CN101909842A

CN101909842A - Optical element manufacturing method, and optical element forming mold

Info

Publication number: CN101909842A
Application number: CN2008801224360A
Authority: CN
Inventors: 山本省吾
Original assignee: Konica Minolta Opto Inc
Current assignee: Konica Minolta Opto Inc
Priority date: 2007-12-28
Filing date: 2008-12-08
Publication date: 2010-12-08
Also published as: WO2009084377A1; JPWO2009084377A1

Abstract

Provided is an optical element manufacturing method, which can stably manufacture an optical element such as a high-NA lens having suppressed the occurrence or fluctuation of an aberration and which can release even the optical lens of a small size such as a small-diameter lens reliably from a forming mold. An annular movable sleeve (64a) formed around the mirror core (62) of a movable mold (42) is used to protrude the flange portion (OLb) of a lens (OL). Therefore, when this lens (OL) is released from the mirror core (62), a balanced force of a sufficient force can be applied to the entirety of the flange portion (OLb) of the lens (OL).As a result, the lens (OL) can be reliably released from the side of the movable mold (42). Thus, the lens (OL) can be stably manufactured, and a local force can be prevented from being applied to a portion of the flange portion (OLb), so that formed optical faces (LSa and LSb) can be prevented from being heterogeneously deformed.

Description

The manufacture method of optical element and optical element forming mold

Technical field

The present invention relates to the manufacture method of optical elements such as a kind of lens and be used for the optical element forming mold of this manufacture method.

Background technology

First manufacture method as optical element, (for example there is such method, with reference to patent documentation 1,2), that is, resin injection is formed in the die cavity that is formed by first mould and second mould, then, the die sinking that second mould is retreated, and, make core action as the ejecting mechanism of being located at second mould, the optical function portion that residues in the drip molding in second mould is ejected to first die side, thereby make drip molding from second mold releasability.

In addition, as second manufacture method, (for example there is such method, with reference to patent documentation 3), that is, after the die sinking that second mold is left from first mold, make as a plurality of pins of a plurality of ejection parts of being located at second mold outstanding, promote to be formed at the flange part of periphery of the optical function face of the drip molding that remains in second mold to first die side, thereby make drip molding from second mold releasability.

Patent documentation 1: TOHKEMY 2002-200654 communique

Patent documentation 2: TOHKEMY 2002-200638 communique

Patent documentation 3: TOHKEMY 2007-196665 communique

Summary of the invention

Yet, in above-mentioned first manufacture method, because form the structure that makes core advance and retreat, drip molding is ejected, so, when the material feeding that is shaped each time, core is with respect to side displacement of periphery mould or inclination, the rate of travel, the tilt quantity that are present between first mould and second mould optical function face on each change when material feeding each time, so form accuracy changes easily, at drip molding is the occasion of lens, has the coma problem of unstable that becomes.For example pick up the object lens of usefulness for light, the occasion of the high NA lens more than NA0.6 is because of relatively moving between the optical function face, coma that relative tilt produces become big.Particularly the BD more than NA0.80 (Blu-ray Disc) is with the occasion of object lens, needing to relatively move is suppressed in the pact ± 1.0 μ m, relative tilt is suppressed at approximately ± 0.02 ° in, it is undesirable that core is ejected with respect to displacement of periphery die side or inclination as described above.

In addition, in above-mentioned second manufacture method, drip molding is little optical element, then the area that ejects with the flange part of pin of butt diminishes, have to reduce to eject each diameter of selling of usefulness, so the total sectional area that applies all pins of necessary knockout press when ejecting also diminishes, each pin is applied superfluous pressure.For example, it is the following small diameter lenses of 6mm that the object lens that light picks up usefulness use external diameter more, but in this occasion, be under the situation of the small diameter lenses about 5mm for example at external diameter, typically having a diameter from about 1mm of pin, be under the situation of the small diameter lenses about 3.5mm at external diameter particularly, the diameter of pin is below the 0.4mm.Therefore, the part, butt position of the pin in flange part applies big power, has the problem that the optical function face of lens might be out of shape unevenly.In addition, the durability of pin descends, and some occasion also produces the pin distortion, lens can not be ejected such problem.

Therefore, the object of the present invention is to provide a kind of manufacture method of optical element, the manufacture method of this optical element can stably be made the optical element of the generation to aberrations such as comas, the high NA lens that change suppresses etc., even be the small-sized optical element of small diameter lenses etc., also can carry out the demoulding effectively, when the demoulding, be difficult for taking place the precision deterioration of shape from shaping dies.

In addition, the object of the present invention is to provide a kind of optical element forming mold of enforcement of the manufacture method that is suitable for above-mentioned optical element.

In order to address the above problem, the manufacture method of optical element of the present invention is characterised in that: have first operation, second operation, the 3rd operation; (a) in first operation, by a pair of die forming optical element, this a pair of mould is made of first mould and second mould; (b) in second operation, first mould and second mould are left, thereby make optical element from first mold releasability; (c) in the 3rd operation, the flange surface that the liftout component that use has a ring-type front end face will be formed at around the optical surface of optical element ejects, thereby make optical element from the core demoulding, the ring-type front end face spread all over the formation optical element of being located at second mould optical surface core around and be provided with.

According to above-mentioned manufacture method, in the 3rd operation, use has the liftout component of the ring-type front end face that is provided with around the core of second mould, the flange surface of optical element is ejected, so, when making the optical element demoulding from core, can apply the sufficient knockout press that has obtained balance to flange part in optical surface periphery more in the outer part than optical element, the area that can make liftout component be connected to flange surface increases.Like this, can make optical element, not only can carry out the stable manufacturing of optical element, and can prevent that the optical surface after the part of flange surface applies local power, shaping is out of shape unevenly effectively from the second die side demoulding.In addition, make optical element when the core demoulding, do not need to make the core displacement, so, can prevent that in second mould core from producing displacement when the material feeding that is shaped each time, can reduce the reason of the position skew that the forming face of the forming face of first mould and second mould relatively moves, tilts such.Therefore, can make the generation that suppresses various aberrations, the high performance optical element of change in large quantities.

For concrete mode of the present invention or viewpoint, in first operation of above-mentioned manufacture method, in the die cavity that forms by a pair of mould, inject resin, thereby carry out the shaping of optical element.In this occasion, can stably make high-precision resinous optical element.

In another way of the present invention, in the 3rd operation,, liftout component is being moved from the direction of second mould towards first mould having interfixed core and under the state of the periphery mould that is provided with around the liftout component.In this occasion, core does not change with the relative configuration relation of periphery mould, can stably keep both configuration relations.

In another way of the present invention, first mould is a fixed mould, and second mould is a moveable die.In this occasion, at moveable die side pack into core, liftout component.

In another way of the present invention, optical element is lens.In this occasion, can provide the generation that has suppressed coma, the high performance lens of change.Particularly pick up the object lens of usefulness for high performance light, specifically for the laser that uses 380～420nm, as the high NA lens more than the side numerical aperture NA0.75, even though there be relatively moving, tilting between the two sides that produces very little optical surface, optical property is the problem of remarkable deterioration also, but can prevent this problem effectively.

Optical element forming mold of the present invention (a) is by a pair of die forming optical element; It is characterized in that: in a side mould, have core and liftout component; (b) this core forms the optical surface of described optical element; (c) this liftout component has the front end face of the ring-type that is provided with that spreads all over described core on every side, in order to eject the flange surface on every side of the optical surface that is formed on described optical element, can advance and retreat towards the direction of the opposing party's mould at the mould from a described side.

According to above-mentioned optical element forming mold, one side's mould has liftout component, this liftout component has the front end face of the ring-type that is provided with around core, can advance and retreat towards the direction of the opposing party's mould at mould from a described side, the forming face of one side's die side is formed by core and liftout component at least, so the optical surface flange surface on every side that uses liftout component will be formed at optical element ejects, thereby can make optical element from the core demoulding.When this, the periphery that can more be in the outside at the optical surface than optical element applies the enough knockout presses that obtained balance to flange part, so, can make the die side demoulding of optical element effectively from a side, not only can carry out the stable manufacturing of optical element, and can prevent that the part at flange surface from applying local power and optical surface after causing being shaped is out of shape unevenly.In addition, make optical element when the core demoulding, do not need to make the core displacement, so, can prevent to produce displacement during in the material feeding that is shaped each time at a side mould core mould, the reason of the position skew that the forming face of a side the forming face of mould and the opposing party's mould relatively moves, tilts such can be reduced, the generation that has suppressed various aberrations, the high performance optical element of change can be made in large quantities.

In concrete mode of the present invention, in above-mentioned optical element forming mold, a side mould has the periphery mould that is provided with around liftout component.In this occasion, Yi Bian can be on one side guiding by the periphery mould prevent that falling of optical element from making optical element from the core demoulding.

In another way of the present invention, varying in size of the gap of the gap of core and liftout component and liftout component and periphery mould, the position of the fore head in the smaller side's in the position of the fore head in a bigger side's gap gap more constitutes highlightedly to the opposing party's die side.In this occasion, the shaping burr corresponding with a bigger side's gap can be configured in the opposing party's die side, the position that the shaping burr is produced is recessed, and it is outstanding from optical element to suppress the shaping burr.

The meaning of the fore head in gap is as follows.That is, the gap refers to result from two gaps between mould, and leading section is the position that is in the opposing party's die side most.Therefore, for example in Fig. 4, suitable with edge LSb1 and edge F11.

In another way of the present invention, core is bigger than the gap of liftout component and periphery mould with the gap of liftout component.In this occasion, make the liftout component advance and retreat, thereby the core that can suppress costliness is impaired, can prolong its life-span.

In another way of the present invention, core is littler than the gap of liftout component and periphery mould with the gap of liftout component, and the shape of the front end face of the ring-type of liftout component more is being in the mold tabs of the position of periphery mould side towards the opposing party than core side.In this occasion, around corresponding to the forming face in the gap of core and liftout component, the shaping burr relatively is difficult to form or form lessly, to be configured in the opposing party's die side corresponding to the shaping burr in the gap of liftout component and periphery mould, make the position that produces the shaping burr recessed, the burr that can suppress to be shaped is outstanding from optical element.

In another way of the present invention, the front end face of the ring-type of liftout component is to be used for the forming face of at least a portion that transfer printing forms the flange surface of optical element.In this occasion, be configured for forming the forming face of flange surface by the front end face of the ring-type of liftout component at least.

Description of drawings

Fig. 1 is the sectional view of the structure of explanation fixed mould of first embodiment and moveable die.

Fig. 2 is the local amplification view of the mould of Fig. 1.

Fig. 3 is that end view drawing is amplified in the part of the moveable die of Fig. 1.

Fig. 4 is the partial enlarged drawing by the lens of the die forming of Fig. 1.

Fig. 5 is the front view of the manufacture method etc. of explanation second embodiment.

Fig. 6 is the front view of the manufacture method etc. of explanation the 3rd embodiment.

The explanation of symbol

41... fixed mould

42... moveable die

51... periphery mould

52... minute surface core

53... fixed cap

56... shaping minute surface

56a... optical surface forming face

56b... forming face

61... periphery mould

62... minute surface core

64... movable sleeve pipe

64d... core inserting hole

65... core sleeve inserting hole

66a... optical surface forming face

66b... forming face

66c... forming face

67... advancement mechanism

68... retreat mechanism

69... spacer member

73... sleeve pipe knock pin

74... pin drive plate

76... shoulder bolt

77... spring

AX... the axle

CV... die cavity

LSa, LSb... optical surface

OL... drip molding

OA... optical axis

OL... lens

OLa... central part

OLb... flange part

PL... parting line

The specific embodiment

First embodiment

Below, with reference to the manufacture method of the optical element of description of drawings first embodiment of the invention.

The side partial cross-sectional of the structure of the mould that Fig. 1 is made of fixed mould 41 and moveable die 42 for explanation, Fig. 2 be the amplification view of the P1 part of Fig. 1, Fig. 3 be from the A direction watch moveable die 42 to view.In addition, Fig. 4 is the partial enlarged drawing of the lens that are shaped by the mold injects of Fig. 1., the occasion of having used horizontal forming machine is described here, but also can uses vertical forming machine.

Fixed mould 41 and moveable die 42 can be that the border opens and closes with parting line PL.Corresponding as the die cavity CV (with reference to Fig. 2) in the space that is sandwiched in two

moulds

41,42 with shape as the lens OL of the optical element of drip molding.Lens OL is made of plastics, and is provided with the central part OLa with optical function and the flange part OLb of the OLa ring-type of extending to the external diameter direction from central division.Here, the external diameter of the lens OL that is formed by two

moulds

41,42 is below 6mm.External diameter for lens OL, the occasion below φ 3.5mm for example, precision when by the mould of present embodiment lens OL being shaped guarantees that effect improves, the occasion below φ 2.0mm, and the precision the when mould by present embodiment can improve lens OL especially and is shaped is guaranteed effect.

Fixed mould 41 has as the fixing fixed cap 53 of periphery mould 51 and minute surface core 52 of the minute surface core 52 of the core of fixation side and one.Periphery mould 51 has the end face 51a that forms parting line PL.In addition, in periphery mould 51 inside, be formed for inserting the core inserting hole 55 of supporting minute surface core 52.

Moveable die 42 has minute surface core 62, periphery mould 61, movable sleeve pipe 64, advancement mechanism 67 and retreats mechanism 68; This minute surface core 62 is as the core of movable side; This periphery mould 61 has the structure that can support and fix movable side core integratedly; This movable sleeve pipe 64 is as ejecting the liftout component that lens OL makes its demoulding; This advancement mechanism 67 is used to make movable sleeve pipe 64 to advance mobile to fixed mould 41 sides; This retreats mechanism 68 and is used to make movable sleeve pipe 64 to retreat mobile.

Periphery mould 61 has the end face 61a that forms parting line PL.In addition, in the inside of periphery mould 61, be formed for inserting and supporting the core sleeve inserting hole 65 of minute surface core 62 and movable sleeve pipe 64.Fixed mould 41 sides in the core sleeve inserting hole 65 form minor diameter, retreat mechanism's 68 sides and form major diameter.In addition, the axiality of minor diameter and large-diameter portion is controlled in the following degree of 1 μ m.In addition, the axiality of the periphery forming face 66c of flange part and the large-diameter portion of inserting hole is controlled in the following degree of 5 μ m, the periphery of the main shaped flange OLb of portion of periphery forming face 66c of described flange part.

Minute surface core 62 is inserted into the core inserting hole 64d of movable sleeve pipe 64 in front, is inserted into the core sleeve inserting hole 65 of periphery mould 61 in the root side, is fixed on the periphery mould 61 in the root side.The leading section of minute surface core 62 has columned outer peripheral face, allows moving along the axle AX of movable sleeve pipe 64 described later in the core inserting hole 64d of the inner peripheral surface with correspondingly-shaped.Front end face at the leading section of being located at minute surface core 62 is provided with the optical surface forming face 66a that is used to form die cavity CV.This optical surface forming face 66a is a concave surface, the side's of the central part OLa of formation lens OL optical surface LSb.Minute surface core 62 directly is bearing on the periphery mould 61 by screw etc., and the position relation of optical surface forming face 66a and flange formation portion 63 critically is maintained.Though omit in the accompanying drawings, can between the root front end face of minute surface core 62 and periphery mould 61 rear end faces, spacer member be set.Like this, can adjust the interval of optical surface forming face 66a with the optical surface forming face 56a of the minute surface core 52 of facing it of minute surface core 62.

Movable sleeve pipe 64 is inserted into the core of periphery mould 61. sleeve pipe inserting hole 65.The leading section of movable sleeve pipe 64 has the outer peripheral face of columned minor diameter, can move along axle AX in the core sleeve inserting hole 65 of the inner peripheral surface with correspondingly-shaped.In addition, the root of movable sleeve pipe 64 also has columned large diameter outer peripheral face, can slide along axle AX in the core sleeve inserting hole 65 of the inner peripheral surface with correspondingly-shaped.That is, movable sleeve pipe 64 can be in the core sleeve inserting hole 65 of periphery mould 61 advances or retreats to opposition side to fixed mould 41 sides.Be provided with the forming face 66b of a part that forms flange formation portion 63 at the front end of movable sleeve pipe 64, described forming face 66b is used to form die cavity CV.This forming face 66b and the forming face 66c co-operating that forms as the part of the flange formation portion 63 of the part of periphery mould 61, the flange surface F1 of the flange part OLb of molded lens OL, i.e. a side annular end face.And, between the large diameter root front end face of the rear end face of movable sleeve pipe 64 and minute surface core 62, insert spacer member 69, by inserting the different spacer member of thickness, can adjust forming face 66b and face the interval of its optical surface forming face 56a.This spacer member 69 also can be fixed on the either party in movable sleeve pipe 64 and the minute surface core 62.

Advancement mechanism 67 have the sleeve pipe knock pin 73 of the active force that applies direction of advance with spacer member 69 butts, for movable sleeve pipe 64 and carrying sleeve knock pin 73 rearward end 73a, make it at the axial pin drive plate 74 of advance and retreat.Sleeve pipe knock pin 73 is inserted in the pin-and-hole non-contactly, and this pin-and-hole forms in the mode that connects minute surface core 62 and retreat the back panel 78 of mechanism 68, and this sleeve pipe knock pin 73 is parallel to the axle AX of movable sleeve pipe 64 and extends, and can advance and retreat along axle AX.Sleeve pipe knock pin 73 only illustrates 1 in the accompanying drawings, but preferably disposes axisymmetricly about 2～6 about axle AX.Pin drive plate 74 is driven by the knock-pin of not shown forming machine, and being in due course along axle AX changes the amount of the required distance of the demoulding.

Retreat mechanism 68 have be fixed in movable sleeve pipe 64 at leading section spring fixedly usefulness shoulder bolt 76, remain in shoulder bolt 76 back-moving spring 77, accommodate the back panel 78 of shoulder bolt 76 etc.Shoulder bolt 76 is inserted into the pin-and-hole 79b that forms in the mode that connects minute surface core 62 and back panel 78 non-contactly, and be parallel to the axle AX of movable sleeve pipe 64 and extend, and can be in the direction advance and retreat of axle AX.But, back-moving spring 77 is located between the rear end of the head part of shoulder bolt 76 and minute surface core 62, rearward to movable sleeve pipe 64 application of forces, so, movable sleeve pipe 64 is subjected to remaining the active force of the state that has moved back to back panel 78 rear flank usually the time, and is subjected to the power of self-marketing drive plate 74 and ejects necessary amount.And, though omit in the drawings, can between minute surface core 62 and back panel 78, spacer member be set.In addition, in the accompanying drawings, retreat mechanism 68 and only represent 1, dispose axisymmetricly about 2～6 about axle AX but be preferably in not the position of interfering with sleeve pipe knock pin 73.

In the fixed mould 41 in above mould, about the chimeric gap of the fitting portion of the larger diameter side between periphery mould 51 and the minute surface core 52 (the following gap that also simply is called) A1 for example is located at below the 1 μ m (below, the value representation external diameter (diameter) in gap is poor with internal diameter (diameter)).In addition, the gap A3 of the fitting portion of smaller diameter side also can little degree below 1 μ m, perhaps also the gap can be increased to the degree (for example about 2～10 μ m) that produces the shaping burr that does not influence installation in lens OL.In addition, in moveable die 42, periphery mould 61 similarly is located at for example following degree of 1 μ m with the gap A2 and the above-mentioned gap A1 of the fitting portion of the larger diameter side of minute surface core 62.

In the moveable die 42 in above mould, be equivalent between the inner peripheral surface of core inserting hole 64d of the leading section outer peripheral face of minute surface core 62 and movable sleeve pipe 64 interplanar distance from gap B1, for example be set at about 3～10 μ m by diameter.In addition, in moveable die 42, be equivalent between the inner peripheral surface of the core sleeve inserting hole 65 in the flange formation portion 63 of the leading section outer peripheral face of movable sleeve pipe 64 and periphery mould 61 interplanar distance from gap B2, similarly for example be set at about 3～10 μ m with above-mentioned gap B1 by diameter.In addition, the core that is equivalent to the root side of the major diameter root of movable sleeve pipe 64 and periphery mould 61. the interplanar distance between the inner peripheral surface of sleeve pipe inserting hole 65 from gap B3, set forr a short time, in this is set than inside and outside gap B1, the B2 of movable sleeve pipe 64, as scope, for example be made as about 1～5 μ m.By making gap B1, B2 ratio gap B3 greatly to a certain degree, can prevent that minor diameter 62a, movable sleeve pipe 64 from contacting with on every side parts and injured, thereby can prevent lens OL because of injured produce apparent bad.In addition, if the gap about 3～10 μ m even then produce the burr that is caused by the gap on lens OL, also can suppress the size for negligible degree.

In the present embodiment, make the thickness t radially 1 of leading section of movable sleeve pipe 64 of moveable die 42 narrower, form the outer edge of flange part OLb by periphery mould 61 than the width t2 of the radial direction of the flange part OLb of lens OL.Guarantee the form accuracy of thickness etc. of the outer edge of flange part OLb like this, easily.Here, size for example is preferably about 0.5～0.9 than t1/t2, if then better about 0.7～0.9.By size is set in more than 0.7 than t1/t2, can apply the good ejecting force of balance to flange part OLb integral body, obtain effectively to alleviate the effect that ejects pressure, can carry out stable the ejecting of lens OL, can suppress the distortion that ejects generation by lens OL.In addition, by make size than t1/t2 below 0.9, in the forming face of periphery mould 61, can be adjacent to the forming face 66b outer edge side of movable sleeve pipe 64 front ends of moveable die 42, in flange formation portion 63, guarantee the forming face 66d of sufficient size.Corresponding among the flange surface F1 of this forming face 66d and flange part OLb to the side-prominent end face portion 66f of dish.By such forming face 66d is set, can prevent that movable sleeve pipe 64 from touching the flange formation portion 63 of periphery mould 61, can improve the mobility that ejects action of being undertaken by movable sleeve pipe 64.

In addition, because the error when making, the front end face of the movable sleeve pipe 64 of moveable die 42 retreats than the optical surface forming face 66a of minute surface core 62, movable sleeve pipe 64 moves in the figure of Fig. 4 to the left with the fore head of the gap B1 of minute surface core 62, and the shaping burr that may cause resulting from this gap B1 thus is more more outstanding than the summit (intersection point of optical surface LSb and optical axis OA) of the optical surface LSb of dish side.For this reason, in the present embodiment, the front end face that makes movable sleeve pipe 64 than the fore head in the fore head in movable sleeve pipe 64 and the gap of periphery mould 61 and movable sleeve pipe 64 and the gap of minute surface core 62 to the inner protruding distance d1 of die cavity CV.Like this, among the lens OL after shaping, one of starting point of shaping burr is in full week of edge LSb1 of the most peripheral side of optical surface LSb, another is in full week of edge F11 of the most peripheral side of recessed flange surface F1, burr is more outstanding than the summit of the optical surface LSb of dish side so can prevent from effectively to be shaped, can alleviate the shaping burr to the installation of lens OL exert an influence, be the operating distance of lens OL be shaped burr influence and produce the danger of change.

In the present embodiment, represented that the position of movable sleeve pipe 64 and the fore head in the gap of periphery mould 61 and movable sleeve pipe 64 and the position of the fore head in the gap of minute surface core 62 are in the example of the occasion of same position, but the different occasion in position at the fore head in these gaps, as long as with respect to the fore head that is positioned at more near the gap of the position of a side of the opposing party's mould (fixed mould 41), the front end face that makes movable sleeve pipe 64 more gets final product to die cavity CV inside protruding distance d1 than the position of the fore head in this gap.

Use above mould to make optical element.Like this, the movable sleeve pipe 64 that ring-type is set on every side that spreads all over the minute surface core 62 of moveable die 42, the front end face of ring-type that the front end of movable sleeve pipe 64 is located in use is forming face 66b, eject the flange part OLb of lens OL, so, make lens OL when 62 demouldings of minute surface core, can increase the area that ejects part, can apply the enough knockout presses that obtained balance on the whole at the flange part OLb of lens OL.Like this, can make lens OL effectively, can carry out the stable manufacturing of lens OL, simultaneously, can improve the durability of the moveable die 42 that comprises movable sleeve pipe 64 grades from the moveable die 42 side demouldings.In addition, can prevent from the part of flange part OLb, to apply local power and optical surface LSa, LSb after causing being shaped is out of shape unevenly.In addition, at lens OL when 62 demouldings of minute surface core, do not need to make 62 displacements of minute surface core, so, can prevent in moveable die 42 that minute surface core 62 from producing displacement when the material feeding that is shaped each time, the optical surface forming face 56a that can reduce fixed mould 41 relatively moves with the optical surface forming face 66a of moveable die 42 or the reason of inclination.Therefore, can make the generation that has suppressed various aberrations, the high performance lens OL of change in large quantities.

Specifically, in moveable die 42, make movable sleeve pipe 64 displacements, but fixing minute surface core 62, so, can suppress relatively moving between a pair of optical surface LSa, the LSb of lens OL, the generation of relative tilt, change, can suppress the generation of the coma of lens OL.By using the

mould

41,42 of above such core precision, at for example lens OL is that light more than the NA0.65 picks up with object lens (as concrete example, the HD DVD object lens that comprise NA0.65), particularly the object lens more than the NA0.75 are (as concrete example, the BD that comprises NA0.85 is with object lens etc.) occasion, can be suppressed at relatively moving in the pact ± 1.0 μ m, relative tilt can be suppressed at approximately ± 0.02 ° in, so, can obtain to reduce the high performance object lens of coma etc.

Second embodiment

Below, the manufacture method of the optical element of second embodiment is described.The manufacture method of second embodiment is the mode that first embodiment has been out of shape, and does not have the part that specifies with first embodiment identical.

Fig. 5 is the amplification view of the mould of present embodiment.As from figure also as can be seen, in moveable die 42, the forming face 66d that makes periphery mould 61 is unanimous on the whole with the front end face of movable sleeve pipe 64.But the front end face and first embodiment of movable sleeve pipe 64 are same, than the front position of minute surface core 62 more to minute surface core 52 side-prominent interval d1.In this occasion, the shaping burr that is formed by the gap B2 between periphery mould 61 and the movable sleeve pipe 64 is that benchmark is formed on the position of further leaving from the summit of the optical surface LSb that coils side with the direction of optical axis OA.Therefore, though at the gap B2 in the outside of movable sleeve pipe 64 than the inboard bigger occasion of gap B1, the burr that also can prevent to be shaped exerts an influence to the installation of lens OL, that is, the operating distance of lens OL produces change because of the influence of shaping burr.In addition, in such occasion, also ratio gap B1 is big to make gap B3 (with reference to Fig. 1), the contact site in the time of thereby backing-out punch can being moved only is limited between movable sleeve pipe 64 and the minute surface core 62, compare with the occasion that has a plurality of contacts site, can reduce the happening part of the scar that is produced by the mutual contact of member, it is bad to reduce the bad such shaping of action.

The 3rd embodiment

Below, the manufacture method of the optical element of the 3rd embodiment is described.The manufacture method of the 3rd embodiment is the method that second embodiment has been out of shape, and does not have the part that specifies with second embodiment identical.

Fig. 6 is the amplification view of the mould of present embodiment.In this occasion, in moveable die 42, the forming face 66d that makes periphery mould 61 is roughly consistent with the end face of the outer circumferential side of movable sleeve pipe 64, and the end face of interior all sides that makes movable sleeve pipe 64 is than the recessed interval d3 of the end face of outer circumferential side.In addition, the end face of interior all sides of movable sleeve pipe 64 than the outer circumference end of the optical surface forming face of minute surface core 62 more to fixed mould 41 side-prominent interval d2.Therefore, the flange forming face 66d of periphery mould 61 than the endface position of interior all sides of minute surface core 62 to fixed mould 41 lateral processes at interval d4 (＞d2).In the occasion of the 3rd embodiment, to compare with the occasion of second embodiment, the shaping burr that is formed by the gap B2 in the outside of movable sleeve pipe 64 is that benchmark is formed on the position of further having left from the summit of the optical surface LSb of dish side with the direction of optical axis OA.Therefore, though the gap in the outside that makes movable sleeve pipe 64 B2 than inboard gap B1 bigger occasion, the burr that also can prevent to be shaped exerts an influence to the installation of lens OL, that is, the operating distance of lens OL produces change because of the influence of shaping burr.In addition, in such occasion, also ratio gap B1 is big by making gap B3 (with reference to Fig. 1), contact site in the time of backing-out punch can being moved only is limited between movable sleeve pipe 64 and the minute surface core 62, compare with the occasion that has a plurality of contacts site, can reduce the happening part of the scar that is produced by the mutual contact of member, it is bad to reduce the bad such shaping of action.

More than utilize embodiment that the present invention has been described, but the present invention is not limited to above-mentioned embodiment, can carries out various distortion.For example, the die cavity CV that is located at the mould that is made of fixed mould 41 and moveable die 42 is not limited to 1, also can be for a plurality of.That is, can for example embed a plurality of minute surface cores 52 in the periphery mould 51, corresponding therewith, can in moveable die 42, embed the assembly that many groups are made of minute surface core 62 and movable sleeve pipe 64.In this occasion, the shaping of a material feeding that can be by utilizing two

moulds

41,42 obtains a plurality of lens OL.

In addition, the shape of the optical surface forming face 66a of the shape of the optical surface forming face 56a of the front of the minute surface core 52 shown in Fig. 2 etc., the front of minute surface core 62 only is an illustration, can carry out appropriate change corresponding to purposes of lens OL etc.For example also can substitute the shape of two optical surface forming face 56a, 66a, be formed in the lens that moveable die 42 sides have formed the face of deep camber.

In addition, as shown in Fig. 3 waits like that, the leading section of movable sleeve pipe 64 has profile cylindraceous, but can form the tubular of various cross sectional shapes such as quadrangle.But, by forming the tubular of circular cross-section, can easily make moveable die 42, can improve the precision of moveable die 42.

In addition, in the above-described 3rd embodiment, be provided with the step that highly radially changes at the front end face of movable sleeve pipe 64, but be not limited thereto, height also can be set along the step that circumferentially changes.

In addition, lens OL is not limited to plastics and makes, and also can make glass lens by the building mortion 100 of having assembled

same mould

41,42 etc.

Claims

1. the manufacture method of an optical element is characterized in that: have first operation, second operation, the 3rd operation;

In described first operation, by a pair of die forming optical element, this a pair of mould is made of first mould and second mould;

In described second operation, described first mould and described second mould are left, thereby make described optical element from described first mold releasability;

In described the 3rd operation, the flange surface that the liftout component that use has a ring-type front end face will be formed at around the optical surface of described optical element ejects, thereby make described optical element from the core demoulding, described ring-type front end face spread all over the described optical element of formation of being located at described second mould optical surface described core around and be provided with.

2. the manufacture method of optical element according to claim 1 is characterized in that: in described first operation, inject resin in the die cavity that is formed by described a pair of mould, thereby carry out the shaping of described optical element.

3. the manufacture method of optical element according to claim 1, it is characterized in that: in described the 3rd operation, interfixed described core and spread all over described liftout component around and under the state of the periphery mould that is provided with, described liftout component is being moved towards the direction of described first mould from described second mould.

4. according to the manufacture method of any one described optical element in the claim 1～3, it is characterized in that: described first mould is a fixed mould, and described second mould is a moveable die.

5. according to the manufacture method of any one described optical element in the claim 1～4, it is characterized in that: described optical element is lens.

6. optical element forming mold is by a pair of die forming optical element; It is characterized in that:

In a side mould, have core and liftout component; This core forms the optical surface of described optical element; This liftout component has the front end face of the ring-type that is provided with that spreads all over described core on every side, in order to eject the flange surface on every side of the optical surface that is formed on described optical element, can advance and retreat towards the direction of the opposing party's mould at the mould from a described side.

7. optical element forming mold according to claim 6 is characterized in that: a described side's mould has the periphery mould that is provided with that spreads all over described liftout component on every side.

8. optical element forming mold according to claim 7, it is characterized in that: the varying in size of the gap of the gap of described core and described liftout component and described liftout component and described periphery mould, the position of the fore head in the smaller side's in the position of the fore head in a bigger side's gap the gap more die side to described the opposing party are outstanding.

9. according to any one described optical element forming mold in claim 7 and 8, it is characterized in that: the gap of described core and described liftout component, bigger than the gap of described liftout component and described periphery mould.

10. optical element forming mold according to claim 8 is characterized in that: described core is littler than the gap of described liftout component and described periphery mould with the gap of described liftout component,

The shape of the front end face of the described ring-type of described liftout component more is being in the mold tabs of the position of described periphery mould side towards described the opposing party than described core side.

11. according to any one described optical element forming mold in the claim 6～10, it is characterized in that: the front end face of the described ring-type of described liftout component is to be used for the forming face of at least a portion that transfer printing forms the described flange surface of described optical element.