CN102590903A - Design method for glass Fresnel lens mould - Google Patents

Abstract

A design method for a glass Fresnel lens mould is characterized in that the conformity of contour line heights of edge teeth are ensured through changing widths or heights of the edge teeth having different distances to a center of the glass Fresnel lens mould, that is, the heights of the edge teeth closed to the center and close to edges of the glass Fresnel lens mould are basically same, so that the thicknesses of outer wall contour lines of the glass Fresnel lens mould represent the basically uniform state, that is, the uniformity of outer wall contour line thicknesses of the glass Fresnel lens mould are basically ensured. Therefore, necessary conditions are provided for the smooth realization of running water cooling of the mould and the technological requirement for uniform glass stress distribution.

Description

A kind of glass Fresnel Lenses Mould design method

Technical field

The invention belongs to the manufacturing field, be specifically related to a kind of glass Fresnel Lenses Mould design method.

Background technology

Fresnel lens is used for Salar light-gathering and exists volume little, and is in light weight, advantages such as handling ease; Again because the sun and photoreceptor provide convenience in the both sides of lens to manufacturing articles.Material as Fresnel lens is generally PMMA (organic glass), but the PMMA life-span is short, during as Salar light-gathering, be prone under ultraviolet irradiation, wear out, and the glass Fresnel lens can be good at overcoming this shortcoming.

When making Fresnel lens, consider the important requirement that reduces production costs in the face of market, adopt the method for rolling process compression molding to become optimal selection with glass.But its center of Fresnel Lenses waiting the tooth pitch method to design and produce usually is different with the rib tooth height at edge, can differ generally speaking about one times, and corresponding mould structure designing requirement also is identical.To such an extent as to and the unevenness that the difference of rib tooth height forms the outer wall thickness of mold roller on this mould is carried out the flowing water cooling for mould in the processing process and is brought very big difficulty can't implement suitability for industrialized production to the glass pressure technological requirement that evenly distributes.

Mould with linear Fresnel lens is that example describes below:

In linear Fenier lens synoptic diagram shown in Figure 1, suppose that the width of Fresnel Lenses is 600mm=2l, waiting partial width is k ₀, focal distance f=600mm, the refractive index n of glass=1.5 can be known from O to the L Fresnel Lenses to have 150 rib teeth, make the angle of this 150 rib tooth be respectively α ₁, α ₂, α ₃α ₁₄₉, α ₁₅₀, rib tooth center to the Fresnel Lenses center also just the distance of primary optical axis be a ₁, a ₂, a ₃A ₁₄₉, a ₁₅₀, a then ₁=1mm, a ₂=3mm, a ₃=5mm ... A ₁₄₉=297mm, a ₁₅₀=299mm, α _iDetermine by following formula:

${\mathrm{\α}}_i=\arctan \frac{a_i}{n\sqrt{{a_i}^2+f^2}-f}---\left(1\right)$

Promptly have:

${\mathrm{\α}}_i=\arctan \frac{a_i}{1.5\sqrt{{a_i}^2+{600}^2}-600}---\left(2\right)$

Specifically be calculated as follows:

α ₁To α ₈

0.1910?0.5729?0.9547?1.3364?1.7178?2.0988?2.4795 2.8597

α ₉To α ₁₆

3.2394?3.6185?3.9969?4.3745?4.7513?5.1273?5.5023?5.8763

……

α ₁₃₅To α ₁₄₂

34.8506?34.9642?35.0762?35.1868?35.2958?35.4033?35.5093?35.6139

α ₁₄₃To α ₁₅₀

35.7170?35.8187?35.9189?36.0178?36.1152?36.2113?36.3061?36.3995

Conclusion:

1, Fei Nieer prism rib tooth maximum angle α ₁₅₀==36.4 °, pairing rib tooth height is maximum, is h _Max=2tan α ₁₅₀=1.4745mm;

2, Fei Nieer prism rib tooth minimum angles α ₁==0.19 °, pairing rib tooth height is minimum, is h _Min=2tan α ₁=0.0066mm.

Above-mentioned data show: when waiting partial width is under the 2mm situation, rib tooth height maximal value (h _Max=1.4745mm) be minimum value (h _Min=0.0066mm) 200 times; Certainly along with the five equilibrium width value increases to x, the maximum height value h of parallel edge _Max=xtan α ₁Also with proportional increase.Require through the even cooling die roller of flowing water in the production Fenier lens technology and adopt the minimum rolling process of cost to make, but the mold roller outer wall that designs and produces owing to this method causes the different rolling effects that have a strong impact on of its cooled temperature by Fresnel Lenses tooth height difference.Effectively the key problem in technology of head it off is exactly that the Fenier lens mold roller outer wall outline line thickness that designs and produces of requirement has basic homogeneity.

Summary of the invention

The object of the present invention is to provide a kind of through width that reduces the big rib tooth of glass Fresnel Lenses corner angle and the approach that increases the height of the little rib tooth of rib tooth; Realize the basic homogeneity of mold roller outer wall outline line thickness, in the production run mould being carried out the glass Fresnel Lenses Mould design method that the flowing water cooling creates conditions.

For achieving the above object, the technical scheme that the present invention adopts is:

According to be divided into two parts of A and B apart from the optical axis distance, wherein A partly is the part near Fresnel Lenses mold center with the Fresnel Lenses mould, and B partly is a Fresnel Lenses die edge part; The rib tooth of A part is on the basis of adopting common Fresnel Lenses die design method; Keep rib facewidth degree and rib tooth angle degree constant, raise the height of rib tooth successively, make the rib tooth height consistent; Thereby make rib gear tooth profile thickness even; The tooth depth methods for designing such as rib tooth employing of B part, promptly the rib tooth height is certain, and rib facewidth degree does not wait; Its concrete design process is following:

The width of supposing this Fresnel Lenses mould is 2l, and focal length is f, and the optically focused spot width is k ₀, the Desired Height that the rib tooth allows is d ₀, beginning to monosymmetric rib tooth number consecutively from Fresnel Lenses mould primary optical axis is 1,2,3 ... I ..., the width that makes first rib tooth is k ₁=k ₀, then first rib tooth center to primary optical axis apart from a ₁=k ₀/ 2, at this moment confirm that by formula (1) angle of this rib tooth is: ${\mathrm{\α}}_1=\mathrm{Arctan}\frac{a_1}{n\sqrt{{a_1}^2+f^2}-f},$ The rib tooth height is d ₁=k ₁Tan α ₁

Then with below several formulas try to achieve the 2nd successively, the 3rd, the 4th ... Up to the width of i rib tooth, angle, highly, rib tooth center is to the distance of primary optical axis;

k _i＝k ₀ (7)

a _i＝a _i-1+k _i/2 (4)

${\mathrm{\α}}_i=\arctan \frac{a_i}{n\sqrt{{a_i}^2+f^2}-f}---\left(1\right)$

d _i＝k _itanα _i (3)

Judge d _iWhether greater than d ₀If, d _i＜d ₀, k then _i=k ₀, and make d again _i=d ₀If, d _i＞d ₀, then make i=N, and with the following three formulas angle of definite N rib tooth again, width, highly, the distance of primary optical axis is arrived at rib tooth center,

k _itanα _i＝d ₀ (5)

${\mathrm{\α}}_i=\arctan \frac{a_i}{n\sqrt{{a_i}^2+f^2}-f}---\left(1\right)$

a _i＝a _i-1+k _i/2 (4)

Continue to calculate the parameter of next rib tooth then, all be determined until all rib teeth of this Fresnel Lenses mould by last three formulas.

The present invention guarantees that apart from the width of the rib tooth of optical axis certain distance or the approach of height the height of rib gear profile is consistent through changing glass Fresnel Lenses mould; Thereby make Fresnel lens basic identical near the height of the rib tooth at the rib tooth at center and edge; So that make the thickness of the outer wall outline line of glass Fresnel Lenses mould present basic uniform state; The promptly basic homogeneity that guarantees the outer wall outline line thickness of mold roller, thus the condition of necessity is provided for evenly the distribute smooth realization of technological requirement of the flowing water cooling of mould and pressure.

Description of drawings

Fig. 1 waits tooth pitch Fresnel lens die synoptic diagram;

The Fresnel lens die synoptic diagram of profile thickness such as Fig. 2 is;

Fig. 3 is rib facewidth degree k _i, rib tooth angle [alpha] _iCalculation flow chart.

Embodiment

Referring to Fig. 2, according to be divided into two parts of A and B apart from the optical axis distance, wherein A partly is the part near Fresnel Lenses mold center with the Fresnel Lenses mould in the present invention; B partly is a Fresnel Lenses die edge part, and the rib tooth of A part keeps rib facewidth degree and rib tooth angle degree constant on the basis of adopting common Fresnel Lenses die design method; Raise the height of rib tooth successively; Make the rib tooth height consistent, thereby make rib gear tooth profile thickness even, the tooth depth methods for designing such as rib tooth employing of B part; Be that the rib tooth height is certain, rib facewidth degree does not wait; The following (see figure 3) of its concrete design process:

The width of supposing this Fresnel Lenses mould is 2l, and focal length is f, and the optically focused spot width is k ₀, the Desired Height that the rib tooth allows is d ₀, the rib tooth number consecutively that begins to both sides from Fresnel Lenses mould primary optical axis is 1,2,3 ... I ..., the width that makes first rib tooth is k ₁=k ₀, then first rib tooth center to primary optical axis apart from a ₁=k ₀/ 2, at this moment confirm that by formula (1) angle of this rib tooth is:

The rib tooth height is d ₁=k ₁Tan α ₁

Then with below several formulas try to achieve the 2nd successively, the 3rd, the 4th ... Up to the width of i rib tooth, angle, highly, rib tooth center is to the distance of primary optical axis;

k _i＝k ₀ (7)

a _i＝a _i-1+k _i/2 (4)

${\mathrm{\α}}_i=\arctan \frac{a_i}{n\sqrt{{a_i}^2+f^2}-f}---\left(1\right)$

d _i＝k _itanα _i (3)

Judge d _iWhether greater than d ₀If, d _i＜d ₀, k then _i=k ₀, and make d again _i=d ₀If, d _i＞d ₀, then make i=N, and with the following three formulas angle of definite N rib tooth again, width, highly, the distance of primary optical axis is arrived at rib tooth center,

k _itanα _i＝d ₀?(5)

${\mathrm{\α}}_i=\arctan \frac{a_i}{n\sqrt{{a_i}^2+f^2}-f}---\left(1\right)$

a _i＝a _i-1+k _i/2(4)

Continue to calculate the parameter of next rib tooth then, all be determined until all rib teeth of this Fresnel Lenses mould by last three formulas.

$k_i\frac{a_{i-1}+\frac{1}{2}{k}_i}{n\sqrt{{(a_{i-1}+\frac{1}{2}{k}_i)}^2+f^2}-f}=d_0---\left(6\right)$

Until a _i＞1 finishes.

Specifically be calculated as follows:

α ₁To α ₈

0.19?10?0.5729?0.9547?1.3364?1.7178?2.0988?2.4795?2.8597

α ₉To α ₁₆

3.2394?3.6185?3.9969?4.3745?4.7513?5.1273?5.5023?5.8763

……

N＝31

α ₃₁To α ₃₈

11.3226?11.6667?11.9991?12.3200?12.6307?12.9329?13.2263?13.5111

k ₃₁To k ₃₈

1.9977?1.9372?1.8820?1.8315?1.7850?1.7419?1.7019?1.6647

h ₃₁To h ₃₈

0.4000?0.4000?0.4000?0.4000?0.4000?0.4000?0.4000?0.4000

……

Conclusion:

1, profile thickness Fenier lens rib tooth minimum angles α such as ₁=0.19 °, pairing rib tooth height is h=d ₀=0.4m.

2, etc. profile thickness Fei Nieer prism rib tooth is from the 31st beginning degree α ₃₁=11.3226 °, the height of pairing rib tooth is: h=k ₃₁Tan α ₃₁=k ₃₂Tan α ₃₂=k ₃₃Tan α ₃₃=...=d ₀=0.4mm

Above-mentioned data show: the thickness that waits outline line thickness Fresnel lens is d ₀, while d ₀Can get littler value as required.So just can effectively the angulodentate difference in height of mould be kept near zero, guarantee the homogeneity of the outer wall thickness of mold roller basically.

The rib tooth height difference of center and peripheral that the present invention is directed to the existing mold roller that waits the Fresnel lens that the tooth pitch method designs and produces is excessive and cause the serious heterogeneity of mould outer wall outline line thickness, gives that even cooling die roller strap comes very big difficulty when adopting calendering technology to make the glass Fresnel Lenses.Be head it off, in the method for designing that guarantees effectively to realize to propose under the prerequisite of sun energy line light gathering efficiency a kind of new glass Fresnel lens die.In the design of this glass Fresnel Lenses mould through the suitable regulating tooth width (near border area B) or the method for (central area A) highly; The height that can realize the rib tooth on the Fresnel Lenses mould is consistent; On engineering, realize the essentially identical target of Fresnel Lenses mould outer wall profile thickness, thereby do not influence the light gathering efficiency of Fresnel Lenses again when on production line, realizing easily cooling off.

Claims (1)

1. glass Fresnel Lenses Mould design method, it is characterized in that: according to be divided into two parts of A and B apart from the optical axis distance, wherein A partly is the part near Fresnel Lenses mold center with the Fresnel Lenses mould; B partly is a Fresnel Lenses die edge part, and the rib tooth of A part keeps rib facewidth degree and rib tooth angle degree constant on the basis of adopting common Fresnel Lenses die design method; Raise the height of rib tooth successively; Make the rib tooth height consistent, thereby make rib gear tooth profile thickness even, the tooth depth methods for designing such as rib tooth employing of B part; Be that the rib tooth height is certain, rib facewidth degree does not wait; Its concrete design process is following:

The width of supposing this Fresnel Lenses mould is 2l, and focal length is f, and the optically focused spot width is k ₀, the Desired Height that the rib tooth allows is d ₀, beginning to monosymmetric rib tooth number consecutively from Fresnel Lenses mould primary optical axis is 1,2,3 ... I ..., the width that makes first rib tooth is k ₁=k ₀, then first rib tooth center to primary optical axis apart from a ₁=k ₀/ 2, at this moment confirm that by formula (1) angle of this rib tooth is: ${\mathrm{\α}}_1=\mathrm{Arctan}\frac{a_1}{n\sqrt{{a_1}^2+f^2}-f},$ The rib tooth height is d ₁=k ₁Tan α ₁

Then with below several formulas try to achieve the 2nd successively, the 3rd, the 4th ... Up to the width of i rib tooth, angle, highly, rib tooth center is to the distance of primary optical axis;

k _i＝k ₀ (7)

a _i＝a _i-1+k _i/2 (4)

${\mathrm{\α}}_i=\arctan \frac{a_i}{n\sqrt{{a_i}^2+f^2}-f}---\left(1\right)$

d _i＝k _itanα _i (3)

Judge d _iWhether greater than d ₀If, d _i＜d ₀, k then _i=k ₀, and make d again _i=d ₀If, d _i＞d ₀, then make i=N, and with the following three formulas angle of definite N rib tooth again, width, highly, the distance of primary optical axis is arrived at rib tooth center,

k _itanα _i＝d ₀ (5)

${\mathrm{\α}}_i=\arctan \frac{a_i}{n\sqrt{{a_i}^2+f^2}-f}---\left(1\right)$

a _i＝a _i-1+k _i/2 (4)

Continue to calculate the parameter of next rib tooth then, all be determined until all rib teeth of this Fresnel Lenses mould by last three formulas.

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