JP2007250080A - Optical head and optical recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress resonation of an optical head and to prevent peeling of constituent components. <P>SOLUTION: The optical head 1 has an objective lens drive 2 and a housing 3. The objective lens drive 2 drives an objective lens 12. The housing 3 supports the objective lens drive 2. The objective lens drive 2 is fixed to the housing 3 at an upper peripheral edge part 21a of a penetration part 21 by using adhesives 41 to 44 and at a lower peripheral edge part of the penetration part 21 by using an adhesives having hardness values different from those of the adhesives 41 to 44 in a state in which the objective lens drive 2 is loosely fitted in the penetration part 21 of the housing 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical head for recording or reproducing data on an optical recording medium such as an optical disk, and an optical recording / reproducing apparatus including the optical head.

  The conventional optical head (optical pickup) is provided with an actuator base that houses the objective lens movably in the focus direction and the tracking direction, and the actuator base is adjusted to fix the actuator base to the housing (pickup housing). There is what I did. In this optical head, a fitting convex portion is formed in the actuator base, a fitting concave portion in which the fitting convex portion is fitted with a minute clearance is formed in the housing, and at least the fitting convex portion and the fitting concave portion are formed. These fitting convex portions and fitting concave portions are bonded in a fitted state by an adhesive applied to one surface (see, for example, Patent Document 1). Hereinafter, this technique is referred to as a first conventional example.

  Also, in the conventional optical head, a plurality of pins project from the upper surface of the housing, and when an actuator (objective lens actuator) is assembled to the housing, a plurality of openings that can receive the pins are provided in the actuator base. Some are. In this optical head, after the tilt of the objective lens is adjusted, the actuator base is bonded and fixed to the housing by filling the opening with an adhesive such as solder while the pins are fitted in the openings (for example, patents). Reference 2). Hereinafter, this technique is referred to as a second conventional example.

  Further, in the conventional optical head, a lens barrel having a first hole formed from one end to a predetermined length and a second hole that is continuous with the first hole and has a diameter slightly larger than the first hole. A laser diode is accommodated and fixed at one end. A portion where the first hole and the second hole are connected after the collimating lens whose outer peripheral surface is coated with the thermosetting adhesive is accommodated in the first hole of the lens barrel and adjusted to a preset position. An ultraviolet curable adhesive is filled between the stepped portion formed on the collimating lens and the collimating lens, and ultraviolet rays are irradiated to temporarily fix the collimating lens to the lens barrel. Next, a nut is screwed into a second hole having a threaded portion formed on the inner peripheral surface, a light beam is emitted from the laser diode, and the collimating lens is pressed against the end surface of the nut to slightly move the fixing position of the collimating lens. However, the emitted light of the collimating lens is observed, and heat is applied to the portion where the thermosetting adhesive is applied at a position where the emitted light is parallel to fix the collimating lens (see, for example, Patent Document 3). ). Hereinafter, this technique is referred to as a third conventional example.

  Further, in a conventional optical recording / reproducing apparatus, a plurality of protrusions are provided on an objective lens driving apparatus that drives an objective lens in a focus and radial direction on an optical disc, and an optical base that holds a light emitting and receiving element includes: There are a plurality of recesses for fixing the projections of the objective lens driving device, and these recesses fix the projections and define the adjustment range of the objective lens driving device. In this conventional optical recording / reproducing apparatus, the protrusion on the fixing portion side is fixed using an adhesive that is solidified by optical reaction or the like. On the other hand, the protrusions on the non-fixed part side are fixed by brazing such as soldering or metal bonding such as welding (for example, see Patent Document 4). Hereinafter, this technique is referred to as a fourth conventional example.

Japanese Patent Laid-Open No. 7-311951 (Claim 1, [0018] to [0023], FIG. 1) JP-A-2001-319343 (Claims 1, [0005] to [0007], FIGS. 1 and 2) JP-A-4-143929 (page 3, upper left column, 9th line to upper right column, 14th line, FIGS. 2 and 3) JP 2000-285495 A (Claim 1, Claim 2, [0022] to [0027], [0031], [0032], FIGS. 5 and 6)

  In the first to third conventional examples described above, there is no mention of specific physical characteristics of the adhesive for fixing each component of the optical head, in particular, hardness after curing. However, an adhesive having a high hardness is generally used in consideration of prevention of positional deviation and skew deviation of the objective lens or reliability such as characteristics under a high temperature environment. As described above, when a high-hardness adhesive is used as an adhesive for fixing the components of the optical head, for example, when the optical recording medium rotates eccentrically, the open-loop phase characteristics in the tracking direction of the optical head , Resonance occurs at a frequency of about 5 to 9 kHz, and the tracking servo becomes unstable. As a result, there is a possibility that tracking servo tracking cannot be performed on the optical recording medium.

  Further, for example, when an optical recording / reproducing apparatus equipped with an optical head is mounted on an automobile and the automobile is left under a hot summer sun, the temperature near the dashboard where the optical recording / reproducing apparatus is installed is 70-80. It rises to about ℃. Thereafter, when a passenger such as a driver gets on the automobile and operates the air conditioner, the in-vehicle temperature falls to about 26 to 28 ° C. which is comfortable for the passenger. As described above, when the ambient temperature of the optical recording / reproducing apparatus equipped with the optical head changes suddenly, if the components of the optical head are closely fixed with the above-described high-hardness adhesive, the adhesive is included. Since each component has a different thermal expansion coefficient, for example, the actuator base may be peeled off from the housing due to shrinkage or expansion of the adhesive or the like. Thereby, for example, when the objective lens is tilted, the optical recording medium is not correctly irradiated with the light beam emitted from the laser diode, and there is a possibility that data cannot be recorded or reproduced on the optical recording medium.

  On the other hand, in the above-described fourth conventional example, there is a problem that the process becomes complicated because different fixing methods are used. Further, in the case of using a metallic bond, heat generated at the time of fixing is transmitted to a part that is not scheduled to be fixed via an object to be fixed, which may increase the temperature of the part. In this case, when the melting temperature of the part is low, it may be deformed by heat, which may adversely affect parts unrelated to fixing.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an optical head and an optical recording / reproducing apparatus capable of solving the above-described problems.

  In order to solve the above problems, an optical head according to a first aspect of the present invention includes an objective lens driving device that drives an objective lens, and a housing that supports the objective lens driving device through adhesives having different hardnesses. It is characterized by having.

The invention according to claim 2 relates to the optical head according to claim 1, wherein the adhesive has a first adhesive having a Shore D hardness of 65 to 90 and a Shore A hardness of 30 to 50. It is characterized by being a second adhesive.
According to a third aspect of the present invention, an optical recording / reproducing apparatus includes the optical head according to the first or second aspect.

  According to the present invention, an optical head according to the first aspect of the present invention includes an objective lens driving device that drives an objective lens, and a housing that supports the objective lens driving device through adhesives having different hardnesses. Therefore, when this optical head is used in an optical recording / reproducing apparatus, resonance of the entire optical head is suppressed, tracking servo is stabilized, and peeling of components is prevented.

  According to the invention, an optical recording / reproducing apparatus according to a third aspect of the invention includes the optical head according to the first or second aspect. Therefore, in this optical recording / reproducing apparatus, even when the optical recording medium rotates eccentrically, tracking servo tracking with respect to the optical recording medium can be performed satisfactorily. Even when the ambient temperature changes rapidly, data can be recorded or reproduced on the optical recording medium.

Embodiment 1 FIG.
FIG. 1 is a perspective view showing an external configuration of an optical head 1 according to Embodiment 1 of the present invention, FIG. 2 is a perspective view of the external configuration of the optical head 1 shown in FIG. It is a disassembled perspective view which shows the external appearance structure of the optical head 1 shown in FIG. The optical head 1 in this example has an objective lens driving device 2 and a housing 3.

As shown in FIG. 3, the objective lens driving device 2 has an objective lens 12 fixed to the outer periphery of a through-hole 11b formed in the vicinity of one end portion 11a of the lens holder 11 with an adhesive or the like. Drive in direction and tracking direction. The through portion 11c formed substantially in the center of the lens holder 11, the permanent magnets 13 _1, 13 ₂ and the yoke 14 constituting a magnetic circuit is disposed. Further, a focusing coil 19 and a tracking coil 20 are provided in the penetrating portion 11 a of the lens holder 11.

The housing 3 is made of, for example, a metal such as aluminum (Al), zinc (Zn), or magnesium (Mg), or a synthetic resin such as liquid crystal polymer (LCP). The housing 3 is formed with a through-hole 21 that is substantially similar to the outer peripheral shape of the objective lens driving device 2 and into which the objective lens driving device 2 is loosely fitted. As shown in FIGS. 4 and 5, the objective lens driving device 2 is loosely fitted into the through-hole 21 of the housing 3 and several places at two or more places on the upper peripheral edge 21 a of the through-hole 21 in the housing 3. (Four places in the example of FIG. 1) are fixed by the adhesives 4 ₁ to 4 ₄ , and two or more places of the lower peripheral edge portion 21 b of the penetrating portion 21 (four places in the example of FIG. 2). Are fixed by adhesives 5 _{1 to} 5 ₄ . Thereby, the housing 3 supports the objective lens driving device 2.

  Although not shown in the figure, the optical path of the light beam emitted from the laser diode is changed to be emitted from the objective lens 12, and the light beam incident from the objective lens 12 is made of a photodiode or the like. An optical system including a beam splitter, a collimating lens, and the like for focusing on the light receiving surface of the detector is provided.

The adhesives 4 ₁ to 4 ₄ play a role of fixing the upper peripheral edge of the objective lens driving device 2 to the housing 3 and positioning the objective lens driving device 2 on the housing 3 with a predetermined accuracy. On the other hand, the adhesives 5 _{1 to} 5 ₄ serve to fix the lower peripheral edge of the objective lens driving device 2 to the housing 3, and also serve as dampers for damping the vibration of the objective lens driving device 2, shock buffering, and the like. Plays.

In this case, the hardness of the adhesive ₄₁ to _4, for example, it is preferred Shore D hardness of 65 to 90. On the other hand, the hardness of the adhesive ₅ 1 to 5 _4, for example, it is preferable Shore A hardness of 30 to 50. Here, the Shore D hardness is a hardness measured with a type D durometer of JIS K-6253 (DIN 53 505), and a Shore A hardness is a type A durometer of JIS K-6253 (DIN 53 505). Refers to the measured hardness.

Adhesives 4 ₁ to 4 ₄ and 5 _{1 to} 5 ₄ are, for example, epoxy, cyanoacrylate, polyurethane, urea resin, melamine resin, phenol resin, vinyl acetate resin, synthetic rubber, chloroprene rubber Solvent type, synthetic rubber latex type, pressure sensitive, emulsion type, hot melt type, elastomeric hot melt type, polyamide hot melt type, and the like.

Next, a detailed method for fixing the objective lens driving device 2 to the housing 3 with the adhesives 4 ₁ to 4 ₄ and 5 _{1 to} 5 ₄ will be described. As shown in FIG. 3, the lens holder 11 constituting the objective lens driving device 2 has a joint portion 15 for fixing the objective lens driving device 2 to the housing 3 in the approximate center of the outer periphery and in the vicinity of the other end 11 d. 18 is provided. The joint portions 15 to 18 have a substantially rectangular parallelepiped shape and may be formed integrally with the lens holder 11, or are manufactured separately from the lens holder 11 and joined to the lens holder 11 with an adhesive or the like. May be. On the other hand, as shown in FIGS. 3 to 5, the penetration portion 21 of the housing 3 is joined at a position facing the joint portions 15 to 18 when the objective lens driving device 2 is loosely fitted in the penetration portion 21. Recesses 22a to 25a and 22b to 25b are formed.

First, as shown in FIG. 4, the objective lens driving device 2 is adjusted to a preset position in a state where the objective lens driving device 2 is loosely fitted in the through portion 21 of the housing 3. Then, the adhesive 4 ₁ was applied in order to bond the bonding recesses 22a and nearby side surfaces constituting the upper portion 15a near the side surface and the housing 3 of the joint 15 constituting the objective lens driving device 2, an objective lens driving the adhesive 4 ₂ applying a bonding recess 23a and its proximity to a side surface of the device 2 of the upper portion 16a near the side surface and the housing 3 of the joint 16 for joining. Similarly, the adhesive 4 ₃ was applied in order to bond the bonding recesses 25a and nearby side surfaces constituting the upper portion 17a near the side surface and the housing 3 of the junction 17 of the objective lens driving device 2, the objective lens driving device 2 to the application of an adhesive 4 ₄ in order to bond the bonding recesses 25a and nearby side surfaces of the upper portion 18a near the side surface and the housing 3 of the joint 18. Thereby, the objective lens driving device 2 is temporarily fixed to the housing 3 with a predetermined positional accuracy.

Next, as shown in FIG. 5, after the housing 3 to which the objective lens driving device 2 is temporarily fixed is turned over, the side surface near the lower end 15 b of the joining portion 15 of the objective lens driving device 2, the joining recess 22 b of the housing 3, and the adhesive 5 ₁ was applied in order to bond the near side, the adhesive for joining the joining recess 23b and its proximity to a side surface of the lower portion 16b near the side surface and the housing 3 of the joint portion 16 of the objective lens driving device 2 the agent _{5 2} is applied. Similarly, the adhesive 5 ₃ was applied in order to bond the bonding recess 25b and its proximity to a side surface constituting the lower portion 17b near the side surface and the housing 3 of the junction 17 of the objective lens driving device 2, the objective lens driving device 2 to the application of an adhesive 5 ₄ in order to bond the bonding recess 25b and its proximity to a side surface of the lower portion 18b near the side surface and the housing 3 of the joint 18. Thereby, the objective lens driving device 2 is permanently fixed to the housing 3.

Here, FIG. 6 shows an enlarged perspective view of a portion A shown in FIG. 1, and FIG. 7 shows a view taken along the line BB ′ of FIG. In FIG. 6, the adhesives 4 ₃ and 4 ₄ and other components of the objective lens driving device 2 are shown for easy understanding of the relationship between the joint portions 17 and 18 and the joint recesses 24a, 25a and 25b. Absent. On the other hand, also in FIG. 7, other components of the objective lens driving device 2 are not shown in order to make it easy to understand the joined state between the joined portions 17 and 18 and the joined recesses 24a, 25a, and 25b.

Each adhesive _{4 3} and _{5 3,} for example, _{h 1} the height of the housing 3, the thickness of the adhesive _{4 3} (coating amount) _{h 2,} the thickness of the adhesive _{4 3} (coating amount) _{h 3} Then, the coating is performed so as to satisfy the expressions (1) to (3).
_{h 2 = h 1 / 6~5h 1} /6 ··· (1)
_{h 3 = h 1 / 6~5h 1} /6 ··· (2)
h ₂ + h ₃ <h ₁ (3)
As for the coating amounts of the other adhesives 4 ₁ , 4 ₂ , 4 ₄ , 5 ₁ , 5 ₂ and 5 ₄ , coating is performed so as to satisfy the three formulas corresponding to the formulas (1) to (3). To do.

The reason why the coating amounts of the adhesives 4 ₁ to 4 ₄ and 5 _{1 to} 5 ₄ are defined by the above formulas (1) to (3) is as follows. First, if the coating amount of the adhesive _{41 to 4} and ₅ 1 to 5 ₄ are less than _h 1/6 is not obtained a predetermined bonding strength, during use of the optical head 1, the adhesive ₄ 1 4 ₄ or 5 _{1 to} 5 ₄ may be peeled off and the objective lens driving device 2 may fall off the housing 3. On the other hand, if the amount of adhesive applied ₄₁ to ₄ and ₅ 1 to 5 ₄ is more than _5h 1/6 has an adhesive ₅ 1 to 5 ₄ corresponding to the adhesive ₄₁ to ₄ is mixed There is a risk that. To avoid mixing of the adhesive ₅ 1 to 5 ₄ corresponding to the adhesive ₄₁ to ₄ to ensure the coating amount of the adhesive ₄₁ to ₄ and ₅ 1 to 5 ₄ to about _4h 1/6 More preferably. Furthermore, the fact that the sum of the application amount of the adhesives 4 ₁ to 4 ₄ and the corresponding application amount of the adhesives 5 _{1 to} 5 ₄ is larger than the height h _{1 of the} housing 3 corresponds to the adhesives 4 ₁ to 4 _4. an adhesive 5 ₁ to 5 ₄ are mixed with one another to, in conjunction with the movement of the objective lens driving device 2 is limited, or not a predetermined positional accuracy is obtained, the function as a damper of the adhesive 5 ₁ to 5 ₄ There is a risk that it will not be fulfilled sufficiently.

FIG. 8 is an example of phase characteristics in the open loop in the tracking direction of the optical head 1 having the above-described configuration. 8, curve a, the hardness of the adhesive ₄₁ to ₄ is Shore D hardness 65 to 90 is the characteristic when the hardness of the adhesive ₅ 1 to 5 ₄ are Shore A hardness 30 to 50 . On the other hand, the curve b is a characteristic when the hardness of the adhesives 4 ₁ to 4 ₄ and 5 _{1 to} 5 ₄ is a Shore D hardness of 65 to 90.

As can be seen from FIG. 8, in the optical head 1, when the hardness of the adhesives 5 _{1 to} 5 ₄ is lower than the hardness of the adhesives 4 ₁ to 4 ₄ , the resonance of the entire optical head 1 at about 7 kHz. Can be suppressed. On the other hand, the gain characteristic of the open loop in the tracking direction the optical head 1 having the above configuration, in the case where the hardness of the adhesive 5 ₁ to 5 ₄ lower than the hardness of the adhesive ₄₁ to _4, comb low There is no difference in the case of not having.

As described above, in the first embodiment of the present invention, the objective lens driving device 2 is provided in the housing 3 with the adhesive 4 having a hardness of Shore D hardness 65 to 90 at four locations on the upper peripheral edge 21a of the penetrating portion 21. together are fixed by _{1-4 4,} hardness in four positions of the lower peripheral edge portion 21b of the penetrating portion 21 is fixed by adhesive ₅ 1 to 5 ₄ Shore a hardness 30 to 50.

Accordingly, the adhesives 4 ₁ to 4 ₄ serve to position the objective lens driving device 2 with respect to the housing 3 with a predetermined accuracy, while the adhesives 5 _{1 to} 5 ₄ are vibrations of the objective lens driving device 2. It plays a role as a damper for damping and shock buffering. Therefore, resonance of the entire optical head 1 at about 7 kHz in the tracking direction is suppressed, and the tracking servo is stabilized. Thereby, even when the optical recording medium rotates eccentrically, tracking servo tracking with respect to the optical recording medium can be performed satisfactorily.

Further, in the first embodiment of the present invention, the objective lens driving device 2 has the adhesive 5 having a Shore A hardness of 30 to 50 at four locations on the lower peripheral edge portion 21b of the through portion 21 formed in the housing 3. It is fixed by _{1-5 4.} Therefore, in the optical recording / reproducing apparatus provided with the optical head 1 having such a configuration, the adhesives 5 _{1 to} 5 ₄ are peeled off and the objective lens driving device 2 is formed even when the ambient temperature changes suddenly. Separation from the housing 3 can be prevented.

Furthermore, in Embodiment 1 of the present invention, the adhesives 4 ₁ to 4 ₄ and the adhesives 5 _{1 to} 5 ₄ are different in hardness, but the fixing method is the same. Therefore, unlike the fourth conventional example using different fixing methods, the process is not complicated. Further, in the first embodiment of the present invention, since the metallic coupling as in the above-described fourth conventional example is not used, there is no possibility that the heat generated at the time of fixing adversely affects parts unrelated to the fixing.

Embodiment 2. FIG.
FIG. 9 is a schematic diagram showing a configuration of an optical recording / reproducing apparatus according to Embodiment 2 of the present invention. This optical recording / reproducing apparatus is roughly composed of the optical head 1 according to Embodiment 1 described above, a spindle motor 31, a controller 32, a laser drive circuit 33, and a lens drive circuit.

  The spindle motor 31 rotates the optical disc 35 under the control of the controller 32. The controller 32 controls the spindle motor 31, the laser drive circuit 33, and the lens drive circuit 34 based on the photodetector detection signal supplied from the optical head 1. The laser drive circuit 33 generates a laser drive signal for driving a laser diode that is a light source (not shown) constituting the optical head 1 under the control of the controller 32, and supplies the laser drive signal to the optical head 1. The lens driving circuit 34 generates a lens driving signal for controlling the focusing and tracking of the objective lens 12 (for example, see FIG. 1) constituting the optical head 1 under the control of the controller 32 and supplies the lens driving signal to the optical head 1. To do.

  The controller 32 includes a focus servo tracking circuit 36, a tracking servo tracking circuit 37, and a laser control circuit 38. The focus servo follow-up circuit 36 is a focus servo signal for focusing the light beam emitted from the optical head 1 on the information recording surface of the rotating optical disc 35 based on the photodetector detection signal supplied from the optical head 1. Is supplied to the lens driving circuit 34.

  The tracking servo tracking circuit 37 tracks the beam spot of the light beam emitted from the optical head 1 with respect to the eccentric signal track of the optical disk 35 based on the photodetector detection signal supplied from the optical head 1. Tracking servo signals are generated and supplied to the lens driving circuit 34. The laser control circuit 38 generates an appropriate laser drive signal based on the recording condition setting information recorded on the optical disc 35 extracted from the photodetector detection signal supplied from the optical head 1.

  Thus, according to Embodiment 2 of the present invention, an optical recording / reproducing apparatus is configured using the optical head 1 according to Embodiment 1 described above. Therefore, the optical recording / reproducing apparatus can satisfactorily follow the tracking servo with respect to the optical recording medium even when the optical recording medium rotates eccentrically. Even when the ambient temperature changes rapidly, data can be recorded or reproduced on the optical recording medium.

Embodiment 3 FIG.
In the first and second embodiments described above, an example of an optical head provided with only one light source or an optical recording / reproducing apparatus provided with only one optical head has been described. However, the present invention is not limited to this. The present invention can also be applied to an optical head provided with a plurality of light sources and an optical recording / reproducing apparatus provided with a plurality of optical heads. Such an optical head and an optical recording / reproducing apparatus are disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-295982.

As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present invention.
For example, in each of the above-described embodiments, an example in which the optical recording medium is a disk-shaped optical disk has been described. However, the present invention is not limited to this, and the optical recording medium may be rectangular.

Further, in each of the above-described embodiments, the head driving device 2 is fixed to the housing 3 and the upper peripheral edge portion 21 a of the penetrating portion 21 with the adhesives 4 ₁ to ₄ 4 having high hardness, and the lower peripheral edge portion of the penetrating portion 21. shows an example in which the hardness is fixed at a lower adhesive ₅ 1 to 5 ₄ to 21b. However, the present invention is not limited to this. In short, it is only necessary to prevent resonance of the entire optical head 1 at about 7 kHz in the tracking direction and separation of the objective lens driving device 2 from the housing 3. Therefore, as long as this object can be achieved, the type of adhesive, the location where the adhesive is applied, and the number of locations where the adhesive is applied are not limited.

Further, in each of the above-described embodiments, an example in which the adhesives 5 _{1 to} 5 ₄ themselves function as a damper has been shown. However, the present invention is not limited to this, and a material with low hardness in which a high-hardness adhesive is applied to both sides. May be inserted between the objective lens driving device 2 and the housing 3.

It is a perspective view which shows the external appearance structure of the optical head concerning Embodiment 1 of this invention. It is the perspective view which looked at the external appearance structure of the optical head shown in FIG. 1 from the back side. It is a disassembled perspective view which shows the external appearance structure of the optical head shown in FIG. FIG. 4 is a perspective view showing a state where the optical head shown in FIG. 3 is loosely fitted in the housing shown in FIG. 3. FIG. 4 is a perspective view of a state where the optical head shown in FIG. 3 is loosely fitted in the housing shown in FIG. 3 as viewed from the back side. FIG. 2 is an enlarged perspective view of a portion A of the optical head shown in FIG. It is a BB 'arrow line view of FIG. In the optical head shown in FIG. 1 and FIG. 2, a case where a high-hardness adhesive is used for bonding the objective lens driving device and the housing, and a low hardness bonding is used for bonding the lower peripheral edge of the objective lens driving device and the housing. It is a figure which shows an example of the phase characteristic in the open loop of the tracking direction in each at the time of using an agent. It is the schematic which shows the structure of the optical recording / reproducing apparatus which concerns on Embodiment 2 of this invention.

Explanation of symbols

1 the optical head 2 objective lens driving device 3 housing 4 _{1-4 4} adhesive (first adhesive)
5 _{1 to} 5 ₄ adhesive (second adhesive)
11 the lens holder 11a end 11b, 11c, 21 through portion 11d and the other end portion 12 the coil 20 of the objective lens 13 _1, 13 ₂ permanent magnet 14 yoke 15 to 18 joint 15a~18a upper portion 15b~18b lower portion 19 for focusing Coil for tracking 21a Upper peripheral edge 21b Lower peripheral edge 22a-25a, 22b-25b Joint recess 31 Spindle motor 32 Controller 33 Laser drive circuit 34 Lens drive circuit 35 Optical disk 36 Focus servo tracking circuit 37 Tracking servo tracking circuit 38 Laser control circuit

Claims (3)

An objective lens driving device for driving the objective lens;
An optical head comprising: a housing that supports the objective lens driving device via adhesives having different hardnesses.   2. The optical head according to claim 1, wherein the adhesive is a first adhesive having a Shore D hardness of 65 to 90 and a second adhesive having a Shore A hardness of 30 to 50.   An optical recording / reproducing apparatus comprising the optical head according to claim 1.

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