CN100575987C - Plastic rod lens, rod lens array, rod lens plate, imageing sensor and printer - Google Patents

Abstract

The present invention relates to a kind of plastic rod lens, it has the cylindrical shape of radius R, refractive index n _DReduce from the outside perimembranous of central shaft, and satisfy following condition (1)～(3): (1) 43≤ν ₁≤ 60; (2) | { n _A* ν _A/ (n _A-1) }-{ n _B* ν _B/ (n _B-1) } |＜5; (3) n ₀-n ₁〉=0.01.In the formula, n ₁, n ₀, n _AAnd n _BThe refractive index n of representing peripheral part, center, arbitrfary point A and the arbitrfary point B of plastic rod lens respectively _Dν ₁, ν _AAnd ν _BThe Abbe number ν that represents peripheral part, arbitrfary point A and arbitrfary point B respectively.

Description

Plastic rod lens, rod lens array, rod lens plate, imageing sensor and printer

Technical field

The present invention relates to be used as plastic rod lens and rod lens array, rod lens plate, imageing sensor and the printer of the light drive access of light-focusing type rod-shaped lens, optical sensor etc.

Background technology

Generally speaking, plastic rod lens be material by the lens element that plastics constitute, have cylindrical shape, refractive index reduces continuously from the outside perimembranous of central shaft, times erect images such as formation.Plastic rod lens is become its both ends of the surface to become the parallel plane vertical with central shaft by mirror ultrafinish, a plurality of lens are closely arranged and bonding being integral, form with rod lens array, the part of using as the imageing sensor in the various scanners of manual scanning device etc., duplicating machine, facsimile recorder etc., and be widely used in the writing station etc. of LED printer.Plastic rod lens is because cost is low and can make the reason of optical system compactness etc., and its use field just enlarges.

Particularly owing to have the popularizing rapidly of printer compounding machine of the colour scanner function of the above high resolution of 600dpi in recent years, good to color characteristic, promptly the plastic rod lens that aberration is little is had higher requirement.But,, be difficult to obtain the little plastic rod lens of aberration because plastic rod lens is compared the range of choice of material with the excellent lens of glass narrow etc.

Patent documentation 1 discloses by combination ester ring type methacrylate and MMA, can obtain Abbe number difference in plastic rod lens and be the little plastic rod lens of aberration below 2.In addition, patent documentation 2 also discloses by using the system of ester ring type methacrylate and MMA, methacrylic acid fluorinated alkyl esters, can obtain the little plastic rod lens of aberration.In these technology, the Abbe number of plastic rod lens central part is less than or equal to the Abbe number of plastic rod lens peripheral part, and aberration is less than former plastic rod lens, but can not get the aberration little plastic rod lens the same with the excellent lens of glass.

In addition, the plastic refractive index distribution type optical element that is made of the interpolymer that uses three kinds of monomers is disclosed in patent documentation 3.In this system, can obtain having the eyeglass lens or the contact lenses of the refractive index characteristic that high Abbe number is big more more.Yet its monomer as high index of refraction uses and contains the monomer of bromine (manufacturing equipment is corrosive) or the monomer of bridging property, is difficult to be applicable to the manufacture process of plastic rod lens.

In addition, in non-patent literature 1, record the following formula of expression aberration.

$\frac{\mathrm{\&Delta;p}}{\mathrm{\&rho;}}=-\frac{1}{2}\frac{\mathrm{\&Delta;A}}{A}=\frac{1}{2}\frac{{\mathrm{<figure-callout\; id="0"\; label="N"\; filenames="C2006800263470033H1.png,C2006800263470034H1.png"\; state="\{\{state\}\}">N</figure-callout>}}_0\&times;\mathrm{\&Delta;}{N}_{r0}-{\mathrm{<figure-callout\; id="0"\; label="N\; r"\; filenames="C2006800263470033H1.png,C2006800263470034H1.png"\; state="\{\{state\}\}">N</figure-callout>}}_r\&CenterDot;\mathrm{\&Delta;}{N}_0}{(N_0-N_{r0})\&CenterDot;{\mathrm{<figure-callout\; id="0"\; label="N"\; filenames="C2006800263470033H1.png,C2006800263470034H1.png"\; state="\{\{state\}\}">N</figure-callout>}}_0}......\left(1\right)$

(in the formula, P indication cycle length, Δ is represented the variation that wavelength causes, A represents positive constant, N ₀Refractive index on the expression central shaft, N _R0The refractive index at expression distance center axle r0 place, P, A and N ₀Following relation is arranged).

$P=\frac{2\mathrm{\&pi;}}{\sqrt{A}}......\left(2\right)$

$N=N_0(1-\frac{A\&CenterDot;r^2}{2})$

(N: the refractive index at distance center axle r place)

Yet, do not have the concrete record of the little plastic rod lens of relevant aberration.

Patent documentation 1: the spy opens flat 7-35929 communique

Patent documentation 2: the spy opens the 2000-35517 communique

Patent documentation 3: the spy opens flat 9-127310 communique

Non-patent literature 1:K.Nishizawa, Appl.Opt.19,1052 (1980)

Summary of the invention

Task of the present invention provides aberration and good plastic rod lens and rod lens array, rod lens plate, the imageing sensor that uses it and the printer of color characteristic that reduces plastic rod lens.

Present inventors have derived the following formula that improves aberration from the described formula of above-mentioned non-patent literature, find when by reducing from the central shaft of the plastic rod lens refractive index n to peripheral part _DWhen satisfying following relational expression, can reduce aberration significantly.

$\frac{{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="C2006800263470033H1.png,C2006800263470034H1.png"\; state="\{\{state\}\}">n</figure-callout>}}_0\&CenterDot;v_0}{n_0-1}=\frac{n_r\&CenterDot;v_r}{n_r-1}(=K)---\left(3\right)$

(v _i: the position is positioned at the Abbe number at i place, n: the refractive index at position r place)

That is, the 1st aspect of the present invention relates to a kind of plastic rod lens, and it has the cylindrical shape of radius R, refractive index n _DReduce from the outside perimembranous of central shaft, and meet the following conditions (1)～(3):

(1)43≤v ₁≤60

(2)|{n _A×v _A/(n _A-1)}-{n _B×v _B/(n _B-1)}|＜5

(3)n _o-n ₁≥0.01

(in the formula, n ₁, n ₀, n _AAnd n _BThe refractive index n of representing peripheral part, center, arbitrfary point A and the arbitrfary point B of plastic rod lens respectively _Dv ₁, v _AAnd v _BThe Abbe number v that represents peripheral part, arbitrfary point A and arbitrfary point B respectively _D).

In the present invention, the refractive index at so-called center is meant that distance center axle 0.07mm is with the refractive index of interior scope on the cross section vertical with central shaft.Refractive index is the value of measuring down at 25 ℃.

In above-mentioned plastic rod lens, the polymkeric substance that constitutes plastic rod lens comprises following formation unit (A)～(C):

(A) contain (methyl) acrylic ester unit of alicyclic ring and/or heterocycle;

(B) contain the monomeric unit of aromatic rings; And

(C) (methyl) acrylic acid fluorinated alkyl ester units.

(methyl) acrylate is represented the general name of methacrylate and acrylate in the present invention.In order further to improve the thermotolerance of plastic rod lens, preferably use methacrylate.

Above-mentioned polymkeric substance also can comprise (D) (methyl) methyl acrylate unit as constituting the unit.

In above-mentioned plastic rod lens, the distance at the decentering axle is in the scope of 0.8R～R at least, and the containing ratio of shared formation unit (B) increases continuously to peripheral part in the polymkeric substance.

In above-mentioned plastic rod lens, be that the scope of 0～0.5R contains and comprises the polymkeric substance that constitutes unit (A) in the distance of decentering axle at least; In the distance of decentering axle is that the scope of 0～R contains and comprises the polymkeric substance that constitutes unit (D); In the distance of decentering axle at least is that the scope of 0.5R～R contains and comprises the polymkeric substance that constitutes unit (B) and formation unit (C).

Above-mentioned plastic rod lens can obtain in the following way: refractive index n after will solidifying and Abbe number v are n ₁＞n ₂＞...＞n _nAnd v ₁＞v ₂＞...＞v _nThe N of (N 〉=3) uncured thing, dispose in the mode that reduces successively from the outside perimembranous refractive index of central shaft and Abbe number, thereby form the stacked uncured duplexer (hereinafter referred to as " thread like body ") of concentric circles, when thereby the mutual DIFFUSION TREATMENT of carrying out the material between adjacent layer makes the index distribution of this each interlayer of thread like body preferably be continuous distribution, perhaps after carrying out mutual DIFFUSION TREATMENT, thread like body is cured processing.

The 2nd aspect of the present invention relates to a kind of rod lens array, and it is to make by the above described plastic rod lens of configured in parallel 1 row.

When setting conjugate length for the rod lens array of the light of wavelength X nm and be Tc (λ), above-mentioned rod lens array satisfies following condition:

(4) Tc (630)-Tc (470)≤0.3mm; And Tc (525)≤12mm.

The 3rd aspect of the present invention relates to a kind of rod lens plate, and it is made by disposing described plastic rod lens two-dimensionally.

A fourth aspect of the present invention relates to a kind of imageing sensor, and it uses described rod lens array or described rod lens plate.

A fifth aspect of the present invention relates to a kind of printer, and it uses described rod lens array or described rod lens plate.

A sixth aspect of the present invention relates to a kind of composition, and it comprises following composition (A)～(F):

(A) contain (methyl) acrylate of alicyclic ring and/or heterocycle: 0～15 quality %;

(B) contain the monomer of aromatic rings: 1～30 quality %;

(C) (methyl) acrylic acid fluorinated alkyl esters: 10～50 quality %;

(D) (methyl) methyl acrylate: 30～80 quality %; And

(F) polymerization initiator: 0.01～2 quality %.

Adopt the present invention can obtain plastic rod lens, rod lens array, the rod lens plate that aberration is little, color characteristic is good.In addition, by using this rod lens array or rod lens plate, can obtain the color image sensor of high resolution or the color printer of high resolution.

Description of drawings

Fig. 1 represents to be used to make the brief configuration figure of the device of the former line of plastic rod lens.

Fig. 2 represents to carry out the brief configuration figure of the device that adds hot-stretch and relaxation processes of the former line of plastic rod lens.

Fig. 3 is the figure of the index distribution of the former line of plastic rod lens of expression embodiment 1.

Fig. 4 is the figure of the index distribution of the former line of plastic rod lens of expression embodiment 4.

Symbol description

5 thread like bodies, 6 mutual diffusion parts

7 (A) the 1st solidifies handling part (the 1st rayed part)

7 (B) the 2nd solidifies handling part (the 2nd rayed part)

The former line of 8 carry-over pinch rolls, 9 plastic rod lens

11 inert gas introducing ports, 12 inert gas escape holes

Compound nozzle 14 the 1st carry-over pinch rolls that spin of 13 concentric circles

15 the 2nd carry-over pinch rolls 16 the 3rd carry-over pinch rolls

17 heating furnaces (stretching), 18 heating furnaces (relaxing)

19 plastic rod lens

Embodiment

Below describe preferred implementation of the present invention in detail.

Plastic rod lens of the present invention is on the cross section vertical with central shaft, and when radius was set at R, the preferred distribution with the quafric curve of being stipulated by following formula (5) in the index distribution in the 0.3R～0.7R scope of the outside perimembranous of central shaft at least was similar to.

n(L)＝n ₀{1-(g ²/2)L ²} (5)

(in the formula, n ₀It is the refractive index n of the central shaft of plastic rod lens _D(refractive index of the centre), L are from the distance of the central shaft of plastic rod lens (0≤L≤R), g is the index distribution constant of plastic rod lens, and n (L) is that the distance from the central shaft of plastic rod lens is the refractive index of the position of L).

In the present invention, preferred index n _DV reduces with Abbe number.In addition, preferred index n _DAnd Abbe number v reduces continuously from the outside perimembranous of central shaft.

Plastic rod lens of the present invention must satisfy the condition of above-mentioned formula (1)～(3).By satisfying the condition of (1),, can reach the effect that improves yield rate owing to reduce with respect to the variations in refractive index of wavelength change.Consider the change of refractive that reduces with respect to wavelength variations, preferred k is more than 150.

Significantly reduce by the condition aberration that satisfies (2).(2) the left side is more preferably less than 2.

In addition, can obtain the big bright plastic rod lens of angular aperture by the condition that satisfies (3).

The Abbe number that is characterized as peripheral part and the refractive index of plastic rod lens of the present invention are all low.Comprise the polymkeric substance that constitutes unit (B) and constitute unit (C) by on the peripheral part of plastic rod lens, using, can make peripheral part become low-refraction and low Abbe number.The refractive index that constitutes unit (B) be 1.55～1.65 and Abbe number be 20～40, refractive index height, Abbe number are low.

In addition, the refractive index that constitutes unit (C) be 1.39～1.41 and Abbe number be 62～68, refractive index is low, Abbe number is high.The polymkeric substance that comprises this formation unit (B) and formation unit (C) gives the low-refraction and the low Abbe number of peripheral part necessity of plastic rod lens.

Wherein, will constituting unit (B), to be set at the weight ratio that preferably constituted unit (C) at 1 o'clock be 1～15.Make refractive index n thus easily _DReduce continuously from the outside perimembranous of central shaft with Abbe number v.

The refractive index of the preferred peripheral part of plastic rod lens of the present invention is 1.400～1.500, Abbe number is 45.0～57.0, more preferably the refractive index of peripheral part is 1.470～1.490, Abbe number is 52.0～55.0, and the refractive index at center is 1.490～1.510, Abbe number is 54.0～57.0.By such setting, in constituting the unit, comprise easy (methyl) methyl acrylate that spins easily.

In addition,, can improve color characteristic, also can make the optical system compactness, shorten distance (optical path length) from original copy to image by shortening conjugate length in the mode that satisfies following formula (4) and reducing poor in the conjugate length of 470nm and 630nm.

Consider the design of satisfying following formula (1)～(3) easily, the polymkeric substance that constitutes plastic rod lens preferably comprises as constituting the unit:

(A) contain (methyl) acrylic ester unit of alicyclic ring and/or heterocycle;

(B) contain the monomeric unit of aromatic rings; And

(C) (methyl) acrylic acid fluorinated alkyl ester units.

Consider and carry out spinning of plastic rod lens easily that preferred above-mentioned polymkeric substance comprises (D) (methyl) methyl acrylate unit as constituting the unit.

Preferred in the present invention, the distance at the decentering axle is in the scope of 0.8R～R at least, and the shared containing ratio in formation unit (B) in the polymkeric substance increases continuously to peripheral part.In addition, preferred is in the scope of 0.5R～R in the distance of decentering axle at least, the formation unit (B) in the polymkeric substance and constitute that the unit is (C) to be increased to peripheral part with shared containing ratio.Thus, can when excessively rising, peripheral part reduce Abbe number in the inhibition refractive index.

Preferred in the present invention, be that the scope of 0～0.5R contains and comprises the polymkeric substance that constitutes unit (A) in the distance of decentering axle at least; In the distance of decentering axle is that the scope of 0～R contains and comprises the polymkeric substance that constitutes unit (D); At least be that the scope of 0.5R～R contains and comprises the polymkeric substance that constitutes unit (B) and formation unit (C) in the distance of decentering axle.

Wherein, more preferably above-mentioned polymkeric substance comprises as the formation unit in the distance of decentering axle is the zone of 0.5R～R:

(A) contain (methyl) acrylic ester unit of alicyclic ring and/or heterocycle: 0～40 quality %;

(B) contain the monomeric unit of aromatic rings: 1～50 quality %;

(C) (methyl) acrylic acid fluorinated alkyl ester units: 5～50 quality %; And

(D) (methyl) methyl acrylate unit: 10～80 quality %,

In being the zone of 0～0.5R, the distance of decentering axle comprises:

(A) contain (methyl) acrylic ester unit of alicyclic ring and/or heterocycle: 5～60 quality %;

(B) contain the monomeric unit of aromatic rings: 0～10 quality %;

(C) (methyl) acrylic acid fluorinated alkyl ester units: 0～50 quality %; And

(D) (methyl) methyl acrylate unit: 60～90 quality %.

Wherein, further preferred above-mentioned polymkeric substance comprises as the formation unit in the distance of decentering axle is the zone of 0.5R～R:

(A) contain (methyl) acrylic ester unit of alicyclic ring and/or heterocycle: 0～30 quality %;

(B) contain the monomeric unit of aromatic rings: 1～30 quality %;

(C) (methyl) acrylic acid fluorinated alkyl ester units: 5～50 quality %; And

(D) (methyl) methyl acrylate unit: 30～80 quality %,

In being the zone of 0～0.5R, the distance of decentering axle comprises:

(A) contain (methyl) acrylic ester unit of alicyclic ring and/or heterocycle: 5～50 quality %;

(B) contain the monomeric unit of aromatic rings: 0～5 quality %;

(C) (methyl) acrylic acid fluorinated alkyl ester units: 0～20 quality %; And

(D) (methyl) methyl acrylate unit: 60～90 quality %.

Preferred especially above-mentioned polymkeric substance comprises as the formation unit in the distance of decentering axle is the zone of 0.8R～R:

(A) contain (methyl) acrylic ester unit of alicyclic ring and/or heterocycle: 0～10 quality %;

(B) contain the monomeric unit of aromatic rings: 1～30 quality %;

(C) (methyl) acrylic acid fluorinated alkyl ester units: 10～50 quality %; And

(D) (methyl) methyl acrylate unit: 30～80 quality %.

The composition that polymerization constitutes unit (A) is carried out in explanation now.

As (methyl) acrylate that contains alicyclic ring, (refractive index of polymkeric substance is 1.53 for example can to enumerate methacrylic acid diamantane ester (adamantyl methacrylate), Abbe number is 54), (refractive index of polymkeric substance is 1.50 to isobornyl methacrylate, Abbe number is 54), three ring [5.2.1.0 ^2.6] decyl-octyl methacrylate (TDMA, the refractive index of polymkeric substance is 1.53, Abbe number is 55).

As (methyl) acrylate that contains heterocycle, comprise oxygen, nitrogen or sulphur in the preferred heterocycle, refractive index is high therefore preferred especially when comprising sulphur.The metering system olefin(e) acid ester (refractive index of polymkeric substance is that Abbe number is more than 55 more than 1.5) that for example preferably has the sulphonyl skeleton.As the example of methacrylate, can enumerate 3-methacryl hydroxyl sulfolane (SFMA), 3,3-dioxy-3-sulphur three ring (5.2.1.0 with sulphonyl skeleton ^2.6) decyl-8-methyl-prop diluted acid ester and 3,3-dioxy-3-sulphur three ring (5.2.1.0 ^2.6) decyl-9-methyl-prop diluted acid ester (DTTCMA), 1,1-dioxy tetrahydro thiene-3-yl-methacrylate (DTHTMA) etc.

Constitute the composition of unit (A) as carrying out polymerization, can use any one in (methyl) acrylate that contains alicyclic ring and (methyl) acrylate that contains heterocycle, also can use (methyl) acrylate that contains alicyclic ring and heterocycle in a part, also can use (methyl) acrylate that contains alicyclic ring and the potpourri that contains (methyl) acrylate of heterocycle.

Constitute the composition of unit (B) as carrying out polymerization, for example can enumerate (methyl) phenyl acrylate, benzyl acrylate, benzyl methacrylate (BzMA), (methyl) phenylethyl, (methyl) acrylic acid naphthalene ester, styrene (n=1.59), chlorobenzene second rare (n=1.61), vinyl naphthalene etc.

Constitute the composition of unit (C) as carrying out polymerization, for example can enumerate (methyl) acrylic acid 2,2,2-trifluoro ethyl ester, (methyl) acrylic acid 2,2,3,3-tetrafluoro ethyl ester, acrylic acid 2,2,3,3,4,4,5,5-octafluoro the eleventh of the twelve Earthly Branches base ester, methacrylic acid 2,2,3,3,4,4,5,5-octafluoro the eleventh of the twelve Earthly Branches base ester (8FM).Wherein, consider and the copolymerization of the monomer of other (methyl) acrylate etc., the good aspect of intermiscibility of multipolymer, preferred 8FM.

In the present invention, the viewpoint from the transparency, intermiscibility, the easiness that spins preferably contains and carries out the composition that polymerization constitutes unit (D).As preferred especially (methyl) methyl acrylate of this composition, further preferable methyl methyl acrylate (MMA).

Plastic rod lens of the present invention can also comprise above-mentioned (A)～(D) formation unit (E) in addition.The content that constitutes unit (E) is preferably 0～20 quality %.Constitute the monomer of unit (E) as carrying out polymerization, can enumerate (methyl) ethyl acrylate, (methyl) acrylic acid hydroxyalkyl acrylate, (methyl) acrylic acid binary alcohol esters, two (methyl) acrylic acid trihydroxy methyl propyl ester, three (methyl) acrylic acid trihydroxy methyl propyl ester, two (methyl) acrylic acid season the eleventh of the twelve Earthly Branches tetrol ester, three (methyl) acrylic acid season the eleventh of the twelve Earthly Branches tetrol ester, four (methyl) acrylic acid season the eleventh of the twelve Earthly Branches tetrol ester, four (methyl) acrylic acid double glyceride, six (methyl) two season of acrylic acid the eleventh of the twelve Earthly Branches tetrol ester etc. (methyl) esters of acrylic acid, other also can enumerate vinyl acetate (n=1.47), diethylene glycol bis-allyl carbonate, fluoridize poly-(methyl) acrylate of dibasic alcohol etc.

Represent that below conduct constitutes the one-tenth component selections TDMA of unit (A), constitutes the one-tenth component selections 8FM of unit (C), the one-tenth component selections methyl methacrylate that conduct constitutes unit (D) as the one-tenth component selections BzMA that constitutes unit (B), conduct, with the example of the 1st layer～the 5th layer under the situation of 5 layers of formation plastic rod lens stoste composition.

Table 1

The refractive index of the centre n of plastic rod lens of the present invention ₀Be preferably 1.4≤n ₀≤ 1.6.

Preferred radius R is below the above 0.4mm of 0.08mm in plastic rod lens of the present invention.When radius R is 0.4mm when following, can shorten conjugate length, make the optical system compactness.In addition, by shortening conjugate length, since littler in the difference of the conjugate length of 470nm and 630nm, color characteristic improved.

On the other hand, in order to make processing or assembling easily when making rod lens array or imageing sensor, preferred radius R is more than the 0.08mm.

In addition, in plastic rod lens of the present invention, under the wavelength of 525nm, index distribution constant g is preferably 0.4mm ^-1≤ g≤2.0mm ^-1By making index distribution constant g is 2.0mm ^-1Below, can prolong 1 Cycle Length of plastic rod lens, when making rod lens array, make processing or assembling easily.

When index distribution constant g greater than 0.4mm ^-1The time, because 1 Cycle Length of plastic rod lens shortens, conjugate length Tc diminishes, and can realize the densification of optical system.By making the scope of index distribution constant g, can take into account the assembling of the densification and the plastic rod lens of optical system in above-mentioned value.

In addition, long-pending (gR) of the index distribution constant g of preferred plastic rod lens of the present invention and radius R satisfies 0.1≤gR≤0.3.Thus, can obtain the plastic rod lens that the depth of focus is dark, conjugate length is short, quantity of light emission is big.

In order to remove the flash of light or the light of crosstalk to improve lens performance, plastic rod lens of the present invention is preferably on the cross section vertical with central shaft, 80 μ m from the plastic rod lens outer peripheral face towards central shaft with interior scope in and in the scope in the outside more than decentering axle 0.6R, be formed with light absorber and contain layer, this layer contains the light absorber that absorbs the light of the wavelength region may of at least a portion in visible light and the near infrared light zone.

On the peripheral part of plastic rod lens, form light absorber as described above and contain layer, can can not reduce significantly under the situation of quantity of light emission, prevent because the caused flash of light of irregular part of the index distribution that on the plastic rod lens peripheral part, forms or the crosstalk when making rod lens array.When containing under the situation of light absorber in the distance of a decentering axle side littler than 0.6R, perhaps containing under the situation of light absorber from the plastic rod lens outer peripheral face towards central shaft above the zone of 80 μ m, quantity of light emission will reduce.

As light absorber of the present invention, can use various dyestuffs or the pigment and the pigment of the light that can be absorbed in the wavelength that uses in the optical system of using plastic rod lens.These light absorbers also can be used in combination the different respectively light absorber of wavelength that absorbs more than two kinds for only absorbing the light absorber of particular wavelength region.For example, under the situation about in color scanner, using, can be used in combination the dyestuff of the light that absorbs each wavelength of RGB with rod lens array.In addition, as mentioned above, can use the light absorber that only absorbs particular wavelength region in visible light (about 400nm～700nm) and the near infrared (about 700nm～1000nm) as light absorber of the present invention, also can use the light absorber that absorbs the long zone of all-wave.Under the situation of the layer that forms the light that absorbs whole visible regions, can use and mix the light absorber that multiple light absorber becomes the light absorber of black or uses the black of carbon black or graphitic carbon etc.

In addition, contain in the layer at light absorber, the preferred light absorbing agent exists as far as possible equably.Preferably in constituting the macromolecule that light absorber contains layer, disperse equably this moment or be combined with the light absorber molecule.

In addition, light absorber is preferably 0.001～10 quality % at the content that light absorber contains layer, more preferably 0.01～1 quality %.

The manufacture method that is suitable for well when making plastic rod lens of the present invention now is described.

To the formation method of the index distribution of plastic rod lens without limits, can use the addition reaction method, copolymerization process, the gel polymerisation method, the monomer volatility process, any method of diffusion method etc. mutually, but consider precision and the preferred diffusion method mutually of productivity.

Mutual diffusion method now is described.

At first, be n with refractive index n and Abbe number v after solidifying ₁＞n ₂＞...＞n _nAnd v ₁＞v ₂＞...＞v _nThe N of (N 〉=3) uncured thing, use compound nozzle that spins etc. to dispose in the mode that reduces successively from the outside perimembranous refractive index of central shaft and Abbe number, thereby form the stacked uncured duplexer (hereinafter referred to as " thread like body ") of concentric circles, when thereby the mutual DIFFUSION TREATMENT of carrying out the material between adjacent layer makes the index distribution of this each interlayer of thread like body preferably be continuous distribution, perhaps after carrying out mutual DIFFUSION TREATMENT, thread like body is cured processing, thereby obtains the former line of plastic rod lens (operation spins).In addition, mutually DIFFUSION TREATMENT be meant under blanket of nitrogen, 10～60 ℃, preferably 20～50 ℃ to thread like body give the several seconds～several minutes hot resume.

Wherein, as uncured thing preferably use the 1st～5 layer each layer consist of following 5 layers:

The 1st layer comprises:

(a) refractive index after solidifying be 1.50～1.54 and solidify after Abbe number be 53～63 monomer: 20～45 quality %;

(d) refractive index after solidifying be 1.48～1.50 and solidify after Abbe number be 55～58 monomer: 55～80 quality %;

(b) refractive index after solidifying be 1.55～1.65 and solidify after Abbe number be 20～40 monomer: 0～5 quality %;

(c) refractive index after solidifying be 1.39～1.41 and solidify after Abbe number be 62～68 monomer: 0～5 quality %,

The 2nd layer comprises:

Above-mentioned (a) composition: 1～30 quality %;

Above-mentioned (d) composition: 20～80 quality %;

Above-mentioned (b) composition: 0～10 quality %; And

Above-mentioned (c) composition: 0～10 quality %,

The 3rd layer comprises:

Above-mentioned (a) composition: 0～15 quality %;

Above-mentioned (d) composition: 50～80 quality %;

Above-mentioned (b) composition: 1～10 quality %; And

Above-mentioned (c) composition: 1～20 quality %,

The 4th layer comprises:

Above-mentioned (a) composition: 0～10 quality %;

Above-mentioned (d) composition: 50～80 quality %;

Above-mentioned (b) composition: 1～15 quality %; And

Above-mentioned (c) composition: 10～30 quality %,

The 5th layer comprises:

Above-mentioned (d) composition: 30～50 quality;

Above-mentioned (b) composition: 5～30 quality %; And

Above-mentioned (c) composition: 20～50 quality %.

The plastic rod lens that contains (d) composition is cheap, has the transparency and the high characteristics of thermotolerance.

In addition, preferably using refractive index and Abbe number after the 1st～5 layer the curing as uncured thing is following 5 layers:

The 1st layer: refractive index 1.500～1.510, Abbe number are 55.0～59.0;

The 2nd layer: refractive index 1.490～1.500, Abbe number are 54.0～58.5;

The 3rd layer: refractive index is 1.480～1.495, and Abbe number is 54.0～58.0;

The 4th layer: refractive index is 1.475～1.485, and Abbe number is 53.5～57.5; And

The 5th layer: refractive index is 1.465～1.474, and Abbe number is 53.0～55.5.

Above-mentioned (a)～(d) composition preferably constitutes by giving the above-mentioned monomer that constitutes unit (A)～(D) respectively.

Utilize the said method manufacturing to form the former line of plastic rod lens of index distribution, then, after adding the former line of the resulting plastic rod lens of hot-stretch as required, carry out relaxation processes, cut into suitable given size, thereby obtain plastic rod lens of the present invention.For the approaching desirable distribution of the index distribution that makes the plastic rod lens that obtains, the number N that wishes employed uncured thing is 4～6 scope.

Under the situation of N=5, be preferably from the thickness ratio of each layer of the 1st layer to the 5th layer:

5～30/15～50/15～40/10～25/0.5～10。

The viscosity of uncured thing is preferably 102～107Pas.When viscosity is too small, when being shaped, be easy to generate broken string, be difficult to form thread like body.But when viscosity was excessive, the operability during shaping was bad, and the concentric circles characteristic of each layer is impaired, and the situation of the thread like body appearance of even thickness difference is arranged.

Can use free-radical polymerised vinyl monomer as the material that constitutes this uncured thing, or by free-radical polymerised vinyl monomer and polymer soluble constitutes in this monomer composition etc.

The viscosity of the uncured thing when forming thread like body by these uncured things for easy adjustment, and in order to form continuous index distribution from the central shaft of thread like body towards peripheral part, uncured thing preferably by monomer and in this monomer the composition of polymer soluble (soluble polymer) constitute.

As the polymkeric substance use and by the above-mentioned good polymkeric substance of polymer phase dissolubility that constitutes unit (A)～(E) generation, the polymkeric substance that for example preferably constitutes unit (D) is polymethylmethacrylate (n=1.49), and polymethylmethacrylate is co-polymer (n=1.47～1.50).

In each layer, use when having the soluble polymer of identical refractive index for the viscosity of adjusting uncured thing, can obtain the plastic rod lens that has continuous index distribution from the outside perimembranous of central shaft, therefore preferred.Particularly therefore transparent good, the refractive index height of itself of polymethylmethacrylate are suitable as the soluble polymer that uses very much when making plastic rod lens of the present invention.

In order to solidify the thread like body that forms by uncured thing, preferably in uncured thing, add the polymerization initiator (F) of 0.01～2 quality %.(F) has heat curing initiating agent and trigger for optical solidification as polymerization initiator, can use they any one.

Usually use the initiating agent of peroxide or azo class as the heat curing initiating agent.Can enumerate benzophenone, benzoin alkylether, 4 '-isopropyl-2-hydroxy-2-methyl propiophenone, 1-hydroxycyclohexylphenylketone, benzyl methyl ketal, 2 as trigger for optical solidification, 2-diethoxy acetophenone, chlorothiaxanthenone, thioxanthone compounds, benzophenone compound, 4-dimethylamino ethyl benzoate, the different the eleventh of the twelve Earthly Branches ester of 4-dimethylamino benzoic acid, N methyldiethanol amine, triethylamine etc.

In order to solidify uncured thing, the thread that contains heat curing initiating agent and/or trigger for optical solidification is heat-treated and/or the photocuring processing.Contain at uncured thing under the situation of heat curing initiating agent and trigger for optical solidification, can heat-treat with photocuring and handle both.

Handling as photocuring can be by from carrying out the uncured thing irradiation ultraviolet radiation that contains trigger for optical solidification on every side.The light source of handling usefulness as photocuring can be enumerated the carbon arc lamp, high-pressure sodium lamp, medium pressure mercury lamp, low pressure mercury lamp, ultrahigh pressure mercury lamp, chemical lamp, xenon lamp, laser of the light that 150～600nm wavelength takes place etc.

Handle as heat curing and can carry out the thermal treatment of stipulated time to the uncured thing that contains the heat curing initiating agent by curing handling part and carry out at the heating furnace that is controlled as uniform temperature etc.

In order stably to make thread like body, prevent from before solidifying processing, to carry out polymerization, preferably add polymerization and forbid agent.Forbid that as polymerization agent can enumerate the naphtoquinone compounds of p-dihydroxy-benzene, hydroquinone monomethyl ether etc., the aminated compounds of phenothiazine etc., 4-hydroxyl-2,2,6, the N-hydroxy kind compound of 6-tetramethyl croak pyridine-N-hydroxyl etc. etc.

Solidify the former line of the resulting plastic rod lens of thread like body and can directly deliver to the heating stretching process as required, deliver to the heating stretching process after perhaps also can temporarily being wound on the bobbin.Adding hot-stretch can carry out with intermittent mode, also can carry out in a continuous manner.Operation preferably relaxes behind the heating stretching process.Operation preferably relaxes behind the heating stretching process.Heating stretching process and lax operation also can be carried out continuously, also can each operation separation carry out.

The heating stretching process can carry out with known method.For example, can enumerate following method: with the 1st niproll the former line of plastic rod lens that curing obtains is supplied with to heating furnace, utilized the 2nd niproll also to stretch with the speed drawing faster by the former line of the plastic rod lens of heating furnace than the 1st niproll.The temperature of the hot atmosphere of heating stretching process can suitably be set according to the material of plastic rod lens etc., but is preferably more than the vitrifacation transition temperature (Tg)+20 ℃ of plastic rod lens.In addition, stretching ratio is suitably determined by the diameter of desirable plastic rod lens, can utilize the peripheral speed of the 1st and the 2nd niproll recently to regulate.

Lax operation can utilize known method to carry out.For example can enumerate following method: the former line of the plastic rod lens that utilizes the 3rd niproll to be stretched is supplied with to heating furnace, will utilize the 4th niproll with than slow speed drawing of the 3rd niproll and lax method etc. by the former line of the plastic rod lens of heating furnace.The temperature of the hot atmosphere of lax operation can suitably be set according to the material of plastic rod lens etc., is preferably set to more than the Tg of plastic rod lens.In addition, relaxation rate (length before the length/relaxation processes after the relaxation processes) is suitably determined by the diameter of desirable plastic rod lens, is preferably about 99/100～3/5.Can suppress the contraction of plastic rod lens by the operation that relaxes.The lack of homogeneity of lens diameter when relaxation rate is too small, therefore not preferred.Lax multiplying power can utilize the peripheral speed of the 3rd and the 4th niproll recently to regulate.

The molecular weight of the preferred plastic rod lens that finally obtains is 10000～100000.

An example of the manufacturing installation of the former line of expression plastic rod lens of the present invention in Fig. 1 and Fig. 2.

Fig. 1 is the simplified diagram of the manufacturing installation of the former line of plastic rod lens of the present invention, represents mutual diffusion part and the part of solidifying handling part with longitudinal section.In Fig. 1,13 are the compound nozzle that spins of concentric circles, 5 is the uncured thread like body of extruding, 6 is that the monomer of each layer that constitutes thread like body is reciprocally spread to be used to form the mutual diffusion part of continuous index distribution, 7 (A), 7 (B) are for being cured the curing handling part of processing to uncured thing, 8 is carry-over pinch rolls, and 9 is the former line of plastic rod lens, 11 is the inert gas introducing port, and 12 is the inert gas escape hole.

In order to import inert gases (for example nitrogen) from inert gas introducing port 11, and to discharge from the volatile matter of the free monomer of thread like body 5 etc. from mutual diffusion part 6 and solidify handling part 7 and remove from inert gas escape hole 12.

The former line 9 of the plastic rod lens that obtains perhaps temporarily is wound on after bobbin etc. goes up from above-mentioned manufacturing installation continuously, supplies with and gives the device that adds hot-stretch and relaxation processes shown in Fig. 2.In device shown in Figure 2, heat in the heating furnace 17 that is stretching between the 1st carry-over pinch rolls 14 and the 2nd carry-over pinch rolls 15 and carry out; Carry out in the heating furnace 18 of relaxation processes between the 2nd carry-over pinch rolls 15 and the 3rd carry-over pinch rolls 16.Can use the heating furnace of known structure as heating furnace 17,18.

The former line of the plastic rod lens that obtains thus can directly cut into desirable length continuously, cuts off after perhaps also can be on being wound in bobbin etc.

Then rod lens array of the present invention is described.

Constituting of rod lens array of the present invention is at the of the present invention a plurality of plastic rod lens that dispose abreast between two substrates more than 1 row.When fixed plastics rod lens and substrate, use bonding agent etc.Adjacent plastic rod lens can closely dispose mutually, and also certain interval configuration at interval in this case, keeps certain clearance between preferred plastic rod lens and the plastic rod lens.In addition, overlay configuration more than two sections plastic rod lens and under the situation of the rod lens array that obtains, preferably with the mode intersecting of the gap minimum between the plastic rod lens.

Rod lens array of the present invention is because aberration is little, so the conjugate length difference of the light of different wave length is little, color characteristic is good, can form the color image sensor of high resolution.

Rod lens array of the present invention can be with well-known method manufacturing.For example, at first, the plastic rod lens that cuts into certain-length is disposed abreast and is fixed between two substrates, make between the plastic rod lens compact configuration each other.Under this state, be injected into the bonding agent that adds opacifier such as carbon black between the plastic rod lens and in the gap that between plastic rod lens and substrate, forms, and make its curing.Then, as required this rod lens array is cut into desirable length, utilize the mirror-polishing of the end face that the adamas sword cuts etc. to handle.

Then, rod lens plate of the present invention is described.

Constituting of rod lens plate of the present invention, dispose a plurality of plastic rod lens of the present invention two-dimensionally in the optical axis direction of plastic rod lens mode parallel to each other, on the plane vertical, on mutually different two directions, dispose plastic rod lens with the optical axis of plastic rod lens.Use bonding agent etc. to fix between the plastic rod lens.Adjacent plastic rod lens can be closely alternately laminated mutually, and also certain interval is configured at interval.In this case, keep certain clearance between preferred plastic rod lens and the plastic rod lens.

Rod lens plate of the present invention is owing to be configured to two-dimentional shape, so can be used for reading the imageing sensor etc. of the information of wide area.In addition, because aberration is little, rod lens plate of the present invention can be used for the color image sensor of high resolution.

Rod lens plate of the present invention can be made with known method.For example, at first, with the plastic rod lens that cuts into certain-length with alternately laminated mode configured in parallel and fixing two-dimensionally, thereby make plastic rod lens compact configuration each other.Under this state, the bonding agent that adds opacifier such as carbon black is injected in the gap that forms between the plastic rod lens, and makes its curing.Then, as required this rod lens plate is cut into desirable length, utilize methods such as cutting of adamas sword or optical grinding that end face is carried out mirror-polishing and handle.In addition, in order to reduce at the rod lens plate end face, also can be coated with anti-reflection coating owing to the light loss that causes of reflection.

Then, imageing sensor of the present invention is described.

Imageing sensor of the present invention has as basic structure: accept light and it is transformed to the components of photo-electric conversion of electric signal; Be used to illuminate the light source of the original copy that will read; To be imaged on bright rod lens array or the rod lens plate of basis on the above-mentioned components of photo-electric conversion from the reflected light that reads original copy.Also can have glass cover that is used for stably fixing original copy etc.

The light source that uses in the imageing sensor of the present invention is the light source that is used to illuminate the original copy surface, can use incandescent lamp, cold-cathode tube, LED etc., considers the light that utilizes specific wavelength easily, preferably uses LED.In order to cut off specific wavelength, these light sources also can be used in combination with filter element.

Imageing sensor of the present invention also can use the different multiple LED of emission wavelength to be used as color image sensor.In this case, light source preferably is made of the different a plurality of LED of the emission wavelength that is equivalent to red, green, blue three looks respectively.Under situation about using as color image sensor, from obtaining the purpose of good colorrendering quality, the peak value of emission wavelength preferably is respectively 450～480nm (indigo plant), 510～560nm (green), 600～660nm (red).Lighting device with this light source is constituted as, and light incides the light conductor from light source, from the bright original copy of the illumination surface that light conductor penetrates.

For example, lighting device is made of RGB three-color LED light source and light conductor, this RGB three-color LED is that red (R) LED element, green (G) LED element, this three-color LED element of indigo plant (B) LED element as light source is assembled into one light source, and this light conductor is made of the good parts of photopermeabilities such as acryl resin.RGB three-color LED light source is configured to, and light is incident on the light conductor from a side of the end of the length direction of light conductor or the both sides of end, and incident light carries out total reflection repeatedly on the interface of light conductor and air, thereby propagates in light conductor.

It now is the action that example illustrates imageing sensor of the present invention with the color image sensor.Utilize lighting device successively R, G, B three coloured light to be shone to the original copy that is compressed and support by glass cover with switching from tilted direction.From the light of the colouring information that has R, G, B three looks of original copy reflection by rod lens array imaging on the components of photo-electric conversion.The light that the components of photo-electric conversion will have the colouring information of R, G, B three looks is transformed to electric signal.The image information that is transformed to electric signal is sent to the Account Dept with computing machine etc., handles the electric signal of R, G, B three looks in Account Dept, reproduces coloured image.

Imageing sensor of the present invention can read distinct coloured image because color characteristic is good, can be used in the colour scanner etc. of high resolution.

Then printer of the present invention is described.

Printer of the present invention uses rod lens array of the present invention or rod lens plate to constitute, for example, by being configured to led chip, rod lens array of the present invention or rod lens plate and photoreceptor or light-sensitive surface (photographic paper) formation that array-like forms as the LED of light source.It uses colored three primary colors light source that image information is write on photoreceptor or the light-sensitive surface.

So printer of the present invention is little owing to writing fashionable fuzzy problem of all kinds with 3 primary colors again owing to having used rod lens array of the present invention or rod lens plate aberration little, can be used as the color printer and the image printing apparatus of high resolution.

In addition, be not limited to led array, can use the light source of liquid crystal shutter (liquid crystal shutter), EL array etc. as the light source of printer of the present invention.

Embodiment

Below utilize embodiment to specifically describe the present invention.Polymethylmethacrylate uses viscosity [η]=0.40[P in an embodiment] polymethylmethacrylate of (in MEK, measuring) at 25 ℃.Use the 1-hydroxycyclohexylphenylketone as trigger for optical solidification, use p-dihydroxy-benzene (HQ) as polymerization inhibitor.

In addition, the mensuration of rerum natura is carried out in the following manner.

(index distribution)

Utilize the Interphako interference microscope of Carl Zeiss corporate system to measure.

(conjugate length (Tc) and resolving power (MTF))

Use have spatial frequency 12 (line is right/mm, Lp/mm) grid pattern, make the light that sends from light source be incident on the rod lens array that the both ends of the surface vertical with optical axis are ground by grid pattern, the ccd line sensor that utilization is arranged on the imaging surface reads grid images, measure the maximal value (imax) and the minimum value (imin) of this mensuration light quantity, utilize following formula to ask MTF (modulation transfer function).

MTF(％)＝{(imax-imin)/(imax+imin)}×100

At this moment, make the distance of the incident end of grid pattern and rod lens array be equal to the distance of the ejecting end and the ccd line sensor of rod lens array.In addition, grid pattern and ccd line sensor are moved symmetrically with respect to rod lens array, thereby measure MTF, the grid pattern when getting the MTF optimum and the distance of ccd line sensor are conjugate length.

(embodiment 1)

The stoste of each layer of modulation shown in following table 2.

In addition, in order to suppress crosstalk light and flash of light, in each stoste of the 4th layer and the 5th layer usefulness before adding hot milling, all stoste is added dyestuff BlueACR (NIPPON KAYAKU CO. in mode as shown in the table, LTD. make), dyestuff Blue 4G (Mitsubishi Chemical's manufacturing), dyestuff MS yellow HD-180 (dyestuff (strain) system is pressed in Mitsui east), dyestuff MS MagentaHM-1450 (dyestuff (strain) system is pressed in Mitsui east), dyestuff KAYASORB CY-10 (NIPPONKAYAKU CO., LTD. makes).

Table 3

Dyestuff	The 4th layer (quality %)	The 5th layer (quality %)
			Blue ACR	0.014	0.571
Blue 4G	0.011	0.011
			MS Magenta HM-1450	0.014	0.143
MS Yellow HD-180	0.014	0.143
			KAYASORB CY-10	0.011	0.011

Afterwards, each layer added hot milling to 70 ℃, 5 layers of compound spinning of concentric circles that the refractive index after solidifying from center configuration successively reduces, and it is extruded simultaneously from nozzle.The temperature of the compound nozzle that spins is 50 ℃.The output ratio of each layer is, is scaled the ratio of thickness (being radius in the 1st layer) of each layer of the radial direction of plastic rod lens, the 1st layer/the 2nd layer/the 3rd layer/the 4th layer/the 5th layer=21/25/33/19/2.

Secondly, the thread like body that to extrude from the compound nozzle that spins, utilize niproll traction (200cm/ minute), making it is the mutual DIFFUSION TREATMENT portion of 30cm by length, then make thread like body the 1st solidify handling part (the 1st illumination part) in the heart by to be cured, the 1st curing handling part is with length 60cm, 18 chemical lamps of 20W form uniformly-spaced to dispose around the central shaft that two sections connects up and down, further, thread like body is passed through in the 2nd curing handling part (the 2nd illumination part) in the heart, thereby make its full solidification, the 2nd curing handling part is forming with the high-pressure sodium lamp that equally spaced disposes 3 2.0KW around central shaft.Nitrogen flow in the DIFFUSION TREATMENT portion is 80L/ minute mutually.The radius of the former line of plastic rod lens that obtains is 0.295mm.

Mensuration is removed peripheral part and is not contained the index distribution of dyestuff with the former line of plastic rod lens of external application same procedure manufacturing, and it is illustrated among Fig. 3.The refractive index at center is 1.497, and the refractive index of peripheral part is 1.478, and refractive index reduces continuously to peripheral part.Comprising under the situation of dyestuff index distribution too.

Under 135 ℃ atmosphere,, under 115 ℃ atmosphere, carry out relaxation processes, make relaxation rate reach 510/714 3.75 times of the former line drawings of this plastic rod lens.

The radius R of the plastic rod lens that obtains is 0.185mm, and refractive index of the centre is 1.497, is similar to formula (5) in index distribution in the 0.2R～0.8R scope of the outside perimembranous of central shaft, and index distribution constant g is 0.84mm under 525nm wavelength situation ^-1

In addition, the outer peripheral face from plastic rod lens roughly mixes the layer that exists equably to the dyestuff that central part forms the 40 μ m thickness of having an appointment.

A plurality of resulting plastic rod lens are disposed (0.37mm at interval) with row close parallel ground between two phenolic resin system substrates, filling adhesive (Vantico corporate system " Araldite Rapid ") in the crack betwixt, make between plastic rod lens and the bonding agent between plastic rod lens and substrate solidify.Then, on the face vertical with the central shaft of plastic rod lens, with the adamas sword both ends of the surface are carried out mirror-finish cutting, the length that produces plastic rod lens is the rod lens array of 4.4mm.The conjugate length Tc of this rod lens array under the 525nm situation is 9.8mm, and the MTF of this moment is 72.6%.

Measure the Tc (table 8) of this rod lens array under each wavelength situation of 470nm, 525nm, 630nm.In addition, under the situation of the MTF of 3 wavelength of certain Tc relatively, the Tc of the maximum of minimum MTF is 9.8mm.At the Tc of this color characteristic optimum the MTF (table 8) that measures each wavelength under the condition of 9.8mm.

(comparative example 1)

Shown in above-mentioned table 2, modulated the stoste of each layer.In the 4th layer and the 5th layer, shown in following table 4, added dyestuff.

Table 4

Dyestuff	The 4th layer (quality %)	The 5th layer (quality %)
			Blue ACR	0.571	0.571
Blue 4G	0.023	0.023
			MS Magenta HM-1450	0.143	0.143
MS Yellow HD-180	0.143	0.143
			KAYASORB CY-10	0.023	0.023

These 5 kinds of stostes are added hot milling to 70 ℃, 5 layers of compound spinning of concentric circles that the refractive index after solidifying from center configuration successively reduces, and it is extruded simultaneously from nozzle.The temperature of the compound nozzle that spins is 40 ℃.The output ratio of each layer is to be scaled the ratio of each layer thickness (being radius in the 1st layer) of the radial direction of plastic rod lens, the 1st layer/the 2nd layer/the 3rd layer/the 4th layer/the 5th layer=18/50/29/2/1.

Secondly, similarly to Example 1, with niproll traction on one side carry out mutual DIFFUSION TREATMENT and solidify handle on one side, thereby obtain the former line of plastic rod lens.The radius of the former line of plastic rod lens that obtains is 0.24mm.

Under 135 ℃ atmosphere,, under 150 ℃ atmosphere, carry out relaxation processes, make relaxation rate reach 10/11 2.2 times of the former line drawings of this plastic rod lens.

The radius R of the plastic rod lens that obtains is 0.17mm, and refractive index of the centre is 1.497, is similar to formula (5) in index distribution in the 0.2R～0.8R scope of the outside perimembranous of central shaft, and index distribution constant g is 0.84mm under 525nm wavelength situation ^-1

In addition, the outer peripheral face from plastic rod lens roughly mixes the layer that exists equably to the dyestuff that central part forms the 5 μ m thickness of having an appointment.

Except using a plurality of resulting plastic rod lens, and beyond the interval of plastic rod lens changed to 0.34mm from 0.37mm, make similarly to Example 1, thereby the length that produces plastic rod lens is the rod lens array of 4.4mm.The conjugate length Tc of this rod lens array under the 525nm situation is 10.0mm, and MTF at this moment is 65.0%.

Measure the Tc (table 8) of this rod lens array under each wavelength situation of 470nm, 525nm, 630nm.Under the situation of the MTF of 3 wavelength of certain Tc relatively, the Tc of the maximum of minimum MTF is 10.1mm.In table 8, be illustrated in Tc and be the MTF of each wavelength of measuring under the 10.1mm.

(embodiment 2)

Change to 500/700 except stretching ratio changes to 3.50 times, relaxation rate, make similarly to Example 1, thereby produce plastic rod lens.

The radius R of the plastic rod lens that obtains is 0.187mm, and refractive index of the centre is 1.497, is similar to formula (5) in index distribution in the 0.2R～0.8R scope of the outside perimembranous of central shaft, and index distribution constant g is 0.84mm under 525nm wavelength situation ^-1

Secondly, except the interval with plastic rod lens changes to 0.39mm, bonding agent is changed to SEKISUI FULLER Co. from " Araldite Rapid " from 0.37mm, Ltd. " the s-dine 9607K " of Zhi Zaoing in addition, makes similarly to Example 1, thereby produces rod lens array.

The conjugate length Tc of this rod lens array under the 525nm situation is 10.0mm, and MTF at this moment is 72.6%.

Measure the Tc (table 8) of this rod lens array under each wavelength situation of 470nm, 525nm, 630nm.In addition, under the MTF situation of 3 wavelength that compare certain Tc, the Tc of the maximum of minimum MTF is 10.0mm.At the Tc of this color characteristic optimum the MTF (table 8) that measures each wavelength under the condition of 10.0mm.

(embodiment 3)

Change like that the 4th layer the dyestuff addition except as shown in table 5 below, make similarly to Example 2, thereby produce plastic rod lens and rod lens array.

Table 5

Dyestuff	The 4th layer (quality %)
		Blue ACR	0.003
Blue 4G	0.003
		MS Magenta HM-1450	0.003
MS Yellow HD-180	0.006
		KAYASORB CY-10	0.003

The radius R of the plastic rod lens that obtains is 0.187mm, and refractive index of the centre is 1.497, is similar to formula (5) in index distribution in the 0.2R～0.8R scope of the outside perimembranous of central shaft, and index distribution constant g is 0.84mm under 525nm wavelength situation ^-1

The conjugate length Tc of rod lens array under the 525mm situation is 10.0mm, and MTF at this moment is 62.4%.

Measure the Tc (table 8) of this rod lens array under each wavelength situation of 470nm, 525nm, 630nm.In addition, under the situation of the MTF of 3 wavelength of certain Tc relatively, the Tc of the maximum of minimum MTF is 10.0mm.At the Tc of this color characteristic optimum the MTF (table 8) that measures each wavelength under the condition of 10.0mm.

(comparative example 2)

Except the interval of plastic rod lens array is changed to 0.36mm and bonding agent changed to " s-dine 9607K " from 0.34mm, similarly make with comparative example 1, thereby produce rod lens array.

(mensuration of light quantity)

Go up scanning white light source and imageing sensor in the configuration direction (length direction) of rod lens array, and measure the light quantity on the optical axis, with the mean value of each point as light quantity.Configuration optical filter and diffuser plate between white light source and rod lens array.The light quantity of the wavelength of 470nm, the 525nm of the rod lens array of embodiment 2,630nm is taken as 100 respectively, the light quantity of embodiment 2,3 and comparative example 2 is measured and compared, the result is illustrated in the table 8.

(embodiment 4)

Modulate the stoste of each layer as shown in table 6 belowly.

Such dyestuff that adds as shown in table 7 below.

Table 7

Dyestuff	The 5th layer (quality %)
		Blue ACR	0.571
Blue 4G	0.011
		MS Magenta HM-1450	0.143
MS Yellow HD-180	0.143
		KAYASORB CY-10	0.011

Afterwards, each layer added hot milling to 70 ℃, 5 layers of compound spinning of concentric circles that the refractive index after solidifying from center configuration successively reduces, and it is extruded simultaneously from nozzle.The temperature of the compound nozzle that spins is 55 ℃.The output ratio of each layer is, is scaled thickness (being radius in the 1st layer) ratio of each layer of the radial direction of plastic rod lens, the 1st layer/the 2nd layer/the 3rd layer/the 4th layer/the 5th layer=6/40/35.5/17/1.5.

Secondly, the thread like body that to extrude from the compound nozzle that spins, utilize niproll traction (200cm/ minute), making it is the mutual DIFFUSION TREATMENT portion of 30cm by length, then make thread like body the 1st solidify handling part (the 1st illumination part) in the heart by to be cured, the 1st curing handling part is with length 60cm, 18 chemical lamps of 20W form uniformly-spaced to dispose around the central shaft that two sections connects up and down, further, thread like body is passed through in the 2nd curing handling part (the 2nd illumination part) in the heart, thereby make its full solidification, the 2nd curing handling part is forming with the high-pressure sodium lamp that equally spaced disposes 3 2.0KW around central shaft.The nitrogen flow of DIFFUSION TREATMENT portion is 84L/ minute mutually.The radius of the former line of plastic rod lens that obtains is 0.298mm.

Measure the index distribution of the former line of resulting plastic rod lens, and it is illustrated among Fig. 4.The refractive index at center is 1.498, and the refractive index of peripheral part is 1.48, and refractive index reduces continuously to peripheral part.

Under 135 ℃ atmosphere,, under 118 ℃ atmosphere, carry out relaxation processes, make relaxation rate reach 430/538 2.69 times of the former line drawings of this plastic rod lens.

The radius R of the plastic rod lens that obtains is 0.205mm, and refractive index of the centre is 1.498, is similar to formula (5) in index distribution in the 0.2R～0.8R scope of the outside perimembranous of central shaft, and index distribution constant g is 0.84mm under 525nm wavelength situation ^-1

In addition, the outer peripheral face from plastic rod lens roughly mixes the layer that exists equably to the dyestuff that central part forms the 3 μ m thickness of having an appointment.

A plurality of resulting plastic rod lens are disposed (0.43mm at interval) with row close parallel ground between two phenolic resin system substrates, filling adhesive (" s-dine 9607K ") in the crack betwixt, make between plastic rod lens and the bonding agent between plastic rod lens and substrate solidify.Then, on the face vertical with the central shaft of plastic rod lens, with the adamas sword both ends of the surface are carried out mirror-finish cutting, the length that produces plastic rod lens is the rod lens array of 4.4mm.The conjugate length Tc of this rod lens array under the 525nm situation is 9.9mm, and MTF at this moment is 57.2%.

Measure the Tc (table 8) of this rod lens array under each wavelength situation of 470nm, 525nm, 630nm.In addition, under the MTF situation of 3 wavelength that compare certain Tc, the Tc of the maximum of minimum MTF is 9.9mm.At the Tc of this color characteristic optimum the MTF (table 8) that measures each wavelength under the condition of 9.9mm.

Measure the light quantity of this rod lens array, the light quantity of rod lens array under the wavelength situation of 470nm, 525nm, 630nm of getting embodiment 2 respectively is 100 to compare (table 8).

The aberration of the rod lens array of embodiment 1～4 is very little, and Δ Tc (Tc (470) is poor with Tc's (630)) is 0.1～0.3mm.In addition, the deviation of the MTF of each wavelength is little.

The aberration of the rod lens array of comparative example 1 is very big, and Δ Tc is 0.6mm.In addition, because aberration is big, the deviation of each wavelength MTF is big.In addition, the MTF under the wavelength situation of 630nm, 470nm differs from more than 15% than the MTF of the wavelength separately of embodiment 1.

The plastic rod lens of embodiment 3,4 has suppressed the deviation of aberration Δ Tc and the MTF under each wavelength situation, and good brightness.The plastic rod lens of embodiment 4 particularly, because the refringence of its central shaft and peripheral part is big, can increased radius R.In addition, by making the layer attenuation that has dyestuff, the zone (effective diameter) that can increase transmitted light, thereby raising light quantity.

The possibility of utilizing on the industry

Adopt the present invention can obtain plastic rod lens, rod lens array, the rod lens plate that aberration is little and color characteristic is good. In addition, by using this rod lens array or rod lens plate, can obtain the color image sensor of high resolution and the color printer of high resolution.

Claims (8)

1, a kind of plastic rod lens is characterized in that:

Shape is that radius is the cylindrical shape of R, refractive index n _DReduce from the outside perimembranous of central shaft, and satisfy following condition (1)～(3):

(1)43≤v ₁≤60；

(2)|{n _A×v _A/(n _A-1)}-{n _B×v _B/(n _B-1)}|＜5；

(3)n ₀-n ₁≥0.01；

In the formula, n ₁, n ₀, n _AAnd n _BThe refractive index n of representing peripheral part, center, arbitrfary point A and the arbitrfary point B of plastic rod lens respectively _Dv ₁, v _AAnd v _BThe Abbe number v that represents peripheral part, arbitrfary point A and arbitrfary point B respectively,

The polymkeric substance that constitutes plastic rod lens comprises following formation unit (A)～(C):

(A) contain (methyl) acrylic ester unit of alicyclic ring and/or heterocycle;

(B) contain the monomeric unit of aromatic rings;

(C) (methyl) acrylic acid fluorinated alkyl ester units,

At least the distance at the decentering axle is in the scope of 0.8R～R, and the shared containing ratio in formation unit (B) in the polymkeric substance increases continuously to peripheral part.

2, plastic rod lens as claimed in claim 1 is characterized in that,

Also comprise (D) (methyl) methyl acrylate unit as constituting the unit in the above-mentioned polymkeric substance.

3, plastic rod lens as claimed in claim 2 is characterized in that,

At least be that the scope of 0～0.5R contains and comprises the polymkeric substance that constitutes unit (A) in the distance of decentering axle;

In the distance of decentering axle is that the scope of 0～R contains and comprises the polymkeric substance that constitutes unit (D);

At least be that the scope of 0.5R～R contains and comprises the polymkeric substance that constitutes unit (B) and constitute unit (C) in the distance of decentering axle.

4, a kind of rod lens array is characterized in that,

Be to make by disposing the above described plastic rod lens of claim 1 of 1 row abreast.

5, rod lens array as claimed in claim 4 is characterized in that,

In the time of will being set at Tc (λ) for the conjugate length of the rod lens array of the light of wavelength X nm, satisfy following condition:

Tc (630)-Tc (470)≤0.3mm; And

Tc(525)≤12mm。

6, a kind of rod lens plate is characterized in that,

Make by disposing the described plastic rod lens of claim 1 two-dimensionally.

7, a kind of imageing sensor is characterized in that,

Use described rod lens array of claim 4 or the described rod lens plate of claim 6.

8, a kind of printer is characterized in that,

Use described rod lens array of claim 4 or the described rod lens plate of claim 6.

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