarily fixed in this state. Thereafter, the metal spring 102 is inserted by being deformed by pressing while maintaining the temporarily fixed state, and then bonded. Therefore, there is a problem that insertion of the metal spring is troublesome and cannot be performed without a dedicated holding jig.

  A metal spring 102 is used to fix the half mirror 100. Therefore, the support surface 100b of the half mirror and the metal spring 102 are unstable due to point contact. In addition, the half mirror has a problem that the stress of the metal spring is easily applied, and aberration is easily generated.

  Furthermore, there is a problem that the cost increases when a metal spring is used.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a half mirror fixing device having sufficient fixing accuracy of a half mirror.

  The half mirror fixing device according to the present invention includes a half mirror housing portion formed in a housing, three mirror fixing reference walls with which one side surface of the half mirror provided in the half mirror housing portion abuts, and pressing the half mirror A fixing member made of an elastic material, and the half mirror is stored in the half mirror storing portion, and the half mirror is linearly pressed by the fixing member and fixed to the mirror fixing reference wall. To do.

  According to the present invention, the half mirror fixing device includes the three mirror fixing reference walls with which the half mirror provided in the half mirror housing portion abuts, and a fixing member made of an elastic material that presses the half mirror. Therefore, the half mirror housed in the half mirror housing section can press one end of the half mirror linearly with the fixing member. Further, the fixing member can maintain the state by pressing the half mirror toward the mirror fixing reference wall side with a force restoring from the compressed state at the time of insertion. Therefore, the half mirror is stabilized by line contact, and the stable fixing accuracy of the half mirror can be greatly improved.

  Moreover, since the fixing member made of an elastic material can eliminate the need for a metal spring, the cost can be reduced.

  Further, the half mirror linearly presses only the fixed region that contacts the fixing member. Therefore, no stress is applied to the optical region that becomes the optical path of the optical system of the half mirror. Therefore, the half mirror does not generate aberration and has good stability.

  Furthermore, the elastic material fixing member can be easily inserted in a compressed state between the half mirror and the wall surface of the half mirror housing. Therefore, workability is improved. In addition, since the fixing member can be easily compressed, the fixing member can be carried out without special equipment necessary for the deformation insertion of the conventional metal spring.

  Further, when the fixing member insertion groove is provided in the half mirror fixing device, the fixing member can be inserted more easily. Further, when a funnel-shaped guide port is formed in the upper part of the fixing member insertion groove, the workability is increased.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the optical pick-up apparatus of this invention, (A) is a perspective view which shows the optical pick-up apparatus which made the upper surface the side which an objective lens exposes, (B) is a perspective view which shows a housing. It is a figure which shows the optical system integrated in the optical pick-up apparatus of this invention. It is a perspective view which shows the half mirror fixing device of this invention. It is a figure which shows the half mirror fixing device of this invention, (A) is the sectional view on the aa line shown in FIG. 3, (B) is the sectional view on the bb line shown in FIG. It is sectional drawing which shows the half mirror fixing device of background art.

  With reference to FIG. 1, the optical pick-up apparatus 10 of this form is demonstrated. FIG. 1A is a perspective view showing the optical pickup device 10 when the surface from which the objective lens is exposed is the upper surface, and FIG. 1B is a perspective view showing the housing of FIG.

  Referring to FIG. 1A, an optical pickup device 10 focuses laser light of DVD (Digital Versatile Disk) and CD (Compact Disk) standards on an information recording layer of an optical disk (information recording medium). It has a function of receiving reflected light from the information recording layer and converting it into an electrical signal. Thereby, reading of information from the optical disk and writing of information to the optical disk are performed. Here, the optical pickup device 10 does not necessarily correspond to the laser light of these two types of standards. In addition to these, it may be compatible with BD (Blu-ray (registered trademark) Disc) standard laser light, or only one of these standards.

  The optical pickup device 10 includes a housing 12 and various optical elements incorporated in the housing 12. The housing 12 incorporates an actuator 18 that holds the objective lens 26 so as to be movable.

  The housing 12 is made of a resin material that is integrally formed by injection molding, and has a storage area inside which can store optical elements and electronic components. As a resin material constituting the housing 12, polycarbonate, modified PPE, ABS resin, PPS or the like is employed. A part of the housing 12 is provided with a curved portion in an area where the turntable is close. And the guide hole 14 and the guide groove 16 are provided in the both ends so that this curved part may be pinched | interposed. Under use conditions, a guide shaft is inserted into the guide hole 14, and another guide shaft is engaged with the guide groove 16. The optical pickup device 10 moves along these guide axes.

  Referring to FIG. 1A, the upper surface of the housing 12 from which the objective lens 26 is exposed is mostly covered with the cover 11. The cover 11 is formed by bending a metal plate having a thickness of about 0.1 mm into a predetermined shape, and its periphery is fitted to a convex portion provided on the side surface of the housing 12. The cover 11 is coupled to the housing 12 via a screw 31 that passes through the hole. On the other hand, a region on the upper surface of the housing 12 where the objective lens 26 is exposed is not covered with the cover 11 in order to enable laser light irradiation. Specifically, the actuator 18 that holds the objective lens 26 in a predetermined position elastically supports the holder 24 via a plurality of support wires 22 and a box-shaped holder 24 that holds the objective lens 26. It is comprised from the support part 20. FIG. In this embodiment, at least the objective lens 26 and the holder 24 are exposed to the outside without being covered with the cover 11. Further, a wiring sheet 29 electrically connected to the optical element built in the housing 12 is led out to the outside.

  Referring to FIG. 1B, the housing 12 of the optical pickup device has a housing area in which an optical element and an electronic component can be housed. A half mirror fixing device 50 is provided in the storage area, and is disposed on the optical path between the light emitting element 28 and an objective lens 26 (not shown) that irradiates the optical disk with laser light emitted from the light emitting element 28. The half mirror 32 is fixed to the half mirror fixing device 50. A diffraction grating 30 is disposed in the optical path between the half mirror 32 and the light emitting element 28, and a collimator lens 38 and a quarter wavelength plate 36 are raised in the optical path between the half mirror 32 and the objective lens 26 (not shown). A mirror 40 is arranged.

  A specific configuration of the half mirror fixing device 50 will be described later with reference to FIGS. 3 and 4.

  With reference to FIG. 2, the optical element built in the optical pick-up apparatus 10 is demonstrated.

  The optical pickup device 10 includes a light emitting element 28, a diffraction grating 30, a half mirror 32, a collimator lens 38, a rising mirror 40, a quarter wavelength plate 36, an AS plate 42, a PDIC 44, and an FMD 34. The main features.

  The light emitting element 28 incorporates one or a plurality of laser chips, and emits the laser light of each standard described above from the light emitting point of the laser chip.

  The diffraction grating 30 separates each laser beam emitted from the light emitting element 28 into 0th order diffracted light, + 1st order diffracted light, and −1st order diffracted light.

  The half mirror 32 reflects the forward laser light emitted from the light emitting element 28 and passing through the diffraction grating 30 and the like, and transmits the backward laser light (return light) reflected by the optical disk.

  The quarter-wave plate 36 has an action of converting the laser light reflected by the half mirror 32 from linearly polarized light to circularly polarized light, and conversely, the return light reflected by the optical disk is linearly polarized from the circularly polarized light. Convert to light.

  The collimator lens 38 converts the laser light reflected by the half mirror 32 into parallel light.

  The raising mirror 40 has a function of reflecting the laser light transmitted through the collimator lens 38 toward the objective lens.

  The PDIC 44 detects laser light of each standard and is used for focus servo and tracking servo.

  An FMD 34 (front monitor diode) detects laser light emitted from the light emitting element 28 and transmitted through the half mirror 32.

  An LDD 46 (laser diode driver) receives the output of the FMD 34 and adjusts the intensity of the laser light emitted from the light emitting element 28.

  The AS plate 42 gives aberration to the return laser beam that passes through the half mirror 32.

  Next, a read operation and a write operation of the optical pickup device 10 configured as described above will be described. The optical path of the laser beam used for reading and writing of each standard is the same as follows.

  First, the laser light emitted from the light emitting element 28 is separated into 0th-order diffracted light, + 1st-order diffracted light, and −1st-order diffracted light by passing through the diffraction grating 30. This is because servo is performed using the PDIC 44. The laser light that has passed through the diffraction grating 30 is reflected by the half mirror 32, and then the laser light is converted into circularly polarized light by the quarter wavelength plate 36, and then converted into parallel light by the collimator lens 38, The light is reflected by the rising mirror 40 and travels in the direction perpendicular to the optical disk. After that, the signal recording surface of the optical disk is focused by the refraction or diffraction action of an objective lens (not shown).

  The laser light (returned light) reflected by the signal recording surface of the disc passes through the quarter wavelength plate 36 through the objective lens, the rising mirror 40, and the collimator lens 38, so that a straight line having a polarization direction different from that of the forward path. Converted to polarized light. Specifically, the direction of polarization is reversed when the laser light converted into circularly polarized light in the forward path is reflected by the information recording layer of the disk, and the circularly polarized light in this state passes through the quarter wavelength plate 36 in the backward path. Thus, the polarization direction is converted by using the linearly polarized light. Next, the laser light that has become the linearly polarized light passes through the half mirror 32 and passes through the AS plate 42, and after being given and corrected for aberrations, is irradiated onto the light receiving surface of the PDIC 44. The PDIC 44 reads information and outputs signals for focus servo and tracking servo.

  Further, a part of the forward laser light emitted from the light emitting element 28 passes through the half mirror 32 and is irradiated to the FMD 34. The LDD 46 adjusts the laser light emitted from the light emitting element 28 to have a predetermined intensity based on the intensity of the laser light irradiated on the FMD 34.

  The above is the description of the optical configuration and operation of the optical pickup device 10.

  With reference to FIG. 3, the structure of the half mirror fixing apparatus 50 employ | adopted by this form is demonstrated.

  In this embodiment, the half mirror fixing device 50 provided in the housing of the optical pickup device includes a half mirror housing portion 51, three mirror fixing reference walls 52, 53, and 54 with which the half mirror contacts, and an elastic material fixing member 56. And have.

  The half mirror 32 is formed in a flat rectangular parallelepiped as illustrated by a dotted line. The half mirror 32 is provided with a fixed region in contact with the mirror fixing reference walls 52, 53, 54 and the fixing member 56, and an optical region used as an optical path of the optical system. Specifically, the fixing area of the half mirror includes an area that contacts the mirror fixing reference walls 53 and 54 and the fixing member 56 shown at the right end in the figure, and a mirror fixing reference wall 52 shown at the lower left end in the figure. It is an area | region to contact | abut.

  The half mirror housing 51 has mirror fixing reference walls 52, 53, and 54 on one side surface of the half mirror housing. The mirror fixing reference walls are spaced apart at three locations, and one side surface of the half mirror 32 is brought into contact therewith.

  Specifically, as shown in FIG. 3, the first mirror fixing reference wall 52 is disposed at the left end of the half mirror housing 51. Further, a projecting surface 55 is disposed at a position facing the first mirror fixing reference wall 52. As shown in FIG. 4A, the first mirror fixing reference wall 52 and the projecting surface 55 are disposed on the V-shaped groove surface, and the lower end of the half mirror 32 is sandwiched and fixed therebetween. The half mirror 32 is in contact with the first mirror fixing reference wall 52 at the lower left end.

  The second and third mirror fixing reference walls 53 and 54 are arranged at the right end of the half mirror housing 51. The second and third mirror fixing reference walls 53 and 54 are spaced apart in the vertical direction. These are desirably arranged on a straight line, and may be arranged shifted from side to side. As shown in FIG. 4B, the half mirror 32 is sandwiched between the second and third mirror fixing reference walls 53 and 54 and the fixing member 56. The upper right end of one side of the half mirror 32 is in contact with the second mirror fixing reference wall 53, and the lower right end of one side of the half mirror 32 is in contact with the third mirror fixing reference wall 54. Is done. The opposite side surface of the half mirror 32 is abutted linearly with the right end portion in the length direction of the fixing member 56. That is, the half mirror 32 is pressed in surface contact with the mirror fixing reference walls 52, 53, 54 at three points and in line contact with the fixing member 56.

  The half mirror housing 51 has a stopper (not shown) on the bottom surface. The stopper is a protrusion formed in a spherical or columnar shape. Thereby, the half mirror is positioned in the vertical direction.

  The fixing member 56 is manufactured using an elastic material. As for the shape of the fixing member 56, it is desirable that the end of the half mirror 32 can be pressed in a line shape in the vertical direction so that it can come into contact. Specifically, the fixing member 56 is formed in a tube shape or a columnar shape, and is formed substantially the same as the length of the half mirror 32 in the vertical direction. The elastic material is a resin, plastic, rubber, or the like using a material that does not permanently deform.

  The fixing member insertion groove 57 is formed in a cylindrical shape so as to face the second and third mirror fixing reference walls 53 and 54. The fixing member insertion groove 57 is provided with a funnel-shaped guide port 58 at the top. Thereby, it becomes easy to insert the fixing member. The fixing member insertion groove 57 is formed so as to open so as to contact the half mirror. Specifically, the fixing member insertion groove 57 is disposed adjacent to the half mirror housing 51, and a half-moon shaped opening is formed. As a result, when the fixing member 56 inserted into the fixing member insertion groove 57 is restored by the elastic force, the half mirror 32 can be pressed toward the mirror fixing reference walls 52, 53, 54, and the half mirror 32 can be It can be pressed linearly in the vertical direction. Therefore, the half mirror is stably fixed only in the fixed region.

  Note that the fixing member 56 may be inserted between the half mirror 32 and the wall surface of the half mirror storage portion 51 using the wall surface of the half mirror storage portion 51 without providing the fixing member insertion groove 57.

  With reference to FIG. 4, the structure of the half mirror fixing device 50 of this embodiment will be further described. 4A is a sectional view taken along line aa of the half mirror fixing device 51 shown in FIG. 3, and FIG. 4B is a sectional view taken along line bb of the half mirror fixing device 51 shown in FIG.

  Referring to FIG. 4A, the half mirror 32 is sandwiched between the first mirror fixing reference wall 52 and the projection surface 55. The half mirror 32 abuts the lower left end of the first mirror fixing reference wall 52, and abuts the lower left end of the opposite side surface against the projection surface 55. The protruding surface 55 positions the half mirror 32 in the vertical direction.

  With reference to FIG. 4B, the half mirror 32 is sandwiched between the second and third mirror fixing reference walls 53 and 54 and the fixing member 56. The side surface of the half mirror housing 51 is formed in a tapered shape with an upper part from the center and a lower part from the center. As a result, the second and third mirror fixing reference walls 53 and 54 protrude in a planar shape and are arranged in a gentle taper shape. Therefore, the half mirror 32 is inserted with a slight inclination. Therefore, the half mirror fixing device 50 corresponding to a thin optical pickup device is obtained.

  The half mirror 32 abuts the upper right end portion of one side surface against the second mirror fixing reference wall 53 and the right lower end portion abuts against the third mirror fixing reference wall 54. Further, the opposite side surface of the half mirror 32 is pressed linearly by the fixing member 56. At this time, the half mirror 32 is linearly fixed by the restoring force of the fixing member 56. The half mirror 32 is pressed linearly only in the fixed region, and no stress is applied to the optical axis region.

  Next, a method for assembling the half mirror will be described.

  First, the half mirror 32 is inserted in the vertical direction until the bottom surface of the half mirror contacts the stopper on the bottom surface of the half mirror housing 51. One side surface of the half mirror 32 is in surface contact with three points of the mirror fixing reference walls 52, 53, and 54. In addition, the opposite side surface of the half mirror 21 is in contact with the projection surface 55. The half mirror 32 is positioned in the vertical direction by the stopper and the projection surface 55. Since the thickness of the thin optical pickup device is as thin as 6 mm or less, the half mirror 32 is stored with a slight inclination as shown in FIG.

  Thereafter, the fixing member 56 is pressed and inserted while being deformed in the vertical direction. The fixing member 56 is inserted between the wall surface of the half mirror housing 51 and the half mirror 32, or is inserted between the fixing member insertion groove 57 and the half mirror 32. The fixing member presses and abuts one side surface of the half mirror 32 against the mirror fixing reference walls 52, 53, and 54 by an elastic force restored from the pressed state, and presses the end of the half mirror 32 in a linear shape. To do. The fixing member fixes the half mirror.

  Thereafter, the guide port 58 of the fixing member insertion groove 57 is covered with an adhesive, and the half mirror 32 is fixed to the half mirror fixing device 50.

DESCRIPTION OF SYMBOLS 10 Optical pick-up apparatus 11 Cover 12 Housing 14 Guide hole 16 Guide groove 18 Actuator 20 Support part 22 Support wire 24 Holder 26 Objective lens 28 Light emitting element 29 Wiring sheet 30 Diffraction grating 31 Screw 32 Half mirror 34 FMD
36 1/4 wavelength plate 38 Collimator lens 40 Rising mirror 42 AS plate 44 PDIC
46 LDD
50 Half mirror fixing device 51 Half mirror housing 52, 53, 54 Reference wall 55 for mirror fixing Projection surface 56 Fixing member 57 Fixing member insertion groove 58 Guide port

Claims (5)

A half mirror housing formed in the housing;
Three mirror fixing reference walls with which one side surface of the half mirror provided in the half mirror housing part abuts,
An elastic material fixing member that presses the half mirror;
The half mirror fixing device, wherein the half mirror is housed in the half mirror housing portion, and the half mirror is linearly pressed by the fixing member to be fixed to the mirror fixing reference wall.   The half mirror fixing device according to claim 1, wherein the fixing member is inserted into a fixing member insertion groove disposed to face a part of the reference wall for fixing the mirror.   The half mirror fixing device according to claim 2, wherein the fixing member insertion groove has a funnel-shaped guide port at an upper portion thereof.   2. The half mirror fixing device according to claim 1, wherein the half mirror fixing device has a protruding surface that faces one of the mirror fixing reference walls and forms a V-shaped groove.   The half mirror fixing device according to claim 1, wherein the fixing member is formed in a tube shape or a column shape.

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