JP4349106B2 - Optical pickup and optical disc apparatus - Google Patents

Description

  The present invention relates to an optical disk device mounted on an electronic device such as a personal computer, a notebook computer, or a mobile terminal device, and an optical pickup suitably used for the optical disk device.

  As optical recording media, various optical discs such as DVD (digital video disc), CD-R (writeable compact disc), CD-RW (rewritable compact disc) have been developed. In a DVD, information is recorded or reproduced by a laser beam having a wavelength of about 650 nm. On the other hand, in CD-R and CD-RW, information is recorded or reproduced by laser light having a wavelength of about 780 nm. An optical disc apparatus that records or reproduces information on a plurality of types of optical discs has been proposed.

  Further, in such an optical disc apparatus that records or reproduces information on a plurality of types of optical discs, a single laser element that emits light beams of different wavelengths is used as a light source of an optical pickup mounted on the optical disc apparatus. A device disposed adjacent to a package (a so-called hybrid two-wavelength semiconductor laser) or a device in which light sources having a plurality of wavelengths are integrated on a single semiconductor substrate (a so-called monolithic two-wavelength semiconductor laser) is used.

  Further, in accordance with demands for thinning and miniaturization, these light sources mount a semiconductor laser element on a lead frame, cover the semiconductor laser element with a protective film, and electrically connect the lead frame to a line capable of supplying current. Configuration is adopted. This configuration is called a so-called frame laser light source.

  As a prior example using a frame laser light source, there are (Patent Document 1) to (Patent Document 5) and the like.

In addition, in order to accurately position the light source and the light receiving element, there is a configuration in which the light source and the light receiving element are joined to the coupling member as shown in (Patent Document 6).
JP-A-10-241195 JP-A-10-241189 JP 2000-137924 A JP 2002-74722 A JP 2003-59094 A JP 2001-31835 A

  However, in the configurations of the above (Patent Document 1) to (Patent Document 5), since the light source or the light receiving element is fixed to the plate, it is very difficult to position the light source and the light receiving element, and accurate assembly is required, and productivity is increased. It is difficult to improve. In particular, when a two-wavelength semiconductor laser element is used as a light source (see Patent Document 2), the positional relationship between the light source and the light receiving element is required to have extremely high accuracy, and it is difficult to improve productivity as well. .

As a method for accurately adjusting the position of the light source and the light receiving element, as described in (Patent Document 6), using the coupling member, the position of the light source and the light receiving element is adjusted and joined to the coupling member. Although there is a method and the position adjustment is relatively easy, an aberration is caused in the light beam due to the influence of the bonding material interposed between the light source and the light guide member, leading to deterioration of the optical characteristics.

  The present invention solves the above-mentioned conventional problems, and even when a frame laser light source is used and particularly preferably a two-wavelength semiconductor laser light source is used, productivity and workability can be improved, or An object of the present invention is to provide an optical pickup and an optical disc apparatus that can realize at least one of the improvement of optical characteristics.

The present invention provides a light source in which a plate and a plurality of terminal portions are fixed to each other with a molding member and a semiconductor laser element is provided on the plate, a light receiving element, and light from the light source provided between the light source and the light receiving element. And a second optical member that emits the light from the first optical member to the outside and reflects the light from the outside to the light receiving element. A coupling base having a space portion for disposing the light source, a placement portion for placing the first and second optical members, and a pair of attachment portions for attaching the light receiving elements; Is provided with a pair of joint portions in which both side portions of the plate of the light source are disposed, and the placement portion includes a small diameter portion that communicates with the space portion and allows light from the light source to pass therethrough and the small diameter portion. The first optical member so as to close The light source and the first optical member have a through-hole provided with a large-diameter portion to be accommodated, and the second optical member is placed on a peripheral portion of the opening portion of the large-diameter portion of the through-hole. And a gap between the first optical member and the second optical member is provided with a predetermined gap in which no bonding material is interposed .

In the present invention, even if a frame laser light source is used according to the above configuration, by using a coupling base so that each of the light receiving element and the light source can be adjusted, each part is fixed, so that optical adjustment can be easily performed, workability, etc. Can be improved and productivity can be improved. In addition, since the bonding material is not disposed between the light source and the first optical member and between the first optical member and the second optical member , aberration is generated in the light flux. Can be suppressed.

  In this way, even if a light source that emits light beams having a plurality of different wavelengths that are difficult to optically adjust is used, adjustment is easy at the time of assembly, and deterioration of optical characteristics can be prevented, so that a compact configuration can be obtained. Can be superior in terms of characteristics.

According to the first aspect of the present invention, a plate and a plurality of terminal portions are fixed to each other with a molding member, a light source provided with a semiconductor laser element on the plate, a light receiving element, and light from a light source provided between the light source and the light receiving element A first optical member that allows light to pass through, a second optical member that emits light from the first optical member to the outside, reflects light from the outside, and emits the light to the light receiving element, and a light source And a coupling base having a mounting portion on which the first and second optical members are mounted and a pair of mounting portions to which the light receiving elements are mounted. The mounting portion is provided with a small diameter portion that communicates with the space portion and allows light from the light source to pass therethrough, and a large diameter that houses the first optical member so as to close the small diameter portion. And a large-diameter opening in the through-hole. The second optical member is placed on the peripheral part of the minute, so that the bonding material is not interposed between the light source and the first optical member and between the first optical member and the second optical member. The optical pickup is characterized by providing a gap between the two , and even if a frame laser light source is used, each part is fixed by using a coupling base so that the light receiving element and the light source can be adjusted, thereby optical adjustment. It is easy to perform, and workability etc. improve and productivity can be improved. In addition, since the bonding material is not disposed between the light source and the first optical member and between the first optical member and the second optical member , aberration is generated in the light flux. Can be suppressed. Further, by providing the first optical member in the large diameter portion, it is possible to reduce the size of the apparatus. Moreover, when attaching a 1st optical member to a coupling | bonding base, a 1st optical member can be hold | maintained in a through-hole and an assembly property improves.

The invention according to claim 2 is the optical pickup according to claim 1 , wherein a plurality of protrusions are provided on the peripheral portion, and a second optical member is provided on the plurality of protrusions. A gap can be accurately formed between the optical member and the second optical member, and variations in optical characteristics can be suppressed.

According to a third aspect of the present invention, there is provided an optical pickup according to any one of the first to second aspects , a rotation driving means for rotating the medium, and a moving means for moving the optical pickup closer to or away from the rotation driving means. Even if a frame laser light source is used, optical adjustment is performed by fixing each part using a coupling base so that the light receiving element and the light source can be adjusted respectively. It is easy, workability and the like are improved, and productivity can be improved. In addition, since the bonding material is not disposed between the light source and the first optical member and between the first optical member and the second optical member, aberration is generated in the light flux. Can be suppressed. Further, by providing the first optical member in the large diameter portion, it is possible to reduce the size of the apparatus. Moreover, when attaching a 1st optical member to a coupling | bonding base, a 1st optical member can be hold | maintained in a through-hole and an assembly property improves. Further, it is possible to reduce the thickness and size.

  1 and 2 are a perspective view and an exploded perspective view showing an optical pickup according to an embodiment of the present invention.

  1 and 2, 1 is a light source, 2 is a light receiving element, 3 is a coupling base, and 4 and 5 are optical members. The light source 1, the light receiving element 2 and the optical members 4 and 5 are respectively joined to the coupling base 3. There is a through hole 3a provided in the coupling base 3 between the light source 1 and the optical members 4 and 5, and the light emitted from the light source 1 passes through the through hole 3a and enters the optical members 4 and 5. The light emitted from the optical member 5 is irradiated onto an optical disk (not shown) through at least condensing means such as an objective lens (not shown) to perform predetermined information recording on the optical disk.

  The light reflected from the optical disk passes through at least the objective lens and the like, is incident on the optical member 5, is reflected one or more times inside the optical member 5, and then enters the light receiving element 2. In the light receiving element 2, incident light is converted into an electric signal, and the electric signal is sent to a circuit section of a signal generation system, which generates a tracking error signal, a focus error signal, an RF signal, etc. Based on the signal, tracking control and focus control of the optical pickup are performed, and further desired information is generated from the RF signal.

  The light source 1 is attached from the rear part of the coupling base 3, and is attached to the coupling base 3 so that the light emitting part at the tip of the light source 1 and the optical member 4 attached to the coupling base 3 face each other. The light incident surface of the light receiving element 2 faces at least the side part of the optical member 5, and the optical member 4 faces the bottom of the optical member 5.

  Hereinafter, each part will be described in detail.

  First, the light source 1 will be described.

  As the light source 1, for example, a frame laser light source shown in FIGS. 3 and 4 is preferably used. The frame laser light source as the light source 1 is configured to cover a part of the plate 6 with a mold member 7. The plate 6 is preferably a metal plate such as copper, copper alloy, silver, silver alloy, aluminum, aluminum alloy, iron, iron alloy, and more preferably soldered on the plate. It is preferable to coat a good material by means such as plating or vapor deposition. In the present embodiment, the plate-like body is made of a metal material. However, a material having good thermal conductivity and high conductivity other than the metal material, such as a conductive ceramic, can be used. In the present embodiment, as the plate 6, a plated film made of Ag or an Ag alloy is provided on a plate-like body made of copper or a copper alloy. The plate 6 is provided with side portions 6a and 6b that protrude from both sides, and the side portions 6a and 6b are provided so as to promote heat dissipation or to improve the mounting property to other members. And so on.

A semiconductor laser element 9 is provided on the plate 6 via a submount 8 having an insulating portion, and the upper surface of the semiconductor laser element 9 is electrically connected to the plate 6 by a wire such as gold. At this time, the light emitting surface of the semiconductor laser element 9 is disposed above the frame laser light source. Base submount 8 is composed of an insulating material, the surface on which the semiconductor laser device 9 of the submount 8 are formed are electrodes 11 and 12 which are separated form, the semiconductor laser device 9 on the electrodes 11 and 12 Electrically joined.

The semiconductor laser element 9 is configured to emit light of one to a plurality of different wavelengths in a monoblock, that is, one block. In the present embodiment, the semiconductor laser element 9 that emits laser light having a wavelength of about 650 nm (for example, DVD system) and laser light having a wavelength of about 780 nm (CD system) is used. The light emitted from the semiconductor laser element 9 may be one, or three or more lights having different wavelengths may be irradiated. The optical pickup according to the present embodiment is particularly suitable when a plurality of semiconductor laser elements 9 that emit light having different wavelengths are used. In the present embodiment, when emitting a plurality of lights having different wavelengths, a monoblock is used as the semiconductor laser element, but a plurality of semiconductor lasers emitting a light beam of one wavelength in one block. The element 9 may be mounted on the plate 6 to emit a plurality of lights having different wavelengths. In this case, although the size of the light source 1 may be increased, the semiconductor laser element 9 that emits light beams having arbitrary different wavelengths can be mounted, so that a plurality of light beams having significantly different wavelengths are emitted. Easy to do.

  Reference numerals 13, 14, and 15 denote terminal portions, and the terminal portion 13 is formed integrally with the plate 6. That is, the plate 6 and the terminal portion 13 are electrically connected. The terminal portions 14 and 15 are provided separately from the plate 6 and the terminal portion 13, and are fixed to each other by the mold member 7. The end portion of the terminal portion 14 is electrically joined to the electrode 12 via a conductive wire 16, and the terminal portion 15 is electrically joined to the electrode 13 via a wire 17.

  For example, when the semiconductor laser element 9 emits a light beam that performs at least one of information recording / reproduction with respect to a DVD optical disk and a light beam that performs at least one of information recording / reproduction with respect to a CD optical disk The terminal unit 13 is connected to the ground, the terminal unit 14 is connected to a circuit that supplies a current that emits a DVD-type light beam, and the terminal unit 15 supplies a current that emits a CD-type light beam. Connected to the circuit. That is, when a DVD-type light beam is emitted, for example, current flows in the order of the terminal portion 14, the wire 16, the electrode 12, the semiconductor laser element 9, the wire 10, the plate 6, and the terminal portion 13. In the case of emitting a CD light beam, for example, current flows in the order of the terminal portion 15, the wire 17, the electrode 11, the semiconductor laser element 9, the wire 10, the plate 6, and the terminal portion 13.

  The mold member 7 is preferably made of an insulating material such as a resin material or a ceramic material. Sometimes, a resin material is preferably used, and the use of the resin material makes it very easy to manufacture the light source 1. Among the resin materials, a material having high heat resistance (250 ° C. or higher) and less generation of burrs is preferable. In this embodiment, PPS (polyphenylene sulfide) is used. Moreover, as a usable resin material, an epoxy resin, a urethane resin, a liquid crystal polymer, or the like can be suitably used.

  As described above, the mold member 7 fixes the plate 6 and the terminal portions 14 and 15 integrated with the terminal portion 13 to each other. Further, as shown in FIG. It has the wall part which opened the exit slope side. In the wall portion, a submount 8, a semiconductor laser element, a part of the plate 6, a wire 10, a wire 16, a wire 17, a part of the terminal part 14, and a part of the terminal part 15 are arranged. As shown in FIG. 4, a mold member 7 is provided on the back surface of the light source 1 so that a part of the surface of the plate 6 opposite to the side where the semiconductor laser element 9 is provided is exposed. The mold member 7 on the front side and the mold member 7 on the back side are integrated.

  Next, the coupling base 3 will be described in detail with reference to FIGS.

The coupling base 3 is preferably formed of a material having relatively light weight, high precision shape workability, heat dissipation, etc., for example, zinc, zinc alloy, aluminum, aluminum alloy, titanium, titanium alloy, etc. Preferably used. In the present embodiment, the bonding base 3 is configured by zinc die casting in consideration of cost and the like. Note that, for various purposes such as improving the bondability between the coupling base 3 and other members or providing the coupling base 3 with weather resistance, the entire surface of the coupling base 3 or at least a part of the surface thereof is provided. It is preferable to provide a film, a film, or the like made of Au, Au alloy, Sn, Sn alloy (Sn—Cu, Sn—Ag—Sn, etc.). Sometimes, it is preferable in terms of mass productivity to form the aforementioned metal material by plating or the like. At this time, the thickness of the film or film is preferably 3 μm or more, and is preferably 20 μm or less in consideration of cost. Further, when the film is formed as a film, it is formed using a plating technique such as electroplating or electroless plating, but may be formed using a technique such as vapor deposition or sputtering.

  The coupling base 3 is provided with fixing portions 18 and 19 for fixing the coupling base 3 to other members and the like, and fastening means such as screws and caulking pins are inserted into the fixing members 18 and 19 respectively. Through-holes 18a and 19a are provided. In the present embodiment, screws are inserted into the through holes 18a and 19a, and the screws are inserted into screw holes of other members and fastened to be fixed.

  In this embodiment, the attachment to other members is performed with screws, but the coupling base 3 using a bonding material such as an organic adhesive or solder or welding means such as ultrasonic welding is attached to the other members. In this case, the through holes 18a and 19b may not be provided. Instead, the bonding surface or the bonding surface is provided with unevenness or a predetermined surface roughness, or a groove or the like is provided. May be improved.

  In the present embodiment, the through holes 18a and 19a are provided in the fixing portions 18 and 19, respectively. However, for example, the through hole 18a is provided only in one fixing portion 18, and the through hole 19a is not provided in the fixing portion 19. It may be configured. In this case, the fixing portion 18 is fixed to another member such as a screw, and the fixing portion 19 is provided with an insertion portion or the like of the fixing portion 19 on another member to be locked, and the coupling base 3 is connected to the other member. It is also possible to fix it to. In the present embodiment, the cross-sectional shape of the through holes 18a and 19a is a circle, a substantially square shape with corners arcuate, or an oval shape. A C-shaped through-hole or a semicircular cross section may be used.

  Further, preferably, as shown in FIGS. 5 and 6, positioning substantially V-shaped or U-shaped concave portions 18 b and 19 b may be provided at the outer ends of the fixing portions 18 and 19. The recesses 18b and 19b are provided for positioning when the coupling base 3 is attached to another member, or a reference for assembly work for attaching the light source 1, the light receiving element 2, and the optical members 4 and 5 to the coupling base 3. It may be used as a part. In this embodiment, the recesses 18b and 19b are provided. However, the recesses 18b and 19b may be provided on at least one of the fixing parts 18 and 19, or an assembly of the optical pickup using another jig or the like, When attaching to a member, it is not necessary to provide the recesses 18b and 19b. However, when the recesses 18b and 19b are necessary for other reasons, the recesses 18b and 19b may be provided in the fixing portions 18 and 19 even when assembling with another jig or the like.

  A main body 20 for attaching at least the light source 1, the light receiving element 2, the optical members 4 and 5 is provided between the fixing parts 18 and 19. The fixing parts 18 and 19 are integrally provided on both sides of the main body 20. It has a configuration that can be. In the present embodiment, the main body portion 20 and the fixing portions 18 and 19 are integrally formed. However, a member corresponding to the fixing portions 18 and 19 is provided as a separate member, and the main body portion 20 corresponds to the fixing portions 18 and 19. The member to be attached may be attached using any one method such as adhesion, locking, engagement, and welding.

A pair of opposite side walls 21 and 22 are erected on the main body 20, and the optical member 5 is disposed between the side walls 21 and 22. The side wall 21 is provided with wall portions 21a and 21b. The wall portion 21a is higher than the wall portion 21b, and the wall portion 21a and the wall portion 21b are integrally connected by an inclined portion 21c. Has been. Similarly, the side wall 22 is provided with wall portions 22a and 22b, the wall portion 22a is higher than the wall portion 22b, and the wall portion 22a and the wall portion 22b are integrated with an inclined portion 22c. It is connected to. The wall portions 21b and 22b are provided with tapered portions 21d and 22d that face each other.

  Further, on the opposite side of the wall portions 21a and 22b from the inclined portions 21c and 22c, mounting portions 23 and 24 of the substantially flat light receiving element 2 are provided, respectively, and the light receiving element 2 is bonded to the mounting portions 23 and 24. It is fixed using methods such as. In addition, it is desirable for the attachment parts 23 and 24 to be substantially the same plane. The attachment parts 23 and 24 are connected at the bottom part by a connection part of substantially the same plane. Since the wall portions 21a and 22a are provided with the attachment surfaces 23 and 24 for attaching the light receiving element 2 in this way, a certain degree of mechanical strength is required. As an example of the countermeasure, by providing the inclined portions 21c and 22c, the bottom portions of the wall portions 21a and 22a are widened, and the mechanical strength of the side portions 21a and 22a is increased.

  The tapered portions 21d and 22d are provided, for example, so that the optical members 4 and 5 can be easily inserted when the optical members 4 and 5 are attached to the main body portion 20, or the optical members 4 and 5 are not damaged. ing. Further, by providing the tapered portions 21d and 22d, when the optical member 5 is mounted and the optical member 5 is fixed to the main body portion 20 with an adhesive as will be described later, the adhesive is attached to the tapered portions 21d and 22d and the optical member. 5, the bonding strength can be increased.

  One side surface portion of the main body portion 20 is provided with a raised portion 25 that is higher than the other portion, and this raised portion 25 is provided at the bottom of the main body portion 20 and between the fixing portions 18 and 19. The first raised portion 24a and the second raised portion 25b provided on the side portion of the main body portion 20 and on the side surface portion of the wall portion 21a. Moreover, the 1st protruding part 25a and the 2nd protruding part 25b are connected, and it is comprised by the substantially inverted T shape in FIG.

  By providing the raised portion 25, the thickness of the portion can be increased. For example, the mechanical strength of the main body portion 20 can be increased, and the bending and deformation of the coupling base 3 can be suppressed. Furthermore, since the second raised portion 25b is also provided on the side portion of the wall portion 21a, the mechanical strength of the wall portion 21a can be further increased, and the light receiving element 2 can be stably fixed.

  Depending on the material, size, and shape of the coupling base 3, this raised portion 25 may not be provided, and even when it is provided, the shape is not limited to the shape shown in FIG. The raised portion 25 can be provided in various shapes such as a letter shape, a substantially elliptical shape, a substantially F shape, and a substantially E shape.

  The wall portion 21a is provided with a recessed portion 26 reaching the end portion, and the wall portion 22a is provided with a substantially V-shaped or substantially U-shaped groove 27. As described later, this is provided so that the adhesive does not easily reach the optical member 4 when the light receiving element 2 is joined to the attachment portions 23 and 24 with an adhesive or the like. Since the wall portion 21a is provided with the raised portion 25 as described above, the attachment portion 23 having a sufficiently wide area can be obtained. Therefore, the wall portion 21a is formed as the recess portion 26 reaching the end portion of the wall portion 21a. In the portion 22a, since the area of the mounting portion 24 is reduced by providing a recess portion that reaches the end portion because the raised portion 25 is not provided, the groove 27 does not reach the end portion.

  Note that the recess 26 and the groove 27 may not be provided depending on the specifications.

Further, the side walls 21a and 22a face each other, and the side walls 21b and 22b face each other.
22 is provided.

  The main body 20 is provided with mounting portions 28 for the optical members 4 and 5, and side walls 21 and 22 are integrally provided on both sides of the mounting portion 28. In the present embodiment, the side walls 21 and 22 are erected integrally with the mounting portion 28, but the side walls 21 and 22 are formed of separate members, and the side walls 21 and 22 are disposed on both sides of the mounting portion 28. It may be attached using any one method such as adhesion, locking, engagement, and welding.

  The mounting portion 28 is provided with a through hole 3a, and the through hole 3a is configured by connecting a large diameter portion 32 having a large cross section and a small diameter portion 33 having a small cross section. In the present embodiment, the large-diameter portion 32 and the small-diameter portion 33 both have a substantially rectangular shape with a cross-sectional shape having an arcuate corner portion, and a substantially similar shape, but the cross-sectional shape is circular, elliptical, 5 Other shapes such as a polygonal shape more than a square may be used, and the cross-sectional shapes of the large diameter portion 32 and the small diameter portion 33 may be different. That is, the large diameter portion 32 may be substantially rectangular as described above, and the small diameter portion 33 may be substantially circular.

  Since the large-diameter portion 33 can accommodate the optical member 4, the large-diameter portion 33 has a cross section and a depth enough to accommodate the optical member 4. In the present embodiment, the provision of the large diameter portion 32 and the small diameter portion 33 has an advantage that the optical member 4 can be prevented from falling off even when the optical member 4 is stored in the large diameter portion 32. If the process is taken into consideration so as to be held in the through-hole 3a with another jig or the like, the through-hole 3a may be formed in a straight structure without providing the large-diameter portion 32 and the small-diameter portion 33. it can. That is, for example, the cross-section of the through-hole 3a can be circular with a predetermined radius in all regions.

  Further, when the through hole 3a has a straight structure, as described above, the optical member 4 prevents the through hole 3a from dropping out. Etc. can also be provided. In such a configuration, the optical member 4 can be prevented from falling off, and the assemblability is improved.

  Protrusions 29, 30, and 31 are provided on the peripheral edge portion of the opening portion of the through hole 3 a in the mounting portion 28. The protrusions 29, 30, and 31 are provided integrally or separately on the placement unit 28. When provided separately, the protruding piece may be attached to the periphery of the opening of the through hole 3a of the mounting portion 28 by using any one of methods such as adhesion, locking, engagement, and welding.

  In the present embodiment, the through hole 3a is provided in the coupling base 3. However, the opening is not limited to the through hole but may be an opening such as a U-shaped notch.

  In this embodiment, as shown in FIGS. 5 and 6, one relatively large protrusion 29 is provided on one side of the opening of the through-hole 3 a that is not opposed to the side walls 21 and 22, and the other portion is provided. Are provided with relatively small protrusions 30 and 31 in parallel. At this time, the heights of the protrusions 29, 30, and 31 are preferably substantially the same. Further, the optical member 5 is placed on the upper surfaces of the protrusions 29, 30, 31. As a result, the optical member 5 has a predetermined distance from the optical member 4 by the height of the protrusions 29, 30, 31. The optical members 4 and 5 are separated from each other and are not in contact with each other.

In the present embodiment, one protrusion 29 is provided on one side of the opening of the through hole 3a, and the protrusions 30 and 31 are provided in parallel to each other. When the optical member 5 is placed, three-point support is provided. However, in either case, one protrusion may be provided, or a plurality of protrusions may be provided. In addition, when the optical member 5 is intentionally attached at the time of optical adjustment or the like, the height of the protrusions may be different on the left and right. That is, in the configuration shown in FIGS. 5 and 6, the optical member 5 is attached with an inclination by, for example, increasing the protrusion 29 and decreasing the height of the protrusions 30 and 31.

  In the present embodiment, the cross-sectional shape of the protrusions 29, 30, and 31 is a substantially rectangular shape, but the shape can be appropriately changed according to specifications and processes such as a substantially circular shape, a substantially polygonal shape, and a substantially triangular shape. .

  Furthermore, although the projections 29, 30, and 31 are provided in the present embodiment, for example, by increasing the depth of the large diameter portion 32 by a predetermined amount or more than the thickness of the optical member 4, the optical member is changed to the large diameter portion 32. If it is configured so that a gap is created between the opening and the optical member 4 when stored, the optical member 5 is placed on the placement portion 28 without providing the projections 29, 30, 31. Since the optical member 4 is completely stored in the large-diameter portion 32, a gap can be easily formed between the optical members 4 and 5.

  In the present embodiment, the through hole 3a is constituted by the large diameter portion 32 and the small diameter portion 33. However, the medium diameter portion may be provided between the large diameter portion and the small diameter portion, and two step portions may be provided. good. Furthermore, in the present embodiment, a step portion is provided between the large diameter portion 32 and the small diameter portion 32. However, the diameter may be continuously reduced as the distance from the placement portion 28 increases. good. That is, the cross-sectional area of the opening on the mounting portion 28 side in the through hole 3a is configured to be larger than the cross-sectional area of the opening on the opposite side to the mounting portion 28 side.

  Furthermore, the structure which has a small diameter part in the middle part of the through-hole 3a like the large diameter part 32, the small diameter part 33, and the large diameter part 32 from the mounting part 28 side may be sufficient.

  When the through hole 3a is other than a circular shape such as a square cross section or a polygonal cross section, the large diameter portion 32 and the small diameter portion 33 have a large cross section in which the large diameter portion 32 is wide and the small diameter portion 33 has a cross sectional area. It means small.

  On the bottom side of the mounting portion 28, the main body portion 20 is provided with a support portion 34 that integrally connects the mounting portion 28 and the fixing portions 18 and 19, and a space portion 35 into which the light source 1 is inserted. Further, a protruding portion 36 protruding from the placement portion 28 toward the space portion 35 is provided. The projecting portion 36 and the support portion 34 face each other through a space. A support portion 34 and a space portion 35 are provided between the fixing portions 18 and 19.

  The space portion 35 communicates with the through hole 3a. Further, projecting portions 37 and 39 project from the fixed portions 18 and 19 toward the space portion 35, and gaps 38 and 40 are provided between the projecting portions 37 and 39 and the support portion 34. . The side portions 6 a and 6 b of the light source 1 are mainly inserted into the gaps 38 and 40. The support portion 34 facing the gaps 38 and 40 is provided with joint portions 41 and 42 to which the side portions 6a and 6b are joined.

  Further, a through hole 100 communicating with the space portion 35 is provided on the side of the main body 20 where the raised portion 25 is provided, so that observation can be performed when the light source 1 is aligned. Although the process is somewhat complicated, the through hole 100 may be covered with a transparent glass or resin film, or a transparent resin or glass may be embedded in the through hole 100.

  Next, the light receiving element 2 will be described in detail with reference to FIGS.

  The light receiving element 2 includes a light receiving element body 43 on which reflected light from the optical disk or light emitted from the light source 1 and incident without passing through the optical disk is incident, a substrate 44 on which the light receiving element body 43 is mounted, and a substrate 44 Capacitors 45 and 46 that are mounted and can stabilize the power supply voltage are provided.

  The light receiving element body 43 includes a photo sensor substrate 43c provided with a photo detector in a case 43a made of mold resin or the like. The photo sensor substrate 43c has a photo detector in a predetermined pattern according to the specifications. Several are arranged. A plurality of leads 43a are exposed to the outside from the case 43a, and the leads 43b are electrically connected to the photosensor substrate 43c. The lead 43b has a function of transmitting electric power necessary for driving the light receiving element body 43a to the internal photosensor substrate 43c, or converting light received by the photosensor substrate 43c into an electrical signal, and guiding the electrical signal to the outside. Have. The case 43a is configured such that at least the window portion 43d facing the photosensor substrate 43c is transparent to translucent. More preferably, at least a portion of the photosensor substrate 43c where the sensor is provided and the window portion 43d are configured to face each other. Further, the case 43a is entirely formed by molding with a transparent resin such as a clear resin, so that a transparent window portion can be provided without providing a separate member. Further, in order to prevent unnecessary light such as stray light from entering from other than the window portion 43d, the portion other than the window portion 43 is made of an opaque resin or ceramic, and a transparent glass is formed on the window portion 43. , A transparent resin film or the like may be provided. Further, in the present embodiment, the case 43a is made of a transparent clear resin, the window portion 43 is stepped down from other portions, made thin and transparent, and other portions are provided with embossing or surface roughness. Was made rough and non-transparent. When dust countermeasures are taken by other means, the window portion 43d may be provided with nothing and the sensor portion of the photosensor substrate 43c may be exposed.

  In this embodiment, the substrate 44 is a flexible substrate such as a flexible printed substrate or a multilayer flexible printed substrate. In the case where the shape of the substrate 44 does not need to be particularly variable, a substrate 44 having a certain degree of elasticity or rigidity such as a ceramic substrate, a ceramic multilayer substrate, a glass epoxy substrate, or a multilayer glass epoxy substrate is used. it can.

  The substrate 44 is formed in a substantially L-shape or a substantially T-shape, and the substrate 44 includes a connection portion 44a having an external connection terminal 44b for connection to the outside, and members such as the light receiving element body 43 and the capacitors 45 and 46. The mounting part 44c to be mounted is provided, and the mounting part 44c and the connection part 44a are integrally formed with a substantially vertical or predetermined inclination. In this way, by configuring the mounting portion 44c and the connection portion 44a as one body, it is sufficient that the substrate 44 having a predetermined shape is manufactured, so that the substrate 44 can be easily manufactured and the productivity is improved. In the present embodiment, the substrate 44 is substantially L-shaped or substantially T-shaped, but naturally various shapes can be adopted depending on the specifications.

  In the case of the shape of the present embodiment, for example, the mounting portion 44c and the connecting portion 44a are integrally configured. For example, the mounting portion 44c and the connecting portion 44a are separately configured, and each member is mounted on the mounting portion 44c. The connection portion 44a may be attached to the mounting portion later, or a substrate 44 having a shape such as a disk, a square plate, or a belt is used, and the external connection terminals 44b and the light receiving element body 43 are formed on the substrate 44. May be provided.

  In the present embodiment, the region where the external connection terminal 44b is arranged, that is, the tip of the connection portion 44a is wider than other portions to facilitate connection to other circuits.

  The capacitors 45 and 46 are preferably ceramic capacitors and are used for the purpose of preventing oscillation caused by an operational amplifier or the like provided in the light receiving element body 43. In the present embodiment, the capacitors 45 and 46 are formed of ceramic capacitors, but multilayer ceramic capacitors, tantalum capacitors, electrolytic capacitors, and the like may be used depending on the specifications.

  Next, the optical members 4 and 5 will be described in detail with reference to FIGS.

  The optical member 4 is provided on a base 47 made of transparent optical glass having a substantially rectangular parallelepiped shape, a diffraction grating 48 provided on a surface of the base 47 facing the light source 1 and separating light emitted from the light source 1 into three beams. An opening limiting film 49 is provided on the surface of the substrate 47 opposite to the surface facing the light source 1 (the surface facing the optical member 5).

The opening limiting film 49 is configured to absorb light by laminating, for example, an SiO ₂ film and an Al ₂ O ₃ film alternately a plurality of times, and is provided in a substantially annular shape. In other words, the light that has passed through the region surrounded by the aperture limiting film 49 passes through the emitted light having a desired cross-sectional area. That is, by adjusting the size of the opening at the center of the opening limiting film 49, the cross-sectional area of the light emitted from the light source 1 can be adjusted. In this embodiment, the opening restriction film 49 is provided to restrict the opening. However, a sheet-like opening restriction member or other opaque block may be attached. An opening may be provided. Moreover, you may adjust the magnitude | size of the cross section of the through-hole 3a as an opening restriction part. That is, by adjusting the size of the opening of the through hole 3a on the light source 1 side of the optical member 4, the through hole 3a itself functions as an opening restricting portion, and the optical member 4 or the like is not provided with the opening restricting film 49 or the like separately. May be.

In the present embodiment, the opening shape formed by the opening limiting film 49 is a substantially rectangular shape, but may be a circular shape, a polygonal shape, or an elliptical shape depending on the optical design of the optical pickup. Further, although the base body 47 has a substantially rectangular parallelepiped shape, it may have a cubic shape or a hemispherical shape. The diffraction grating 48 is provided on the surface of the base 47. For the purpose of protecting the diffraction grating 48, a transparent substrate or a transparent film made of the same material as the base 47 is provided on the surface where the diffraction grating 48 is provided. Alternatively, a transparent protective film may be provided.

  The optical member 5 is formed by joining blocks 50, 51, 52, and 53 made of transparent optical glass or optical resin with glass or UV curable resin, and has a substantially rectangular parallelepiped shape as a whole. The optical member 5 includes inclined surfaces 54, 55, and 56 that are substantially parallel to each other. The inclined surface 54 is formed between the blocks 50 and 51, and the inclined surface 54 corresponds to the joint surface of the blocks 50 and 51. The inclined surface 54 is provided with a wavelength selection film, and this wavelength selection film is formed on at least one surface of the blocks 50 and 51. The inclined surface 55 is formed between the blocks 51 and 52, and the inclined surface 55 corresponds to the joint surface of the blocks 51 and 52. The inclined surface 55 is provided with a polarization separation film, and this polarization separation film is formed on at least one of the blocks 51 and 52. The inclined surface 55 is formed between the blocks 52 and 53, and the inclined surface 55 corresponds to the joint surface of the blocks 52 and 53. The inclined surface 55 is provided with a hologram used for servo and the like, and this hologram is formed on at least one surface of the blocks 52 and 53.

  In the present embodiment, the optical member 5 is composed of four blocks. However, depending on optical design specifications, the optical member 5 may be composed of five or more blocks. As a result, the optical member 5 is composed of four or more inclined surfaces. It may be built in.

  In the present embodiment, the optical member 4 can be omitted. That is, when performing at least one of recording / reproduction with one beam, the diffraction grating 48 is unnecessary, and when the aperture limitation is not particularly required, the aperture limiting film 49 is unnecessary. Further, when only the aperture limiting film 49 is necessary, it can be integrally provided on the light incident surface side of the optical member 5 from the light source 1.

An optical path when the optical members 4 and 5 configured as described above are used will be described with reference to FIG. In FIG. 11, since the optical member 5 is separated for explanation, the optical path is somewhat different from the actual one. In the present embodiment, it is assumed that the light source 1 emits light having a wavelength effective for DVD and a wavelength effective for CD. When light having a wavelength capable of realizing at least one of information recording / reproduction is emitted from the light source 1 to the DVD, it passes through the diffraction grating 48 and the aperture limiting film 49 provided in the optical member 4 and is separated into three beams. At the same time, the light beam has a predetermined aperture (A1). After passing through the optical member 4 and entering the optical member 5, light is emitted from the upper surface of the block 52 through the inclined surface 54 having the wavelength selection film and the polarization separation film provided on the inclined surface 55 ( The light passes in the order of A2, A3 and A4). The light paths A1 to A4 of light are substantially linear. The light reflected by the optical disc is linearly incident on the inclined surface 54 in the order of the optical paths A4 and A3, reflected by the wavelength selection film provided on the inclined surface 54, transmitted through the inclined surface 55 by the optical path A5, and the optical path. The light enters the light receiving element 2 at A6.

  When light having a wavelength capable of realizing at least one of information recording / reproduction is emitted from the light source 1 to the CD, the light passes through the diffraction grating 48 and the aperture limiting film 49 provided in the optical member 4 to be separated into three beams. At the same time, the light beam has a predetermined aperture (B1). After passing through the optical member 4 and entering the optical member 5, light is emitted from the upper surface of the block 52 through the inclined surface 54 having the wavelength selection film and the polarization separation film provided on the inclined surface 55 ( Light passes in the order of B2, B3, B4). The light paths B1 to B4 of light are substantially linear. The light reflected by the optical disk is reflected by the polarization separation film when entering the inclined surface 55 in the optical path B4, is incident on the inclined surface 56 by the optical path B5, is further reflected by being incident on the hologram used for servo control, etc. The light travels at B6, is reflected by the inclined surface 55, and enters the light receiving element 2 through the optical path B7.

  An assembly method of the optical pickup configured as described above will be described with reference to the drawings.

  As shown in FIG. 12, an instantaneous adhesive or the like is formed on at least one of the stepped portion in the through hole 3a or the surface of the optical member 4 on which the diffraction grating 48 is provided (the side opposite to the side on which the opening limiting film 49 is provided). Apply glue. The optical member 4 is inserted into the large diameter portion 32, and the optical member and the coupling base 3 are joined so as to close the through hole 3a.

  Next, as shown in FIG. 13, the optical member 5 is placed on the placement portion 28. At this time, the optical member 5 is placed on the protrusions 29, 30, and 31 and is disposed so that the side is sandwiched between the side walls 21 and 22. Further, the optical member 5 is moved in the XY direction shown in FIG. 13 to be positioned in a predetermined manner. As shown in FIG. 14, the adhesives 60 and 61 are disposed between the side walls 21 and 22 and the optical member 5. And the positioned optical member 5 and the coupling base 3 are fixed in a short time. As the adhesives 60 and 61 used at this time, an adhesive containing an ultraviolet curable resin, an adhesive having water absorption, or an instantaneous curing is preferably used. At this time, by providing the wall portions 21a, 21b, 22a, and 22b with height differences on the side walls 21 and 22, the position adjustment of the optical member 5 in the XY direction can be easily realized, and the tapered portions 21d and 22d can be formed. By providing, the adhesives 60 and 61 can be prevented from flowing out to other places, and the adhesives 60 and 61 can be stored between the optical member 65 and the side walls 21 and 22, so that the respective parts can be reliably joined. Moreover, since it can suppress flowing out to another part, the influence on another member can be made small.

  Further, by providing the protrusions 29, 30, and 31, a gap of 0.05 mm to 0.17 mm can be provided between the optical members 4 and 5, and the adhesive can be configured not to intervene in the gap. Therefore, it is possible to prevent the occurrence of light aberration caused by the presence of an adhesive between the optical members 4 and 5, and to improve the optical characteristics.

Next, as shown in FIG. 15, the light source 1 is inserted into the space portion 35 from the bottom side of the coupling base 3, and the side portions 6 b and 6 a are arranged in the gaps 40 and 41. The light receiving element 2 is also brought into contact with the attachment portions 23 and 24 of the side walls 21 and 22, and an ultraviolet curable adhesive is applied to at least one surface of the light receiving element 2 or the attachment portions 23 and 24. Then, the balance adjustment is performed by causing the light source 1 to emit light and moving in the X-axis direction, and the light receiving element 2 is also moved in the Y-axis and Z-axis directions to perform height adjustment and S-shaped adjustment. In this way, by adopting a configuration in which the light source 1 and the light receiving element 2 are moved relative to each other, even if the light source 1 emits light of two different wavelengths at an extremely small interval, it can be surely and accurately performed easily. The light source 1 and the light receiving element 2 can be positioned. For example, productivity can be improved by causing these positions to be adjusted by an automatic machine or the like.

Each member is adjusted to a predetermined position, and in the positional relationship between the light source 1 and the light receiving element 2, the light from the light source 1 is reliably guided to the optical disk, and the light from the optical disk is incident on the light receiving element 2. If it is almost confirmed, this time, an ultraviolet curing adhesive or Ag paste is applied between the light source 1 and the coupling base 3, and the light source 1 is moved along the Z axis shown in FIG. The defocus adjustment of the light used for DVD is performed. When the defocus adjustment is completed, the light source 1 and the coupling base 3 are temporarily fixed by irradiating ultraviolet rays or directly or indirectly applying heat. At this time, the ultraviolet curing adhesive or Ag paste is applied to at least one of the side portions 6a and 6b or the joint portions 41 and 42. In addition, when the position of the light source 1 is adjusted, the light source 1 is observed while being observed through human eyes or image recognition by an automatic machine from the through hole 100. When the light source 1 and the coupling base 3 are temporarily fixed, as shown in FIG. 16, is the viscosity of Ag paste, cream solder, solder foil, etc. relatively high in at least three positions of the protrusions 36, 37, 39 and the plate 6? Alternatively, a bulk material (including powders and granules) is supplied, and the joining material 200 is melted by irradiating a heat gun or a laser beam, so that the light source 1 and the coupling base 3 can be reliably connected. Bonding can be performed. Note that, since the metal bonding material 200 such as solder or Ag paste having relatively good thermal conductivity has a high thermal conductivity, the heat generated by the light source 1 can be effectively released to the coupling base 3. This is effective for heat countermeasures of the light source 1. In addition, when the heat countermeasure of the light source 1 is unnecessary, the ultraviolet-curing adhesive for temporary fixing may be used as the main fixing bonding material 200 , or after the temporary fixing, the bonding material 200 used as the main fixing is used. It is good also as organic adhesives, such as an epoxy resin adhesive, an instant adhesive, and an ultraviolet curing adhesive.

  Next, as shown in FIG. The light receiving element 2 is rotated around the X axis to perform defocus adjustment of light used for, for example, a CD. When the defocus adjustment is completed, the ultraviolet curing adhesive provided between the light receiving element 2 and the coupling base 3 is cured by irradiating ultraviolet rays, and the light receiving element 2 and the coupling base 3 are joined.

  In addition, as shown in FIG. 17, when an ultraviolet curable adhesive is provided between the light receiving element 2 and the coupling base 3, the bonding material 300 may flow between the optical members 4 and 5. Alternatively, when the bonding material 300 in contact with the optical members 4 and 5 (particularly the optical member 5) is cured, the optical members 4 and 5 (particularly the optical member 5) may be moved. In order to solve this problem, by providing the groove 27 and the recessed portion 26, it is possible to prevent the flow of the bonding material 300 toward the optical members 4 and 5 side.

  As described above, in the present embodiment, assuming that the light source 1 that emits a plurality of light beams having different wavelengths is used, the positional relationship with the light receiving element 2 is used with high accuracy and good workability. As it is assembled, productivity is good and yield can be improved.

  Furthermore, since no bonding material is interposed between the optical members 4 and 5 and between the light source 1 and the optical member 4, it is possible to suppress the occurrence of aberrations in the light, and the optical characteristics and the like are improved.

  An optical system configuration using such an optical pick will be described with reference to FIG.

  The light emitted from the light source 1 passes through the optical members 4 and 5, enters the collimating lens 400, is reflected by the BS plate 401 (beam splitter plate), and is guided to the rising prism 403. At this time, a part of the emitted light is transmitted through the BS plate 401, guided to the light receiving sensor 402 that monitors the light amount of the light source 1, and the light emission power of the light source 1 is adjusted by the output of the light receiving sensor 402. The light from the BS plate is reflected by the surface 403 a of the rising prism 403, further reflected by the surface 403 b, is transmitted through the surface 403 a, is incident on the hologram 404 sandwiching the liquid crystal, is guided to the objective lens 405, and is applied to the optical disk 406. Focused. The light reflected by the optical disk 406 is guided to the rising prism 403 via the objective lens 405 and the hologram, passes through the surface 403a, is reflected by the surface 403b, is then reflected by the surface 403a, and is guided to the BS plate 401. The light is reflected by the plate 401, passes through the collimator lens 400, enters the optical member 5, and reaches the light receiving element 2.

  FIG. 19 is a diagram showing an optical disc device using an optical pickup according to an embodiment of the present invention. In FIG. 19, reference numeral 500 denotes a casing, and casing 500 is a combination of upper casing portion 500a and lower casing portion 500b. Configured. The upper housing part 500a and the lower housing part 500b are fixed to each other using a spiral or the like. Reference numeral 501 denotes a tray that can be freely moved in and out of the housing, 502 is a spindle motor provided in the tray 501, 503 is an optical pick, and the optical pick 503 uses the optical pickup shown in FIGS. At least one of an operation of writing information or reading information is performed. The optical pick 503 is mounted on a carriage (not shown) held so as to be movable in the radial direction of the optical disc. Reference numeral 504 denotes a bezel provided on the front end surface of the tray 501, and the bezel 504 is configured to close the entrance / exit 505 of the tray 501 when the tray 501 is stored in the housing 500. Reference numerals 506 and 507 are rails slidably attached to both the tray 501 and the casing 500, respectively. The rails 506 and 507 are provided on both sides of the tray 501, and the rails 506 and 507 are shown in FIG. A tray 501 is attached from the housing 500 in the direction indicated by the arrow P.

  A bezel 504 provided on the front end surface of the tray 501 is provided with an eject button 508. By pressing the eject switch 508, an engagement portion (not shown) provided in the housing 500 and the tray 501 are provided. The engagement with the provided engaging portion (not shown) is released.

  The optical pickup and the optical disk apparatus of the present invention can improve productivity and workability even when a frame laser light source is used, and particularly preferably a two-wavelength semiconductor laser light source is used. At least one of the improvements can be realized and can be applied to electronic devices such as personal computers, notebook computers, and mobile terminal devices.

The perspective view which shows the optical pick-up in one embodiment of this invention 1 is an exploded perspective view showing an optical pickup according to an embodiment of the present invention. The perspective view which shows the light source of the optical pick-up in one embodiment of this invention The perspective view which shows the light source of the optical pick-up in one embodiment of this invention The perspective view which shows the coupling | bonding base of the optical pick-up in one embodiment of this invention The perspective view which shows the coupling | bonding base of the optical pick-up in one embodiment of this invention The perspective view which shows the light receiving element of the optical pick-up in one embodiment of this invention The perspective view which shows the light receiving element of the optical pick-up in one embodiment of this invention The perspective view which shows the optical member of the optical pick-up in one embodiment of this invention The perspective view which shows the optical member of the optical pick-up in one embodiment of this invention The figure which shows the optical member of the optical pick-up in one embodiment of this invention The figure which shows the assembly method of the optical pick-up in one embodiment of this invention The figure which shows the assembly method of the optical pick-up in one embodiment of this invention The figure which shows the assembly method of the optical pick-up in one embodiment of this invention The figure which shows the assembly method of the optical pick-up in one embodiment of this invention The figure which shows the assembly method of the optical pick-up in one embodiment of this invention The figure which shows the assembly method of the optical pick-up in one embodiment of this invention The figure which shows the example of the optical design of the optical pick-up in one embodiment of this invention The figure which shows the optical disk apparatus using the optical pick-up in one embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Light receiving element 3 Coupling base 3a Through-hole 4,5 Optical member 6 Plate 6a, 6b Side part 13,14,15 Terminal part 21,22 Side wall 28 Mounting part 29,30,31 Projection 32 Large diameter part 33 Small diameter part 48 Diffraction grating 49 Aperture limiting film 503 Optical pick 502 Spindle motor

Claims (3)

A light source in which a plate and a plurality of terminal portions are fixed to each other with a molding member and a semiconductor laser element is provided on the plate; a light receiving element; A first optical member, a second optical member that emits the light from the first optical member to the outside, reflects the light from the outside inside, and emits the light to the light receiving element, and the light source And a coupling base having a mounting portion for mounting the first and second optical members, and a pair of mounting portions for mounting the light receiving element. A pair of joint portions in which both side portions of the plate are disposed are provided, and the placement portion is connected to the space portion so as to block the small diameter portion and the small diameter portion that allow light from the light source to pass therethrough. Storing the first optical member A through hole provided with a diameter portion, and placing the second optical member on a peripheral portion of an opening portion of the large diameter portion of the through hole, thereby placing the second optical member between the light source and the first optical member. And a predetermined gap in which a bonding material is not interposed between the first optical member and the second optical member. 2. The optical pickup according to claim 1, wherein a plurality of protrusions are provided on the peripheral edge , and the second optical member is provided on the plurality of protrusions. An optical pickup according to any one of claims 1 to 2, a rotation driving unit that rotates a medium, and a moving unit that moves the optical pickup closer to or away from the rotation driving unit. An optical disk device.

Images