CN102821924A

CN102821924A - Moulding die, optical element, and method for manufacturing optical element

Info

Publication number: CN102821924A
Application number: CN2011800162782A
Authority: CN
Inventors: 清水勉; 富士健太
Original assignee: Konica Minolta Opto Inc
Current assignee: Konica Minolta Opto Inc
Priority date: 2010-03-30
Filing date: 2011-01-28
Publication date: 2012-12-12
Anticipated expiration: 2031-01-28
Also published as: JPWO2011122090A1; WO2011122090A1; JP2012153145A; CN102821924B; JP5163832B2

Abstract

Resistance to mould release caused by resin contraction produced by cooling solidification during injection moulding can be suppressed, even in a comparatively deep range in which the value (Y/X) of the vertical/horizontal ratio of the step shapes of, for example, a three-wavelength-compatible optical element is 0.50 = maximum value of (Y/X) = 1.0, by performing mould release in which a first optical transfer face (11A) having step shapes (13A, 15A) that form a diffraction structure is released from a plastic lens (PL) before a second optical transfer face (21A) is released when injection moulding the plastic lens (PL). The plastic lens (PL) can therefore be smoothly released from a fixed mould (10) with substantially no resistance even in the case of an optical element that has a microstructure having deep steps therein, thereby making it possible to prevent deformation of the steps, namely the micro-shapes, of the diffraction structure of the plastic lens (PL).

Description

The manufacturing approach of mould, optical element and optical element

Technical field

The present invention relates to the mould of moulding used for optical elements, the optical element of this mould moulding of usefulness, and the manufacturing approach of this optical element.

Background technology

When the moulding optical surface has the optical element of stairstepping microstructures such as diffraction structure; The optics transfer surface of mould and the optical surface of optical element depart from when preventing die sinking, have a kind of elder generation not have the optical surface of microstructure greatly, have the method (please reference example such as patent documentation 1) of the optical surface of microstructure for a short time from the opposing party's mold releasability radius of curvature then from side's mold releasability radius of curvature.

The look-ahead technique document

Patent documentation

Patent documentation 1: the spy opens the 2002-200652 communique

The problem that the invention desire solves

But, in the patent documentation 1 described mould, compare when side's mold releasability radius of curvature does not have the optical surface of microstructure greatly the state of cooling progress of optical element when the opposing party's mold releasability radius of curvature has the optical surface of microstructure for a short time.The words resin shrinkage of optical element cooling is so the demoulding obstacle of optical element increases when having microstructure on the optical surface.Therefore, in the patent documentation 1 described mould, when the opposing party's mold releasability had the optical surface of microstructure, the wall of the wall of optical element microstructure and mould microstructure produced friction, caused the microstructure distortion of optical element, existing problems.

For example; As objective lens for optical pickup device; Useful numerical aperture (NA) 0.45 is concentrated on CD (Compact Disc) wavelength (780nm) on the CD CD, with numerical aperture (NA) 0.6 DVD (Digital Versatile Disc) wavelength (650nm) is concentrated on the CD/DVD two wavelength exchange type objective optical element for optical pickup device on the DVD CD, and also useful numerical aperture (NA) 0.45 is concentrated on wavelength (780nm) on the CD CD, with numerical aperture (NA) 0.6 DVD wavelength (650nm) is concentrated on the DVD CD, with numerical aperture (NA) 0.85 BD (Blu-ray Disc) wavelength (405nm) is concentrated on the CD/DVD/BD three-wavelength exchange type objective optical element for optical pickup device on the BD CD.Wherein, CD/DVD/BD three-wavelength exchange type objective optical element for optical pickup device is compared with CD/DVD two wavelength exchange type objective optical element for optical pickup device, and the microstructure that optical element is provided with has darker step shape.Therefore; Compare with CD/DVD two wavelength exchange type objective optical element for optical pickup device; During CD/DVD/BD three-wavelength exchange type objective optical element for optical pickup device, the demoulding obstacle of optical element is bigger, when the demoulding has the optical surface of microstructure, the distortion of optical element microstructure occurs more easily.To this; Compare with CD/DVD two wavelength exchange type objective optical element for optical pickup device; CD/DVD/BD three-wavelength exchange type objective optical element for optical pickup device is asked to higher formed precision and optical property, so must further reduce the distortion of optical element microstructure in the moulding.Therefore, causing the demoulding problem on obstacle of microstructure distortion during moulding CD/DVD/BD three-wavelength exchange type objective optical element for optical pickup device, is a very large problem.

As stated, when the microstructure of optical surface had dark step shape, above-mentioned demoulding obstacle was bigger, when the demoulding has the optical surface of microstructure, more was easy to generate the microstructure distortion of optical element.The words that the deflection of optical element microstructure is big can cause the optical property of optical element to reduce.Therefore, the present inventor finds that when moulding had the optical element of microstructure, above-mentioned demoulding obstacle was the very large problem that can not ignore.

Summary of the invention

Even also can make the on-deformable mould of microstructure when the object of the present invention is to provide the optical element that has dark step on a kind of microstructure, the demoulding, with the optical element of this mould moulding, and the manufacturing approach of this optical element.

With the means that solve problem

In order to solve above-mentioned problem; Mould of the present invention is that Guan Mo the 1st mould the 2nd mould forms the mould that die space carries out optical element forming, it is characterized in that; The 1st mould has the 1st optics transfer surface of the 1st optical surface that forms optical element; Earlier from the optical element demoulding, the 2nd mould has the 2nd optics transfer surface of the 2nd optical surface that forms optical element than the 2nd mould, supporting optical element during the 1st mold releasability; The absolute value of the radius of curvature of the 1st optics transfer surface is less than the absolute value of the radius of curvature of the 2nd optics transfer surface; The 1st optics transfer surface has the step shape that forms diffraction structure, is that the height of X, step shape is Y with the width of step shape, and formula meets the following conditions:

0.50≤(Y/X) maximum≤1.0.

Wherein, (Y/X) be step shape width with the height ratio.

According to above-mentioned mould; Through making the 1st optics transfer surface more first from the optical element demoulding than the 2nd optics transfer surface with the step shape that forms diffraction structure; Satisfying the darker scope of 0.50≤(Y/X) maximum≤1.0, the demoulding obstacle that brings owing to the resin shrinkage of cooling curing in the time of also injection moulding can being suppressed even exchange the step shape of optical element as multi-wavelength.Thus, optical element can almost not have obstacle successfully from the 1st mold releasability, can prevent the optical element diffraction structure step, be the distortion of fine shape.(Y/X) little less than 0.50 o'clock step, produce the problem as above-mentioned hardly.If but (Y/X) of step surpasses 1.0, so, even adopt gimmick of the present invention also to occur transfer printing deterioration, non-practicality easily.

Concrete form of the present invention or one side; It is above-mentioned mould; It is characterized in that; The 1st optics transfer surface has optical axis regions that is configured in the optical axis side and the exterior lateral area that is configured in the optical axis regions outside at least, and the maximum of (Y/X) on the exterior lateral area is less than the maximum of (Y/X) on the optical axis regions.In general optical element begins to cool down curing from the outside.Therefore, on the exterior lateral area of optical element, form when having the microstructure of dark step shape, demoulding obstacle is big when on the optical axis regions of optical element, forming the microstructure with dark step shape.For this problem; Among the present invention; Being conceived to optical element is to begin to cool down the curing this point from the outside; The maximum of (Y/X) through making exterior lateral area acts on the demoulding obstacle of exterior lateral area step shape wall less than the maximum of (Y/X) of optical axis regions in the time of can relaxing the demoulding, convenient from the 1st mold releasability.

Another side of the present invention is characterized in that, the interior sidewall surface of step shape and the angle of optical axis are smaller or equal to the outer side surface of step shape and the angle of optical axis.At this moment; Though the angle that is interior sidewall surface and the optical axis of step shape is smaller or equal to the variable big mold structure of the demoulding obstacle of the angle of the outer side surface of step shape and optical axis; But, can realize the demoulding smoothly through from the 1st big optics transfer surface of demoulding obstacle, the preferential demoulding when it is still hot.

Another of the present invention, it is characterized in that the interior sidewall surface of step shape is parallel to optical axis.At this moment, can make step shape be for example rectangular-shaped and interior flamboyancy.

Another of the present invention, it is characterized in that step shape comprises rectangular-shaped.At this moment, can form the multi-layered type diffraction grating.

Another of the present invention, it is characterized in that the minimum of a value of the outer side surface of the step shape on the exterior lateral area and the angle of optical axis is greater than the minimum of a value of the angle of the outer side surface of the step shape on the optical axis regions and optical axis.At this moment; Being conceived to optical element is to begin to cool down the curing this point from the outside; Angle through making the above-mentioned outer side surface on the exterior lateral area is greater than the angle of the above-mentioned outer side surface on the optical axis regions; Like this, the step shape on the exterior lateral area lacks than the demoulding obstacle that the step shape resin shrinkage on the optical axis regions causes, can be conveniently from the 1st mold releasability.

Another of the present invention, it is characterized in that the minimum of a value of the outer side surface of the step shape on the exterior lateral area and the angle of optical axis is smaller or equal to the minimum of a value of the angle of the outer side surface of the step shape on the optical axis regions and optical axis.At this moment; Though the angle that is the above-mentioned outer side surface on the exterior lateral area is smaller or equal to the demoulding obstacle of the angle of the above-mentioned outer side surface on the optical axis regions mold structure big than mutability in the outside; But, can realize the demoulding smoothly through from the 1st big optics transfer surface of demoulding obstacle, the preferential demoulding when it is still hot.

Another of the present invention; It is characterized in that; The optical axis regions has middle section that is configured in the optical axis side and the zone line that is configured in the middle section outside at least; Exterior lateral area has the neighboring area that is configured in the zone line outside at least, and the maximum of (Y/X) on the neighboring area is less than the maximum of (Y/X) on any one at least of middle section and zone line.At this moment; Being conceived to optical element is to begin to cool down the curing this point from the outside; The maximum of (Y/X) through making neighboring area is less than the maximum of (Y/X) on any one at least of middle section and zone line; Act on the demoulding obstacle of neighboring area step shape wall in the time of can relaxing the demoulding, convenient from the 1st mold releasability.

Another of the present invention, it is characterized in that the step shape on the step shape on the middle section, the step shape on the zone line, the neighboring area has nothing in common with each other.At this moment,, the objective lens for optical pickup device of multi-wavelength's exchange type can be realized simply, the diffraction efficiency of optical element can be improved through having different step shapes on each zone.

Another of the present invention, it is characterized in that the minimum of a value of the outer side surface of the step shape on the neighboring area and the angle of optical axis is greater than the minimum of a value of the angle of the outer side surface of the step shape on any one of middle section and zone line and optical axis.At this moment; Being conceived to optical element is to begin to cool down the curing this point from the outside; The minimum of a value of the angle through making above-mentioned outer side surface and optical axis on the neighboring area is greater than the minimum of a value of the angle of above-mentioned outer side surface on any one zone of middle section and zone line and optical axis, like this; Step shape on the neighboring area lacks than the demoulding obstacle that the step shape resin shrinkage on middle section and the zone line causes, can prevent just from the 1st mold releasability.

Another of the present invention; It is characterized in that; The minimum of a value of the outer side surface of the step shape on the neighboring area and the angle of optical axis is smaller or equal to the minimum of a value of the angle of the outer side surface of the step shape on any one zone of middle section and zone line and optical axis.At this moment; Though be that the angle of the above-mentioned outer side surface on the neighboring area is easier to the mold structure that becomes big in the outside smaller or equal to the demoulding obstacle of the angle of the above-mentioned outer side surface on any one zone of middle section and zone line; But, can realize the demoulding smoothly through from the 1st big optics transfer surface of demoulding obstacle, the preferential demoulding when it is still hot.

Another of the present invention, it is characterized in that the 1st mould is a cover half, the 2nd mould is a dynamic model.

Optical element of the present invention; It is optical element with the 1st optical surface and the 2nd optical surface; It is characterized in that; The absolute value of the radius of curvature of the 1st optical surface is less than the absolute value of the radius of curvature of the 2nd optical surface; The 1st optical surface has the step that forms diffraction structure at least on the optical axis regions that is configured in the optical axis side and the exterior lateral area that is configured in the optical axis regions outside, be that the height of X, step is Y with the width of step, and the maximum of (Y/X) on the exterior lateral area is less than the maximum of (Y/X) on the optical axis regions.In general optical element begins to cool down curing from the outside.Therefore, on the exterior lateral area of optical element, form when having the microstructure of dark step shape, demoulding obstacle is big when on the optical axis regions of optical element, forming the microstructure with dark step shape.For this problem; Being conceived to optical element among the present invention is to begin to cool down the curing this point from the outside; Maximum through making (Y/X) on the exterior lateral area is less than the maximum of (Y/X) on the optical axis regions; Act on the demoulding obstacle on the exterior lateral area step shape wall in the time of can relaxing from the 1st mold releasability thus, convenient from the 1st mold releasability.

Another of the present invention; It is characterized in that; The optical axis regions has middle section that is configured in the optical axis side and the zone line that is configured in the middle section outside at least; Exterior lateral area has the neighboring area that is configured in the zone line outside at least, and the maximum of (Y/X) on the neighboring area is less than the maximum of (Y/X) on any one at least of middle section and zone line.At this moment; Being conceived to optical element is to begin to cool down the curing this point from the outside; Maximum through making (Y/X) on the neighboring area is less than the maximum of (Y/X) on any one at least of middle section and zone line; Act on the demoulding obstacle on the step shape wall of neighboring area in the time of can relaxing from the 1st mold releasability, can be conveniently from the 1st mold releasability, can the high accuracy transfer printing.

Another of the present invention, it is characterized in that formula meets the following conditions:

0.50≤(Y/X) maximum≤1.0.

Optical element manufacturing approach of the present invention; It is optical element manufacturing approach with mould moulding optical element; It is characterized in that; Mould has the 1st mould that under die opening state, does not leave optical element, the 2nd mould that under die opening state, leaves optical element, and the 1st mould has the 1st optics transfer surface that forms optical element the 1st optical surface, and the 2nd mould has the 2nd optics transfer surface that forms optical element the 2nd optical surface; The absolute value of the radius of curvature of the 1st optics transfer surface is less than the absolute value of the radius of curvature of the 2nd optics transfer surface; The 1st optics transfer surface has the step shape that forms diffraction structure, is that the height of X, step shape is Y with the width of step shape, and formula meets the following conditions:

0.50≤(Y/X) maximum≤1.0,

After the die sinking operation, have and make the stripping process of optical element from the 2nd mold releasability.

According to above-mentioned manufacturing approach; Through making the 1st optics transfer surface more first from the optical element demoulding than the 2nd optics transfer surface with the step shape that forms diffraction structure; Like this; Satisfying the darker scope of 0.50≤(Y/X) maximum≤1.0, the demoulding obstacle that brings owing to the resin shrinkage of cooling curing in the time of also injection moulding can being suppressed even exchange the step shape of optical element as multi-wavelength.Thus, optical element can almost not have obstacle swimmingly from the 1st mold releasability, can prevent the optical element diffraction structure step, be the distortion of fine shape.(Y/X) little less than 0.50 o'clock step, produce the problem as above-mentioned hardly.If but (Y/X) of step surpasses 1.0, so, even adopt gimmick of the present invention also to occur transfer printing deterioration, non-practicality easily.

Description of drawings

Fig. 1: the concept map that the 1st embodiment mould is described.

Fig. 2: the key diagram of the 1st embodiment mould the 1st optics transfer surface.

Fig. 3: with the key diagram of the optical element of Fig. 1 mould moulding.

Fig. 4: the key diagram of the 2nd embodiment mould the 1st optics transfer surface.

Fig. 5: the key diagram of the 3rd embodiment mould the 1st optics transfer surface.

Fig. 6: the key diagram of the 4th embodiment mould the 1st optics transfer surface.

The specific embodiment

The 1st embodiment

With reference to Fig. 1, Fig. 2, mould of the present invention is explained.Mould 100 is through closing cover half 10 that mould is the 1st mould, being that the dynamic model 20 of the 2nd mould forms die space CV, carries out optical element plastic lens PL (please with reference to Fig. 3) forming mould.Mould 100 is assembled in the Coinjection molding apparatus that has temperature regulation section 30, dynamic model drive division 40, resin injection portion 50 etc.

As shown in Figure 1, mould 100 has cover half 10, dynamic model 20.Through making dynamic model 20 and cover half 10 involutory couplings, at two moulds 10, form die space CV between 20.On the part around the die space CV, formed the cast gate GP that is communicated with die space CV.By resin injection portion 50 via cast gate GP to above-mentioned die space CV internal feed, filling molten resin.

Plastic lens PL to by mould 10 moulding explains.The left figure of Fig. 3 is the side cross-sectional, view of plastic lens PL, and right figure is the concept map of the 1st optical surface OL.Plastic lens PL is small-sized diffraction refraction compound lens, as the for example object lens of optical take-up apparatus.Plastic lens PL has the central part OL that possesses optical function, the ring-type lip portions FL that extends to the external diameter direction of OL from central division.Central part OL has little the 1st protruding optical surface OL1 of radius of curvature and big the 2nd protruding optical surface OL2 of radius of curvature.The 1st optical surface OL1 is relative with the 2nd optical surface OL2, and is middle across body thick, that have photopermeability.Lip portions FL has the 1st bead face FL1 in the 1st optical surface OL1 side, has the 2nd bead face FL2 in the 2nd optical surface OL2 side.

On the central part OL, the 1st optical surface OL1 has the diffraction structure step that is used for multi-wavelength and exchanges, is microstructure.That is to say; Plastic lens PL exchanges optical element with short wavelength's high-NA specification, the moderate numerical aperture specification of medium wavelength, 3 corresponding wavelength of the low numerical aperture specification of long wavelength; The microstructure that the 1st optical surface OL1 is provided with has the shape that can be suitable for each wavelength optically focused.In the illustrated example, for 3 wavelength light beams different with numerical aperture are corresponding, the 1st optical surface OL1 is divided into 3 concentric zones, from the inboard laterally, comprises that 3 wavelength exchange regional AR1,2 wavelength exchange regional AR2,1 wavelength specific zone AR3.By above-mentioned All Ranges AR1, AR2, AR3, with for example numerical aperture (NA) 0.85, make wavelength (405nm) optically focused of BD (Blu-ray Disc), on the BD CD, form best spot.By except away from the regional AR1 the perimeter sides of optical axis OA, AR2, with for example numerical aperture (NA) 0.6, make wavelength (650nm) optically focused of DVD (Digital Versatile Disc), on the DVD CD, form best spot.At this moment, DVD wavelength (650nm) light beam that passes NA0.6 to NA0.85 respective optical face zone becomes the solar flare composition, and the spot that is used for DVD video disc recording/regeneration is formed not contribution.In addition, by optical axis OA regions AR1, with for example numerical aperture (NA) 0.45, make wavelength (780nm) optically focused of CD (Compact Disc), on the CD CD, form best spot.At this moment, CD wavelength (780nm) light beam that passes NA0.45 to NA0.85 respective optical face zone becomes the solar flare composition, and the spot that is used for CD video disc recording/regeneration is formed not contribution.The concrete microstructure of relevant the 1st optical surface OL1 is because be the microstructure of stating cover half 10 the 1st optics transfer surface 11A after the transfer printing, the Therefore, omited explanation.

Return Fig. 1, cover half 10 has the core 11 of center side and the periphery mould 12 of perimeter sides.Core 11 for example forms with same steel with periphery mould 12, is fixed to one each other.In the

cover half

10,11 of cores that face toward dynamic model 20 are provided with the ring-band shape diffraction pattern into microstructure, and integral body is the 1st optics transfer surface 11A with concave surface.The 1st optical surface OL1 (with reference to Fig. 3) that the 1st optics transfer surface 11A and the radius of curvature of moulding article plastic lens PL are little is corresponding.By ambient side the 1st forming surface 12A that periphery mould 12 forms, corresponding with plastic lens PL the 1st bead face FL1 (with reference to Fig. 3) on every side.

Following with reference to Fig. 2, the microstructure of detailed description optics transfer surface 11A.Fig. 2 is the model utility side cross-sectional enlarged drawing of the 1st optics transfer surface 11A.As stated, by the face that the 1st optics transfer surface 11A forms, be the 1st optical surface OL1 of plastic lens PL.

The 1st optics transfer surface 11A is divided into the optical axis regions 11C of toroidal and the exterior lateral area 11D of ring-band shape with one heart from the optical axis OA side direction radial direction outside of the 1st optics transfer surface 11A.And optical axis regions 11C is divided into concentric middle section A1 and zone line A2 from the mediad exterior lateral area 11D of the 1st optics transfer surface 11A.3 wavelength of middle section A1 corresponding diagram 3 plastic lens PL exchange regional AR1, and corresponding 2 wavelength of zone line A2 exchange regional AR2.In addition, exterior lateral area 11D is neighboring area A3, the 1 wavelength specific zone AR3 of corresponding diagram 3 plastic lens PL.

On the 1st optics transfer surface 11A,, on middle section A1, zone line A2, neighboring area A3, be the center respectively, formed a plurality of fine step shapes ring-band shape with optical axis OA in order to form the step of plastic lens PL diffraction structure.When seeing the step shape of this ring-band shape with the cross section; The interior sidewall surface of recessed step shape that causes demoulding obstacle is parallel with optical axis OA; The angle 1 of the interior sidewall surface of step shape and optical axis OA, α 3 are respectively smaller or equal to the outer side surface of step shape and angle β 1, the β 3 of optical axis OA.Specifically then can know by diagram; Step shape 13A on the middle section A1 of the 1st optics transfer surface 11A is rectangular-shaped, and the angle β 1 of the outer side surface 13C of the angle 1 of the interior sidewall surface 13B of all step shape 13A and optical axis OA and step shape 13A and optical axis OA equally is 0 degree in the zone.Step shape 15A on the neighboring area A3 is a flamboyancy.

Each step shape 15A on the neighboring area A3, the value of the angle β 3 of its outer side surface 15C and optical axis OA has situation about having nothing in common with each other.During flamboyancy, be not only neighboring area A3, in the zone of middle section A1 (zone line A2 too), the value of the angle β 1 of each outer side surface and optical axis OA (angle beta 2 too) has situation about having nothing in common with each other.Yet the angle 3 of the interior sidewall surface 15B of each step shape 15A and optical axis OA is less than the angle β 3 of outer side surface 15C and optical axis OA.

Can know by diagram in addition; The minimum of a value of the outer side surface 15C of step shape 15A on the neighboring area A3 of exterior lateral area 11D and the angle β 3 of optical axis OA is greater than the outer side surface 13C of the step shape 13A on the middle section A1 among the optical axis regions 11C and the angle β 1 of optical axis OA.Diagram has been omitted the step shape on the zone line A2, and it for example is rectangular-shaped, the interior sidewall surface of zone line A2 step shape and the angle of optical axis OA, and smaller or equal to the outer side surface of zone line A2 step shape and the angle of optical axis OA, for example they equate.The minimum of a value of the outer side surface of step shape 15A on the neighboring area A3 and the angle β 3 of optical axis OA is greater than the outer side surface of the step shape on the zone line A2 and the angle of optical axis OA.

On the 1st optics transfer surface 11A, be that the height of X, step shape is Y with the width of step shape, the ratio in length and breadth (Y/X) of the step shape formula that meets the following conditions:

0.50≤(Y/X) maximum≤1.0,

The step shape of the 1st optics transfer surface 11A is darker.The darker optics transfer surface of this step shape is indispensable forming multi-wavelength exchange optical element, specifically then being when forming 3 wavelength exchange optical element.The maximum of the width X of the step shape that each regional 11C, 11D are last and the ratio in length and breadth (Y/X) of height Y when having " コ " font step shape at step shape, is that benchmark is tried to achieve with the ratio of the width X of " コ " font step shape and height Y.For example as shown in Figure 2, be that ratio with the width X1 of " コ " font step shape UN1 and height Y1 is that benchmark is asked the maximum of (Y/X) at middle section A1.The height Y1 of " コ " font step shape UN1 is as shown in Figure 2, is Y1 with the height at a high wall of optical axis OA direction height in 2 walls that are parallel to optical axis OA that form " コ " font step shape UN1.When step shape does not have " コ " font step shape, for example during the flame type step shape, be that the ratio with the width X of flame type step shape and height Y is that benchmark is tried to achieve.For example as shown in Figure 2, be that ratio with the width X3 of flame type step shape UN3 and height Y3 is that benchmark is asked the maximum of (Y/X) at neighboring area A3.

As shown in Figure 2; Each regional 11C, 11D, specifically then be that regional A1, the last step shape of A3 have nothing in common with each other; For the maximum of (Y/X) on the neighboring area A3 of exterior lateral area 11D, less than the maximum of (Y/X) on the middle section A1 of optical axis regions 11C.Diagram has been omitted the step shape on the zone line A2, and it for example is rectangular-shaped, the maximum of (Y/X) on the zone line A2, in concrete example greater than the maximum of (Y/X) on the neighboring area A3.

Formed step on each regional AR1 of the 1st optical surface OL1, the AR3 etc., they are that slightly upset is formed on step shape 13A, the 15A on the 1st each regional A1 of optics transfer surface 11A, the A3 etc.

Return Fig. 1, dynamic model 20 has the core 21 of center side and the periphery mould 22 of perimeter sides.Core 21 for example forms with same steel with periphery mould 22, and periphery mould 22 is from peripheral support core 21.In the dynamic model 20, facing to the 2nd optics transfer surface 21A that has the smooth concave surface that does not have step on 21 of the cores of cover half 10.Big the 2nd optical surface OL2 (please with reference to Fig. 3) of the corresponding moulding article plastic lens PL radius of curvature of the 2nd optics transfer surface 21A.The 2nd bead face FL2 (please with reference to Fig. 3) around the corresponding plastic lens PL of ambient side the 2nd forming surface 22A that forms by periphery mould 22.

Core 21 plays the function as ejection part in this embodiment, it is inserted leads among the hole 22B that on periphery mould 22, is provided with, and sows discord a little between the two, under this state, can move back and forth in axle AX direction.Making dynamic model 20 after the die sinking that cover half 10 is sowed discord, core 21 is moved to cover half 10 relative to periphery mould 22, can make the plastic lens PL demoulding of staying in the dynamic model 20 thus simply.

Below explanation is with the moulding of the plastic lens PL of mould 100 shown in Figure 1.At first make dynamic model 20 engage Guan Mo with cover half 10.Through closing mould, at two moulds 10, form the land area PA1 of cover half 10 and the close-shaped die space CV of land area PA2 of dynamic model 20 between 20.

Subsequently in the die space CV of 10,20 formation of two moulds, inject molten plastic resin.Promptly, molten plastic resin is imported among the die space CV of 10,20 on two moulds, with molten plastic resin filling die space CV via cast gate GP.

Be filled in molten plastic resin heat release, cooling among the die space CV then.Be expelled to the molten plastic resin among the die space CV; Temperature is generally 200～300 ℃; In case contact remains on

optics transfer surface

11A, 21A and forming surface 12A, the 22A of 100～180 ℃ two

moulds

10,20 usually by temperature regulation section 30, molten plastic resin is just from the contact-making surface of contact moudling mould 100 cooling curing gradually.

Still make dynamic model 20 sow discord die sinking from cover half 10 in the heat with dynamic model drive division 40 at molten plastic resin then.Like this; The demoulding obstacle that resin shrinkage causes in the time of can suppressing cooling curing; Even the 1st optics transfer surface 11A of mould 100 has darker step shape, the 1st optical surface OL1 of plastic lens PL can almost not have the demoulding smoothly of obstacle ground from cover half 10 yet.The die sinking distance that dynamic model 20 is retreated, the for example degree more than diffraction lens thickness.

The core 21 that uses dynamic model drive division 40 to drive to ejection part then makes it the illustrated state of keeping out of the way from be accommodated in periphery mould 22, to also giving prominence to the operating state in cover half 10 1 sides than the 2nd forming surface 22A.Thus, the tangible plastic lens PL of resin shrinkage is from dynamic model 20 demouldings, separation in the time of can making cooling.As shown in Figure 3, the plastic lens PL after the separation, its 1st optical surface OL1 is corresponding with the 1st optics transfer surface 11A, is the convex surface with ring-band shape diffraction pattern, and the 2nd optical surface OL2 is corresponding with the 2nd optics transfer surface 21A, is smooth convex surface.Around plastic lens PL, corresponding with forming

surface

12A, 22A, formed lip portions FL.

According to above-mentioned mould 100; Have the step shape 13A that forms diffraction structure through making, the 1st optics transfer surface 11A of 15A is more first from the plastic lens PL demoulding than the 2nd optics transfer surface 21A; Like this; Even exchange the step shape 13A of optical element, 15A darker scope, the demoulding obstacle that the resin shrinkage that cooling curing causes in the time of also can suppressing injection moulding is brought in satisfied 0.50≤(Y/X) maximum≤1.0 as 3 wavelength for example.Thus, plastic lens PL can almost not have the smoothly demoulding of obstacle ground from cover half 10, can prevent plastic lens P L the diffraction structure step, be the fine shape distortion.

In addition; Maximum through making (Y/X) on the neighboring area A3 of exterior lateral area 11D is less than the maximum of (Y/X) on optical axis regions 11C middle section A1 etc.; Like this; Can relax the demoulding obstacle on the neighboring area A3 step shape 15A interior sidewall surface 15B during demoulding, though plastic lens PL begin to cool down curing from the outside also can be conveniently from cover half 10 demouldings.

In addition; The minimum of a value of outer side surface 15C through making the step shape 15A on the neighboring area A3 of exterior lateral area 11D and the angle β 3 of optical axis OA; Minimum of a value greater than the angle β 1 of the outer side surface 13C of the step shape 13A on the optical axis regions 11C middle section A1 and optical axis OA; Like this; Step shape 15A on the neighboring area A3 lacks than the demoulding obstacle that the step shape 13A resin shrinkage on the middle section A1 causes, though plastic lens PL begin to cool down curing from the outside also can be conveniently from cover half 10 demouldings.

Embodiment 1

[table 1]

Middle section	Neighboring area
		Step shape (Y1/X1)	Step shape (Y3/X3)
0.038～0.617	0.005～0.030

The ratio in length and breadth (Y/X) of the step shape on the 1st optics transfer surface 11A of table 1 couple Fig. 2 is described.As shown in table 1, the ratio in length and breadth (Y1/X1) of middle section A1 step shape UN1 is 0.038～0.617.The ratio in length and breadth (Y3/X3) of neighboring area A3 step shape UN3 is 0.005～0.030.The maximum of (Y/X) on the middle section A1 is 0.617, and the maximum of (Y/X) on the neighboring area A3 is 0.030.

Be summarized as follows, the 1st optics transfer surface 11A top bar shape in length and breadth the maximum of ratio (Y/X) be 0.617, in the scope of the maximum 0.50≤(Y/X)≤1.0.In addition, the maximum (0.030) of (Y/X) on the neighboring area A3 of exterior lateral area 11D is less than the maximum (0.617) of (Y/X) on the optical axis regions 11C middle section A1.

The 2nd embodiment

Below the mould of the present invention's the 2nd embodiment is explained.The mould of the 2nd embodiment is the distortion of the 1st embodiment mould, and the part of not doing to specify is identical with the 1st embodiment.

Following with reference to Fig. 4, specify the microstructure of the 2nd embodiment mould 100 optics transfer surface 11A.

On the 1st optics transfer surface 11A,, be that center ring has formed a plurality of fine step shapes bandedly with optical axis OA in order to form the diffraction structure step of plastic lens PL.When seeing the step shape of this ring-band shape with the cross section; The interior sidewall surface of the recessed step shape of generation demoulding obstacle is parallel with optical axis OA, and the angle 1 of the interior sidewall surface of step shape and optical axis OA, α 2, α 3 are respectively smaller or equal to the outer side surface of step shape and angle β 1, β 2, the β 3 of optical axis OA.Specifically then can know by diagram; The middle section A1 of the 1st optics transfer surface 11A shape 13A that tops bar is rectangular-shaped, and the angle β 1 of the outer side surface 13C of the angle 1 of the interior sidewall surface 13B of all step shape 13A and optical axis OA and step shape 13A and optical axis OA 0 spends in the zone.In addition, the zone line A2 shape 14A that tops bar is rectangular-shaped, and the angle β 2 of the outer side surface 14C of the angle 2 of the interior sidewall surface 14B of all step shape 14A and optical axis OA and step shape 14A and optical axis OA 0 spends in the zone.In addition, the neighboring area A3 shape 15A that tops bar is a flamboyancy, and the angle 3 of the interior sidewall surface 15B of each step shape 15A and optical axis OA is less than the angle β 3 of outer side surface 15C and optical axis OA.

Can know by diagram in addition; The minimum of a value of the outer side surface 15C of step shape 15A on the neighboring area A3 of exterior lateral area 11D and the angle β 3 of optical axis OA is greater than outer side surface 13C and the angle β 1 of optical axis OA and the same angle β 2 on the zone line A2 of the step shape 13A on the middle section A1 among the optical axis regions 11C.

0.50≤(Y/X) maximum≤1.0,

The step shape of the 1st optics transfer surface 11A is darker.The maximum of the width X of the step shape that each regional 11C, 11D are last and the ratio in length and breadth (Y/X) of height Y when having " コ " font step shape at step shape, is that benchmark is tried to achieve with the ratio of the width X of " コ " font step shape and height Y.For example as shown in Figure 4, be that ratio with the width X1 of " コ " font step shape UN1 and height Y1 is that benchmark is asked the maximum of (Y/X) at middle section A1.The height Y1 of " コ " font step shape UN1 is as shown in Figure 4, is to be Y1 with the height at a high wall of optical axis OA direction height in 2 walls that are parallel to optical axis OA that form " コ " font step shape UN1.In addition, be that ratio with the width X2 of " コ " font step shape UN2 and height Y2 is that benchmark is asked the maximum of (Y/X) at zone line A2.The height Y2 of " コ " font step shape UN2 is as shown in Figure 4, is to be Y2 with the height at a high wall of optical axis OA direction height in 2 walls that are parallel to optical axis OA that form " コ " font step shape UN2.When step shape does not have " コ " font step shape, for example during the flame type step shape, be that the ratio with the width X of flame type step shape and height Y is that benchmark is tried to achieve.For example as shown in Figure 4, be that ratio with the width X3 of flame type step shape UN3 and height Y3 is that benchmark is asked the maximum of (Y/X) at neighboring area A3.

Each regional 11C, 11D, specifically then be that regional A1, A2, the last step shape of A3 are the shapes that has nothing in common with each other; The maximum of (Y/X) on the neighboring area A3 of exterior lateral area 11D is less than the maximum of (Y/X) on any one zone of the middle section A1 of optical axis regions 11C and zone line A2.

Each regional AR1 of the 1st optical surface OL1, AR2, the last step that formed of AR3, they are that slightly upset is formed on the 1st each regional A1 of optics transfer surface 11A, A2,

last step shape

13A, 14A, the 15A of A3.

According to above-mentioned mould 100; The minimum of a value of outer side surface 15C through making the step shape 15A on the neighboring area A3 of exterior lateral area 11D and the angle β 3 of optical axis OA; Angle β 1, β 2 greater than

outer side surface

13C, 14C and the optical axis OA of the step shape 13A on optical axis regions 11C middle section A1 and the zone line A2,14A; Like this; Step shape 15A on the neighboring area A3 lacks than the demoulding obstacle that the step shape 13A on middle section A1 and the zone line A2,14A resin shrinkage cause, though plastic lens PL begin to cool down curing from the outside also can be conveniently from cover half 10 demouldings.

Embodiment 2

[table 2]

Middle section	Zone line	Neighboring area
			Step shape (Y1/X1)	Step shape (Y2/X2)	Step shape (Y3/X3)
0.006～0.090	0.421～0.517	0.007～0.086

The ratio in length and breadth (Y/X) of the step shape on the 1st optics transfer surface 11A of table 2 couple Fig. 4 is described.As shown in table 2, the ratio in length and breadth (Y1/X1) of the step shape UN 1 on the middle section A1 is 0.006～0.090.The ratio in length and breadth (Y2/X2) of step shape UN2 on the zone line A2 is 0.421～0.517.The ratio in length and breadth (Y3/X3) of step shape UN3 on the neighboring area A3 is 0.007～0.086.The maximum of (Y/X) on the middle section A1 is 0.090, and the maximum of (Y/X) on the zone line A2 is 0.517, and the maximum of (Y/X) on the neighboring area A3 is 0.086.

Be summarized as follows, the 1st optics transfer surface 11A top bar shape in length and breadth the maximum of ratio (Y/X) be 0.517, in the scope of the maximum 0.50≤(Y/X)≤1.0.In addition; The maximum (0.086) of (Y/X) on the neighboring area A3 of exterior lateral area 11D is less than the maximum (0.090) of (Y/X) on the optical axis regions 11C middle section A1 and the maximum (0.517) of (Y/X) on the optical axis regions 11C zone line A2.

The 3rd embodiment

Below the mould of the present invention's the 3rd embodiment is explained.The mould of the 3rd embodiment is the distortion of the 1st embodiment mould, and the part of not doing to specify is identical with the 1st embodiment.

Following with reference to Fig. 5, specify the microstructure of the 3rd embodiment mould 100 optics transfer surface 11A.

On the 1st optics transfer surface 11A,, be that center ring has formed a plurality of fine step shapes bandedly with optical axis OA in order to form the diffraction structure step of plastic lens PL.When seeing the step shape of this ring-band shape with the cross section; The interior sidewall surface of the recessed step shape of generation demoulding obstacle is parallel with optical axis OA, and the angle 1 of the interior sidewall surface of step shape and optical axis OA, α 2, α 3 are respectively smaller or equal to the outer side surface of step shape and angle β 1, β 2, the β 3 of optical axis OA.Specifically then can know by diagram; The middle section A1 of the 1st optics transfer surface 11A shape 13A that tops bar is rectangular-shaped, and the angle β 1 of the angle 1 of the interior sidewall surface 13B of step shape 13A and optical axis OA and the outer side surface 13C of step shape 13A and optical axis OA equally is 0 degree.Step shape 14A on the zone line A2 is a flamboyancy, and the angle 2 of the interior sidewall surface 14B of each step shape 14A and optical axis OA is less than the angle β 2 of outer side surface 14C and optical axis OA.The neighboring area A3 shape 15A that tops bar is a flamboyancy, and the angle 3 of the interior sidewall surface 15B of each step shape 15A and optical axis OA is less than the angle β 3 of outer side surface 15C and optical axis OA.

Can know by diagram in addition; The minimum of a value of the outer side surface 15C of step shape 15A on the neighboring area A3 of exterior lateral area 11D and the angle β 3 of optical axis OA; Greater than the outer side surface 13C of the step shape 13A on the middle section A1 among the optical axis regions 11C and the angle β 1 of optical axis OA, less than the minimum of a value of the angle β 2 of the outer side surface 14C of the step shape 14A on the zone line A2 of optical axis regions 11C and optical axis OA.

0.50≤(Y/X) maximum≤1.0,

The step shape of the 1st optics transfer surface 11A is darker.The maximum of the width X of the step shape that each regional 11C, 11D are last and the ratio in length and breadth (Y/X) of height Y when having " コ " font step shape at step shape, is that benchmark is tried to achieve with the ratio of the width X of " コ " font step shape and height Y.For example as shown in Figure 5, be that ratio with the width X1 of " コ " font step shape UN1 and height Y1 is a benchmark at middle section A1, ask the maximum of (Y/X).The height Y1 of " コ " font step shape UN1 is as shown in Figure 5, is Y1 with the height at a high wall of optical axis OA direction height in 2 walls that are parallel to optical axis OA that form " コ " font step shape UN1.When step shape does not have " コ " font step shape, for example during the flame type step shape, be that the ratio with the width X of flame type step shape and height Y is that benchmark is tried to achieve.For example as shown in Figure 5, be that ratio with the width X2 of flame type step shape UN2 and height Y2 is that benchmark is asked the maximum of (Y/X) at zone line A2.At neighboring area A3 is that ratio with the width X3 of flame type step shape UN3 and height Y3 is that benchmark is asked the maximum of (Y/X).

last step shape

13A, 14A, the 15A of A3.

According to above-mentioned mould 100; The minimum of a value of outer side surface 15C through making the step shape 15A on the neighboring area A3 of exterior lateral area 11D and the angle β 3 of optical axis OA; Greater than the outer side surface 13C of the step shape 13A on the middle section A1 of optical axis regions 11C and the angle β 1 of optical axis OA; Like this; Step shape 15A on the neighboring area A3 lacks than the demoulding obstacle that the step shape 13A resin shrinkage on the middle section A1 causes, though plastic lens PL begin to cool down curing from the outside also can be conveniently from cover half 10 demouldings.

Embodiment 3

[table 3]

Middle section	Zone line	Neighboring area
			Step shape (Y1/X1)	Step shape (Y2/X2)	Step shape (Y3/X3)
0.110-0.957	0.039-0.112	0.064-0.362

The ratio in length and breadth (Y/X) of the step shape on the 1st optics transfer surface 11A of table 3 couple Fig. 5 is described.As shown in table 3, the ratio in length and breadth (Y1/X1) of the step shape UN1 on the middle section A1 is 0.110～0.957, and the ratio in length and breadth (Y2/X2) of the step shape UN2 on the zone line A2 is 0.039～0.112.The ratio in length and breadth (Y3/X3) of step shape UN3 on the neighboring area A3 is 0.064～0.362.The maximum of (Y/X) on the middle section A1 is 0.957, and the maximum of (Y/X) on the zone line A2 is 0.112, and the maximum of (Y/X) on the neighboring area A3 is 0.362.

Be summarized as follows, the 1st optics transfer surface 11A top bar shape in length and breadth the maximum of ratio (Y/X) be 0.957, in the scope of the maximum 0.50≤(Y/X)≤1.0.In addition, the maximum (0.362) of (Y/X) on the neighboring area A3 of exterior lateral area 11D is less than the maximum (0.957) of (Y/X) on the optical axis regions 11C middle section A1.

The 4th embodiment

Below the mould of the present invention's the 4th embodiment is explained.The mould of the 4th embodiment is the distortion of the 1st embodiment mould, and the part of not doing to specify is identical with the 1st embodiment.

Following with reference to Fig. 6, specify the microstructure of the 4th embodiment mould 100 optics transfer surface 11A.

On the 1st optics transfer surface 11A,, be that center ring has formed a plurality of fine step shapes bandedly with optical axis OA in order to form the diffraction structure step of plastic lens PL.When seeing the step shape of this ring-band shape with the cross section; The interior sidewall surface of the recessed step shape of generation demoulding obstacle is parallel with optical axis OA, and the angle 1 of the interior sidewall surface of step shape and optical axis OA, α 3 are respectively smaller or equal to the outer side surface of step shape and angle β 1, the β 3 of optical axis OA.Can be known by diagram then that specifically the middle section A1 of the 1st optics transfer surface 11A shape 13A that tops bar is a flamboyancy, the angle 1 of the interior sidewall surface 13B of each step shape 13A and optical axis OA is less than the angle β 1 of outer side surface 13C and optical axis OA.The neighboring area A3 shape 15A that tops bar is rectangular-shaped, and the angle 3 of the interior sidewall surface 15B of all step shape 15A and optical axis OA all is 0 degree.The outer side surface 15C of step shape 15A and the angle β 3 of optical axis OA can corresponding female aspheric surface (basal plane) angle, get a plurality of different values more than or equal to 0 degree.That is to say that inboard angle beta 1 is smaller or equal to outside angle beta 3.

Can know by Fig. 6 in addition; The minimum of a value of the outer side surface 15C of step shape 15A on the neighboring area A3 of exterior lateral area 11D and the angle β 3 of optical axis OA is less than the outer side surface 13C of the step shape 13A on the middle section A1 among the optical axis regions 11C and the angle β 1 of optical axis OA.Diagram has been omitted the step shape on the zone line A2, and it for example is a flamboyancy, and the angle of the interior sidewall surface of each step shape of zone line A 2 and optical axis OA is smaller or equal to the angle of outer side surface and optical axis OA.The minimum of a value of the outer side surface of step shape 15A on the neighboring area A3 and the angle β 3 of optical axis OA is less than the minimum of a value of the angle of the outer side surface of the step shape on the zone line A2 and optical axis OA.

0.50≤(Y/X) maximum≤1.0,

The step shape of the 1st optics transfer surface 11A is darker.The maximum of the width X of the step shape that each regional 11C, 11D are last and the ratio in length and breadth (Y/X) of height Y when having " コ " font step shape at step shape, is that benchmark is tried to achieve with the ratio of the width X of " コ " font step shape and height Y.For example as shown in Figure 6, be that ratio with the width X3 of " コ " font step shape UN3 and height Y3 is a benchmark at neighboring area A3, ask the maximum of (Y/X).The height Y3 of " コ " font step shape UN3 is as shown in Figure 6, is to be Y3 with the height at a high wall of optical axis OA direction height in 2 walls that are parallel to optical axis OA that form " コ " font step shape UN3.When step shape does not have " コ " font step shape, for example during the flame type step shape, be that the ratio with the width X of flame type step shape and height Y is that benchmark is tried to achieve.For example as shown in Figure 6, be that ratio with the width X1 of flame type step shape UN1 and height Y1 is that benchmark is asked the maximum of (Y/X) at middle section A1.

As shown in Figure 6; Each regional 11C, 11D, specifically then be that regional A1, the last step shape of A3 are the shapes that has nothing in common with each other; The maximum of (Y/X) on the neighboring area A3 of exterior lateral area 11D is less than the maximum of (Y/X) on the middle section A1 of optical axis regions 11C.And diagram has been omitted the step shape on the zone line A 2, and it for example is a rectangle, the maximum of (Y/X) on the zone line A2, in concrete example greater than the maximum of (Y/X) on the neighboring area A 3.

According to above-mentioned mould 100; Though be the minimum of a value of angle β 3 of outer side surface 15C and the optical axis OA of the step shape 15A on the neighboring area A3 of exterior lateral area 11D; Be demoulding obstacle less than the minimum of a value of the angle β 1 of the outer side surface 13C of the step shape 13A on the optical axis regions 11C middle section A1 and optical axis OA in the outside variable big mold structure; But; Through from the 1st big optics transfer surface 11A of demoulding obstacle, the preferential demoulding when it is still hot, can realize the demoulding smoothly.

It is rectangular-shaped also can making the step shape 13A of middle section A1 in the 3rd embodiment.At this moment; The minimum of a value of the outer side surface 15C of step shape 15A on the neighboring area A3 of exterior lateral area 11D and the angle β 3 of optical axis OA; Identical with the angle β 1 of the outer side surface 13C of step shape 13A on the middle section A1 among the optical axis regions 11C and optical axis OA, all be 0 degree.

More than this embodiment mould is described, but that mould of the present invention is not limited to is above-mentioned.For example, be to make the plastic lens PL demoulding of staying in the dynamic model 20 in the mould 100, but also can eject the 2nd bead face FL2 of plastic lens PL from dynamic model 20 by the knock pin that is embedded in the dynamic model 20 through ejecting core 21.

The shape of

step shape

13A, 14A, 15A is an illustration in the above-mentioned embodiment, and combination of shapes can freely design in condition and range.For example, can be at the identical or similar pattern of formation on the middle section A1 that constitutes optical axis regions 11C and the zone line A2.Can also make all step shapes of middle section A1, zone line A2 and neighboring area is rectangular-shaped or flamboyancy.

Symbol description

100 moulds

10 cover half

20 dynamic models

30 temperature regulation section

40 dynamic model drive divisions

50 resin injection portions

11A, 21A optics transfer surface

11C optical axis regions

The 11D exterior lateral area

12A, 22A forming surface

13A, 14A, 15A step shape

The A1 middle section

The A2 zone line

The neighboring area of A3

The CV die space

The OL central part

OL1, OL2 optical surface

The FL lip portions

FL1, FL2 bead face

The PL plastic lens

The OA optical axis

Claims

1. mould is that Guan Mo the 1st mould and the 2nd mould form die space, carry out the mould of optical element forming, it is characterized in that,

Said the 1st mould has the 1st optics transfer surface of the 1st optical surface that forms said optical element, and is more first from the said optical element demoulding than said the 2nd mould,

Said the 2nd mould has the 2nd optics transfer surface of the 2nd optical surface that forms said optical element, supports said optical element during said the 1st mold releasability,

The absolute value of the radius of curvature of said the 1st optics transfer surface, less than the absolute value of the radius of curvature of said the 2nd optics transfer surface,

Said the 1st optics transfer surface has the step shape that forms diffraction structure,

With the width of said step shape is that the height of X, said step shape is Y, and formula meets the following conditions:

0.50≤(Y/X) maximum≤1.0.

2. like the mould of record in the claim 1, it is characterized in that,

Said the 1st optics transfer surface has optical axis regions that is configured in the optical axis side and the exterior lateral area that is configured in the said optical axis regions outside at least,

The maximum of said (Y/X) on the said exterior lateral area is less than the maximum of said (Y/X) on the said optical axis regions.

3. the mould as putting down in writing in any one of claim 1 and 2 is characterized in that the interior sidewall surface of said step shape and the angle of optical axis are smaller or equal to the outer side surface of said step shape and the angle of optical axis.

4. the mould as putting down in writing in any one of claim 1 to 3 is characterized in that the interior sidewall surface of said step shape is parallel to optical axis.

5. the mould as putting down in writing in any one of claim 1 to 4 is characterized in that said step shape comprises rectangular-shaped.

6. the mould as putting down in writing in any one of claim 2 to 5; It is characterized in that; The minimum of a value of the outer side surface of the step shape on the said exterior lateral area and the angle of optical axis is greater than the minimum of a value of the angle of the outer side surface of the step shape on the said optical axis regions and optical axis.

7. the mould as putting down in writing in any one of claim 2 to 6 is characterized in that,

Said optical axis regions has middle section that is configured in the optical axis side and the zone line that is configured in the said middle section outside at least,

Said exterior lateral area has the neighboring area that is configured in the said zone line outside at least,

The maximum of said (Y/X) on the said neighboring area is less than the maximum of said (Y/X) on any one at least of said middle section and said zone line.

8. like the mould of record in the claim 7, it is characterized in that the step shape on the step shape on the step shape on the said middle section, the said zone line, the said neighboring area has nothing in common with each other.

9. the mould as putting down in writing in any one of claim 7 and 8; It is characterized in that; The minimum of a value of the outer side surface of the step shape on the said neighboring area and the angle of optical axis is greater than the minimum of a value of the angle of the outer side surface of the step shape on any one of said middle section and said zone line and optical axis.

10. the mould as putting down in writing in any one of claim 2 to 5; It is characterized in that; The minimum of a value of the outer side surface of the step shape on the said exterior lateral area and the angle of optical axis is smaller or equal to the minimum of a value of the angle of the outer side surface of the step shape on the said optical axis regions and optical axis.

11. the mould as putting down in writing in any one of claim 2 to 5 and 10 is characterized in that,

12. the mould like record in the claim 11 is characterized in that, the step shape on the step shape on the step shape on the said middle section, the said zone line, the said neighboring area has nothing in common with each other.

13. like the mould of putting down in writing in any one of claim 11 and 12; It is characterized in that; The minimum of a value of the outer side surface of the step shape on the said neighboring area and the angle of optical axis is smaller or equal to the minimum of a value of the angle of the outer side surface of the step shape on any one of said middle section and said zone line and optical axis.

14. the mould as putting down in writing in any one of claim 1 to 13 is characterized in that said the 1st mould is a cover half, said the 2nd mould is a dynamic model.

15. an optical element is the optical element with the 1st optical surface and the 2nd optical surface, it is characterized in that,

The absolute value of the radius of curvature of said the 1st optical surface, less than the absolute value of the radius of curvature of said the 2nd optical surface,

Said the 1st optical surface has the step that forms diffraction structure at least on the optical axis regions that is configured in the optical axis side and the exterior lateral area that is configured in the said optical axis regions outside,

With the width of said step is that the height of X, said step is Y, and the maximum of (Y/X) on the said exterior lateral area is less than the maximum of (Y/X) on the said optical axis regions.

16. the optical element like record in the claim 15 is characterized in that,

17. the optical element as putting down in writing in any one of claim 15 and 16 is characterized in that formula meets the following conditions:

0.50≤(Y/X) maximum≤1.0.

18. an optical element manufacturing approach is with the optical element manufacturing approach of mould moulding optical element, it is characterized in that,

Said mould has the 1st mould that under die opening state, does not leave said optical element and the 2nd mould that under die opening state, leaves said optical element,

Said the 1st mould has the 1st optics transfer surface that forms said optical element the 1st optical surface, and said the 2nd mould has the 2nd optics transfer surface that forms said optical element the 2nd optical surface,

Said the 1st optics transfer surface has the step shape that forms diffraction structure, is that the height of X, said step shape is Y with the width of said step shape, and formula meets the following conditions:

0.50≤(Y/X) maximum≤1.0,

After the die sinking operation, have and make the stripping process of said optical element from said the 2nd mold releasability.