CN102401979A

CN102401979A - Image reading lens, image reading device using the same and image forming device

Info

Publication number: CN102401979A
Application number: CN2011102691636A
Authority: CN
Inventors: 伊藤昌弘; 仁科喜一朗
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2010-09-13
Filing date: 2011-09-13
Publication date: 2012-04-04
Anticipated expiration: 2031-09-13
Also published as: CN102401979B

Abstract

To provide an image reading lens for reducing and imaging image information in a document on an imaging element formed by arraying elements linearly, and reading the image information by the imaging element. In this image reading lens, a first group 1 is a meniscus lens having a convex face facing the object side; a second group 2 is a biconvex lens, a third group 3 is a cemented lens constituted of a plurality of lenses, wherein the face closest to the object side has a convex face on the object side, and the face closest to the image side has a convex face on the image side; and a fourth group 4 is a meniscus lens having a concave face facing the object side. When the focal length of the whole system of the image reading lens is f, the thickness of the whole system of the image reading lens is [Sigma]d, the thickness of the cemented lens of the third group is d<SB>3g</SB>, the following conditions: (1) 0.4<d<SB>3g</SB>/[Sigma]d<0.6, and (2) 0.6f<[Sigma]d<0.8f are satisfied.

Description

Image reading lens, image read-out and imaging device

Technical field

The present invention relates to image reading lens, image read-out and imaging device; Be specifically related to be used for the image reading lens of imaging devices such as digital copier or facsimile recorder; This image reading lens reads and is dwindled the image information that is imaged onto with the original image on the imaging apparatus of linear array, and forms image according to the image information that reads.

Background technology

In imaging devices such as digital copier or facsimile recorder, image reading unit or image analyzer dwindle the image that need read with image reading lens, and imaging apparatuss such as confession CCD are carried out to picture and signal Processing.

In order to read colored original; For example utilize so-called three-way CCD; Promptly on a substrate, arrange the three row imaging apparatuss that have the red, green, blue filtrator respectively, to each imaging apparatus face, then convert image imaging into signal being decomposed into trichromatic colored original.

Image planes at above-mentioned image reading lens are in the imaging apparatus, not only require to have high-contrast in the high spatial frequency zone, and need the aperture efficiency around the image to reach near 100%.

And then, in order to read colored original well, need the red, green, blue image space at optical axis direction of all kinds consistent, for this reason must to of all kinds carry out good Chromatically compensated.

Moreover, in order to realize the image read-out miniaturization, to reduce the image read-out cost, require composing images to read the eyeglass miniaturization of camera lens and reduce eyeglass quantity.

To this, the image reading lens of prior art adopts Gaussian to read camera lens in order to obtain high quality graphic.

Gaussian reads camera lens can obtain good curvature of the image compensation 20 ° of half angle of view scopes with interior, even if bore more also can suppress comet hot spot (comatic flare).Yet; Gauss reads camera lens and adopts protruding, recessed, four groups of structures of concave, convex basically, generally is the distressed structure that utilizes this basic structure, for this reason; It is big that diameter of lens becomes, the miniaturization and the reduction of cost that are an impediment to image reading lens and use the image read-out of this image reading lens.

To the problems referred to above; Prior art adopts the four group of four chip architecture telephong type camera lens that not only reduces the eyeglass number but also can keep high image quality, and this camera lens constitutes from object one side negative meniscus four set of contact lenses of convex surface towards positive falcate first set of contact lenses, bi-concave second set of contact lenses, biconvex the 3rd set of contact lenses and the concave surface of object towards object is set.

Patent documentation 1 (TOHKEMY 2008-275783 communique) etc. discloses the telephong type image reading lens, and the f-number of four lens structures wherein is F6, is difficult to obtain sufficient brightness and broad optical properties such as visual angle.

In addition; Patent documentation 2 (TOHKEMY 2005-234068 communique), patent documentation 3 (TOHKEMY 2005-266771 communique) etc. also disclose with what five eyeglasses constituted and have read camera lens with great visual angle; But the lightness of these camera lenses also is F6, on lightness with four lens structures to read camera lens as broad as long.

Summary of the invention

In view of above-mentioned problem, the present invention is purpose so that a kind of the 3rd set of contact lenses to be provided with the image reading lens that the multi-disc eyeglass constitutes, though this camera lens has with great visual angle, f-number is about 5, and is brighter, can obtain the good optical performance.

Technical scheme of the present invention is specific as follows.

(1) at first; The present invention provides a kind of image reading lens; Wherein begin to set gradually: the 4th set of contact lenses that have first set of contact lenses of positive refractive power, second set of contact lenses, aperture, has the 3rd set of contact lenses of positive refractive power and have negative refractive power with negative refractive power from object one side; It is characterized in that said first set of contact lenses is the meniscus shaped lens of convex surface towards object one side; Said second set of contact lenses is a biconcave lens; Said the 3rd set of contact lenses is the gummed eyeglass that constitutes with many pieces of eyeglasses, and the face near object one side is the convex surface towards object one side; Said the 4th set of contact lenses is the meniscus shaped lens of concave surface towards object one side, the whole focal length f of said image reading lens, the integral thickness of said image reading lens be total length ∑ d and, the gummed lens thickness d of said the 3rd set of contact lenses _3gBetween meet the following conditions formula (1) and (2),

(1)0.4＜d _3g/∑d＜0.6

(2)0.6f＜∑d＜0.9f。

Above-mentioned conditional (1) has been stipulated the scope of the 3rd set of contact lenses thickness with the ratio of image reading lens total length.If this ratio less than the lower limit of this scope, then need be provided with between the 3rd set of contact lenses and the 4th set of contact lenses at interval with compensation meridianal image surface, the diameter that is difficult to shorten the camera lens total length and reduces lens for this reason.Otherwise,, can't keep sufficient aberration compensation if this ratio greater than the upper limit of above-mentioned scope, then is difficult to guarantee the aberration compensation ability of the lens set beyond the 3rd set of contact lenses.

Above-mentioned conditional (2) has been stipulated the image reading lens total length.If this total length less than the lower limit of specialized range, then need be strengthened the refracting power of each eyeglass, be difficult to carry out good image planes compensation for this reason.Otherwise if exceed higher limit, then the effective diameter of camera lens total length and camera lens all becomes greatly, is difficult to realize the miniaturization of image reading lens.

Therefore, satisfying conditional of the present invention (1) and (2) is the necessary condition that realizes the image reading lens miniaturization, obtains high image quality.

In addition, aperture being set between second set of contact lenses and the 3rd set of contact lenses helps compensating well crooked.(2) the present invention also provides based on above-mentioned (1) described image reading lens, it is characterized in that said the 3rd set of contact lenses and the spacing d of said the 4th set of contact lenses on optical axis _3g-4gBetween the formula (3) that meets the following conditions,

(3)0.08＜d _3g-4g/∑d＜0.2。

Above-mentioned conditional (3) has been stipulated the scope of the spacing size between the 3rd set of contact lenses and the 4th set of contact lenses.If the lower limit of the scope of this spacing less-than condition formula regulation then can need light beam with bigger incident angle incident the 4th lens because of spacing is narrow between the 3rd lens and the 4th lens, marginal ray is difficult to obtain good compensation for this reason.And can increase the image reading lens total length, be unfavorable for the miniaturization of camera lens.

Otherwise if greater than the higher limit of specialized range, then owing to be that an outer light beam gets into the direction that the height of the 4th set of contact lenses increases, therefore the lens diameter of the 4th set of contact lenses increases, and is difficult to realize the miniaturization of image reading lens.And the image reading lens total length reduces, and is difficult for carrying out aberration compensation.

(3) the present invention also provides based on above-mentioned (1) described image reading lens; It is characterized in that; The place ahead set of contact lenses that constitutes with said first set of contact lenses and said second set of contact lenses has negative refractive power; The rear set of contact lenses that constitutes with said the 3rd set of contact lenses and said the 4th set of contact lenses has positive refractive power, the achromatism condition sum ∑ 1/fv of said the place ahead set of contact lenses _Fg, said rear set of contact lenses achromatism condition sum ∑ 1/fv _Bg, and the summation ∑ 1/fv of the whole achromatism condition of said image reading lens _AllBetween meet the following conditions formula (4) and (5)

(4)0.8＜|∑1/fv _fg/∑1/fv _all|＜2

(5)0＜|∑1/fv _bg/∑1/fv _all|＜1。

The scope of the ratio that the aberration of ratio that the aberration of the place ahead set of contact lenses in the whole achromatism condition of image reading lens is shared and rear set of contact lenses is shared has been stipulated in conditional (4) and (5).

If conditional (4) is near lower limit; Then Chromatically compensated in order in whole camera lens, to carry out; The achromatism condition of rear set of contact lenses also will be tending towards reducing, and that is to say that conditional (5) will be infinitely close to 0, for this reason; If conditional (4) is less than lower limit, then the rear set of contact lenses can't be carried out Chromatically compensated.And if greater than condition formula (4) higher limit, then big aberration will take place in the place ahead set of contact lenses, thereby make and carry out taking place when Chromatically compensated difficulty in the set of contact lenses of rear.The formula that satisfies condition (4) and (5) can be carried out Chromatically compensated fully in lightness is about the image reading lens of F5.

(4) the present invention also provides based on above-mentioned (3) described image reading lens, it is characterized in that the achromatism condition sum ∑ 1/fv of said the place ahead set of contact lenses _FgAchromatism condition sum ∑ 1/fv with said rear set of contact lenses _BgBetween satisfying condition (6) down,

(6)-0.5＜∑1/fv _bg/∑1/fv _fg＜0

Conditional (6) is used for reading the place ahead set of shots of camera lens and the achromatism conditional relationship between the set of shots of rear with conditional (4) and (5) specified image.

Identical with conditional (4) and (5); If the ratio of rear set of contact lenses and the achromatism condition of the place ahead set of contact lenses is in the scope of above-mentioned conditional (6) regulation; Then deviation is less between the image space of every kind of color of the eyeglass in the image reading lens, can obtain good Chromatically compensated.

(5) the present invention also provides based on above-mentioned (1) described image reading lens, it is characterized in that the rearmost radius-of-curvature r of said the 3rd set of contact lenses _3glTop radius-of-curvature r with said the 4th set of contact lenses _4gfBetween meet the following conditions (7),

(7)2＜1/r _3gl-1/r _4gf＜5

Conditional (7) has been stipulated the relation between the top radius-of-curvature of rearmost radius-of-curvature and said the 4th set of contact lenses of the 3rd set of contact lenses.If the lower limit of less-than condition formula (7) regulation, then the comet aberration compensation is not enough, and if greater than higher limit, then can cause the comet aberration compensation superfluous.And then, if exceed the scope of conditional (7), even if the formula of satisfying condition (1) and (2) also are difficult to obtain high image quality at periphery.

(6) the present invention also provides based on above-mentioned (1) described image reading lens, it is characterized in that, said the 3rd set of shots is the balsaming lens that constitutes towards object one side's negative lens with biconvex lens and concave surface.

The 3rd arrangement of mirrors has the big biconvex head mirror of positive refractive power, not only can reduce the total length of image reading lens, and can cooperate formation the 3rd set of contact lenses with the lens with big negative refractive power, makes image reading lens have good aberration compensation effect.

(7) the present invention also provides based on above-mentioned (6) described image reading lens, it is characterized in that the d line refractive index n d of first lens ₁, the 5th lens d line refractive index n d ₅, first lens Abbe number vd ₁, the 3rd set of contact lenses the mean value vd of Abbe number of negative lens and the 5th lens ₄₅Between meet the following conditions (8) and (9),

(8)-0.2＜nd ₁-nd ₅＜-0.08

(9)8＜vd ₁-vd ₄₅＜32

Conditional (8) has stipulated that first lens and last eyeglass are the scope of the refringence between the 5th lens.If this refringence is less than the lower limit of above-mentioned conditional (8) regulation, then the bending of image planes peripheral part increases, and is difficult to make near the optical axis and the image space of peripheral part on optical axis direction is consistent.On the contrary, if greater than above-mentioned conditional (8) set upper limit value, then the comet aberration becomes seriously, and periphery is difficult to obtain good imaging performance.

Conditional (9) stipulated in the set of contact lenses of the place ahead positive lens promptly first lens Abbe number, with the rear set of contact lenses in the i.e. mean value vd of the Abbe number of the 4th lens and the 5th lens of negative lens ₄₅Between the difference scope.If the difference of this Abbe number is less than the lower limit of above-mentioned conditional (9) regulation, then short wavelength one side's comet aberration will take place to depart from significantly than the comet aberration of other wavelength, thereby makes short wavelength one side can't obtain good imaging performance.Otherwise if greater than higher limit, then same coma aberration long wavelength one side will take place to depart from significantly, can't obtain good imaging performance.

(8) the present invention also provides based on above-mentioned (6) described image reading lens, it is characterized in that, the ratio of the effective warp of eyeglass and lens thickness that constitutes the biconvex lens of said the 3rd set of contact lenses is below 1.2.

The thickness of the 3rd set of contact lenses need be for the camera lens total length over half, but for the ease of processing, can also glue together many pieces of eyeglasses more than three pieces, the biconvex lens that obtains to have positive refractive power i.e. the 3rd set of contact lenses.

(9) the present invention also provides based on above-mentioned (1) described image reading lens, it is characterized in that the eyeglass in this image reading lens is glass lens, and does not contain the objectionable impurities that comprises arsenic, lead in this eyeglass.

All do not contain the objectionable impurities that comprises lead, arsenic in the glass material of all eyeglasses, like this, the material of image reading lens can recycling, and processing-waste can not take place causes water pollution, helps environmental protection.

(10) the present invention also provides based on above-mentioned (1) described image reading lens, it is characterized in that the profile that has one piece of eyeglass at least is non-circular.

In eyeglass in the image reading lens, especially the 4th set of contact lenses, in order to obtain high image quality, its lens diameter is bigger.Yet; To arrange photoelectric conversion part according to any direction like the linear sensor that constitutes with CCD during as imaging apparatus; For image reading lens, only need guarantee that a direction promptly is parallel in the orientation of photo-electric conversion element and has sufficient width, so that light beam passes through.And on the direction of arranging perpendicular to photo-electric conversion element, lens height can be less than lens diameter., can reduce for this reason, realize the image reading lens miniaturization perpendicular to the size on the direction of linear rows of sensors column direction.

(11) secondly; The present invention provides a kind of image read-out; It reads original copy information with illuminator and image reading lens, and this illuminator is used for irradiation and is placed on original copy lip-deep original copy is set, and this image reading lens is used for the original copy information that receives this illuminator irradiation is imaged onto linear imaging apparatus; It is characterized in that said image reading lens is any described image reading lens in the claim 1～10.

In image read-out, use image reading lens of the present invention, can implement device miniaturization when keeping high quality graphic.

(12) the present invention also provides based on above-mentioned (11) described image read-out; It is characterized in that; At least has one piece of catoptron; This catoptron is with said illuminator, said image reading lens and said imaging apparatus composing images reading unit, and this image fetching unit is along Manuscript scanner, to read said original copy information.

Through integrally formed image fetching unit, not only can further make the image read-out miniaturization, and can one move image reading unit, performance descends when avoiding image fetching unit to move.

(13) moreover, the present invention provides a kind of imaging device, the original copy information that it reads according to image read-out; Come picture carried and put the surface and make public; Form image, it is characterized in that said image read-out is above-mentioned (11) or (12) described image read-out.

Image read-out of the present invention is used for imaging device, can implement device miniaturization when keeping high quality graphic.

Effect of the present invention is following.

According to above-mentioned (1) described invention, can implement device miniaturization when keeping high quality graphic.

According to above-mentioned (2) described invention, wide angle picture reads the miniaturization that also can under the situation that does not increase the lens external diameter, realize image reading lens in the camera lens.

According to above-mentioned (3) described invention, wide angle picture reads the miniaturization that also can under the situation that does not increase the lens total length, realize image reading lens in the camera lens.

According to above-mentioned (4) described invention, near optical axis, can obtain high-contrast, simultaneously, make near the optical axis and the image space of periphery on optical axis direction is consistent, and then, can carry out good Chromatically compensatedly, obtain high image quality.

According to above-mentioned (3) described invention, can realize the image reading lens that aberration is little and lightness is big.

According to above-mentioned (4) described invention, can realize that further effectively Chromatically compensated the and less preferable image of image space deviation every kind of color reads camera lens.

According to above-mentioned (5) described invention, can realize compensating the comet aberration and from all having the image reading lens of good imaging performance to periphery near the optical axis.

According to above-mentioned (6) described invention, can realize small-sized and bright image reading lens.

According to above-mentioned (7) described invention, can realize the look comet aberration of periphery is carried out the image reading lens of good compensation.

According to above-mentioned (8) described invention, can realize being convenient to process and cut image reading lens with good imaging performance.

According to above-mentioned (9) described invention, the camera lens material can recycling, and the processing-waste polluted water can not take place, and can contribute to environmental protection.

According to above-mentioned (10) described invention, can reduce size perpendicular to the image reading lens on the direction of linear rows of sensors column direction, realize the image reading lens miniaturization.

According to above-mentioned (11) described invention, image reading lens of the present invention is used for image read-out, can realize the miniaturization of image read-out.

According to above-mentioned (12) described invention; Image reading unit in (11) described image read-out is constituted the unit, can reduce number of elements, be embodied as the picture equipment miniaturization; Simultaneously can also suppress each component-assembled error in the image reading unit, obtain the preferable image reading quality.

According to above-mentioned (13) described invention, can access in the time of can under any environment for use, keeping duplicating and have the preferable image quality, realize the miniaturization of imaging device simultaneously.

Description of drawings

Fig. 1 is the optical design figure that shows image reading lens embodiment of the present invention.

Fig. 2 is the aberration diagram of image reading lens embodiment 1 of the present invention.

Fig. 3 is the aberration diagram of image reading lens embodiment 2 of the present invention.

Fig. 4 is the aberration diagram of image reading lens embodiment 3 of the present invention.

Fig. 5 is the aberration diagram of image reading lens embodiment 4 of the present invention.

Fig. 6 is the optical design figure that shows image reading lens enforcement 5 of the present invention.

Fig. 7 is the aberration diagram of the image reading lens of Fig. 6.

Fig. 8 is the optical design figure that shows image reading lens enforcement 6 of the present invention.

Fig. 9 is the aberration diagram of the image reading lens of Fig. 8.

Figure 10 is the optical design figure that shows image reading lens enforcement 7 of the present invention.

Figure 11 is the aberration diagram of the image reading lens of Figure 10.

Figure 12 is the optical design figure that shows image reading lens enforcement 8 of the present invention.

Figure 13 is the aberration diagram of the image reading lens of Figure 12.

Figure 14 is the optical design figure that shows image reading lens enforcement 9 of the present invention.

Figure 15 is the aberration diagram of the image reading lens of Figure 14.

Figure 16 is the optical design figure that shows image reading lens enforcement 10 of the present invention.

Figure 17 is the aberration diagram of the image reading lens of Figure 16.

Figure 18 is the optical design figure that shows image reading lens enforcement 11 of the present invention.

Figure 19 is the aberration diagram of the image reading lens of Figure 18.

Figure 20 is the optical design figure that shows image reading lens enforcement 12 of the present invention.

Figure 21 is the aberration diagram of the image reading lens of Figure 20.

Figure 22 is the optical design figure that shows image reading lens enforcement 13 of the present invention.

Figure 23 is the aberration diagram of the image reading lens of Figure 22.

Figure 24 shows with the exploded view of non-circular lens as the image reading lens of the 4th set of contact lenses.

Figure 25 A and Figure 25 B are respectively the front elevation and the side view of the lens barrel that adopts non-circular lens.

Figure 26 is the cut-open view of image read-out embodiment.

Figure 27 is the cut-open view of another embodiment of image read-out.

Figure 28 is the cut-open view of imaging device embodiment.

Description of symbols

1 first set of contact lenses, 2 second set of contact lenses, 3 the 3rd set of contact lenses, 4 the 4th set of contact lenses

Embodiment

Below explanation relates to image reading lens of the present invention and uses the image read-out of this image reading lens and the embodiment of imaging device.

As shown in Figure 1, image reading lens of the present invention is the telephong type lens system that begins to be provided with according to following order towards image planes one side optical element from object one side.

First set of contact lenses 1 is a convex surface towards object one side and positive meniscus shaped lens with positive refractive power; Second set of contact lenses 2 is to have bi-concave negative lens; The 3rd set of contact lenses 3 is to have convexo-convex positive lens and concave surface towards object one side and have the lens that the meniscus shaped lens gummed of negative refractive power constitutes; The 4th set of contact lenses 4 is concave surfaces towards object one side and has the negative meniscus lens of negative refractive power; Between second set of contact lenses 2 and the 3rd set of contact lenses 3, has aperture.

The concrete numerical value of the present invention of below giving an example.The meaning of the symbolic representation among each embodiment is following.

F: the synthetic focal length of total system

FNo: f-number

M: minification

ω: half angle of view (degree)

Y: object height

R: lens material radius-of-curvature

D: interplanar distance

Nd: the refractive index of lens material

Vd: the Abbe number of lens material

The refractive index temperature variation factor of dn/dt:d line

∑ dn/dt (protruding): the refractive index temperature variation factor of d line with lens of positive refractive power

∑ dn/dt (recessed): the refractive index temperature variation factor of d line with lens of negative refractive power

The numeral of above-mentioned each mark afterbody is used to distinguish each numerical value from object one side's the order that is provided with." j " expression said sequence in the form of each embodiment.

[embodiment 1]

f：22.7、FNo＝5.3、m＝0.124、Y＝108

[table 1]

j	r	d	nd	vd	Effective warp	Title material (manufacturer)
							C1	∞	3.20	1.51633	64.1		S-BSL7(OHARA)
C2	∞
							1	7.791	1.62	1.61800	63.4	4.8	S-PHM52(OHARA)
2	24.000	0.68			3.9
							3	-33.582	1.07	1.69895	30.1	3.8	S-TIM35(OHARA)
4	10.338	0.30			4.4
							5	0.000	0.20			7.8
6	12.117	8.40	1.88300	40.8	8.4	S-LAH58(OHARA)
							7	-9.811	1.32	1.48749	70.2	8.6	S-FSL5(OHARA)
8	-59.999	1.99			10.7
							9	-5.847	1.42	1.76182	26.5	4.8	S-TIH14(OHARA)
10	-11.558				3.9
							C3	∞	0.70	1.51633	64.1		S-BSL7(OHARA)
C4	∞

Fig. 2 is the aberration diagram of embodiment 1.

[embodiment 2]

f：22.7、FNo＝5、m＝0.124

[table 2]

j	r	d	nd	vd	Effective warp	Title material (manufacturer)
							C1	∞	3.20	1.51633	64.1		S-BSL7(OHARA)
C2	∞
							1	7.401	1.60	1.61800	63.4	5	S-PHM52(OHARA)
2	20.992	0.52			4.2
							3	-38.635	0.80	1.68893	31.1	4	S-TIM28(OHARA)
4	9.378	0.40			4.5
							5	0.000	0.10			8.1
6	11.503	9.34	1.88300	40.8	8.6	S-LAH58(OHARA)
							7	-10.056	0.80	1.51633	64.1	8.7	S-BSL7(OHARA)
8	-55.158	2.14			10.8
							9	-5.857	1.30	1.76182	26.5	5	S-TIH14(OHARA)
	-11.432				4.2
							C3	∞	0.70	1.51633	64.1		S-BSL7(OHARA)
C4	∞

Fig. 3 is the aberration diagram of embodiment 2.

[embodiment 3]

f：22.4、FNo＝5.5、m＝0.124、Y＝108

[table 3]

j	r	d	nd	vd	Effective warp	Title material (X manufacturer)
							C1	∞	3.20	1.51633	64.1		S-BSL7(OHARA)
C2	∞
							1	7.778	1.60	1.61800	63.4	4.9	S-PHM52(OHARA)
2	23.107	0.57			3.8
							3	-33.162	1.25	1.69895	30.1	3.6	S-TIM35(OHARA)
4	10.561	0.40			4.0
							5	0.000	0.10			7.4
6	11.848	8.32	1.88300	40.8	8.1	S-LAH58(OHARA)
							7	-9.975	1.43	1.48749	70.2	8.3	S-FSL5(OHARA)
8	-41.499	1.90			10.4
							9	-5.805	1.43	1.76182	26.5	4.9	S-TIH14(OHARA)
10	-12.569
							C3	∞	0.70	1.51633	64.1		S-BSL7(OHARA)
C4	∞

Fig. 4 is the aberration diagram of embodiment 3.

[embodiment 4]

f：22.8、FNo＝5.5、m＝0.124、Y＝108

[table 4]

j	r	d	nd	vd	Effective warp	Title material (manufacturer)
							C1	∞	3.20	1.51633	64.1		S-BSL7(OHARA)
C2	∞
							1	6.730	1.53	1.61800	63.4	4.8	S-PHM52(OHARA)
2	17.743	0.29			3.7
							3	-49.658	1.15	1.64769	33.8	3.6	S-TIM22(OHARA)
4	7.771	0.27			4.1
							5	0.000	0.05			7.2
6	9.367	7.99	1.79952	42.2	7.8	S-LAH52(OHARA)
							7	-7.721	0.80	1.56384	60.7	7.9	S-BAL41(OHARA)
8	-41.776	1.85			10.7
							9	-5.235	2.08	1.80518	25.4	4.8	S-T?IH6(OHARA)
10	-10.011				3.7
							C3	∞	0.70	1.51633	64.1		S-BSL7(OHARA)
C4	∞

Fig. 5 is the aberration diagram of embodiment 4.

The conditional (1) of the foregoing description 1 to 4 is as follows to the result of calculation of (4).(value of the conditional of embodiment 1 to 4)

[table 5]

	Conditional (1)	Conditional (2)	Conditional (3)	Conditional (4)
					Embodiment 1	?0.57	0.75f	?0.12	?3.5
Embodiment 2	?0.60	0.75f	?0.13	?3.5
					Embodiment 3	?0.57	0.76f	?0.11	?3.3
Embodiment 4	?0.55	0.70f	?0.12	?3.8

The eyeglass effective diameter of the biconvex lens of the 3rd set of contact lenses and lens thickness such as shown in down.

[table 6]

	Effective warp/lens thickness of biconvex lens
		Embodiment 1	8.6/8.4＝1.02
Embodiment 2	8.7/9.34＝0.93
		Embodiment 3	8.3/8.32＝1.00
Embodiment 4	7.9/7.99＝0.99

[embodiment 5]

f：22.7、FNo＝5.2、m＝0.124、Y＝108

[table 7]

j	r	d	nd	vd	Effective warp	Title material (manufacturer)
							C1	∞	3.20	1.51633	64.1		S-BSL7(OHARA)
C2	∞
							1	7.791	1.62	1.61800	63.4	6.6	S-PHM52(OHARA)
2	24.000	0.68			5.5
							3	-33.582	1.07	1.69895	30.1	4.8	S-TIM35(OHARA)
4	10.338	0.30			3.9
							5	Aperture	0.20			3.78
6	12.117	8.40	1.88300	40.8	4.4	S-LAH58(OHARA)
							7	-9.811	1.32	1.48749	70.2	7.7	S-FSL5(OHARA)
8	-59.999	1.99			8.4
							9	-5.847	1.42	1.76182	26.5	8.6	S-TIH14(OHARA)
10	-11.558				10.7
							C3	∞	0.70	1.51633	64.1		S-BSL7(OHARA)
C4	∞

Fig. 6 is the index path of embodiment 5.Its basic structure is identical with the structure of embodiment 1 shown in Figure 1.Fig. 7 is the aberration diagram of embodiment 5.

[embodiment 6]

f：22.7、FNo＝5.3、m＝0.124、Y＝108

[table 8]

j	r	d	nd	vd	Effective warp	Title material (manufacturer)
							C1	∞	3.20	1.51633	64.1		S-BSL7(OHARA)
C2	∞
							1	7.252	1.71	1.60300	65.44	6.7	S-PHM53(OHARA)
2	25.209	0.66			5.6
							3	-39.765	1.01	1.68893	31.07	4.9	S-TIM28(OHARA)
4	8.689	0.40			3.9
							5	Aperture	0.1			3.70
6	10.561	8.24	1.83400	37.16	4.2	S-LAH60(OHARA)
							7	-7.359	0.80	1.57501	41.50	7.5	S-TIL27(OHARA)
8	-29.474	1.73			8.0
							9	-5.720	2.35	1.76182	26.52	8.2	S-TIH14(OHARA)
10	-13.484				11.1
							C3	∞	0.70	1.51633	64.1		S-BSL7(OHARA)
C4	∞

Fig. 8 is the index path of embodiment 6, and its basic structure is identical with structure shown in Figure 1.Fig. 9 is the aberration diagram of embodiment 6.

[embodiment 7]

f：22.8、FNo＝5.5、m＝0.124、Y＝108

[table 9]

j	r	d	nd	vd	Effective warp	Title material (manufacturer)
							C1	∞	3.20	1.51633	64.1		S-BSL7(OHARA)
C2	∞
							1	7.522	1.67	1.61800	63.33	6.6	S-PHM52(OHARA)
2	22.637	0.77			5.5
							3	-33.469	0.95	1.69895	30.13	4.7	S-TIM35(OHARA)
4	9.325	0.40			3.8
							5	Aperture	0.10			3.60
6	12.237	7.51	1.88300	40.76	4.0	S-LAH58(OHARA)
							7	-9.892	0.80	1.51633	64.14	7.3	S-BSL7(OHARA)
8	-141.129	3.05			7.9
							9	-5.686	1.05	1.80809	22.76	8.6	S-NPH1(OHARA)
10	-8.546				10.7
							C3	∞	0.70	1.51633	64.1		S-BSL7(OHARA)
C4	∞

Figure 10 is the index path of embodiment 7, and its basic structure is identical with structure shown in Figure 1.Figure 11 is the aberration diagram of embodiment 7.

[embodiment 8]

f：22.6、FNo＝5.3、m＝0.124、Y＝108

[table 10]

j	r	d	nd	vd	Effective warp	Title material (manufacturer)
							C1	∞	3.20	1.51633	64.1		S-BSL7(OHARA)
C2	∞
							1	7.039	1.79	1.57135	52.95	6.5	S-BAL3(OHARA)
2	21.259	0.41			5.3
							3	-36.072	1.28	1.69895	30.13	5.0	S-TIM35(OHARA)
4	8.993	0.40			3.9
							5	Aperture	0.10			3.74
6	10.643	8.93	1.88300	40.76	4.2	S-LAH58(OHARA)
							7	-6.992	0.80	1.67270	32.10	7.6	S-TIM25(OHARA)
8	-21.378	1.43			8.2
							9	-5.909	1.17	1.72000	46.02	8.2	S-LAM61(OHARA)
10	-16.777				10.1
							C3	∞	0.70	1.51633	64.1		S-BSL7(OHARA)
C4	∞

Figure 12 is the index path of embodiment 8, and its basic structure is identical with structure shown in Figure 1.Figure 13 is the aberration diagram of embodiment 8.

[embodiment 9]

f：22.8、FNo＝4.9、m＝0.124、Y＝108

[table 11]

j	r	d	nd	vd	Effective warp	Title material (manufacturer)
							C1	∞	3.20	1.51633	64.1		S-BSL7(OHARA)
C2	∞
							1	8.060	1.64	1.69350	50.81	7.1	S-LAL58(OHARA)
2	23.760	0.62			6.1
							3	-40.719	1.58	1.75520	27.51	5.5	S-TIH4(OHARA)
4	10.737	0.40			4.2
							5	Aperture	0.10			4.00
6	13.691	7.00	1.88300	40.76	4.4	S-LAH58(OHARA)
							7	-8.929	1.68	1.51742	52.43	7.3	S-NSL36(OHARA)
8	-446.513	2.18			8.3
							9	-5.532	1.11	1.78470	26.29	8.4	S-TIH23(OHARA)
10	-8.584				10.2
							C3	∞	0.70	1.51633	64.1		S-BSL7(OHARA)
C4	∞

Figure 14 is the index path of embodiment 9, and its basic structure is identical with structure shown in Figure 1.Figure 15 is the aberration diagram of embodiment 9.

[embodiment 10]

f：22.9、FNo＝5.4、m＝0.124、Y＝108

[table 12]

j	r	d	nd	vd	Effective warp	Title material (manufacturer)
							C1	∞	3.20	1.51633	64.1		S-BSL7(OHARA)
C2	∞
							1	6.920	1.73	1.62299	58.16	6.7	S-BSM15(OHARA)
2	17.662	0.39			5.5
							3	-44.486	1.88	1.71736	29.52	5.4	S-TIH1(OHARA)
4	10.829	0.40			3.8
							5	Aperture	0.10			3.58
6	13.909	6.08	1.88300	40.76	3.9	S-LAH58(OHARA)
							7	-8.788	0.80	1.56732	42.82	6.6	S-TIL26(OHARA)
8	675.839	2.10			7.2
							9	-4.849	0.82	1.71736	29.52	7.4	S-TIH1(OHARA)
10	-6.940				8.7
							C3	∞	0.70	1.51633	64.1		S-BSL7(OHARA)
C4	∞

Figure 16 is the index path of embodiment 10, and its basic structure is identical with structure shown in Figure 1.Figure 17 is the aberration diagram of embodiment 10.

[embodiment 11]

f：22.6、FNo＝4.8、m＝0.124、Y＝108

[table 13]

j	r	d	nd	vd	Effective warp	Title material (manufacturer)
							C1	∞	3.20	1.51633	64.1		S-BSL7(OHARA)
C2	∞
							1	7.525	2.20	1.61800	63.33	6.9	S-PHM52(OHARA)
2	22.844	0.41			5.4
							3	-48.885	0.80	1.66680	33.05	5.1	S-TIM39(OHARA)
4	8.994	0.40			4.2
							5	Aperture	0.10			4.04
6	10.585	9.04	1.88300	40.76	4.6	S-LAH58(OHARA)
							7	-16.706	1.02	1.54072	47.23	8.0	S-TIL2(OHARA)
8	-21.378	1.64			8.5
							9	-5.864	4.25	1.75520	27.51	8.6	S-TIH4(OHARA)
10	-15.658				13.4
							C3	∞	0.70	1.51633	64.1		S-BSL7(OHARA)
C4	∞

Figure 18 is the index path of embodiment 11, and its basic structure is identical with structure shown in Figure 1.Figure 19 is the aberration diagram of embodiment 11.

[embodiment 12]

f：22.9、FNo＝5.5、m＝0.124、Y＝108

[table 14]

j	r	d	nd	vd	Effective warp	Title material (manufacturer)
							C1	∞	3.20	1.51633	64.1		S-BSL7(OHARA)
C2	∞
							1	7.298	1.72	1.62299	58.16	6.7	S-BSM15(OHARA)
2	20.923	0.47			5.6
							3	-32.882	1.86	1.71736	29.52	5.3	S-TIH1(OHARA)
4	11.128	0.40			3.8
							5	Aperture	0.10			3.58
6	14.324	5.20	1.88300	40.76	3.9	S-LAH58(OHARA)
							7	-8.291	0.80	1.56732	42.82	6.2	S-TIL26(OHARA)
8	-603.102	2.79			6.8
							9	-4.915	0.96	1.71736	29.52	7.5	S-TIH1(OHARA)
10	-7.041				9.0
							C3	∞	0.70	1.51633	64.1		S-BSL7(OHARA)
C4	∞

Figure 20 is the index path of embodiment 12, and its basic structure is identical with structure shown in Figure 1.Figure 21 is the aberration diagram of embodiment 12.

[embodiment 13]

f：22.8、FNo＝5.0、m＝0.124、Y＝108

[table 15]

j	r	d	nd	vd	Effective warp	Title material (manufacturer)
							C1	∞	3.20	1.51633	64.1		S-BSL7(OHARA)
C2	∞
							1	8.371	1.64	1.73400	51.47	7.3	S-LAL59(OHARA)
2	24.605	1.03			6.3
							3	-77.838	0.88	1.80000	29.84	4.9	S-NBH55(OHARA)
4	10.032	0.40			4.0
							5	Aperture	0.10			3.84
6	11.471	9.28	1.88300	40.76	4.3	S-LAH58(OHARA)
							7	-10.003	0.80	1.56873	63.16	8.1	S-BAL22(OHARA)
8	-72.025	2.22			8.7
							9	-5.716	2.96	1.92286	18.90	8.8	S-NPH2(OHARA)
10	-10.084				12.5
							C3	∞	0.70	1.51633	64.1		S-BSL7(OHARA)
C4	∞

Figure 22 is the index path of embodiment 13, and its basic structure is identical with structure shown in Figure 1.Figure 23 is the aberration diagram of embodiment 13.

The conditional (5) of the foregoing description 5 to 13 is as follows to the result of calculation of (13).

(value of the conditional of embodiment 5 to 13)

[table 16]

	(5)	(6)	(7)	(8)	(9)	(10)	(11)	(12)	(13)
										Embodiment 5	0.749	0.572	0.117	1.336	0.336	-0.251	3.505	-0.144	14.956
Embodiment 6	0.755	0.531	0.102	1.155	0.155	-0.134	3.177	-0.152	30.934
										Embodiment 7	0.715	0.510	0.187	1.559	0.559	-0.359	3.852	-0.190	19.882
Embodiment 8	0.720	0.597	0.088	1.162	0.162	-0.139	2.771	-0.149	13.890
										Embodiment 9	0.716	0.532	0.134	1.534	0.534	-0.348	4.068	-0.091	11.450
Embodiment 10	0.625	0.481	0.147	1.658	0.658	-0.397	4.754	-0.094	21.998
										Embodiment 11	0.878	0.507	0.083	1.210	0.210	-0.173	2.799	-0.137	25.964
Embodiment 12	0.623	0.420	0.195	1.828	0.828	-0.453	4.633	-0.094	21.998
										Embodiment 13	0.846	0.523	0.115	0.980	0.020	0.020	3.672	-0.189	10.469

[table 17]

	Ratio
		Embodiment
5	1.091
		Embodiment 6	1.099
Embodiment 7	1.029
		Embodiment 8	1.175
Embodiment 9	0.959
		Embodiment 10	0.921
Embodiment 11	1.130
		Embodiment 12	0.839
Embodiment 13	1.146

Figure 24 has shown that an example adopts the image reading lens of non-circular eyeglass as its characteristic with the 4th set of contact lenses.This image reading lens sets gradually from object one side: first set of contact lenses 1 is the positive meniscus shaped lens of convex surface towards object one side; Second set of contact lenses 2 is double-concave negative lens; The 3rd set of contact lenses 3 is the positive lens of biconvex and the balsaming lens of negative meniscus lens bonding formation; And, the 4th set of contact lenses 4, concave surface is towards object one side's negative meniscus lens.Be provided with not shown aperture between second set of contact lenses 2 and the 3rd set of contact lenses 3.On direction perpendicular to the photo-electric conversion element orientation of the linear sensor of CCD; As long as the size of the 4th set of contact lenses 4 can be conveyed the light beam of other eyeglass equal extent through just can; For this reason; As shown in the figure, the 4th set of contact lenses 4 is formed the non-circular eyeglass that removes top and the bottom, has realized the miniaturization of image reading lens.

Figure 25 A and Figure 25 B have shown the embodiment of the lens barrel of above-mentioned non-circular lens respectively with front elevation and side view.Horizontal (orientation of photo-electric conversion element) length of lens barrel 21 is rectangle greater than longitudinal length.Have jut 21a～21i in the present embodiment, be used for the location between lens barrel and each lens set (Figure 24 1～4), be pressed into each lens set in this jut, be used for precision fixing len well.The 4th set of contact lenses 4 is set as the unit structure of non-circular usefulness in illustrated example, for this reason, is provided with three juts that are used for first lens set 1 to prismatic glasses group 3 location, and is provided with 6 juts that are used for the 4th lens set 4 location.Jut more than three need be set at least, can correctly draw lens position.

Figure 26 has shown first embodiment of image read-out of the present invention.Mark 31 expression original copys carry and put glass among this figure, mark 33 expressions first running body, and mark 34 expressions second running body, mark 35 presentation videos read camera lens, mark 36 expression imaging apparatuss.

The original copy 32 that needs are read is placed on original copy and carries on the upper surface of putting glass 33.First running body 33 is a long side direction with the direction perpendicular to the figure surface; And catoptron 33c remained carry the original copy of putting glass 31 with respect to original copy and carry and put surface tilt 45 degree; With certain speed V along direction perpendicular to above-mentioned long side direction, position shown in the mark 33 from Figure 26 move to mark 33 ' shown in the position, position.

First running body 33 also keeps lighting device, and this lighting device comprises long fluorescent light 33a and the catoptron 33b of length perpendicular to the figure surface.Fluorescent light 33a is luminous when first running body 33 moves to Figure 26 right-hand, and the irradiation original copy carries the original copy of putting on the glass 31 32.For this reason, first running body 33 move to mark 33 ' shown in during the moving of position in, original copy 32 receives irradiation scanning.

About the fluorescent light 33a of first running body 33, can utilize spots such as Halogen lamp LED, xenon lamp, cold-cathode tube, or utilize with pointolites such as LED form a line the linear light source that constitutes, or utilize with pointolite convert into line source light conductor linear light source so that can also be face illuminating source of representative or the like in order to organic EL.

Second running body 34 is a long side direction with the direction perpendicular to plan, wherein keeps the mutually perpendicular catoptron 34a of a pair of minute surface, 34b, and this second running body 34 and first running body 33 are synchronous, with certain speed V/2 move to mark 34 ' shown in the position.

When original copy 32 receives the scanning illumination; By the light of illuminated reflection of original copy 32 after the catoptron 33c of first running body 33 is reflected; And then the catoptron 34a, the 34b that receive second running body 34 reflect successively, becomes imaging beam, incides image reading lens 35.At this moment, the velocity ratio of first running body 33 and second running body 34 is 2: 1, and thus, it is certain that illuminated optical path length to image reading lens 35 of original copy is able to keep.

The imaging beam that incident image reads camera lens 35 receives the imaging effect of image reading lens 35, forms the reduced image of original copy 32 at the sensitive surface of imaging apparatus 36.Imaging apparatus 36 is a ccd linear sensor, wherein arranges small photoelectric conversion part closely along the direction perpendicular to the figure surface.Along with original copy 32 receives the scanning illumination, this imaging apparatus 36 converts original image into electric signal output with pixel unit.

Imaging apparatus 36 is decomposed into the image look three kinds of colors of red, green, blue and reads look information, and synthetic each photoelectric conversion part electrical signal converted, to read coloured image.

Image reading lens 35 shown in Figure 26 adopts image reading lens of the present invention, is expected to realize the miniaturization of image reading lens.

Figure 27 has shown second embodiment of image read-out of the present invention.Mark 41 expression original copys carry puts glass, mark 43 presentation video reading units, and mark 44 presentation videos read camera lens, mark 45 expression imaging apparatuss.

Original copy carries the upper surface of putting glass 41 lays the original copy 42 that need read.Image fetching unit 43 with perpendicular to figure surperficial direction be long side direction; Wherein keep carrying the original copy of putting glass 41 and carry catoptron 43e, 43f, the 43g that puts the surface tilt setting with respect to original copy; Among Figure 27, this original reading unit 43 with certain speed V from position shown in the mark 43 move to mark 43 ' shown in the position.

Keeping the direction perpendicular to the figure surface in the image fetching unit 43 is long fluorescent light 43a, 43c and catoptron 43b, the 43d of length direction.When image fetching unit 43 during to Figure 27 right-hand mobile, fluorescent light 43a and 43c are luminous, and the irradiation original copy carries the original copy of putting on the glass 41 42.For this reason, original copy 42 moves to 43 at image fetching unit 43 from position shown in the mark 43 ' shown in the position during, original copy 42 receives the scanning illumination.

When original copy 42 received the scanning illumination, illuminated reflected light of original copy 42 received after catoptron 43e, 43f, the 43g reflection successively, reads camera lens 44 as the imaging beam incident image.This moment is because all catoptrons receive the one of image fetching unit keeps, and therefore, the optical path length till from illuminated of original copy to image reading lens 44 keeps certain.

The imaging beam that incident image reads camera lens 44 receives the imaging effect of image reading lens 44, forms the reduced image of original copy 32 at the sensitive surface of imaging apparatus 36.After this, to convert original image into electric signal, read original copy thus with the identical mode of embodiment of previous image read-out.Use above-mentioned image reading lens of the present invention at this image reading lens 44.

Figure 28 shows the embodiment of imaging device of the present invention.This imaging device comprises image read-out 200 that is positioned at device top and the imaging portion 100 that is positioned at these image read-out 200 bottoms.Various piece in identical this image read-out 200 with embodiment shown in Figure 26 of the part of image read-out 200 also adopts the mark of Figure 26.In addition, this image read-out 200 also can adopt image read-out shown in Figure 27.

The picture signal of three-way ccd line sensor in the image read-out 200 and line sensor (imaging apparatus) 36 outputs is sent to signal processing part 120; In this signal processing part 120, handled; Be converted into to write and use signal, be i.e. the write signal of all kinds of yellow, redness, cyan, black.

Have in the imaging portion 100 as sub-image and carry the cylindrical shape photoconductivity photoreceptor 110 of putting body, be provided with charging roller 111, wheeled developing apparatus 113, transfer belt 114, cleaning device 115 around this photoreceptor 110 as charging device.Can use corona charging device as charging device, replace charging roller 111.

Use signal based on writing of signal processing part 120, light scanning apparatus 117 carries out photoscanning between charging roller 111 and developing apparatus 113, carries out writing on the photoreceptor 110.

Mark 116 expression fixing devices, mark 118 expression paper feeding cassettes, a pair of registration roller of mark 119 expressions, mark 122 expression paper feed rollers, mark 121 expression row paper discs, mark S representes the transfer paper as recording medium.

During imaging, photoreceptor 110 constant speed in the direction of the clock rotates, and its surface receives charging roller 111 chargings and uniform charged, and the laser light that then receives based on light scanning apparatus 117 writes exposure and forms electrostatic latent image.This electrostatic latent image machine negative sub-image of doing, image section is made public.

Along with the rotation of photoreceptor 110, once write yellow image, red image, cyan image, black image, the light that carries out image writes.Wheeled each developing cell Y (developing with Yellow toner), M (using red toner development), C (developing with cyan toner), the K (developing with black toner) that shows latent device 113 rebounds to electrostatic latent image successively and develops; Form positive image; Make electrostatic latent image visual; The toner image of all kinds that obtains thus applies roller 114A by means of transfer voltage and is transferred to successively on the transfer belt 114, and these toner images of all kinds are overlapped on transfer belt 114, form coloured image.

The paper feeding cassette 118 that is used to take in transfer paper S can load and unload on the imaging device main frame, under illustrated installment state, is picked up and paper supply by paper feed roller 122 for uppermost one of the transfer paper S in the paper feeding cassette 118, and its leading section is clamped by a pair of registration roller 119.

A pair of registration roller 119 cooperates toner color image to move to the moment on transfer belt 114 transfer position, and transfer paper S is sent to transfer printing portion.In transfer printing portion, the transfer paper S and the color image that are admitted to are overlapping, under the effect of transfer roll 114B, and the static printing coloured image.Transfer roll 114B is pressed onto transfer paper S on the coloured image when transfer printing.

Transfer paper S in transfer printing be admitted to fixing device 116 after the coloured image, coloured image then is sent to transfer passage by not shown guiding element by photographic fixing in fixing device 116, is discharged on the paper disc 121 by a pair of not shown exit roller.After toner image transfer printing of all kinds, remaining toner and paper powder etc. are removed in cleaning device 115 cleaning photoreceptors 110 surfaces.

Imaging device can also be the imaging device that carries out forming monochrome image except above-mentioned color image forming apparatus.In addition; The wheeled developing apparatus of imaging device in imaging device shown in Figure 28; Can also be corresponding colored serial arrangement imaging device, this imaging device comprises the imaging portion with the photoreceptor of corresponding of all kinds as red, green, blue or green, black four looks of difference and the formation of the processing unit around this photoreceptor.

Claims

1. image reading lens wherein begins to set gradually from object one side:

First set of contact lenses with positive refractive power;

Second set of contact lenses with negative refractive power;

Aperture;

The 3rd set of contact lenses with positive refractive power; And,

The 4th set of contact lenses with negative refractive power,

It is characterized in that,

Said first set of contact lenses is the meniscus shaped lens of convex surface towards object one side;

Said second set of contact lenses is a biconcave lens;

Said the 3rd set of contact lenses is the gummed eyeglass that constitutes with many pieces of eyeglasses, and the face near object one side is the convex surface towards object one side;

Said the 4th set of contact lenses is the meniscus shaped lens of concave surface towards object one side,

The whole focal length f of said image reading lens, the integral thickness of said image reading lens are the gummed lens thickness d of total length ∑ d and said the 3rd set of contact lenses _3gBetween meet the following conditions formula (1) and (2),

(1)0.4＜d _3g/∑d＜0.6

(2)0.6f＜∑d＜0.9f。

2. image reading lens according to claim 1 is characterized in that, said the 3rd set of contact lenses and the spacing d of said the 4th set of contact lenses on optical axis _3g-4gBetween the formula (3) that meets the following conditions,

(3)0.08＜d _3g-4g/∑d＜0.2。

3. image reading lens according to claim 1 is characterized in that,

The place ahead set of contact lenses that constitutes with said first set of contact lenses and said second set of contact lenses has negative refractive power, and has positive refractive power with the rear set of contact lenses of said the 3rd set of contact lenses and said the 4th set of contact lenses formation,

The achromatism condition sum ∑ 1/fv of said the place ahead set of contact lenses _Fg, said rear set of contact lenses achromatism condition sum ∑ 1/fv _Bg, and the summation ∑ 1/fv of the whole achromatism condition of said image reading lens _AllBetween meet the following conditions formula (4) and (5)

(4)0.8＜|∑1/fv _fg/∑1/fv _all|＜2

(5)0＜|∑1/fv _bg/∑1/fv _all|＜1。

4. image reading lens according to claim 3 is characterized in that, the achromatism condition sum ∑ 1/fv of said the place ahead set of contact lenses _FgAchromatism condition sum ∑ 1/fv with said rear set of contact lenses _BgBetween satisfy conditional (6) down,

(6)-0.5＜∑1/fv _bg/∑1/fv _fg＜0。

5. image reading lens according to claim 1 is characterized in that, the rearmost radius-of-curvature r of said the 3rd set of contact lenses _3glTop radius-of-curvature r with said the 4th set of contact lenses _4gfBetween the formula (7) that meets the following conditions,

(7)2＜1/r _3gl-1/r _4gf＜5。

6. image reading lens according to claim 1 is characterized in that, said the 3rd set of shots is the balsaming lens that constitutes towards object one side's negative lens with biconvex lens and concave surface.

7. image reading lens according to claim 6 is characterized in that, the d line refractive index n d of first lens ₁, the 5th lens d line refractive index n d ₅, first lens Abbe number vd ₁, and the mean value vd of the Abbe number of the negative lens of the 3rd set of contact lenses and the 5th lens ₄₅Between meet the following conditions formula (8) and (9),

(8)-0.2＜nd ₁-nd ₅＜-0.08

(9)8＜vd ₁-vd ₄₅＜32。

8. image reading lens according to claim 6 is characterized in that, the ratio of the effective warp of eyeglass and lens thickness that constitutes the biconvex lens of said the 3rd set of contact lenses is below 1.2.

9. image reading lens according to claim 1 is characterized in that the eyeglass in this image reading lens is glass lens, and does not contain the objectionable impurities that comprises arsenic, lead in this eyeglass.

10. image reading lens according to claim 1 is characterized in that, the profile that has one piece of eyeglass at least is non-circular.

11. image read-out; It reads original copy information with illuminator and image reading lens; This illuminator is used for irradiation and is placed on original copy lip-deep original copy is set; This image reading lens is used for the original copy information that receives this illuminator irradiation is imaged onto linear imaging apparatus, it is characterized in that said image reading lens is any described image reading lens in the claim 1～10.

12. image read-out according to claim 11; It is characterized in that; At least has one piece of catoptron; This catoptron is with said illuminator, said image reading lens and said imaging apparatus composing images reading unit, and this image fetching unit is along Manuscript scanner, to read said original copy information.

13. an imaging device, the original copy information that it reads according to image read-out is come picture carried and is put the surface and make public, and forms image, it is characterized in that said image read-out is claim 11 or 12 described image read-outs.