JP2008034063A - Fixing structure of optical element and optical head device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bonded structure of optical elements which excels in ability of absorbing a shock or deformation of a fixed member and can bond the optical elements on the fixing member in a state excellent also in swelling-proof property, and an optical head device thereof. <P>SOLUTION: In a bonding area of a polarizing prism 52 to a device flame 2 of the optical head device, a first adhesion bond 31 is located in an inside area and a second adhesion bond 32 is located in an outer side area. After hardening, even if the optical head device 1 is shocked, the first adhesion bond 31 absorbs the shock by just that much of low hardness. After hardening, the first adhesion bond 31 is easy to absorb moisture and low in the swelling-proof property. However, since entire periphery is surrounded by the second adhesion bond 32 of high swelling-proof property and isolated from the outside, the first adhesion bond 31 does not absorb the moisture after hardening. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical element fixing structure in which an optical element is fixed to a member to be fixed with an adhesive, and an optical head device using the fixing structure.

  In an optical head device used for reproduction and recording of an optical recording disk (optical recording medium) such as a CD or a DVD, light emitted from a light emitting element is guided to the optical recording medium, and return light reflected by the optical recording medium is received. An optical system leading to the element is mounted on the apparatus frame. Adhesive fixing is frequently used for fixing optical elements to the apparatus frame (see Patent Document 1).

When such an adhesive fixing method is adopted, after applying an adhesive to the apparatus frame, the optical element is mounted, and then the optical element is pressed down so that the optical element is in close contact with the apparatus frame and bonded. After the agent is made into a thin layer, the adhesive is solidified.
JP-A-5-250709

  In the optical head device, a sufficient impact resistance is required for the bonded portion of the optical element to the device frame. However, such a requirement has been increasing more and more in recent years. Also, in the optical head device, the device frame has been made thinner for the purpose of reducing the size and weight, and the device frame is easily deformed. It is also required that the deformation of the apparatus frame can be absorbed so that the optical axis of the optical element does not shift.

  In order to satisfy such mechanical properties, an adhesive having low hardness may be used. However, such an adhesive generally has a high water absorption rate, and tends to swell and accumulate moisture in a high humidity environment. There is. As a result, there is a problem that the adhesive expands and the optical axis of the optical element is shifted. In addition, when a metal device frame is used, there is a problem that the device frame rusts due to moisture accumulated in the adhesive, resulting in a decrease in adhesive strength and an optical axis shift of the optical element. .

  In view of the above problems, an object of the present invention is to bond an optical element to a member to be fixed in a state excellent in ability to absorb impact and deformation of the member to be fixed, and excellent in swelling resistance to water. It is an object of the present invention to provide an optical element bonding structure and an optical head device.

  In order to solve the above-described problems, the present invention provides an optical element fixing structure in which an optical element is bonded to a fixed member, and the inner region of the bonded portion between the fixed member and the optical element is not 1 is used, and a second adhesive is used outside the bonded portion. The first adhesive has higher impact resistance than the second adhesive, and the first adhesive The adhesive of No. 2 is characterized by having higher resistance to water swelling than the first adhesive.

  In the present invention, the first adhesive has higher impact resistance than the second adhesive, for example, because the hardness is lower than that of the second adhesive.

  In the present invention, a first adhesive having a high impact resistance, for example, a first adhesive having a low hardness is used for the inner region of the bonded portion between the fixed member and the optical element. The second adhesive having a high resistance to swelling with respect to water is used on the outside. For this reason, even when the first adhesive is excellent in the ability to absorb impact and deformation of the member to be fixed, the second adhesive excellent in the swelling resistance is the first even if the first adhesive is inferior in the swelling resistance to water. Protects the adhesive from moisture. Therefore, even when one adhesive is not excellent in both the ability to absorb impact and deformation of the member to be fixed and the swelling resistance, it has excellent ability to absorb impact and deformation of the member to be fixed, and water. The optical element can be bonded to the fixed member in a state excellent in swelling resistance against the fixed member.

  In the present invention, it is preferable that the second adhesive continuously covers the entire circumference of the bonded portion, and the first adhesive is isolated from the outside. If comprised in this way, generation | occurrence | production of the malfunction resulting from a 1st adhesive agent absorbing water can be prevented reliably.

  In the present invention, the first adhesive and the second adhesive preferably have different viscosities before solidification. With this configuration, mixing of the first adhesive and the second adhesive occurs at the boundary between the inner region to which the first adhesive is applied and the outer region to which the second adhesive is applied. It is difficult to prevent the mixing from affecting the curing.

  In the present invention, it is preferable that the optical element has ultraviolet (UV) transparency, and both the first adhesive and the second adhesive have ultraviolet curable properties. If comprised in this way, even when the 1st adhesive agent is apply | coated inside, UV can be irradiated to a 1st adhesive agent via an optical element, and a 1st adhesive agent can be hardened reliably.

  In the present invention, a groove may be formed in the fixed member along a boundary between an inner region where the first adhesive is applied and an outer region where the second adhesive is applied. preferable. If comprised in this way, mixing of a 1st adhesive agent and a 2nd adhesive agent will be in a groove | channel in the boundary of the inner side area | region where the 1st adhesive agent was apply | coated, and the outer area | region where the 2nd adhesive agent was apply | coated. Thus, the first adhesive application region and the second adhesive application region can be appropriately secured with respect to the outside of the groove.

  The optical element fixing structure to which the present invention is applied is applied to, for example, an optical head device. In this case, the fixed member includes a light emitting element, a light receiving element, and an optical system that guides the light emitted from the light emitting element to the optical recording medium and guides the return light reflected by the optical recording medium to the light receiving element. The optical system includes the optical element.

  In the present invention, even when the first adhesive is excellent in the ability to absorb impact and deformation of the fixed member, the second adhesive having excellent swelling resistance is used even when the first adhesive is inferior in swelling resistance. Protect the adhesive from moisture. Therefore, even when one adhesive is not excellent in both the ability to absorb impact and deformation of the member to be fixed and the swelling resistance, it has excellent ability to absorb impact and deformation of the member to be fixed. The optical element can be bonded to the fixed member in a state excellent in swelling property. Therefore, even when an impact is applied or the member to be fixed is deformed, the optical element can be prevented from falling off the member to be fixed. In addition, since it is possible to prevent the expansion of the adhesive and the deterioration of the surface of the fixed member due to the moisture absorption of the adhesive, it is possible to prevent the deviation of the optical axis due to the displacement of the optical element and the dropping of the optical element. it can.

  An optical head device to which the present invention is applied will be described below with reference to the drawings.

[Embodiment 1]
(overall structure)
FIG. 1 is a perspective view of an optical head device to which the present invention is applied as viewed from the side from which light is emitted from an objective lens. FIG. 2 is an exploded perspective view of the optical head device shown in FIG. FIG. 3 is a perspective view of the optical head device shown in FIG. 1 with the main body cover and the objective lens driving mechanism removed.

  The optical head device 1 of this embodiment shown in FIGS. 1 to 3 reproduces and / or records information on an optical recording medium such as a CD and a DVD. The optical head device 1 has a metal device frame 2 made of a die-cast product such as magnesium or zinc, and a guide shaft and a feed screw shaft of a disk drive device are engaged with each of both ends of the device frame 2. A first bearing 21 and a second bearing 22 are formed. One side surface of the device frame 2 is curved in an arc shape to prevent interference when approaching a spindle motor (not shown) of the disk drive mechanism.

  On the upper surface side of the apparatus frame 2, the objective lens 91 is located substantially at the center. A metal body cover 80 (metal cover) is covered on the side where the first bearing 21 is located with respect to the objective lens 91. The body cover 80 is engaged with an upper plate portion 81 that covers the upper surface of the device frame 2 and a protrusion 28 that is bent downward from one side edge of the upper plate portion 81 and formed on the side surface of the device frame 2. The positioning projection 29 protruding upward from the device frame 2 is fitted into the small hole 83 formed in the upper surface portion.

  The optical head device 1 according to the present embodiment can record and reproduce information with respect to a DVD disk and a CD disk by using a first laser beam having a wavelength of 650 nm and a second laser beam having a wavelength of 780 nm. The first laser light source device 41 is a two-wavelength optical head device and includes an AlGaInP-based semiconductor laser (laser diode / laser light source) that emits a first laser beam having a wavelength of 650 nm on the device frame 2. And a second laser light source device 42 including an AlGaAs semiconductor laser (laser diode / laser light source) that emits a second laser beam having a wavelength of 780 nm. Here, the first laser light and the second laser light are DVDs that are optical recording disks via an optical system including a plurality of optical elements arranged in an optical path from the laser light source devices 41 and 42 toward the optical recording disk. An optical element guided to a system disk or CD system disk and constituting this optical system is also mounted on the apparatus frame 2. The return light from the optical recording disk is also guided to the common signal detection light receiving element 50 via the optical system, and the optical element that defines the optical path for the return light and the signal detection light receiving element 50 are also included in the apparatus frame 2. It is mounted on.

  In the optical head device 1 of the present embodiment, the optical system combines an optical path that transmits the laser light emitted from the first laser light source device 41 and reflects the laser light emitted from the second laser light source device 42. Polarizing prism 52, a half mirror 53 that partially reflects the laser light emitted from the polarizing prism 52, a quarter wavelength plate 55 for the laser light reflected by the half mirror 53, and this quarter wavelength plate A collimating lens 56 for converting the laser light transmitted through 55 into parallel light, a rising mirror 57 for raising the parallel light toward the optical recording disk, and a recording surface of the optical recording disk for the laser light from the rising mirror 57 And an objective lens 91 for converging. Further, in the optical system, the return light reflected by the recording surface of the optical recording disk is guided to the signal detecting light receiving element 50 through the rising mirror 57, the collimating lens 56, the quarter wavelength plate 55, and the half mirror 53. A sensor lens (not shown) is also included for providing astigmatism when being applied. A light receiving element 51 for monitoring is disposed behind the half mirror 53 when viewed from the polarizing prism 52. Note that a diffraction element 54 in which a half-wave plate is integrally formed is disposed between the first laser light source device 41 and the polarizing prism 52, and the second laser light source device 42 and the polarizing prism 52 Between them, a diffraction element 58 and a relay lens (not shown) are arranged.

  The objective lens 91 is servo-controlled for the position in the tracking direction and the focusing direction by the objective lens driving mechanism 9, and such an objective lens driving mechanism 9 is also mounted on the apparatus frame 2. In this embodiment, a wire suspension type is used as the objective lens driving mechanism 9, and a known one can be used as the objective lens driving mechanism 9. A lens holder 92 to be held, a holder support portion 94 that supports the lens holder 92 by a plurality of wires 93 so as to be movable in the tracking direction and the focusing direction, and a yoke 95 fixed to the apparatus frame 2 are provided. Yes. The objective lens driving mechanism 9 includes a driving coil (not shown) attached to the lens holder 92 and a magnetic driving circuit composed of a driving magnet 98 attached to the yoke 95, and energizes the driving coil. By controlling the objective lens 91 held by the lens holder 92 in the tracking direction and the focusing direction with respect to the optical recording disk. Note that the objective lens driving mechanism 9 can also perform tilt control for adjusting the tilt of the objective lens 91 in the jitter direction. The objective lens 91 is covered with an actuator cover 85 made of a metal rectangular frame. In addition, the flexible wiring board 70 is disposed on the upper surface of the apparatus frame 2, and the upper surface of the flexible wiring board 70 is covered with the main body cover 80.

(Fixing structure of polarizing prism to device frame)
When manufacturing the optical head device 1 described with reference to FIGS. 1 to 3, an adhesive fixing method is frequently used to fix each component to the device frame 2. The fixing structure will be described with reference to FIG.

  4A, 4B, and 4C are a perspective view, a plan view, and a side view schematically showing a state in which the polarizing prism 52 is fixed to the apparatus frame 2 in the optical head apparatus 1 of the present embodiment. It is. 4D, 4E, and 4F are a perspective view and a plan view showing a state after an adhesive is applied when the polarizing prism 52 is bonded and fixed to the apparatus frame 2 in the optical head apparatus 1 of the present embodiment. It is a figure and a side view.

  As shown in FIGS. 4A to 4F, in the optical head device 1 of the present embodiment, the location where the polarizing prism 52 is mounted in the device frame 2 is, for example, two partition walls 26 from the bottom 20 of the device frame 2. , 27 intersect with each other, and windows 260, 270 are formed in the partition walls 26, 27 to transmit the laser light emitted from the laser light source device described with reference to FIGS. . On the bottom portion 20 of the apparatus frame 2, a portion where the polarizing prism 52 is mounted is a step portion 23 that is one step higher than the surroundings, and on the step portion 23, a seat portion 24 on which the polarizing prism 52 is placed. Is formed. The upper surface of the seat portion 24 is finished so that the polarizing prism 52 can be placed in an appropriate posture, so that the upper surface of the seat portion 24 is smoother than other regions of the bottom portion 20. It is finished.

  The fixing structure of the polarizing prism 52 will be described while explaining the process of fixing the polarizing prism 52 to the seat portion 24 with an adhesive. First, as shown in FIGS. 4D to 4F, after the first adhesive 31 is applied to the inner region of the upper surface of the seat 24, the first adhesive 31 is applied to the outer region of the seat 24. 2 adhesive 32 is applied in a frame shape. Alternatively, after the second adhesive 32 is applied in a frame shape to the outer region on the upper surface of the seat portion 24, the first adhesive 31 is applied to the inner region of the seat portion 24. In any case, the second adhesive 32 continuously surrounds the entire circumference of the application region of the first adhesive 31.

  Here, the first adhesive 31 is made of, for example, an acrylic resin or a modified acrylic resin, and the viscosity thereof is, for example, 7000 mPa · s. The second adhesive 32 is made of, for example, an epoxy resin, and has a viscosity of, for example, 400 mPa · s. The viscosity of the second adhesive 32 is 10 times or more different from that of the first adhesive 31. The first adhesive 31 is lower in hardness and lower in swelling resistance than the second adhesive 32 after being cured, while the second adhesive 32 is the first adhesive after being cured. Compared to 31, the hardness is high and the swelling resistance is high. The first adhesive 31 is an anaerobic imparting type UV curable adhesive, and the second adhesive 32 is a UV curable adhesive. Further, the polarizing prism 52 has UV transparency.

  After applying the first adhesive 31 and the second adhesive 32 as shown in FIGS. 4D to 4F, as shown in FIGS. The polarizing prism 52 is overlaid and the polarizing prism 52 is pressed to make the first adhesive 31 and the second adhesive 32 into a thin layer.

  Next, UV is irradiated onto the first adhesive 31 and the second adhesive 32 from above the polarizing prism 52 by a UV lamp, and the first adhesive 31 and the second adhesive 32 are simultaneously cured. As a result, the first adhesive 31 is located in the inner region of the adhesion portion between the seat portion 24 and the polarizing prism 52, and the second adhesive 32 is located outside the adhesion portion. The second adhesive 32 continuously covers the entire circumference of the bonded portion, and the first adhesive 31 is isolated from the outside.

(Main effects of this form)
In the optical head device 1 configured as described above, the first adhesive 31 used for the bonding portion of the polarizing prism 52 has a low hardness after curing. Therefore, even if an impact is applied to the optical head device 1, such an impact is applied. Absorb. Even when the apparatus frame 2 is thinned to make the optical head apparatus 1 thinner, the first adhesive 31 has a low hardness after curing. Absorbs deformation. Therefore, the polarizing prism 52 is not detached from the device frame 2 even when an impact is applied or when the device frame 2 is deformed.

  Here, the first adhesive 31 tends to absorb moisture after curing and tends to have low swelling resistance to water. However, the first adhesive 31 is a second adhesive 32 having high swelling resistance to moisture. The whole circumference is surrounded by and is isolated from the outside. For this reason, the first adhesive 31 does not absorb moisture after curing. Therefore, the first adhesive 31 does not expand due to moisture absorption, and changes such as rusting of the device frame 2 due to moisture absorbed by the first adhesive 31 do not occur. In addition, since the second adhesive 31 has high resistance to swelling after being cured, the second adhesive 32 does not absorb moisture even when the second adhesive 32 is in contact with the atmosphere. . Therefore, it is possible to prevent an optical axis shift caused by the displacement of the polarizing prism 52 and a decrease in the adhesive strength of the polarizing prism 52.

  Moreover, if the ratio of the area where the first adhesive 31 is applied and the area where the second adhesive 32 is applied is optimized, both impact resistance and swelling resistance can be suitably obtained.

  In this embodiment, the polarizing prism 52 has UV transparency, and the first adhesive 31 and the second adhesive 32 have UV curable properties. Therefore, as shown in FIGS. 4A to 4C, even when the first adhesive 31 is completely surrounded by the second adhesive 32, the first adhesion is performed via the polarizing prism 52. Since both the agent 31 and the second adhesive 32 can be irradiated with UV, the first adhesive 31 and the second adhesive 32 can be cured.

  Furthermore, since the first adhesive 31 and the second adhesive 32 are greatly different in viscosity, when the polarizing prism 52 is pressed and the first adhesive 31 and the second adhesive 32 are made into thin layers, Following the thin deployment of the first adhesive 31, the second adhesive 32 spreads outward. Therefore, the first adhesive 31 and the second adhesive 32 are mixed in the boundary region between the inner region where the first adhesive 31 is applied and the outer region where the second adhesive 32 is applied. It can be minimized. Therefore, when selecting the first adhesive 31 and the second adhesive 32, it is not necessary to consider the influence of the mixing on the curing.

[Embodiment 2]
5A, 5B, and 5C are perspective views schematically showing a state in which the polarization prism 52 is fixed to the device frame 2 in the optical head device 1 according to Embodiment 2 of the present invention. It is a top view and a side view. 5D, 5E, and 5F, the first adhesive 31 is applied when the polarizing prism 52 is bonded and fixed to the apparatus frame 2 in the optical head apparatus 1 according to Embodiment 2 of the present invention. It is the perspective view, top view, and side view which show the mode after having done. Since the basic configuration of the present embodiment and the third embodiment to be described later is the same as that of the first embodiment, portions having common functions are denoted by the same reference numerals, and the description thereof will be given. Omitted.

  As shown in FIGS. 5A to 5F, also in the optical head device of this embodiment, a seat portion 24 on which the polarizing prism 52 is placed is formed on the device frame 2 as in the first embodiment. . In fixing the polarizing prism 52 to the seat portion 24 with an adhesive, in this embodiment, first, as shown in FIGS. 5D to 5F, the first adhesive is applied to the entire upper surface of the seat portion 24. After applying 31, as shown in FIGS. 5A to 5C, the polarizing prism 52 is overlaid on the seat portion 24, and the polarizing prism 52 is pressed to make the first adhesive 31 a thin layer. . Then, the first adhesive 31 is irradiated with UV through the polarizing prism 52 to cure the first adhesive 31.

  Next, after the second adhesive 32 is applied in the form of a fillet around the bonding portion of the polarizing prism 52 by the first adhesive 31 (the overlapping portion of the polarizing prism 52 and the seat portion 24), the polarizing prism 52 is then applied. Via, or directly, the second adhesive 32 is irradiated with UV to cure the second adhesive 32.

  Also in this embodiment, the first adhesive 31 has a lower hardness and lower swelling resistance than the second adhesive 32 after curing, while the second adhesive 32 has a first strength after curing. Compared with the adhesive 31, the hardness is high and the swelling resistance is high.

  Even when the polarizing prism 52 is bonded and fixed to the seat portion 24 in this way, the first adhesive 31 is located in the inner area of the bonded portion, and the second adhesive 32 is positioned outside the bonded portion. To do. The second adhesive 32 continuously covers the entire circumference of the bonded portion, and the first adhesive 31 is isolated from the outside. Accordingly, in the optical head device 1, the first adhesive 31 used for the bonding portion of the polarizing prism 52 has a low hardness after curing. Therefore, when an impact is applied to the optical head device 1 or the device frame 2 is deformed. Even in such a case, the shock and deformation are absorbed, so that the polarizing prism 52 is not detached from the apparatus frame 2. The first adhesive 31 is surrounded by the second adhesive 32 having high swelling resistance and is isolated from the outside. Therefore, the first adhesive 31 absorbs moisture after being cured. There is no. Therefore, it is possible to prevent the occurrence of problems caused by the first adhesive 31 absorbing moisture.

  Further, in this embodiment, since the first adhesive 31 is cured and then the second adhesive 32 is applied and cured, the mixing of the first adhesive 31 and the second adhesive 32 is cured. Even in the case of causing trouble, the first adhesive 31 and the second adhesive 32 can be reliably cured.

[Embodiment 3]
6A, 6B, and 6C are perspective views schematically showing a state in which the polarization prism 52 is fixed to the device frame 2 in the optical head device 1 according to Embodiment 3 of the present invention. It is a top view and a side view. 6D, 6E, and 6F, adhesives 31 and 32 are applied when the polarizing prism 52 is bonded and fixed to the apparatus frame 2 in the optical head apparatus 1 according to Embodiment 3 of the present invention. It is the perspective view which shows the state after, a top view, and a side view.

  As shown in FIGS. 6A to 6F, also in the optical head device of the present embodiment, a seat portion 24 on which the polarizing prism 52 is placed is formed on the device frame 2 as in the first embodiment. . In this embodiment, a groove 240 is formed in a frame shape between the inner region and the outer region on the upper surface of the seat portion 24.

  In fixing the polarizing prism 52 to the seat portion 24 with an adhesive, in this embodiment, first, as shown in FIGS. 6D to 6F, the upper surface of the seat portion 24 is surrounded by the groove 240. After the first adhesive 31 is applied to the inner region, the second adhesive 32 is applied in a frame shape to the outer region of the groove 240 of the seat portion 24. Alternatively, after the second adhesive 32 is applied in a frame shape to the outer region of the groove 240 on the upper surface of the seat portion 24, the first adhesive 31 is applied to the inner region of the groove 240 of the seat portion 24. To do. In any case, the second adhesive 32 continuously surrounds the entire circumference of the application region of the first adhesive 31.

  Here, the first adhesive 31 is made of, for example, an acrylic resin or a modified acrylic resin, and the viscosity thereof is, for example, 7000 mPa · s. The second adhesive 32 is made of, for example, an epoxy resin, and has a viscosity of, for example, 400 mPa · s. The viscosity of the second adhesive 32 is 10 times or more different from that of the first adhesive 31. The first adhesive 31 is lower in hardness and lower in swelling resistance than the second adhesive 32 after being cured, while the second adhesive 32 is the first adhesive after being cured. Compared to 31, the hardness is high and the swelling resistance is high. The first adhesive 31 is an anaerobic imparting type UV curable adhesive, and the second adhesive 32 is a UV curable adhesive.

  After applying the first adhesive 31 and the second adhesive 32 in such a form, as shown in FIGS. 6A to 6C, the polarizing prism 52 is overlaid on the seat portion 24, and The polarizing prism 52 is pressed to make the first adhesive 31 and the second adhesive 32 into a thin layer.

  Next, the first adhesive 31 and the second adhesive 32 are irradiated with UV through the polarizing prism 52, and the first adhesive 31 and the second adhesive 32 are simultaneously cured. As a result, the first adhesive 31 is located in the inner region of the adhesion portion between the seat portion 24 and the polarizing prism 52, and the second adhesive 32 is located outside the adhesion portion. The second adhesive 32 continuously covers the entire circumference of the bonded portion, and the first adhesive 31 is isolated from the outside.

  In the optical head device 1 configured as described above, the first adhesive 31 used for the bonding portion of the polarizing prism 52 has a low hardness after curing, so that when the impact is applied to the optical head device 1 or the device frame Even when 2 is deformed, the shock and deformation are absorbed, so that the polarizing prism 52 is not detached from the apparatus frame 2. Further, the first adhesive 31 is surrounded by the second adhesive 32 having high swelling resistance and is isolated from the outside, so that the first adhesive 31 absorbs moisture. Can be prevented.

  Further, in this embodiment, the seat portion 24 is formed with a groove 240 along a boundary region between the inner region where the first adhesive 31 is applied and the outer region where the second adhesive 32 is applied. . For this reason, when the polarizing prism 52 is disposed on the seat portion 24 after the first adhesive 31 and the second adhesive 32 are applied, the mixing of the first adhesive 31 and the second adhesive 32 is performed. This mainly occurs inside the groove 240. Therefore, even when mixing of the first adhesive 31 and the second adhesive 32 interferes with the curing, the outer sides of the grooves 240 for each of the first adhesive 31 and the second adhesive 32. Therefore, the polarizing prism 52 can be adhered and fixed to the seat portion 24 with the first adhesive 31 and the periphery thereof can be covered with the second adhesive 32. In addition, in this embodiment, even when the influence of the mixing of the first adhesive 31 and the second adhesive 32 is suppressed, the first adhesive 31 and the second adhesive 31 are arranged before the polarizing prism 52 is disposed on the seat portion 24. The adhesive 32 can be applied. Therefore, even when the polarizing prism 52 is disposed on the seat portion 24 and there is no gap around which the nozzle for applying the adhesive can be inserted, the first adhesive 31 and the second adhesive are bonded. There exists an advantage that the influence by mixing with the agent 32 can be excluded.

(Other embodiments)
In the above embodiment, the example in which the present invention is applied to fixing the polarizing prism 52 in the optical system used in the optical head device 1 has been described. However, the present invention is applied to a case where other optical elements are fixed to the device frame 2. May be. Further, the present invention is not limited to the optical head device 1 and may be applied to fix an optical element to a fixed member in various optical devices and the like. Further, in the above embodiment, an anaerobic imparting UV curable adhesive is used for the first adhesive 31, a UV curable adhesive is used for the second adhesive 32, and UV curing is mainly used as both adhesives. However, an adhesive mainly having anaerobic properties may be used. In addition to UV curing, a thermosetting adhesive that cures by heating may be used.

It is the perspective view which looked at the optical head device to which the present invention is applied from the side from which light is emitted from an objective lens. It is a disassembled perspective view of the optical head apparatus shown in FIG. FIG. 2 is a perspective view of a state where a main body cover and an objective lens driving mechanism are removed from the optical head device shown in FIG. 1. It is explanatory drawing which shows the state which adhered and fixed the polarization prism to the apparatus frame in the optical head apparatus which concerns on Embodiment 1 of this invention, and its method. It is explanatory drawing which shows the state which adhered and fixed the polarization prism to the apparatus frame in the optical head apparatus which concerns on Embodiment 2 of this invention, and its method. It is explanatory drawing which shows the state which adhered and fixed the polarizing prism to the apparatus frame in the optical head apparatus which concerns on Embodiment 3 of this invention, and its method.

Explanation of symbols

1 optical head device 2 device frame (fixed member)
6 Driving IC
24 Seat 31 for Polarizing Prism First Adhesive 32 Second Adhesive 41 First Laser Light Source Device 42 Second Laser Light Source Device 52 Polarizing Prism 240 Groove

Claims (7)

An optical element fixing structure in which the optical element is bonded to a fixed member,
The first adhesive is used in the inner region of the bonded portion between the fixed member and the optical element, and the second adhesive is used outside the bonded portion,
The first adhesive has higher impact resistance than the second adhesive,
The structure for fixing an optical element, wherein the second adhesive has a higher resistance to swelling than water as compared with the first adhesive. In claim 1,
The structure for fixing an optical element, wherein the first adhesive has a lower hardness than the second adhesive. In claim 1 or 2,
The structure for fixing an optical element, wherein the second adhesive continuously covers the entire circumference of the bonded portion, and the first adhesive is isolated from the outside. In any of claims 1 to 3,
The structure for fixing an optical element, wherein the first adhesive and the second adhesive have different viscosities before solidification. In any of claims 1 to 4,
The optical element has ultraviolet transparency,
The first adhesive and the second adhesive are both UV curable and have an optical element fixing structure. In any of claims 1 to 5,
The fixed member has a groove formed along a boundary between an inner region to which the first adhesive is applied and an outer region to which the second adhesive is applied. Element fixing structure. An optical head device comprising the optical element fixing structure according to any one of claims 1 to 6,
The fixed member includes a light emitting element, a light receiving element, and an optical system that guides light emitted from the light emitting element to the optical recording medium and guides return light reflected by the optical recording medium to the light receiving element. Device frame,
An optical head device comprising the optical element in the optical system.

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