JP4470046B2 - Optical pickup - Google Patents

Description

  The present invention relates to an optical pickup, and more particularly to an optical pickup in which an optical element interposed in an optical path of an optical system is fixed and held on a base body using an adhesive after temporary fixing.

  An optical pickup is incorporated in a DVD device or the like and used for optically scanning a recording surface of a disk as a recording medium. In this type of optical pickup, an optical system is mounted on a base body that is driven to run in the radial direction of the disk. FIG. 6 is an explanatory diagram of this optical system. In FIG. 6, 1 is a light emitting diode (light emitting element) which is an optical element as a light source, 2 is a diffraction grating, 3 is a half mirror, 4 is a collimator lens, 5 is an objective lens, 6 is a light receiving element, and 7 is light intensity detection. A sensor is shown, and among these optical elements, a light emitting diode 1, a diffraction grating 2, a half mirror 3, a collimator lens 4 and a light receiving element 6 are fixed at fixed positions of the base body 10, whereas The displacement of the lens 5 is controlled in the focus direction and the tracking direction with respect to the disk D.

  In this optical system, the projection light from the light emitting element 1 is irradiated on the recording surface of the disk D as a recording medium via the diffraction grating 2, the half mirror 3, the collimator lens 4 and the objective lens 5, and the reflected light is reflected on the collimator. The light is guided to the light receiving element 6 through the lens 4 and the half mirror 3. Further, the light intensity detection sensor 7 is constituted by a light receiving element as an optical element, and when the light projected from the light emitting diode 1 is detected by the light intensity detection sensor 7, the detection signal is not illustrated. The intensity of the projection light from the light emitting diode 1 is appropriately feedback controlled by an output signal from the control circuit.

  In the conventional optical pickup, the light intensity detection sensor 7 is fixed to the base body 10 with the structure shown in FIG. That is, FIG. 7 is a plan view showing a structure of a portion where the light intensity detection sensor 7 is attached to the base body 10. In FIG. 7, reference numeral 50 denotes a flexible wiring board (FPC). In this flexible wiring board 50, a routing area 51 and an element mounting area 52 are continuously formed and are reinforced by a reinforcing plate 53. The light intensity detection sensor 7 is mounted on the attachment region 52 in an overlapping manner. Moreover, the base body 10 of the same figure is provided with the opening 11, and the attachment part 15 which has the recess 14 in the one side part 12 among the pair of side parts 12 and 13 which the opening 11 opposes is formed. Then, in a state where the light intensity detection sensor 7 is fitted in the recess 14 of the mounting portion 15, the element mounting region 52 of the flexible wiring board 50 is bonded and fixed to the mounting portion 15 with an adhesive (not shown). Yes.

  In such a conventional optical pickup, in the step of attaching the light intensity detection sensor 7 to the attachment part 15 of the base 10, the intermediate part A of the routing area 51 of the flexible wiring board 50 is bent as shown in the figure. 52 is fitted into the opening 11 of the base 10, the light intensity detection sensor 7 mounted in the element mounting region 52 fitted into the opening 11 is fitted into the recess 14 of the mounting portion 15, and the mounting portion 15 is recessed. The light intensity detection sensor 7 fitted in the place 14 is held in a temporarily fixed state so that it does not jump out of the recess 14 by the restoring force of the bent portion of the flexible wiring board 50, and the element attachment region 52 is attached to the attachment portion. 15 is bonded and fixed with an adhesive.

  On the other hand, in an optical pickup device configured to transmit a control signal via a flexible wiring board, the flexible wiring board is bent in the width direction in order to increase the bending rigidity of the flexible wiring board, and the curved portion A technique for fixing the frame to the seating surface of the fixed frame is conventionally known (see, for example, Patent Document 1).

Utility Model Registration No. 3089877

  In the conventional optical pickup described with reference to FIG. 7, as described above, the light intensity detection sensor 7 fitted in the recess 14 of the attachment portion 15 of the base body 10 in the attachment process of the light intensity detection sensor 7. Is temporarily pressed so that the light intensity detection sensor 7 does not jump out of the recess 14 due to the restoring force of the bent portion of the intermediate portion A of the flexible wiring board 50. There is a problem that the process from such temporary fixing to bonding and fixing the element mounting region 52 of the flexible wiring board 50 to the mounting portion 15 with an adhesive is complicated and requires skill. In addition to this, even after the attachment process is completed by bonding and fixing with an adhesive, the force F in the direction of jumping out the light intensity detection sensor 7 from the recess 14 causes the flexible wiring board 50 to bend. Since the bent portion is restored by the restoring force of the bent portion, the element mounting region 52 of the flexible wiring board 50 is peeled off from the mounting portion 15 when the adhesive deteriorates due to factors such as aging. There is a possibility that the intensity detection sensor 7 may be displaced or may be detached from the recess 14 in some cases.

  Thus, in order to improve this point, there has been a measure of increasing the amount of adhesive used, but such a measure cannot be a fundamental solution. In addition, it has been conventional to fix the flexible wiring board with screws or add other parts, but these screws and other parts are necessary and the structure becomes complicated and the parts This is not preferable because it increases costs.

  On the other hand, the bending strength of the flexible wiring board 50 is increased by using the technique proposed by the above-mentioned Patent Document 1, and by doing so, the light intensity detection sensor 7 is urged to jump out of the recess 14. Although it is conceivable that the force F is not generated, the flexible wiring board 50 on which the light intensity detection sensor 7 is mounted cannot be considered in view of the fact that the routing space is extremely narrow.

  The present invention has been made in view of the above problems and circumstances, and temporarily fixing an optical element such as a light intensity detection sensor without increasing the amount of adhesive used or adding screws or other parts. It is an object of the present invention to provide an optical pickup that can be easily and reliably performed, and that is less likely to peel off or drop off of an optical element due to deterioration of an adhesive after the attachment process is completed. To do.

  Further, the present invention is an optical pickup that can easily temporarily fix a light intensity detection sensor as an optical element in particular and can prevent the light intensity detection sensor from being peeled off or dropped after being attached. The purpose is to provide.

In the optical pickup according to the present invention, the routing area and the element mounting area are continuously formed on the flexible wiring board attached to the base body, and the element mounting area includes the mounting portion of the base body. An optical element that is disposed and interposed in the optical path of the optical system is mounted. The mounting portion includes a recess in which the optical element mounted in an overlapping manner on the element mounting region of the flexible wiring board is fitted, and a flat gate-shaped receiving surface positioned around the recess. , together are the lead-to are opposed at intervals in the region folded element mounting region of the flexible wiring board to the lead-to area side, to the base body in opposite positions between the element attachment area of the lead-to region By abutting the provided backup part, the element mounting region is elastically pressed against the receiving surface of the mounting part of the base body by the restoring force of the folded portion of the flexible wiring board, and is also pressed by the receiving surface. A reinforcing plate is joined in an overlapping manner to the element attachment region, and the element attachment region is joined and fixed to the attachment portion with an adhesive.

  With this configuration, the restoring force of the folded portion formed by turning the element mounting area of the flexible wiring board and folding it back to the area side is used to compress the element mounting area on the mounting portion of the base body. The optical element mounted in the element attachment region is held by the restoring force so as not to be detached from the attachment portion of the base body. Therefore, the optical element is securely temporarily fixed to the mounting portion of the base body without using screws or other parts. In addition, after applying the adhesive after temporary fixing and bonding and fixing the element mounting area to the mounting portion of the base body, even if the adhesive deteriorates due to factors over time, the optical element is removed from the mounting portion of the base body. It becomes difficult to peel off or fall off.

  In the present invention, the mounting portion is provided on one side of the pair of opposing sides of the opening provided in the base body, and the backup portion is provided on the other side, respectively. It is desirable that an opposing space between the mounting portion and the backup portion accommodates a portion where the element mounting region of the flexible wiring board faces the element mounting region of the routing region. According to this, only the operation of fitting the element mounting area of the flexible wiring board and the element mounting area of the routing area into the opening of the base body and accommodating between the mounting part and the backup part is performed. Thus, the back-up portion comes into contact with the opposing portion of the flexible wiring substrate by the restoring force of the folded portion of the flexible wiring substrate, and the element mounting region is pressed against the mounting portion of the base body to temporarily fix the optical element. Therefore, it helps to increase the mass productivity of the optical pickup.

  In the optical pickup according to the present invention, a routing area and an element mounting area are continuously formed on the flexible wiring board attached to the base body, and the element mounting area includes a mounting portion of the base body. In an optical pickup in which an optical element disposed and interposed in an optical path of an optical system is mounted, flexible wiring is provided on one side of a pair of opposing sides of the opening provided in the base body. A gate-shaped recess in which the optical element mounted in an overlapping manner on the element mounting region of the substrate fits, and a flat receiving surface positioned around the recess and pressed against the element mounting region. Whereas the mounting part is provided, the other side part is provided with a backup part projecting in an arc shape toward the one side part, and is folded back to the routing area side of the flexible wiring board. By accommodating the element mounting area opposed to the routing area of the wiring body at a distance and the facing portion of the routing area between the element mounting area and the mounting area of the base body and the pack-up section. By fitting the optical element into the recess of the mounting part and bringing the backup part into contact with the opposite part, the element mounting area is received by the mounting part with the restoring force of the folded part of the flexible wiring board. The surface is elastically pressed and a reinforcing plate is joined to the element mounting region in an overlapping manner, and the optical element is used to detect the intensity of a light beam emitted from a light emitting diode as a light source of an optical system. The present invention is further embodied by adopting the configuration of being a light receiving element. The effect | action of this invention is demonstrated in detail with reference to embodiment mentioned later.

According to the present invention, in the process of attaching an optical element such as a light intensity detection sensor, an optical element, for example, a light intensity detection sensor, is mounted by utilizing the restoring force of the folded portion formed by folding the flexible wiring board. The element mounting area of the flexible wiring board is elastically pressed against the flat receiving surface of the mounting portion of the base body, and a reinforcing plate is joined to the element mounting area pressed against the receiving surface in an overlapping manner, and the element mounting area Since it is designed to be bonded and fixed to the mounting part with an adhesive, it is not necessary to use screws or other parts to temporarily fix the light intensity detection sensor, but also after bonding and fixing with an adhesive In this case, the restoring force exerts an action to keep the light intensity detection sensor in the initial position, so even if the adhesive deteriorates over time, the light intensity Situation that out sensor is easily or fall off or displaced in the early stage will not occur. Therefore, an optical pickup whose initial optical performance can be maintained for a long time can be provided at a low cost, which is also beneficial for the user.

  1 is an external perspective view of an optical pickup according to an embodiment of the present invention, FIG. 2 is a partial perspective view of a base body 10 of the optical pickup of FIG. 1 viewed from below, and FIG. FIG. 4 is a perspective view showing a flexible wiring board 50 attached to the base body 10 shown in FIG. 2, and FIG. 5 is a partial plan view showing the optical pickup shown in FIG. is there.

  As shown in FIG. 1, in this optical pick-up, an optical system similar to that described with reference to FIG. 6 is provided on a base body 10 whose travel is guided in the radial direction of the disk by a main shaft 101 and a sub shaft 102. Equipped. Note that the actuator including the objective lens 5 of FIG. 6 is omitted in FIG.

  The base body 10 is provided with a light passage hole 16 facing the objective lens 5 (see FIG. 6), and an opening 20 having a rectangular basic shape, and a pair of opposite sides of the opening 20. One side part 21 of the part is provided with a mounting part 22 to which the light intensity detection sensor 7 as an optical element is attached, whereas the other side part 26 is centered toward the one side part 21. A backup unit 27 that projects in an arc shape is provided. As can be seen from FIG. 2 showing the base body 10 as viewed from below, the mounting portion 22 has a recess 23 formed in a gate shape and a flat gate-shaped receiving portion positioned around the recess 23. Surface 24.

  As shown in FIG. 3, the unfolded flexible wiring board 50 includes a main portion 55 on which a control circuit is mounted, a substantially L-shaped routing area 51 extending from the main portion 55, and the routing area 51. The light intensity detection sensor 7 is mounted on the front side of the element mounting region 52, and the reinforcing plate 53 is mounted on the back side thereof.

  In the step of attaching the light intensity detection sensor 7, the step of temporarily fixing the light intensity detection sensor 7 to the attachment portion 22 of the base body 10 is performed according to the following procedure. That is, as shown in FIG. 4, the base portion 51a of the routing area 51 of the flexible wiring board 50 is bent at a substantially right angle with respect to the main portion 55, and the main portion 55 is bent to the control circuit mounting portion of the base body 10 shown in FIG. In a state of being fixed to 17, the drawing area 51 is bent into a curved shape and drawn to the lower side of the base body 10. Further, as can be inferred from FIG. 4, the element mounting region 52 is routed at its root 52a, folded back toward the region 51, and opposed to the routing region 51. In this state, as shown in FIG. The upper end portions (the lower end portions in FIG. 4) of the region 52 and the portion 51 ′ facing the element mounting region 52 of the routing region 51 are fitted into the opening 20 from the lower side, and they are mounted as described above. The unit 22 is accommodated in a facing space between the backup unit 27 and the backup unit 27. At the same time, the light intensity detection sensor 7 is fitted and positioned in the recess 23 of the gate-shaped attachment portion 22, and the surface of the element attachment region 52 of the flexible wiring board 50 on which the light intensity detection sensor 7 is mounted. It overlaps with the flat receiving surface 24 of the mounting portion 22.

  By the way, the flexible wiring board 50 has a property that when a bent part or a folded part is formed, the bent part or the folded part is opened by a restoring force. Therefore, as described above, when the element mounting region 52 and the facing portion 51 ′ are accommodated in the facing space between the mounting portion 22 and the backup portion 27, the folded portion b of the root 52 a of the element mounting region 52 is reduced. Since the backup portion 27 is brought into contact with the facing portion 51 ′ by opening with the restoring force, the element mounting region 52 is elastically biased by the reaction as shown by the arrow F1 in FIG. 5 and is elastically pressed against the receiving surface 24 of the mounting portion 22. To do. For this reason, the state where the light intensity detection sensor 7 mounted in the element attachment region 52 is fitted and positioned in the recess 14 of the attachment portion 22 is maintained as it is.

  As described above, the element mounting region 52 is elastically pressed against the flat receiving surface 24 of the mounting portion 22 by the restoring force of the folded portion B of the flexible wiring board 50, and the light intensity detection sensor 7 is fitted into the recess 23 for positioning. In this case, it is not necessary to perform the troublesome operation of artificially positioning the element attachment region 52 when the element attachment region 52 is bonded and fixed to the attachment portion 22 by applying an adhesive in the next step. The application | coating operation | work can be accurately performed easily and without requiring much skill. In addition, even after the adhesive is applied and the mounting process of the light intensity detection sensor 7 is completed, the element mounting region 52 is pressed against the flat receiving surface 24 of the mounting portion 22 by the restoring force of the folded portion b. Therefore, even if the adhesive deteriorates due to factors over time, the element attachment region 52 is peeled off from the attachment portion 22 and the light intensity detection sensor 7 is displaced or falls out of the recess 23. The initial performance of the light intensity detection sensor 7 is maintained over a long period of time, and the initial writing accuracy and reading accuracy by the optical pickup are not lowered. As a result, the user can enjoy high-quality images over a long period of time on a DVD device or the like.

  In this embodiment, since the backup portion 27 provided on the base body 10 side is formed in a shape projecting in an arc shape, the opposing space between the mounting portion 22 and the backup portion 27 is wide on both sides of the backup portion 27. A relatively wide space is secured. Therefore, when the work for housing the element mounting region 52 and the facing portion 51 ′ in the facing space between the mounting portion 22 and the backup portion 27 to temporarily fix the light intensity detection sensor 7 is performed, The advantage that the facing portion 51 ′ can be introduced into the facing space between the mounting portion 22 and the backup portion 27 using the wide space on both sides of the backup portion 27, and the temporary fixing work is facilitated accordingly. There is.

  1 to 5, the same reference numerals are given to elements that are the same as or correspond to the elements described with reference to FIG. 6 or FIG. 7.

1 is an external perspective view of an optical pickup according to an embodiment of the present invention. It is the fragmentary perspective view which looked and showed the base body of the optical pick-up of FIG. 1 from the lower side. It is an expanded view of a flexible wiring board. It is the perspective view which showed the flexible wiring board of the form attached to the base body shown in FIG. FIG. 2 is a partial plan view showing the optical pickup of FIG. 1 as viewed from above. It is explanatory drawing of an optical system. It is the top view which showed the structure of the attachment part of the light intensity detection sensor with respect to the base body about a prior art example.

1 Light-emitting diode 7 Light intensity detection sensor (optical element)
DESCRIPTION OF SYMBOLS 10 Base body 20 Opening 21 One side part of opening 22 Mounting part 23 Recessed part 24 Receiving surface 26 Other side part of opening 27 Backup part 50 Flexible wiring board 51 Leading area 51 'Opposition to element attachment area Location 52 Element mounting area 53 Reinforcement plate B Flexible circuit board folded-back location

Claims (3)

A routing area and an element mounting area are continuously formed on the flexible wiring board mounted on the base body, and the element mounting area is disposed at the mounting portion of the base body and is interposed in the optical path of the optical system. In the optical pickup on which the optical element is mounted,
A gate-shaped recess into which the optical element mounted in an overlapping manner on the element mounting region of the flexible wiring board is fitted to one side of a pair of opposing sides of the opening provided in the base body. And the flat receiving surface on which the element mounting area is pressed against the recess, the mounting portion is provided on the other side, and the circle is directed toward the one side. A back-up part projecting in an arc is provided,
The mounting portion of the base body includes the element mounting region which is folded back to the routing region side of the flexible wiring board and is opposed to the routing region with an interval, and the facing portion of the routing region to the element mounting region. And the back-up portion of the flexible wiring board by fitting the optical element into the recess of the mounting portion and bringing the backup portion into contact with the facing portion. The element mounting region is elastically pressed against the receiving surface of the mounting portion by a restoring force, a reinforcing plate is joined to the element mounting region pressed against the receiving surface in an overlapping manner , and the element mounting region is It is designed to be bonded and fixed to the mounting part with an adhesive,
An optical pickup, wherein the optical element is a light intensity detection sensor used for detecting the intensity of a light beam emitted from a light emitting diode as a light source of an optical system. A routing area and an element mounting area are continuously formed on the flexible wiring board mounted on the base body, and the element mounting area is disposed at the mounting portion of the base body and is interposed in the optical path of the optical system. In the optical pickup on which the optical element is mounted,
The mounting portion is provided with a recess in which the optical element mounted in an overlapping manner on the element mounting region of the flexible wiring board is fitted, and a flat gate-shaped receiving surface located around the recess,
The element mounting area of the flexible wiring board is routed back to the area side and is opposed to the routing area with an interval, and provided in the base body at a position facing the element mounting area of the routing area. By bringing the back-up portion into contact, the element mounting region is pressed against the receiving surface of the mounting portion of the base body by the restoring force of the folded portion of the flexible wiring board, and is also pressed against the receiving surface. An optical pickup characterized in that a reinforcing plate is joined to the element attachment area in an overlapping manner, and the element attachment area is joined and fixed to the attachment portion with an adhesive .   Of the pair of opposing sides of the opening provided in the base body, the attachment portion is provided on one side portion and the backup portion is provided on the other side portion, and the attachment portion and the backup portion are provided. The optical pickup according to claim 2, wherein a portion facing the element mounting region of the flexible wiring board and a device mounting region of the routing region are accommodated in a space facing the portion.

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