JP4983588B2 - Optical pickup and optical disk apparatus - Google Patents

Description

  The present invention relates to an optical pickup for performing recording / reproduction with respect to an optical disc and an optical disc apparatus including the same.

  A conventional optical pickup is disclosed in Patent Document 1. The optical pickup includes a lens holder provided with a tracking and focusing coil and two objective lenses, a plurality of wires electrically supporting the lens holder and electrically connected to the coil. And a wiring board attached to the fixing holder while being electrically connected to the ends of the plurality of wires.

  The plurality of wires not only support the lens holder so that it can swing vertically and horizontally, but also serve as conducting wires for supplying power to the coil. The fixed holder is formed with a through hole into which end portions of a plurality of wires can be inserted. The buffer material is made of, for example, an ultraviolet curable silicone resin or acrylic resin, and is in close contact with the ends of the plurality of wires in a state of being filled in the through holes of the fixed holder. The wiring board is, for example, a flexible wiring board, and is joined to the back surface of the fixed holder in a state of being conductively connected to the tips of the wires protruding from the back side of the through hole. Such an optical pickup is required to have strict environmental resistance characteristics when it is incorporated into an in-vehicle optical disk device. For example, strict conditions such as −20 ° C. are imposed as an operating temperature at which tracking and focusing operations can be normally continued, and −40 ° C. is imposed as a low temperature standing temperature at which normal operation can be started from a low temperature standing state.

JP 2006-309911 A

  However, in the above conventional optical pickup, the viscosity of the buffer material is increased in a low temperature environment, which hinders tracking and focusing operations. For example, a low frequency range from around the ambient temperature lower than 0 ° C. to about several tens of Hz. The frequency characteristics tended to deteriorate rapidly. This makes it impossible to incorporate an optical pickup into an in-vehicle optical disc apparatus that requires strict environmental resistance characteristics.

  The present invention has been conceived under the circumstances described above. An object of the present invention is to provide an optical pickup that can operate normally even in a low-temperature environment where the ambient temperature is extremely low, and an optical disk device including the same.

  In order to solve the above problems, the present invention takes the following technical means.

The optical pickup provided by the first aspect of the present invention includes a lens holder provided with a driving coil and an objective lens, and supports the lens holder in a swingable manner and is electrically connected to the coil. A plurality of wires, a fixing holder in which ends of the plurality of wires are fixed via a damping material for vibration damping, and a wiring conductor pattern electrically connected to the ends of the plurality of wires , A wiring board attached to the fixed holder in a state mechanically connected to the plurality of wires, and the wiring board is provided in a layer different from the wiring conductor pattern and is insulated from the plurality of wires. It is a requirement that a heating conductor pattern for applying heat to the cushioning material is provided.

  Preferably, the wiring board includes a wiring conductor that is electrically connected to ends of the plurality of wires, and the heating conductor is more than the wiring conductor with respect to the cushioning material. It is provided to be close.

  Preferably, the heating conductor is made of a material having a higher resistance than the wiring conductor.

  Preferably, the fixing holder is formed with a through-hole into which the ends of the plurality of wires can be inserted, and the cushioning material is inserted into the inside of the through-hole in a state where the ends of the plurality of wires are inserted. Is filled.

An optical disc apparatus provided by the second aspect of the present invention is an optical disc apparatus provided with an optical pickup, wherein the optical pickup swings a lens holder provided with a driving coil and an objective lens, and the lens holder. A plurality of wires that are supported and electrically connected to the coil, a fixed holder in which ends of the plurality of wires are fixed via damping cushions, and ends of the plurality of wires And a wiring board attached to the fixing holder in a state of being mechanically connected to the plurality of wires , the wiring board comprising the wiring conductor pattern. And a heating conductor pattern that provides heat to the cushioning material in a state of being insulated from the plurality of wires.

  Preferably, a temperature sensor for detecting an ambient temperature around the fixed holder is provided, and the heating conductor is configured to be energized when a temperature detected by the temperature sensor is equal to or lower than a predetermined temperature.

  According to such a configuration, for example, when the ambient temperature is extremely low, the buffer material can be warmed by energizing the heating conductor, and the frequency characteristics of the wire supported through the buffer material can be maintained at the normal temperature level. Therefore, it can operate normally even in a low temperature environment.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

  1 to 4 show an embodiment of an optical pickup to which the present invention is applied. FIG. 5 shows an optical disc apparatus provided with the optical pickup. The optical pickup A is provided with two types of lenses corresponding to a plurality of optical discs (for example, Blu-ray disc, DVD, CD) having different optical characteristics, and is provided in an optical disc apparatus that records and reproduces an optical disc. As shown in FIG. 5, the optical disk apparatus has a carriage substrate that can reciprocate along a pair of guide rails 100 in the radial direction of the optical disk (in FIG. 5, the rotation center portion C of the optical disk is indicated by a virtual line). 200 is provided. An optical pickup A is mounted on the carriage substrate 200 together with the light source 300 and various optical components 400, and a temperature sensor 500 is provided in the vicinity of the optical pickup A. In addition, the optical disk apparatus is provided with a spindle motor for rotating the optical disk, and a drive control means for controlling the spindle motor and the optical pickup A. The optical pickup A is used for irradiating an optical disk rotated by a spindle motor with a recording or reproducing laser beam and detecting the laser beam reflected by the optical disk.

  As shown in FIGS. 1 and 2, the optical pickup A includes a lens holder 1, a plurality of wires 2, a fixed holder 3, a fixed base 4, and a wiring board 5.

  As an example, the lens holder 1 is supported in a cantilever shape via four wires 2 and can swing in the focusing direction F and the tracking direction T. Two objective lenses 10 and 11 are provided at the center of the lens holder 1, and two coils 12 for focusing and four coils 13 for tracking are provided on both sides 1A and 1B. Yes. The two coils 12 are conductively connected to each other, and the four coils 13 are also conductively connected to each other. Both ends of the focusing coil 12 are conductively connected to the two wires 2, and both ends of the tracking coil 13 are also conductively connected to the other two wires 2. The entire lens holder 1 is swung in the focusing direction F by controlling the magnitude and direction of the current flowing in the focusing coil 12. On the other hand, the entire lens holder 1 is swung in the tracking direction T by controlling the magnitude and direction of the current flowing in the tracking coil 13.

  The wire 2 serves as a mechanical support means and also serves as an electrical conduction means, and is divided into two side portions 1A and 1B of the lens holder 1 one by one. The distal end portion of the wire 2 is fixed to both side portions 1A and 1B of the lens holder 1 while being electrically connected to the coils 12 and 13. The proximal end portion of the wire 2 is fixed in a state of being inserted into the through holes 3 </ b> A and 3 </ b> B (see FIGS. 2 and 3) of the fixing holder 3.

  The fixed holder 3 is made of, for example, a liquid crystal polymer or aluminum. As shown in FIGS. 2 and 3, through holes 3A and 3B are formed at both ends of the fixed holder 3, and an opening 3C for passing laser light is formed at the center. The through-holes 3 </ b> A and 3 </ b> B are filled with the damping material 30 for vibration damping with the proximal end portion of the wire 2 inserted, and the proximal end portion is in close contact with the cushioning material 30. The distal end portion at the proximal end portion of the wire 2 protrudes from the flat portions 30A and 30B of the cushioning material 30 formed to the outside of the through holes 3A and 3B on the back side of the fixed holder 3. The buffer material 30 is made of, for example, an ultraviolet curable silicone resin or an acrylic resin, and is provided to reduce the vibration of the wire 2.

  As shown well in FIG. 2, the fixed base 4 is provided with a plurality of permanent magnets 40 corresponding to the coils 12 and 13, and rising mirrors 41 and 42 for guiding laser light to the objective lenses 10 and 11. Yes. The fixed base 4 itself has a role as a magnetic yoke. The lens holder 1 is disposed so as to overlap with the fixed base 4, and the lens holder 1 is swung without contacting the fixed base 4.

  The wiring board 5 is used to guide the current from the drive control means located outside to the wire 2 and to apply heat to the buffer material 30, and is joined to the back surface of the fixed holder 3. As shown well in FIG. 4, the wiring board 5 includes a reinforcing plate 50, a first insulating film 51, a heating conductor pattern 52, a second insulating film 53, a wiring conductor pattern 54, and a third insulating film 55. Are laminated. The reinforcing plate 50, the first to third insulating films 51, 53, 55, and the wiring conductor pattern 54 are provided with holes 50A, 51A, 53A, 55A, 54A for passing the tip portions of the wires 2. . The reinforcing plate 50 and the first to third insulating films 51, 53, 55 are also provided with openings 50B, 51B, 53B, 55B corresponding to the openings 3C of the fixed holder 3.

  The reinforcing plate 50 is made of, for example, glass epoxy resin, and has a role of giving the wiring board 5 a certain degree of rigidity.

  The first to third insulating films 51, 53, and 55 are made of, for example, a polyimide film, and have insulating properties as flexibility and electrical characteristics that can be repeatedly deformed.

  The heating conductor pattern 52 is made of, for example, aluminum, and is bent so as to bypass the holes 50A, 51A, 53A, 55A, and 54A and the openings 50B, 51B, 53B, and 55B and occupy as large an area as possible. . The heating conductor pattern 52 is provided in a layer closer to the fixed holder 3 than the wiring conductor pattern 54. That is, the heating conductor pattern 52 generates heat when energized, and the heat is transmitted to the buffer material 30 of the fixed holder 3.

  The wiring conductor pattern 54 is made of, for example, copper having a resistance value smaller than that of the material of the heating conductor pattern 52, and the hole 54 </ b> A serving as a terminal portion bypasses the openings 50 </ b> B, 51 </ b> B, 53 </ b> B, 55 </ b> B. The insulating films 51, 53, 55 are formed so as to overlap the holes 50A, 51A, 53A, 55A. A pair of lines of the wiring conductor pattern 54 corresponds to the focusing coil 12, and the other pair of lines corresponds to the tracking coil 13.

  As shown in FIG. 3, the tip portion of the wire 2 protruding from the flat portions 30A and 30B of the cushioning material 30 is passed through the holes 50A, 51A, 53A, 55A and 54A, and further, as shown in FIG. 2 is fixed to the holes 50A, 51A, 53A, 55A, 54A by the solder 56. As a result, the wiring conductor pattern 54 is electrically connected to the wire 2. On the other hand, the heating conductor pattern 52 is energized separately from the wiring conductor pattern 54 without contacting the wire 2. As a result, the buffer material 30 is warmed by the heating conductor pattern 52 independently of the drive control of the coils 12 and 13.

  Next, the operation of the optical pickup A will be described.

  For example, when the optical disk device is used in a vehicle, the operating temperature at which tracking and focusing operations can be continued normally is -20 ° C., and the low temperature standing temperature at which it can normally start from a low temperature standing state is -40 ° C. Is imposed on the optical pickup A.

  As shown in FIG. 6, the change in characteristics due to the temperature of the wire 2 supported via the cushioning material 30 decreases when the operating characteristics such as the primary resonance frequency, the primary resonance peak amount, and the low frequency sensitivity are examined. It can be seen that their characteristics change suddenly. This is presumably because the viscosity of the buffer material 30 increases as the temperature decreases, and the rigidity of the proximal end portion of the wire 2 supported in close contact with the buffer material 30 increases.

  For this reason, in the optical disk apparatus of this embodiment, when the ambient temperature around the fixed holder 3 is detected by the temperature sensor 500 to be equal to or lower than the predetermined temperature, the heating conductor is separated from the energization of the wire 2 by the drive control means. The pattern 52 is energized. When the heating conductor pattern 52 is energized, the heat generated by the heating conductor pattern 52 is quickly transmitted to the fixed holder 3 and the buffer material 30 is warmed.

  As shown in FIG. 7, as a material for forming the fixed holder 3, aluminum is easier to transfer heat in terms of thermal conductivity than the liquid crystal polymer, and the heating amount of the heating conductor pattern 52 is 0.75 W, for example. In this case, in the aluminum fixed holder 3, a temperature increase from −20 ° C. to over 0 ° C. is recognized in about 20 seconds. Even if it is made of a liquid crystal polymer, it will exceed 0 ° C. in about 20 seconds.

  Such energization of the heating conductor pattern 52 is performed particularly when the optical disk apparatus is started at a low temperature. That is, the buffer material 30 is quickly warmed even at the time of activation, and normal tracking operation and focusing operation at normal temperature level are guaranteed.

  Therefore, according to the optical disc apparatus provided with the optical pickup A of the present embodiment, even when the apparatus is started in a low temperature environment, for example, the buffer material can be quickly provided by energizing the heating conductor pattern 52 for about several tens of seconds. Since 30 can be warmed, the tracking operation and the focusing operation can be normally performed.

  In addition, this invention is not limited to said embodiment.

  For example, the number of wires, the number of coils, and the like can be appropriately changed according to the specifications.

  As for the heating conductor pattern, for example, the heating conductor pattern may be exposed on the surface of the reinforcing plate facing the fixed holder, and the heating conductor pattern may be arranged so as to be in direct contact with the fixed holder.

1 is a perspective view showing an embodiment of an optical pickup to which the present invention is applied. FIG. 2 is an exploded perspective view of the optical pickup shown in FIG. FIG. 2 is a partially exploded perspective view of the optical pickup shown in FIG. 1. It is a principal part exploded view of the optical pick-up shown in FIG. It is an internal block diagram of the optical disk apparatus provided with the optical pick-up shown in FIG. It is explanatory drawing for demonstrating the characteristic change by the temperature of the wire supported via the buffer material. It is explanatory drawing for demonstrating the temperature change of a buffer material.

Explanation of symbols

DESCRIPTION OF SYMBOLS A Optical pick-up 1 Lens holder 2 Wire 3 Fixed holder 3A, 3B Through-hole 5 Wiring board 10,11 Objective lens 12,13 Coil 30 Buffer material 52 Heating conductor pattern 54 Wiring conductor pattern 500 Temperature sensor

Claims (6)

A lens holder provided with a driving coil and an objective lens;
A plurality of wires that swingably support the lens holder and are electrically connected to the coil;
A fixing holder in which end portions of the plurality of wires are fixed via damping materials for vibration suppression;
A wiring board provided with a wiring conductor pattern electrically connected to the ends of the plurality of wires, and attached to the fixed holder in a state mechanically connected to the plurality of wires ;
With
The wiring board is provided in a layer different from the wiring conductor pattern, and includes a heating conductor pattern that applies heat to the buffer material in a state of being insulated from the plurality of wires. Optical pickup.   The wiring board includes a wiring conductor electrically connected to the ends of the plurality of wires, and the heating conductor is closer to the buffer material than the wiring conductor. The optical pickup according to claim 1, wherein the optical pickup is provided.   The optical pickup according to claim 2, wherein the heating conductor is made of a material having higher resistance than the wiring conductor.   The fixing holder is formed with a through-hole into which the ends of the plurality of wires can be inserted, and the cushioning material is filled into the through-hole with the ends of the plurality of wires inserted. The optical pickup according to any one of claims 1 to 3. In an optical disc apparatus equipped with an optical pickup,
The above optical pickup
A lens holder provided with a driving coil and an objective lens;
A plurality of wires that swingably support the lens holder and are electrically connected to the coil;
A fixing holder in which end portions of the plurality of wires are fixed via damping materials for vibration suppression;
A wiring board provided with a wiring conductor pattern electrically connected to the ends of the plurality of wires, and attached to the fixed holder in a state mechanically connected to the plurality of wires ;
With
The wiring board is provided in a layer different from the wiring conductor pattern, and includes a heating conductor pattern that applies heat to the buffer material in a state of being insulated from the plurality of wires. Optical disk device.   The temperature sensor which detects the atmospheric temperature around the said fixed holder is provided, The said conductor for a heating is comprised so that it may become an energized state when the temperature detected by the said temperature sensor is below predetermined temperature. Optical disk device.

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