CN101268511B - Optical pickup device - Google Patents
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- CN101268511B CN101268511B CN2006800341866A CN200680034186A CN101268511B CN 101268511 B CN101268511 B CN 101268511B CN 2006800341866 A CN2006800341866 A CN 2006800341866A CN 200680034186 A CN200680034186 A CN 200680034186A CN 101268511 B CN101268511 B CN 101268511B
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Abstract
An optical pickup device comprising, provided in a housing, a projection light optical system, a light reception optical system and a parallel-flat-shape light beam separating means for separating a light beam advancing through the light reception optical system from a light beam advancing through the projection light optical system, wherein the light beam separating means is kept stable and with a high positioning accuracy against a physical deformation at light beam separating means mounting and against a significant temperature change after its mounting. The light beam separating means (23) has at least respective two location of respective mutually facing two surfaces thereof fixed to the mounting potions (2C, 2D) provided on the floor surface (2A) side of the housing and on the wall surface (2B) side vertical to this with two kinds of adhesives (41, 42) different in hardness after hardened respectively, and the adhesive (41) for fixing the one surface (lower surface) of the light beam separating means (23) to the floor surface (2A) side of the housing is higher in hardness after hardened than the adhesive (42) for fixing the other surface (upper surface) of the light beam separating means (23) to the wall surface (2B) side vertical to the floor surface (2A), whereby it is possible to enhance shape reliability at mounting and position reliability after mounting.
Description
Technical field
The present invention relates to write down and/reproduce the optic pick-up of optical information on the CD (hereinafter be referred to as record and reproduce).
Background technology
Usually, in order on such as the CD of CD or DVD, to realize optical recording and reproduction, various optic pick-ups have been developed.Optic pick-up uses object lens to penetrate light to CD from light source, and guiding from the reflected light of CD to light receiving piece with the various information of reading and recording on CD.Light beam separation unit in the known optic pick-up (for example beam splitter or half reflection and half transmission mirror (half plate mirror)) is arranged between light source and the light receiving piece to separate the optical path (for example referring to patent documentation 1) of projection optical system and light-receiving optical system.
That is to say that as shown in figure 14, this optic pick-up comprises light beam separation unit, for example at the half reflection and half transmission mirror (hereafter is " half-reflecting mirror ") 102 of optical path center section from light source 101 to CD D.In Figure 14, reference number 103 expression collimation lenses, 104 expression rising mirrors (rise mirror), 105 expression object lens, 106 expression parallel flats and 107 expression light receiving pieces.
Patent documentation 1:JP-A-2002-123969
Summary of the invention
The technical matters that the present invention solves
In common optic pick-up, when light beam separation unit is fixed to the bottom surface of shell (for example light pedestal etc.) by suitable adhesive, because the contraction or the bounding force of bonding agent when solidifying can cause such as distorting or the physical deformation of distortion.Be accompanied by this distortion, produced various aberrations, make that record and reproducing characteristic may serious deteriorations such as coma, astigmatism or spherical aberration.In addition, for example when optic pick-up was used for the device that is installed on the vehicle, ambient temperature changed very big.Under this situation, because the heat of the bonding agent that solidifies is degenerated or deterioration, light beam separation unit can not keep its stable tacky state.Thereby the position of light beam separation unit moves, and makes optical convergence position change in the light-receiving optical system.Correspondingly, record and reproducing characteristic deterioration significantly.Therefore, the distortion that requires always to guarantee settling position and prevent to cause owing to bigger temperature change.Especially, the light beam separation unit that is loaded in the optic pick-up in video disc recording and the transcriber that requires to be installed on the vehicle keeps more point-device tacky state over a long time.
As mentioned above, in light beam separation unit, distortion when connecting light beam separation unit or the change in position, light beam separation unit connection back are the factors that has a strong impact on record and reproducing characteristic.Thereby, light beam separation unit to be fixed and is connected to the precalculated position and under stable case, accurately keep this position long period with the suitable attitude that does not have physical deformation with respect to bigger temperature change, this is an important problem.
Consider that above-mentioned situation invented the present invention, and the purpose of this invention is to provide a kind of optic pick-up that comprises light beam separation unit, this light beam separation unit is connected or after light beam separation unit connects during bigger temperature change at light beam separation unit, can keep light beam separation unit to be in steady state (SS) with respect to physical deformation with higher positioning accuracy, in other words, this light beam separation unit can greatly improve shape reliability when attended operation and the position reliability after the attended operation.
The method of dealing with problems
To achieve these goals, optic pick-up of the present invention comprises shell, in this shell, comprise will be projected to from the light beam of light source output be used to write down or the light projecting optical system of the CD of information reproduction, with CD on beam reflected be focused on the light receiving piece to form the light-receiving optical system and the parallel flat shape light beam separation unit of image, the light beam that this parallel flat shape light beam separation unit will be advanced in the light-receiving optical system is opened with the beam separation of advancing in light projecting optical system.Light beam separation unit has two surfaces respect to one another, in described two surfaces each has at least two parts, described at least two parts on described two surfaces are by solidifying back two kinds of different respectively bonding agents of hardness and be respectively fixed to the bottom surface side that is arranged on shell and perpendicular to the connecting portion in the wall surface side of bottom surface side, be used for a surface with light beam separation unit be fixed to shell the bottom surface side bonding agent be used for another surface with light beam separation unit and be fixed to compare and after curing, have higher hardness perpendicular to the bonding agent of the wall surface side of bottom surface.
Light beam separation unit has: lower surface, and to teat, this teat is arranged on two part places of the bottom surface of the light pedestal that forms shell by first adhesive for it; And upper surface, it arrives the roughly upper end face of the support protrusion of column by second adhesive, this support protrusion is positioned at the wall surface of vertically erectting from the bottom surface of this light pedestal, this support protrusion is arranged on the both sides of peristome, the light beam of light-receiving optical system passes this peristome, second bonding agent has predetermined hardness after solidifying, and the hardness after this predetermined hardness solidifies than first bonding agent is low.
Support protrusion and comprise stage portion, be used for supporting the lower surface of light beam separation unit in the lower part of the supporting surface that supports protrusion, this supporting surface is relative with the plane of incidence of light beam separation unit, and the light beam of light-receiving optical system is incident on this plane of incidence; And cutting groove is arranged in the part of the supporting surface relative with the lower end of the plane of incidence of light beam separation unit, thereby guarantees the point-device connection status of light beam separation unit to the bottom surface of light pedestal.
First bonding agent uses has 70 or the bonding agent of higher Shore D (shore D) hardness, and second bonding agent uses and has 40 or the bonding agent of lower Shore D hardness.
In addition, optic pick-up of the present invention comprises shell, comprise in this shell being projected to being used to write down or the light projecting optical system of the CD of information reproduction, will being focused on the light receiving piece to form the light-receiving optical system and the parallel flat shape light beam separation unit of image that the light beam that this light beam separation unit will be advanced is opened with the beam separation of advancing in light projecting optical system in the light-receiving optical system in beam reflected on the CD from the light beam of light source output.Light beam separation unit has the bottom surface side opposing lower surface with shell, described lower surface has at least two parts, and described at least two parts of this lower surface are respectively fixed to first connecting portion in the bottom surface that is arranged on shell by first bonding agent with predetermined hardness; And light beam separation unit has the upper surface relative with lower surface, this upper surface has at least two parts, described at least two parts of this upper surface are by second bonding agent and the 3rd adhesive upper end face to second connecting portion of erectting from the bottom surface of shell, the hardness of this first bonding agent of the hardness ratio of this second bonding agent is low, and the hardness of this second bonding agent of the hardness ratio of the 3rd bonding agent is high and cover at least a portion of this second bonding agent.
The thermal expansivity of the 3rd bonding agent is littler than the thermal expansivity of second bonding agent.
Use thermosetting resin as first bonding agent, and use the ultraviolet curing agent as the second and the 3rd bonding agent.
First connecting portion is arranged on the interior teat of bottom surface of shell, and second connecting portion is arranged on the support protrusion of roughly column of the both sides of peristome, this support protrusion is positioned at the wall surface of vertically erectting from the bottom surface of this light pedestal, and the light beam of light-receiving optical system passes this peristome.
Support protrusion and comprise stage portion, be used to support the lower surface of light beam separation unit in the lower part of the supporting surface that supports protrusion, this supporting surface is relative with the plane of incidence of light beam separation unit, and the light beam of light-receiving optical system is incident on this plane of incidence; And cutting groove is arranged in the part of the supporting surface relative with the lower end of the plane of incidence of light beam separation unit, thereby guarantees the point-device connection status of light beam separation unit to the bottom surface of light pedestal.
Advantage of the present invention
According to the present invention, a kind of optic pick-up with light beam separation unit can be provided, wherein when light beam separation unit connects, can prevent that distortion from producing, and after light beam separation unit connected, light beam separation unit can the constant for a long time fixed position that remains under the steady state (SS), and does not depend on that installation site or environment temperature change, in other words, the shape reliability during the connection be connected after the position reliability can be improved.
Description of drawings
Fig. 1 is the block scheme of optical element that the optic pick-up of the first embodiment of the present invention is shown.
Fig. 2 is the skeleton view of the half-reflecting mirror that is fixed to the light pedestal that the optic pick-up of the first embodiment of the present invention is shown.
Fig. 3 illustrates in the first embodiment of the present invention half-reflecting mirror to the sectional view of the connection status of light pedestal.
Fig. 4 illustrates in the first embodiment of the present invention half-reflecting mirror to the explanatory of the connection status of light pedestal.
Fig. 5 A illustrates in the first embodiment of the present invention half-reflecting mirror to the planimetric map of the connection status of light pedestal, and Fig. 5 B illustrates in the first embodiment of the present invention half-reflecting mirror to the backplan of the connection status of light pedestal.
Fig. 6 A illustrates the curve map of correlativity between the bonding agent hardness of half-reflecting mirror of the first embodiment of the present invention and the fluctuation angle, and Fig. 6 B illustrates the curve map of correlativity between the hardness of last bonding agent on the top that is used for fixing the light pedestal in the first embodiment of the present invention and the aberration.
Fig. 7 A is the curve map that illustrates in the thermal shock test of half-reflecting mirror of the first embodiment of the present invention along the variable quantity of Rad direction, and Fig. 7 B is along the curve map of the variable quantity of Tan direction in the thermal shock test of half-reflecting mirror of the first embodiment of the present invention.
Fig. 8 is the skeleton view of the half-reflecting mirror that is fixed to the light pedestal that the optic pick-up of the second embodiment of the present invention is shown.
Fig. 9 illustrates in the optic pick-up of the second embodiment of the present invention half-reflecting mirror to the sectional view of the connection status of light pedestal.
Figure 10 illustrates in the optic pick-up of the second embodiment of the present invention half-reflecting mirror to the explanatory of the connection status of light pedestal.
Figure 11 A illustrates in the optic pick-up of the second embodiment of the present invention half-reflecting mirror to the planimetric map of the connection status of light pedestal, and Figure 11 B is illustrated in the optic pick-up of the second embodiment of the present invention half-reflecting mirror to the backplan of the connection status of light pedestal.
Figure 12 is the explanatory that four zones that separate on the light receiving surface that is arranged on the light receiving piece in the test machine with structure identical with the optic pick-up of the second embodiment of the present invention are shown.
Figure 13 A illustrates in the optic pick-up of the second embodiment of the present invention, because the chart of an example of the measurement result of the PD that the temperature fluctuation of half-reflecting mirror causes fluctuation, and Figure 13 B is when upper surface when half-reflecting mirror is shown only by second adhesive (individual layer is fixed), because the chart of an example of the measurement result of the PD that the temperature fluctuation of half-reflecting mirror causes fluctuation.
Figure 14 is the block scheme that common ordinary optical pick device is shown.
The reference number explanation
1 optic pick-up, 2 smooth pedestals (shell)
2A bottom surface 2B upright wall surface (wall surface)
2C supports protrusion (connecting portion, second connecting portion) 2D teat (connecting portion, first connecting portion)
3 actuator for objective lenses 21 use the light source of semiconductor laser
22 diffraction grating, 23 half-reflecting mirrors (light beam separation unit)
23A side edge part 24 collimating apparatuss
25 rising mirrors, 26 catoptrons
27 AS correction plates, 28 light receiving pieces (PD)
3 actuator for objective lenses, 31 object lens
41 first bonding agents, 42 second bonding agents
51 first bonding agents, 52 second bonding agents
53 the 3rd bonding agent E exit facets
The optical path of I plane of incidence P projection optics system
Optical path S1 first adhesion area of Q light-receiving optical system
The S2 second adhesion area S3 the 3rd adhesion area
Embodiment
Now, will be described in more detail below embodiments of the invention with reference to the accompanying drawings.
First embodiment
Fig. 1 illustrates the optic pick-up 1 of the optical disc apparatus of embodiments of the invention.Optic pick-up 1 comprises the light pedestal 2 that forms housing department and is connected to the actuator for objective lenses 3 of light pedestal 2 to move with respect to the light pedestal by electromagnetic force.Because be difficult to accurately describe the configuration of the optical element in the inner part, thereby consider that for convenience Fig. 1 shows the state of watching from a plurality of directions at grade.
For light source 21, use semiconductor laser to export the laser beam of predetermined wavelength, to read and to write the data on the CD D.Diffraction grating 22 be used to produce 0 rank light and ± single order diffraction of light light, be used to read with servo.Half-reflecting mirror 23 reflection so that crooked 90 degree of optical path, and is propagated laser light reflected bundle on CD D from the laser beam of light source 21 side incidents, so that the optical path Q of light-receiving optical system and the optical path P of light projecting optical system are separated.AS correction plate 27 is used for proofreading and correct the angle of the astigmatism that produces at half-reflecting mirror 23, realizes good servocontrol to follow mark direction and focus direction.In this embodiment, the AS correction plate has rotated 60 degree with respect to optical axis, makes the angle of direction of astigmatism with respect to the cut-off rule on the light receiving surface that is arranged on light receiving piece 28 (parting line) skew 45 degree.AS correction plate 27 has predetermined relation about its thickness, the angle that incides the incident angle of the laser beam on it and the astigmatism of generation (AS).The AS correction plate has rotated 60 degree by utilizing this relation with respect to optical path, yet, the explanation of having omitted this relation.For light receiving piece 28, photo-electric conversion element uses for example PIN photodiode.
On the other hand, actuator for objective lenses 3 comprises: object lens 31 are used for laser beam is converged to the track (pit) of CD D to write down and to read information; And aperture diaphragm, not shown in figures.Although do not illustrate in the accompanying drawings, the actuator for objective lenses 3 of present embodiment comprises: movable part, and it can be shifted with the application tracking servo along radially (R) direction of CD D, and it can be shifted along the thickness direction of CD D to use focus servo; And yoke portion, be used to support this movable part.
According to said structure, at the tracking control period, actuator for objective lenses 3 (object lens 31) fine moves by not shown servo control mechanism, with the track that allows to follow CD D from the light beam of light source (semiconductor laser) 21.When the move operation more than the preset distance that needs servo control mechanism to follow, use and not shown cross mechanism with mobile light pedestal 2.
In this embodiment, light projecting optical system comprises light source 21, diffraction grating 22, collimating apparatus 24, rising mirror 25, object lens 31 and aperture diaphragm (in the case, half-reflecting mirror 23 is got rid of outside projection optics system).On the other hand, the light-receiving optical system comprises object lens 31 and aperture diaphragm, rising mirror 25, collimating apparatus 24, catoptron 26 and AS correction plate 27 and light receiving piece 28 (in the case, half-reflecting mirror 23 is got rid of outside the light-receiving optical system).In addition, in this embodiment, because use coherent light reading light or writing light inlet as CD D, so polaroid and polarizing beam splitter mirror are capable of being combined and use to substitute half-reflecting mirror 23 together, the optical path P of light projecting optical system and the optical path Q of light-receiving optical system are separated according to polarization state.
Now, referring to figs. 2 to Fig. 5 the method that half-reflecting mirror 23 is fixed to light pedestal 2 according to the first embodiment of the present invention is described.
The initial light pedestal 2 of describing present embodiment.Shown in Fig. 2 and 4, light pedestal 2 comprises: a pair of left and right upright wall surface 2B, and its interval by preset width W separates and is arranged to the upright state from bottom surface 2A, with the optical path Q (to guarantee peristome 2E) that guarantees the light-receiving optical system; Support protrusion (connecting portion) 2C of a pair of roughly column, it is parallel to the opposed end of upright wall surface 2B; And a pair of teat (connecting portion) 2D, its be arranged on respectively with the part that supports the corresponding bottom surface 2A of protrusion 2C on.
As shown in Figure 3, support protrusion 2C and form and make that the height (as the upper surface on two relative surfaces and the distance between the lower surface) of its height and half-reflecting mirror 23 is the same, or bigger slightly than the height of half-reflecting mirror.Wall surface towards the end convergent forms supporting surface 2H, is used to support the plane of incidence I (with exit facet E facing surfaces) of half-reflecting mirror 23.In addition, in supporting protrusion 2C, the stage portion 2F of edge side of lower surface that is used to support half-reflecting mirror 23 is outstanding in the bottom of supporting protrusion 2C, and cutting groove 2G is arranged in the part relative with the side edge part 23A (referring to Fig. 3) of the bottom of the plane of incidence I of half-reflecting mirror 23.
Because can not be vertically formed and may be trickle circle (having formed curved surface), thereby consider above-mentioned thing and form cutting groove 2G as the bight of the boundary portion of bottom surface 2F and supporting surface 2H.That is to say,, cutting groove 2G is set also, make and to guarantee the point-device connection status of half-reflecting mirror 23 to the bottom surface 2A of light pedestal 2 even the bight of bottom surface 2F and supporting surface 2H is circular.
Will be described below half-reflecting mirror 23 now.In this embodiment, half-reflecting mirror 23 forms has the parallel flat shape of lamellar glass, and surface element scribbles dielectric multilayer-film, with the laser beam on the optical path P of reflected light projection optics system, and the laser beam on the optical path Q of refraction and propagates light receiving optics.
Explain the method that half-reflecting mirror 23 is fixed to light pedestal 2 referring now to Fig. 2 to Fig. 5.
(1) initial, as shown in Figure 4, first bonding agent 41 is applied on the bottom surface 2A side that is arranged on light pedestal 2 this to the zone shown in the point on the upper surface of teat 2D.Then, be supported on teat 2D and the stage portion 2F at half-reflecting mirror 23, and the rear surface of half-reflecting mirror 23 abuts against under the state on the supporting surface 2H, the bottom surface side is installed and be fixed to half-reflecting mirror 23 securely.
(2) then, shown in Fig. 2 to Fig. 5 A, use second bonding agent 42 to go up and to extend at the upper surface of half-reflecting mirror 23 and the upper surface (comprising part) of supporting protrusion 2C with the supporting surface 2H of upper surface square crossing.At this,, be preferred at the bonding agent shown in the following table 1 for first bonding agent 41 and second bonding agent 42 that are used for half-reflecting mirror 23 is fixed to light pedestal 2.
[table 1]
| First bonding agent 41 (the fixedly lower surface of half-reflecting mirror 23) | The hardness height of hardness ratio |
Thermosetting resin such as the thermoset epoxy resin |
| Second bonding agent 42 (the fixedly upper surface of half-reflecting mirror 23) | The hardness of hardness ratio first bonding |
Ultraviolet curing epoxy resin |
At this, experimentizing is used to check the fluctuation angle that produces when the bonding agent of various hardness is used for that as first bonding agent 41 and second bonding agent 42 half-reflecting mirror is fixed to light pedestal 2.In the case, solid line represents that Rad fluctuates and dotted line is represented the Tan fluctuation.The Rad fluctuation is by the fluctuation that changes the component definition along the angle of the Rad direction shown in Fig. 5 B, and the Tan fluctuation is by the fluctuation that changes the component definition along the angle of Tan direction shown in Figure 3.
As shown in Figure 6A, when the hardness of bonding agent increases, all reduce along the fluctuation angle of the fluctuation of Rad direction and Tan direction.Thereby judge that the fluctuation angle depends on the hardness of bonding agent.Known fluctuation angle preferably was suppressed to below one minute.Thereby, can learn that the hardness (Shore D) more than 70 can fully satisfy the problems referred to above.At this, Shore D is meant the hardness among the sclerometer type D (duro meter type D).For example, when hardness is 50 when spending, it is expressed with D50 usually.
Yet when the hardness of first bonding agent 41 and second bonding agent 42 increased when cured, the aberration that is caused by the half-reflecting mirror 23 various aberrations of coma, astigmatism, spherical aberration (just such as) increased a little.Correspondingly, when in record and transcriber, using this optic pick-up, wherein half-reflecting mirror 23 is connected to the light pedestal by adopting high first bonding agent 41 and second bonding agent 42 of hardness after solidifying, and record and reproducing characteristic can serious unfriendly deteriorations.Known aberration is preferably below 25 (rms), more preferably below 5 (rms).At this, rms (root mean square) is limited by following equation.
[equation 1]
rms＝[{∑H(ρ，θ)
2/N}-{∑H(ρ，θ)/N}
2]
1/2
At this, and H (ρ, θ): shape function
ρ, θ: polar coordinates
N: data number
Thereby, the present inventor rule of thumb repeats various experiments and analysis for a long time, the bonding agent that uses the hardness (Shore D) more than 70 is as the bonding agent (first bonding agent 41) that is used for fixing the bottom of half-reflecting mirror 23, and the low bonding agent conduct of use hardness is used for the bonding agent (second bonding agent 42) on top.Thereby, find that fluctuation angle and aberration can be suppressed to below the predetermined value.Now, the hardness of second bonding agent 42 and the relation between the aberration will be described below.
Half-reflecting mirror 23 is being fixed in the light pedestal 2, and experimentizing is used to check that various types of bonding agents when different hardness only are used for the amount of the aberration that second bonding agent 42 produces so that half-reflecting mirror 23 is adhered to light pedestal 2.In these experiments, first bonding agent 41 uses 70 hardness (Shore D).
The result is the result who has obtained shown in Fig. 6 B.
When being appreciated that according to these experiments hardness when second bonding agent 42 is higher, the amount of the aberration of generation increases.Thereby, when by high second bonding agent 42 of the hardness after solidifying fixedly during the upper surface of half-reflecting mirror 23, aberration unfriendly from Shore D above 40 the big increase of point pole.Correspondingly, will be appreciated that when the upper surface of half-reflecting mirror 23 fixed by second bonding agent 42 at least, preferably using hardness (Shore D) was bonding agent below 40 in order to suppress aberration.
Then, the half-reflecting mirror 23 of present embodiment is carried out thermal shock test, to check the undulate quantity along Rad direction and Tan direction, wherein this half-reflecting mirror 23 is fixed to light pedestal 2 by fixing means of the present invention.In the case, using hardness (Shore D) on the upper surface of half-reflecting mirror 23 is 25 soft bonding agent.Similarly, using hardness (Shore D) on the lower surface of half-reflecting mirror 23 is 90 high rigidity bonding agent.Thermal shock shown in the horizontal ordinate (HS) has provided at the fixed time predetermined temperature change down at interval.Especially, after+85 ℃ are located to implement heating operation 0.5 hour, located to implement cooling down operation 0.5 hour at-40 ℃, and this is defined as one-period.
As a result, acquisition result as shown in Figure 7.That is to say, according to this experiment, when in 0 to 600[cycle] scope in when implementing thermal shock, the fluctuation Δ X[degree that obtains along Rad direction and Tan direction], Δ Y[degree] be 0 to 0.05[degree] below.In Fig. 7, curve map a to c shows the result who obtains when the test machine by three same performances experimentizes.
Thereby confirm, when the half-reflecting mirror 23 that uses according to present embodiment,, all can be suppressed to less than 0.05[degree along the undulate quantity of Rad direction and Tan direction even under environment with strong thermal shock] value.Correspondingly, can realize this half-reflecting mirror 23, it can suppress undulate quantity and can be fixed to light pedestal 2 very reliably, even under the violent environment that changes of temperature.
Second embodiment
Now, second embodiment of the present invention will be described below.In this embodiment, the parts identical with first embodiment are pointed out with same reference number, to avoid repeat specification.
The optic pick-up 1 of this embodiment comprises: light pedestal 2, and it forms housing department; And actuator for objective lenses 3, it is connected to light pedestal 2 to move with respect to the light pedestal by electromagnetic force.Yet the method that half-reflecting mirror 23 is fixed to light pedestal 2 is different from first embodiment.
Then, use Fig. 8 to Figure 11 to describe the method (fixing means) that half-reflecting mirror 23 is connected to light pedestal 2.
As Fig. 8 and shown in Figure 10, be similar to first embodiment, light pedestal 2 comprises: a pair of left and right upright wall surface 2B, and its interval by preset width W separates and is arranged to the upright state from bottom surface 2A, with the optical path Q (to guarantee peristome 2E) that guarantees the light-receiving optical system; The support protrusion of a pair of roughly column (second connecting portion) 2C, it is arranged to be parallel to the opposed end of upright wall surface 2B; And a pair of teat (first connecting portion) 2D, its be arranged on respectively with the part that supports the corresponding bottom surface 2A of protrusion 2C on.
As Fig. 9 and shown in Figure 10, this to upright wall surface 2B, support protrusion 2C, this has the structure identical with first embodiment to teat (the first connecting portion 2D), peristome 2E, stage portion 2F, cutting groove 2G and supporting surface 2H.
(1) initial, as shown in figure 10, first bonding agent 51 is applied on the bottom surface 2A side that is arranged on light pedestal 2 this to the zone shown in the oblique line on the upper surface of teat 2D.Owing to used first bonding agent 51 at this, shown in the table 2 described as follows, used the thermosetting resin that has predetermined high rigidity after the curing such as the thermoset epoxy resin.
(2) then, as shown in figure 10, be supported on teat 2D and the stage portion 2F at the lower surface that uses not shown stationary fixture with half-reflecting mirror 23, and the rear surface of half-reflecting mirror 23 (plane of incidence I) abuts against under the situation on the wall surface (supporting surface 2H) that supports protrusion 2C, and half-reflecting mirror 23 is fixed to light pedestal 2 sides half-reflecting mirror 23 is fixed firmly to the bottom surface side of light pedestal 2.
(3) after this, comprise that the half-reflecting mirror of stationary fixture and light pedestal are sent to not shown heat curing stove, and be heated to predetermined temperature to solidify first bonding agent 51.
(4) then, as shown in Figure 8, be fixed to by bonding agent 51 at half-reflecting mirror 23 under the state of bottom surface 2A side of light pedestal 2, second bonding agent 52 is applied to two parts (referring to Figure 10 and 11A) of circular zone (being referred to as " the second adhesion area S2 "), thereby extends at the upper surface of half-reflecting mirror 23 and the top, upper surface (comprising the part with the supporting surface 2H of upper surface square crossing) of supporting protrusion 2C.For use second bonding agent 52 at this, use the ultraviolet curing epoxy resin of the low predetermined hardness of the hardness of ratio first bonding agent 51 shown in the table 2 described as follows.
(5) then, use the ultraviolet ray irradiation to use the second adhesion area S2 of second bonding agent 52, to solidify second bonding agent 52.
(6) after this, as shown in Figure 8, the 3rd bonding agent 53 is applied to following zone (being referred to as " the 3rd adhesion area S3 "), and these zones comprise: the subregion (being called " lamination area ") that covers second bonding agent 52 that solidifies; And the direction of extending along the end face of the support protrusion 2C of upper surface from the edge part of lamination area to half-reflecting mirror 23 and light pedestal 2 sides, the outer edge region of the second adhesion area S2 (along oval or avette long axis direction both end sides zone).That is to say that it is wideer and partly be layered in double-decker on second bonding agent 52 than the second adhesion area S2 to have to use the 3rd bonding agent 53.Thereby, in left and right two parts on the upper surface of half-reflecting mirror 23, the upper surface that supports the upper surface of protrusion 2C and half-reflecting mirror 23 partly covers second bonding agent 52 and fixes by low second bonding agent 52 of hardness ratio first bonding agent 51 and by hardness ratio second bonding agent 52 the 3rd high bonding agents 53.
The 3rd bonding agent 53 uses the ultraviolet curing epoxy resin with predetermined hardness higher than second bonding agent 52 shown in the table 2 described as follows.In having the bonding agent of high rigidity, linear expansion coefficient α or coefficient of volumetric expansion β be little than in second bonding agent 52 usually.Correspondingly, half-reflecting mirror 23 can keep its position with respect to light pedestal 2 over a long time accurately.
(7) last, when the 3rd adhesion area S3 that uses the ultraviolet ray irradiation to use the 3rd bonding agent 53 when solidifying the 3rd bonding agent 53, half-reflecting mirror 23 is fixed to light pedestal 2 under the state that half-reflecting mirror is accurately located, shown in Fig. 8 and 11.
For first bonding agent, 51 to the 3rd bonding agents 53 that are used for half-reflecting mirror 23 is fixed to light pedestal 2, the bonding agent shown in the table 2 described as follows is preferred.
[table 2]
| The bonding agent title | Bond site | Shore hardness | Curing type (name of product) | Linear |
Linear |
| |
The lower surface of half-reflecting |
D92 (hardness ratio |
Such as the thermosetting resin of thermoset epoxy resin, for example TB2212B | 4.50×10 -5 | ... |
| Second bonding agent 52 (ground floor) | The upper surface of half-reflecting |
D23 (hardness ratio first bonding |
Ultraviolet curing epoxy resin, for example TB3130 | ... | 2.71×10 -4 |
| The 3rd bonding agent 53 (second layer) | Stacked on second bonding agent, and the upper surface of half-reflecting |
D82 (hardness ratio |
Ultraviolet curing epoxy resin, for example TB3114B | 3.10×10 5 | 8.50×10 -5 |
(annotate 1) all bonding agent is by Three Bond Co., and Ltd. produces.
(annotating 2) linear expansion coefficient α 1 is illustrated in the linear expansion coefficient in the temperature range that is not higher than glass transformation temperature (Tg).
(annotating 3) linear expansion coefficient α 2 is illustrated in the linear expansion coefficient in the temperature range that is not less than glass transformation temperature (Tg).
For first bonding agent 51, second bonding agent 52 and the 3rd bonding agent 53, not only can use at the bonding agent shown in the above-mentioned table 2, can also use the 3rd bonding agent 53 of the high hardness of first bonding agent 51 with predetermined hardness higher and hardness with specific viscosity mixture 52 than the hardness of second bonding agent 52.
Correlativity between the fluctuation angle of the hardness of bonding agent and half-reflecting mirror has used Fig. 6 A to be described in first embodiment.In the present embodiment, after this,, use and first bonding agent 41 of first embodiment and the bonding agent that second bonding agent 42 is roughly the same for first bonding agent 51 and second bonding agent 52.Correspondingly, show the characteristic that is roughly the same with the characteristic shown in Fig. 6 A.
As among first embodiment with reference to as described in the figure 6A, in the present embodiment along in the fluctuation of Rad direction and Tan direction, the fluctuation angle still depends on the hardness of bonding agent.In addition, described in first embodiment, because the fluctuation angle preferably was suppressed to below one minute, the hardness more than 70 (Shore D) can satisfy the problems referred to above fully.
In addition, in the present embodiment similarly, when the hardness after the two solidifies when first bonding agent 51 and second bonding agent 52 increased, the aberration that is caused by the half-reflecting mirror 23 various aberrations of coma, astigmatism, spherical aberration (just such as) increased a little.Correspondingly, when using this optic pick-up in record and transcriber, record and reproducing characteristic can serious unfriendly deteriorations.As described in first embodiment, aberration is preferably below 25 (rms), more preferably is below 5 (rms).
In addition, in the present embodiment, when the hardness of second bonding agent 52 was higher, the amount of the aberration of generation increased, described in first embodiment.The hardness of this moment and the relation between the aberration show the characteristic that is roughly the same with the characteristic shown in Fig. 6 B.Aberration shown in Fig. 6 B represents, the various bonding agents that the hardness when 70 (Shore D) is used for first bonding agent 51 and different hardness only are used for the aberration that second bonding agent 52 obtains so that half-reflecting mirror 23 is adhered to light pedestal 2.
Thereby, similarly in this embodiment, when the upper surface of half-reflecting mirror 23 is fixed by second bonding agent 52, use bonding agent with the hardness (Shore D) below 40, make and aberration can be suppressed to below 5 (rms).
Correspondingly, in this embodiment, bonding agent with the hardness (Shore D) more than 70 is used for fixing the bonding agent of the bottom of half-reflecting mirror 23 (first bonding agent 51), and the low bonding agent of hardness is used for fixing the bonding agent (second bonding agent 52) on top, makes aberration to reduce.
As mentioned above, first bonding agent 51 uses this bonding agent with predetermined hardness, and second bonding agent 52 uses hardness to be lower than the bonding agent of above-mentioned hardness.Thereby the fluctuation during connecting half-reflecting mirror can reduce, and various types of aberrations can reduce simultaneously.
Yet in bonding agent, when hardness was lower, thermal expansivity increased bigger usually.Thereby when the bonding agent by soft fixed half-reflecting mirror 23, the position of half-reflecting mirror 23 may change owing to big temperature change.When the position change of half-reflecting mirror 23, the incoming position of light receiving piece 28 (referring to Fig. 1) also changes (claiming that this is " PD fluctuation "), and wherein the light in reflection on the half-reflecting mirror 23 and refraction incides on this incoming position.Thereby in this embodiment, the 3rd bonding agent 53 has than the high hardness of second bonding agent 52 to reduce this fluctuation.
That is to say, bond strength between the upper surface that the 3rd bonding agent 53 is used to strengthen the upper surface of half-reflecting mirror 23 and support protrusion 2C, and keep this position accurately with stable manner, the upper surface of wherein supporting protrusion 2C is fixed by second bonding agent 52 with soft.As mentioned above, have high rigidity after the bonding agent on the top that is used for fixing half-reflecting mirror 23 solidifies, when for example surpassing 40 Shore D hardness, aberration greatly increases at first.Yet, because after the upper surface of half-reflecting mirror 23 and the upper surface of supporting teat 2C are fixed together by second bonding agent 52, used the 3rd bonding agent 53, even thereby use bonding agent above 40 Shore D hardness, aberration can not change yet.With reference to the result of figure 6A, the bonding agent with the hardness (Shore D) more than 70 is preferred, similar first bonding agent 51.
To describe now because the measurement result of the PD fluctuation of the half-reflecting mirror 23 of the present embodiment that causes of temperature variation, this half-reflecting mirror 23 is fixed to light pedestal 2 by fixing means of the present invention.At this, at the optic pick-up 1 that uses as shown in Figure 1, and from when the light of the LD output of light source 21 is in half-reflecting mirror 23 reflections and on being incident on as the PD of light receiving piece 28 subsequently, the incoming position at the center by checking light beam is measured.At this, Δ PDX (%) and Δ PDY (%) are defined by following equation.
ΔPDX＝[(A+B)-(C+D)]/(A+B+C+D)×100......(1)
ΔPDY＝[(A+D)-(B+C)]/(A+B+C+D)×100......(2)
At this, A to D had both represented the title of four separation region on the light receiving surface of light receiving piece 28 shown in Figure 12 respectively, had represented again from the value of the initial current (photoelectric current) that is arranged on the terminal generation in this zone.In this embodiment, in the test machine that is used for carrying out above-mentioned test, the electric current (photoelectric current) that produces in light receiving piece (PD) 28 converts voltage to by the amplifier that includes, and magnitude of voltage is shown simultaneously.Thereby unit is arranged to mV.
In addition, said apparatus has light beam is applied to the structure of PD with reproducing signal.Yet in half-reflecting mirror, when changing the thermal expansion (or contraction) that causes bonding agent owing to environment temperature, the angle of the plane of incidence of half-reflecting mirror is changed a little by thermal expansion.Correspondingly, for example when incident angle changes θ because based on the change of this angle of optical lever principle with double, so the incoming position of light beam on PD shows as relatively large change.
Experimental result is shown in Figure 13 A and 13B.At this, curve among Figure 13 A shows respectively when the top that use half-reflecting mirror 23 wherein and is fixed to the optic pick-up (having the identical structure of implementing therewith of structure) of light pedestal 2 by having double-deck two kinds of bonding agents (second bonding agent and the 3rd bonding agent), and change in the environment temperature of installation site (from-30 ℃ change to+85 ℃) time, the center of light beam is the incoming position on PD when different temperatures.In addition, Figure 13 B shows when using the top of half-reflecting mirror 23 wherein to be fixed to the optic pick-up (comparative example) of light pedestal 2 by single bonding agent (second bonding agent), and change in the environment temperature of installation site (from-30 ℃ change to+85 ℃) time, the center of light beam is the incoming position on PD when different temperatures.
According to the figure among Figure 13 A,
And
On the other hand, in Figure 13 B,
And
Thereby can confirm that the PD fluctuation among this embodiment is fluctuateed much smaller than the PD in the comparative example.
Thereby can learn: the top of half-reflecting mirror 23 by as use second bonding agent and the 3rd bonding agent to have double-deck glued construction at this embodiment, even make under the environment of big temperature change, the PD fluctuation can be suppressed to minimum level.Thereby, can realize to depend on installation site or environment temperature to change and can under constant steady state (SS), have the half-reflecting mirror 23 that high position precision ground is fixed and is held in a predetermined position for a long time very much, in other words, can greatly improve during connecting the shape reliability be connected after the position reliability.
The present invention is described in detail with reference to special embodiment, yet can understand for those skilled in the art, can carry out various changes or modification under the premise without departing from the spirit and scope of the present invention.
The application is based on two following applications, the Japanese patent application No.2006-023112 that the Japanese patent application No.2005-269814 that on September 16th, 1 filed an application and on January 31st, 2006 file an application, and its whole contents is incorporated herein.
Industrial applicibility
As mentioned above, in optic pick-up of the present invention, can have the distortion and the position that suppress accurately light beam separation unit with respect to the larger temperature change that causes owing to installation site or environment and change, in other words, the position reliability can obtain effectively improving extraordinarily. Especially, this optic pick-up advantageously is applied to and is loaded in and will be installed to the optic pick-up of the electronic equipment on the vehicle with high vibration or temperature change, or is applied to the optic pick-up that is installed in on the recording and reconstruction device that records the CD of future generation of high density information more than DVD.
Claims (9)
1. an optic pick-up comprises shell, comprises in this shell:
Projection optics system will be projected to from the light beam of light source output and be used to write down or the CD of information reproduction;
The light-receiving optical system will beam reflected be focused on the light receiving piece on described CD, to form image; And
The light beam separation unit of parallel flat shape, the light beam that will advance in described light-receiving optical system is opened with the beam separation of advancing in described projection optics system,
Wherein said light beam separation unit has two surfaces respect to one another, in described two surfaces each has at least two parts, described at least two parts on described two surfaces are by solidifying back two kinds of different respectively bonding agents of hardness and be respectively fixed to the bottom surface side that is arranged on described shell and perpendicular to the connecting portion in the wall surface side of bottom surface side
Be used for a surface with described light beam separation unit be fixed to described shell the bottom surface side described bonding agent be used for another surface with described light beam separation unit and be fixed to compare and after curing, have higher hardness perpendicular to the described bonding agent of the wall surface side of described bottom surface.
2. optic pick-up as claimed in claim 1, wherein said light beam separation unit has: lower surface, to teat, described teat is arranged on two part places of the bottom surface of the light pedestal that forms described shell by first adhesive; And upper surface, arrive the roughly upper end face of the support protrusion of column by second adhesive, described support protrusion is positioned at the wall surface of vertically erectting from the bottom surface of described smooth pedestal, described support protrusion is arranged on the both sides of peristome, the light beam of described light-receiving optical system passes described peristome, described second bonding agent has predetermined hardness after solidifying, and the hardness after described predetermined hardness solidifies than described first bonding agent is low.
3. optic pick-up as claimed in claim 2, wherein said support protrusion comprises stage portion, be used in the lower part of the supporting surface of described support protrusion, supporting the lower surface of described light beam separation unit, described supporting surface is relative with the plane of incidence of described light beam separation unit, and the light beam of described light-receiving optical system is incident on the described plane of incidence; And cutting groove is arranged in the part of the described supporting surface relative with the lower end of the described plane of incidence of described light beam separation unit, thereby guarantees the point-device connection status of light beam separation unit to the bottom surface of light pedestal.
4. optic pick-up as claimed in claim 2, wherein said first bonding agent use has 70 or the bonding agent of higher Shore D hardness, and described second bonding agent uses and has 40 or the bonding agent of lower Shore D hardness.
5. an optic pick-up comprises shell, comprises in this shell:
Projection optics system will be projected to from the light beam of light source output and be used to write down or the CD of information reproduction;
The light-receiving optical system will beam reflected be focused on the light receiving piece on described CD, to form image; And
The light beam separation unit of parallel flat shape, the light beam that will advance in described light-receiving optical system is opened with the beam separation of advancing in described projection optics system,
Wherein said light beam separation unit has the bottom surface side opposing lower surface with described shell, described lower surface has at least two parts, and described at least two parts of described lower surface are respectively fixed to first connecting portion in the bottom surface that is arranged on described shell by first bonding agent with predetermined hardness; And
Described light beam separation unit has the upper surface relative with described lower surface, described upper surface has at least two parts, described at least two parts of described upper surface are by second bonding agent and the 3rd adhesive upper end face to second connecting portion of erectting from the bottom surface of described shell, the hardness of described first bonding agent of the hardness ratio of described second bonding agent is low, and the hardness of described second bonding agent of the hardness ratio of described the 3rd bonding agent is high and cover at least a portion of described second bonding agent.
6. optic pick-up as claimed in claim 5, the thermal expansivity of wherein said the 3rd bonding agent is littler than the thermal expansivity of described second bonding agent.
7. optic pick-up as claimed in claim 5 wherein uses thermosetting resin as described first bonding agent, and uses the ultraviolet curing agent as described second bonding agent and the 3rd bonding agent.
8. optic pick-up as claimed in claim 5, wherein said first connecting portion is arranged on the interior teat of bottom surface of described shell, and described second connecting portion is arranged on the support protrusion of roughly column of the both sides of peristome, described support protrusion is positioned at the wall surface of vertically erectting from the bottom surface of described smooth pedestal, and the light beam of described light-receiving optical system passes described peristome.
9. optic pick-up as claimed in claim 8, wherein said support protrusion comprises stage portion, be used in the lower part of the supporting surface of described support protrusion, supporting the lower surface of described light beam separation unit, described supporting surface is relative with the plane of incidence of described light beam separation unit, and the light beam of described light-receiving optical system is incident on the described plane of incidence; And cutting groove is arranged in the part of the described supporting surface relative with the lower end of the described plane of incidence of described light beam separation unit, thereby guarantees the point-device connection status of light beam separation unit to the bottom surface of light pedestal.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP269814/2005 | 2005-09-16 | ||
| JP2005269814A JP4947940B2 (en) | 2005-09-16 | 2005-09-16 | Optical pickup device |
| JP023112/2006 | 2006-01-31 | ||
| JP2006023112A JP4699224B2 (en) | 2006-01-31 | 2006-01-31 | Optical pickup device |
| PCT/JP2006/318198 WO2007032408A1 (en) | 2005-09-16 | 2006-09-13 | Optical pickup device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101268511A CN101268511A (en) | 2008-09-17 |
| CN101268511B true CN101268511B (en) | 2010-09-29 |
Family
ID=37940572
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2006800341866A Active CN101268511B (en) | 2005-09-16 | 2006-09-13 | Optical pickup device |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP4947940B2 (en) |
| CN (1) | CN101268511B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009271976A (en) * | 2008-05-01 | 2009-11-19 | Funai Electric Co Ltd | Optical pickup |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06111357A (en) * | 1992-09-25 | 1994-04-22 | Olympus Optical Co Ltd | Optical pickup |
| JPH10334499A (en) * | 1997-05-29 | 1998-12-18 | Nec Gumma Ltd | Optical pickup device |
| JP2001160229A (en) * | 1999-12-02 | 2001-06-12 | Sankyo Seiki Mfg Co Ltd | Optical head device and method for regulating inclination angle of its objective lens |
| JP2002100062A (en) * | 2000-09-22 | 2002-04-05 | Yamaha Corp | Optical pickup device |
| JP3536914B2 (en) * | 2000-09-26 | 2004-06-14 | 船井電機株式会社 | Disc player pickup device |
| JP4180804B2 (en) * | 2001-02-07 | 2008-11-12 | パイオニア株式会社 | Objective lens collision prevention device and manufacturing method thereof |
| JP3552046B2 (en) * | 2001-09-13 | 2004-08-11 | 船井電機株式会社 | Mounting method of sensor in pickup head and pickup head |
| JP2004347896A (en) * | 2003-05-23 | 2004-12-09 | Sankyo Seiki Mfg Co Ltd | Optical component fixing structure and optical head device |
| JP2005099086A (en) * | 2003-09-22 | 2005-04-14 | Ricoh Co Ltd | Wavefront aberration correction mirror and optical pickup |
| JP2005108336A (en) * | 2003-09-30 | 2005-04-21 | Hitachi Ltd | Optical head device |
-
2005
- 2005-09-16 JP JP2005269814A patent/JP4947940B2/en not_active Expired - Fee Related
-
2006
- 2006-09-13 CN CN2006800341866A patent/CN101268511B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN101268511A (en) | 2008-09-17 |
| JP2007080451A (en) | 2007-03-29 |
| JP4947940B2 (en) | 2012-06-06 |
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