CN1456916A - Composite lens system - Google Patents

Abstract

A composite optical lens system which is composed of plastic positive lens, plastic negative lens and glass positive lens is used to solve the existed mate problem between the imaging effect and production cost. The plastic lens is designed in crescent-shaped structure as well as to set diffraction face and non-spherical face on it so that the system can achieve better performance than the existing system for imaging with comparatively low cost.

Description

Combined lens system

Technical field

The present invention relates to a kind of combined lens system; Particularly, the present invention is that three tool refractive power lens of utilization constitute, and on default lens diffraction face and aspheric surface is set, and with this, the present invention can be issued to best imaging performance in cheaper cost restriction.

Background technology

Because modern scientific and technological level day by day improves, ordinary consumer not only requires to promote again and again for properties of product, and attach great importance to especially for the price of product, for example general being seen lens are the variation of ten minutes just, but also the effect of lens products is limited by the cost of product, so, how to develop and a kind ofly be issued to the lens combination of optimal imaging performance in the restriction of cheaper cost, become developer and manufacturer and wanted most several problems of overcoming.

At present, read in the optical system of purposes as image existing, if the user not only wishes to have good image, bigger visual angle, wish again and can reduce cost, in general, modal constituted mode is to use three glass sphere combination of lensess, and according to the sequential combination of crescent positive lens, double-concave negative lens, biconvex positive lens, that is often claim the Cook-Triplet system; But because the manufacturing cost of glass lens is still very high at present, and generally the glass lens surface is a sphere, when optical system aperture and visual angle increasing, often is difficult to fully eliminate aberration, thereby has limited the room for promotion of existing optical system resolving power; So,,, really be the target that a utmost point waits to lay siege to improvement asking desirable, practical and progressive today at above defective.

Summary of the invention

Primary and foremost purpose of the present invention is to provide a kind of lower-cost combined lens system, the present invention is provided with diffraction face and aspheric surface on plastic lens, with this, optical system of the present invention can be used plastic lens, and plastic lens can adopt the injection molding manufacturing, lower cost when a large amount of production, and material cost is also lower.

Secondary objective of the present invention is to provide a kind of combined lens system with good imaging performance, the present invention can be provided with aspheric surface and diffraction face on plastic lens, not only can provide optical designers more controllable variable,, and can promote resolving power of the present invention with the antagonism aberration.

In order to achieve the above object, the invention provides a kind of combined lens system, constituted with three tool refractive power lens, rise by the thing side, include: first lens of tool positive refracting power, its material are plastics, and this first lens front surface is that convex surface, rear surface are concave surface, and its front and rear surfaces radius-of-curvature is respectively R1 and R2, and satisfies | R1|＜| the relation of R2|; Second lens of tool negative refraction power, its material are plastics, and this second lens front surface is a convex surface, and its shape coefficient X2 is greater than 0.9; If this shape coefficient X:X=(R1+R2)/(R2-R1); When front surface is convex surface, R1＞0, when front surface is concave surface, R1＜0, when the rear surface is concave surface, R2＞0, when the rear surface is convex surface, R2＜0=; The 3rd lens of tool positive refracting power, its material are glass; Plastic lens in the above-mentioned optical system is provided with the diffraction face; Can be provided with aspheric surface on the plastic lens in above-mentioned optical system.

The present invention also provides a kind of combined lens system, and it is that lens by three tool refracting powers constitute, and is risen by the thing side, and be in regular turn: first lens of tool positive refracting power, its material are glass; Second lens of tool negative refraction power, its material are plastics, and its rear surface is concave surface, and the shape coefficient X2 of these second lens is less than-0.9; The 3rd lens of tool positive refracting power, its material are plastics, and the front surface of the 3rd lens is a concave surface, and the rear surface is a convex surface, and its shape coefficient X3 is between-1.0 to-20; Plastic lens in the above-mentioned optical system is provided with the diffraction face; Can be provided with aspheric surface on the plastic lens in above-mentioned optical system.

Description of drawings

Relevant the present invention reaches above-mentioned purpose, the technological means that is adopted and other effect, enumerate now that each embodiment and conjunction with figs. describe in detail as after, believe purpose of the present invention, feature and other advantage, can obtain deeply and concrete understanding:

Fig. 1 is the synoptic diagram of first embodiment of the invention;

Fig. 2 is spherical aberration curve, astigmatism curve and the abnormal curve of first embodiment of the invention;

Fig. 3 is the synoptic diagram of second embodiment of the invention;

Fig. 4 is spherical aberration curve, astigmatism curve and the abnormal curve of second embodiment of the invention;

Fig. 5 is the synoptic diagram of third embodiment of the invention;

Fig. 6 is spherical aberration curve, astigmatism curve and the abnormal curve of third embodiment of the invention;

Fig. 7 is the synoptic diagram of fourth embodiment of the invention;

Fig. 8 is spherical aberration curve, astigmatism curve and the abnormal curve of fourth embodiment of the invention;

Fig. 9 is the synoptic diagram of fifth embodiment of the invention;

Figure 10 is spherical aberration curve, astigmatism curve and the abnormal curve of fifth embodiment of the invention;

Figure 11 is the synoptic diagram of sixth embodiment of the invention;

Figure 12 is spherical aberration curve, astigmatism curve and the abnormal curve of sixth embodiment of the invention;

Figure 13 is the synoptic diagram of seventh embodiment of the invention;

Figure 14 is spherical aberration curve, astigmatism curve and the abnormal curve of seventh embodiment of the invention;

Figure 15 is the synoptic diagram of eighth embodiment of the invention;

Figure 16 is spherical aberration curve, astigmatism curve and the abnormal curve of eighth embodiment of the invention;

Figure 17 is the synoptic diagram of ninth embodiment of the invention;

Figure 18 is spherical aberration curve, astigmatism curve and the abnormal curve of ninth embodiment of the invention;

Figure 19 is the synoptic diagram of tenth embodiment of the invention;

Figure 20 is spherical aberration curve, image curve and the abnormal curve of tenth embodiment of the invention.

Symbol description among the figure:

100 optical system

10 first eyeglass S1 front surfaces

The S2 rear surface

20 second eyeglass S3 front surfaces

The S4 rear surface

30 prismatic glasses S5 front surfaces

The S6 rear surface

40 flat-panel components

50 flat-panel components

101 optical system

11 first eyeglasses, 21 second eyeglasses

31 prismatic glasseses, 41 flat-panel components

51 flat-panel components

Embodiment

At first see also Fig. 1,2 and table one shown in, the first embodiment icon for the first permutatation pattern of the present invention, optical system 100 of the present invention is made of three lens, be respectively first lens 10, second lens 20 and the 3rd lens 30 in regular turn, and be provided with the flat-panel component 40,50 that does not influence system's focal length in lens combination two sides of arranging; Wherein, these first lens 10 are positive lens, and for plastic material is made, front surface S 1 is a convex surface, and rear surface S2 is a concave surface; These second lens 20 are negative lens, and for plastic material is made, its front surface S 3 is a concave surface, and its rear surface S4 is a convex surface; The 3rd lens 30 are positive lens, for glass material is made, front surface S 5 is a concave surface in the 3rd lens 30, its rear surface S6 then is a convex surface, and first, two lens 10, system is provided with aspherical mirror or diffraction face on 20, because before this optical system 100, after flat-panel component 40,50 can not influence system's focal length, so imaging performance of the present invention is controlled at first lens 10, the aspherical mirror of second lens 20 and the 3rd lens 30, and aspheric surface and diffraction face, not only can provide this optical system 100 more controllable variable, with the antagonism aberration, and can promote the resolving power of this optical system 100.

" aspherical mirror of the present invention, can use following formulate:

X(Y)＝(Y^2/R)/(1+sqrt(1-(1+K)*(Y/R)^2))+A4*Y^4+A6*Y^6+……』

X: the depth of section of any on the minute surface.

Y: any is apart from the vertical range of optical axis on the minute surface.

K: whose conic coefficient.

A4, A6, A8 ...: aspheric surface quadravalence, six rank, eight rank ... correction factor.

R: aspheric surface vertex curvature radius.

" diffraction face phase angle change of the present invention, with following formulate:

Ph(Y)＝2*pi/(WL)*(C1*Y^2+C2*Y^4+….)』

Y: any is apart from the vertical range of optical axis on the minute surface.

Pi: circular constant.

WL: reference wavelength.

C1, C2 ...: aspheric surface phase angle difference second order, quadravalence ... correction factor.

A kind of combined lens system that the present invention's first permutatation pattern is provided as first embodiment, it mainly is, use the Negative-Positive-Negative lens configuration, form the configuration of P-P-G, with first lens by the crescent positive lens of common glass material, change the crescent positive lens of plastic material into, second lens are by common glass material double-concave negative lens, change plastic material into, concave surface crescent negative lens forward, the 3rd lens are then by common glass material biconvex positive lens, change concave surface crescent positive lens forward into, and in this optical system 100, dispose at least one aspherical mirror diffraction face on plastic lens, simultaneously also dispose the diffraction face on first lens, and make first lens, second lens, and system's focal length satisfies the following relationship formula:

These first lens 10 meet: | R1|＜| R2|

Front surface S 1 radius-of-curvature is R1.

Rear surface S2 radius-of-curvature is R2.

The shape coefficient X of these second lens 20 is greater than 0.9.

Shape coefficient X=(R1+R2)/(R2-R1)

Front surface S 3 radius-of-curvature are R1.

Rear surface S4 radius-of-curvature is R2.

The 3rd lens 30:R1 is negative for negative, R2.

The radius-of-curvature of front surface S 5 is R1.

The radius-of-curvature of rear surface S6 is R2.

After the collocation of utilization above-mentioned relation formula, these first lens 10 are made as low dispersive plastic material, can use PMMA or COC; These second lens 20 are made as high chromatic dispersion plastic material, can use PS, PC or MS; The 3rd lens 30 are made as the low dispersion material; The present invention is arranged at aperture between two plastic lenss, make two plastic lenss form crescent-shaped, and use concave surface relative, obtain with great visual angle with help, aspheric surface is set again on plastic lens in addition, overcomes spherical aberration, diffraction grating diffraction face can be set in plastic lens in addition with this, the present invention overcomes aberration with this, so can obtain existing better good imaging performance really.

What deserves to be mentioned is, because the index of refraction in lens of plastic material is lower, thus make the shape coefficient X1 of first lens satisfy the following relationship formula, to increase the refractive power of single minute surface:

1.X1＞2.0。

Shape coefficient is defined as: X=(R1+R2)/(R2-R1).

2. when the lens front surface is convex surface, radius of curvature R 1＞0, when the lens rear surface is convex surface, radius of curvature R 2＜0.

3. control the first lens refractive power P1, the second lens refractive power P2, first and second lens synthesize refractive power P12, the 3rd lens refractive power P3, diffraction optical gate refractive power Pd, and the total dioptric power P of system make it satisfy following restrictive condition:

『(P1/P2)＞-1.0

0＞(P12/P1)＞-0.8

0.2＞(Pd/P12)＞-0.4

0.05＞(P12/P3)＞-0.55

0.2＞(P12/P)＞-1.0』

Through after the above-mentioned adjustment, the present invention can access preferable image quality really

The first embodiment of the present invention illustrates; See also Fig. 1,2 and table one shown in.

Order

X1????＝3.77

X2????＝1.72

P1/P2?＝-0.52

P12/P1＝-0.42

P12/P3＝-0.26

P12/P?＝-0.45

Pd/P12＝-0.11

The second embodiment of the present invention illustrates; See also Fig. 3,4 and table two shown in.

Order

X1????＝2.91

X2????＝1.4

P1/P2?＝-0.48

P12/P1＝-0.43

P12/P3＝-0.28

Pd/P12＝-0.11

P12/P?＝-0.53

Pd/P12＝-0.07

Embodiment three of the present invention illustrates; See also Fig. 5,6 and table three shown in.

Order

X1????＝12.2

X2????＝1.46

P1/P2?＝-0.51

P12/P1＝-0.51

P12/P3＝-0.26

P12/P?＝-0.45

Pd/P12＝-0.1

Embodiment four of the present invention illustrates; See also Fig. 7,8 and table four shown in.

Order

X1????＝3.22

X2????＝0.9

P1/P2?＝-0.62

P12/P1＝-0.21

P12/P3＝-0.18

P12/P?＝-0.28

Pd/P12＝-0.52

Embodiment five of the present invention illustrates; See also Fig. 9,10 and table five shown in.

Order

X1????＝4.07

X2????＝1.66

P1/P2?＝-0.51

P12/P1＝-0.41

P12/P3＝-0.25

P12/P?＝-0.48

Pd/P12＝-0.13

Embodiment six of the present invention illustrates; See also Figure 11,12 and table six shown in.

Order

X1????＝4.55

X2????＝1.83

P1/P2?＝-0.53

P12/P1＝-0.42

P12/P3＝-0.25

P12/P?＝-0.44

Pd/P12＝-0.14

Embodiment seven of the present invention illustrates; See also Figure 13,14 and table seven shown in.

Order

X1????＝4.31

X2????＝1.61

P1/P2?＝-0.51

P12/P1＝-0.43

P12/P3＝-0.26

P12/P?＝-0.49

Pd/P12＝-0.07

Embodiment eight of the present invention illustrates; See also Figure 15,16 and table eight shown in.

Order

X1????＝6.37

X2????＝1.73

P1/P2?＝-0.51

P12/P1＝-0.56

P12/P3＝-0.31

P12/P?＝-0.55

Pd/P12＝-0.07

The second permutatation pattern the 9th embodiment of the present invention, see also Figure 17,18 and table nine shown in, the present invention also can adopt the optical system 200 of reversing before and after the structure, forms the configuration of G-P-P, the shape of each lens is also put upside down thereupon; Optical system 101 after the reversing has first lens 11, second lens 21 and the 3rd lens 31 respectively, its optical system 101 forward and backward flat-panel components 41,51 that can not influence system's focal length that are provided with equally, and the shape coefficient scope of plastic lens of the present invention, and the relational expression of refractive power distribution, scope slightly changes as follows:

『X2＜-0.9

-1.0＞X3＞-20

(P3/P2)＞-1.0

0.3＞(P23/P3)＞-0.3

4.0＞(Pd/P23)＞-1.0』

X2: the shape coefficient of second lens.

X3: the shape coefficient of the 3rd lens.

P3: the 3rd lens refractive power.

P2: the second lens refractive power.

P23: first and second lens synthesize refractive power.

Pd: diffraction optical gate refractive power.

Embodiment nine of the present invention illustrates; See also Figure 17,18 and table nine shown in.

Order

X2????＝-1.86

X3????＝-2.23

P3/P2?＝-0.73

P23/P3＝0.1

P23/P1＝0.126

P23/P?＝0.169

P23/Pd＝-0.263

The tenth embodiment of the present invention illustrates; See also Figure 19,20 and table ten shown in.

Order

X2????＝-1.41

X3????＝-2.5

P3/P2?＝-0.86

P23/P3＝0.117

P23/P1＝0.167

P23/P?＝0.189

P23/Pd＝0.828

In sum, the present invention uses plastics positive lens, plastics negative lens and glass positive lens to constitute a complex optics lens combination, and this plastic lens is set to crescent-shaped, and diffraction face and aspheric surface are set on plastic lens, make combined lens system of the present invention under lower cost, obtain existing better good imaging performance; So practicality of the present invention should be unquestionable, in addition, the disclosed structure of this case inventive embodiments, before application, also do not see all publications, also be not disclosed use, not only had the as above fact of effect enhancement, have more the effect that low cost, high imaging performance etc. can not be indiscreet and negligent, so novelty of the present invention and creativeness have all met patent statute, the spy proposes application for a patent for invention in accordance with the law.

Table one is the data refer table of first embodiment of the invention;

Table two is data refer tables of second embodiment of the invention;

Table three is data refer tables of third embodiment of the invention;

Table four is data refer tables of fourth embodiment of the invention;

Table five is data refer tables of fifth embodiment of the invention;

Table six is data refer tables of sixth embodiment of the invention;

Table seven is data refer tables of seventh embodiment of the invention;

Table eight is data refer tables of eighth embodiment of the invention;

Table nine is data refer tables of ninth embodiment of the invention;

Table ten is data refer tables of tenth embodiment of the invention.Table 1A: the systems organization of first embodiment

Aperture=5.7
					The curved surface numbering	Radius-of-curvature	Thickness	The flexion rate	Abbe number
Object plane	The plane	??238.39
					????1	The plane	??3.00	??1.517	??64.2
????2	The plane	??1.00
					????3	??6.46	??1.95	??1.525	??56.3
????4	??11.13	??1.44
					Diaphragm	The plane	??3.19
????6	??-5.29	??2.36	??1.583	??30.2
					????7	??-20.01	??0.94
????8	??-39.69	??3.14	??1.773	??49.6
					????9	??-9.70	??1.00
????10	The plane	??0.70	??1.497	??81.6
					????11	The plane	??25.55
Image planes	The plane	??-0.18

Table 1B: the asphericity coefficient of first embodiment and diffraction coefficient

Aperture	????3	????6
			??K	??0.1768	??5.89
??A4	??7.817E-05	??-2.447E-04
			??A6	??1.151E-05	??-3.261E-05
??A8	??-6.499E-07	??3.662E-06
			??A10	??2.280E-08	??-4.637E-07

??C1	-8.640E-08
			??C2	-5.329E-05

Table 2A: the systems organization of second embodiment

Aperture=7.0
					The curved surface numbering	Radius-of-curvature	Thickness	The flexion rate	Abbe number
Object plane	The plane	??238.40
					????1	The plane	??3.00	??1.517	??64.2
????2	The plane	??1.00
					????3	??6.94	??2.42	??1.525	??56.3
????4	??14.20	??2.21
					Diaphragm	The plane	??2.30
????6	??-5.26	??1.50	??1.583	??30.2
					????7	??-31.63	??1.49
????8	??-307.73	??5.12	??1.773	??49.6
					????9	??-11.03	??0.00
????10	The plane	??0.70	??1.497	??81.6
					????11	The plane	??24.41
Image planes	The plane	??-0.08

Table 2B: the asphericity coefficient of second embodiment and diffraction coefficient

Aperture	????3	????7
			??K	??0.2767
??A4	??1.052E-04	??6.353E-04
			??A6	??-3.459E-06	??-1.122E-05
??A8	??2.876E-07	??3.215E-07
			??A10	??-6.617E-09	??-4.240E-09
??C1		??-6.566E-05
			??C2		??-2.159E-06

Table 3A: the systems organization of the 3rd embodiment

Aperture=7.2
					The curved surface numbering	Radius-of-curvature	Thickness	The flexion rate	Abbe number
Object plane	The plane	??242.98
					????1	The plane	??3.00	??1.517	??64.2
????2	The plane	??0.00
					????3	??5.12	??2.50	??1.525	??56.3
????4	??6.04	??1.33
					Diaphragm	The plane	??0.90
????6	??-7.52	??1.50	??1.583	??30.2
					????7	??-40.09	??0.50
????8	??-373.97	??2.52	??1.773	??49.6
					????9	??-11.82	??0.00
????10	The plane	??0.70	??1.497	??81.6
					????11	The plane	??23.84
Image planes	The plane	??-0.27

Table 3B: the asphericity coefficient of the 3rd embodiment and diffraction coefficient

Aperture	????3	????4
			??K	??0.7961	??3.7757
??A4	??-1.187E-04	??-2.709E-04
			??C1		??-8.041E-04
??C2		??-4.31E-05
			??C3		??-7.76E-07

Table 4A: the systems organization of the 4th embodiment

Aperture=8.4
					The curved surface numbering	Radius-of-curvature	Thickness	The flexion rate	Abbe number
Object plane	The plane	242.31
					????1	The plane	3.00	????1.517	????64.2

????2	The plane	??0.00
					????3	??6.04	??2.50	??1.525	??56.3
????4	??11.48	??1.29
					Diaphragm	The plane	??0.77
????6	??-6.79	??2.50	??1.525	??56.3
					????7	??124.48	??1.15
????8	??120.18	??2.64	??1.773	??49.6
					????9	??-14.92	??1.00
????10	The plane	??0.70	??1.497	??81.6
					????11	The plane	??25.00
Image planes	The plane	??-0.36

Table 4B: the asphericity coefficient of the 4th embodiment and diffraction coefficient

Aperture	????3	????6
			??K	?0.3441	??1.1681
??A4	?2.3031E-04	??-6.8761E-04
			??A6	?7.0437E-06	??-1.0657E-04
??A8	?3.7282E-07	??-1.7625E-05
			??A10	?3.3288E-08	??4.7090E-06
??C1		??-2.6314E-03
			??C2		??-9.3254E-05

Table 5A: the systems organization of the 5th embodiment

Aperture=5.1
					The curved surface numbering	Radius-of-curvature	Thickness	The flexion rate	Abbe number
Object plane	The plane	??241.40
					????1	The plane	??3.00	??1.517	??64.2
????2	The plane	??0.00
					????3	??6.29	??2.50	??1.525	??56.3
????4	??10.38	??0.90

Diaphragm	The plane	??2.85
					????6	??-5.19	??1.50	??1.583	??30.2
????7	??-20.98	??0.75
					????8	??-44.00	??2.87	??1.773	??49.6
????9	??-9.33	??0.00
					????10	The plane	??0.70	??1.497	??81.6
????11	The plane	??25.06
					Image planes	The plane	??-0.02

Table 5B: the asphericity coefficient of the 5th embodiment and diffraction coefficient

Aperture	????3	????4	????6
				??K	??0.2293		??0.761
??A4	??1.379E-04		??1.628E-04
				??A6	??5.660E-06		??-8.525E-05
??A8	??-1.373E-07		??1.228E-05
				??A10	??2.871E-10		??-0.879E-07
??C1		??-1.119E-03
				??C2		??1.574E-04
??C3		??-1.488E-05

Table 6A: the systems organization of the 6th embodiment

Aperture=4.4
					The curved surface numbering	Radius-of-curvature	Thickness	The flexion rate	Abbe number
Object plane	The plane	??239.48
					????1	The plane	??3.00	??1.517	??64.2
????2	The plane	??0.00
					????3	????6.13	??2.29	??1.525	??56.3
????4	????9.57	??1.12
					Diaphragm	The plane	??2.65
????6	????-5.32	??1.50	??1.583	??30.2

????7	??-18.17	??1.26
					????8	??-41.24	??3.24	??1.773	??49.6
????9	??-9.08	??0.00
					????10	The plane	??0.70	??1.497	??81.6
????11	The plane	??26.36
					Image planes	The plane	??-0.10

Table 6B: the asphericity coefficient of the 6th embodiment and diffraction coefficient

Aperture	????3	????4	????6
				??K	??0.5088	??1.3803	??1.0577
??A4	??9.588E-05	??1.763E-04	??2.669E-04
				??A6	??1.068E-06	??1.112E-05	??-9.226E-06
??A8	??4.112E+05	??-5.724E-07	??1.439E-06
				??A10	??-1.146E-08	??-4.156E-08	??-2.176E-08
??C1			??-1.102E-03
				??C2			??2.785E-05
??C3			??-7.342E-06

Table 7A: the systems organization of the 7th embodiment

Aperture=4.5
					The curved surface numbering	Radius-of-curvature	Thickness	The flexion rate	Abbe number
Object plane	The plane	??241.40
					????1	The plane	??3.00	??1.517	??64.2
????2	The plane	??0.00
					????3	??6.15	??2.50	??1.525	??56.3
????4	??9.87	??1.05
					Diaphragm	The plane	??2.53
????6	??-5.39	??1.50	??1.583	??30.2
					????7	??-22.93	??0.69
????8	??-48.88	??2.94	??1.773	??49.6

????9	??-9.49	??0.00
					????10	The plane	??0.70	??1.497	??81.6
????11	The plane	??25.18
					Image planes	The plane	??-0.01

Table 7B: the asphericity coefficient of the 7th embodiment and diffraction coefficient

Aperture	????3	????4	????6
				?K	?0.2433	?1.6129	?1.152E+00
?A4	?1.991E-04	?2.357E-04	?1.864E-04
				?A6	?5.625E-06	?-1.954E-05	?2.524E-05
?A8	?3.259E-07	?2.745E-06	?-1.843E-06
				?A10	?4.788E-09	?-2.042E-07	?1.790E-07
?C1		?-6.161E-04
				?C2		?-5.226E-06
?C3		?-9.300E-07

Table 8A: the systems organization of the 8th embodiment

Aperture=6.2
					The curved surface numbering	Radius-of-curvature	Thickness	The flexion rate	Abbe number
Object plane	The plane	??237.02
					????1	The plane	??3.00	??1.517	??64.2
????2	The plane	??0.00
					????3	??5.04	??2.25	??1.514	??56.8
????4	??7.41	??1.17
					Diaphragm	The plane	??1.17
????6	??-5.75	??1.50	??1.583	??30.2
					????7	??-21.45	??1.08
????8	??-45.25	??2.26	??1.773	??49.6
					????9	??-9.69	??0.00
????10	The plane	??0.70	??1.497	??81.6

??11	The plane	??27.22
					Image planes	The plane	??-0.01

Table 8B: the asphericity coefficient of the 8th embodiment and diffraction coefficient

Aperture	????3	????4	????6	????7
					??K	??1.0543	??4.7399	??0.9259
??A4	??-2.861E-04
					??A12		??5.238E-07	??2.522E-07
??C1				-7.093E-04
					??C2				-1.038E-05

Table 9A: the systems organization of the 9th embodiment

Aperture=5.7
					The curved surface numbering	Radius-of-curvature	Thickness	The flexion rate	Abbe number
Object plane	The plane	??240.24
					????1	The plane	??3.00	??1.517	??64.2
????2	The plane	??0.00
					????3	??11.43	??3.24	??1.773	??49.6
????4	??33.37	??2.71
					????5	??15.69	??1.50
????6	??4.73	??2.54	??1.583	??30.2
					Diaphragm	The plane	??1.25
????8	??-15.63	??2.43	??1.525	??56.3
					????9	??-5.96	??0.00
????10	The plane	??0.70	??1.497	??81.6
					????11	The plane	??23.96
Image planes	The plane	??-0.25

Table 9B: the asphericity coefficient of the 9th embodiment and diffraction coefficient

Aperture

????6

????9

??K	??0.6427	??0.3263
			??A4	??5.385E-05	??-4.266E-05
??A6	??7.057E-05	??-5.133E-06
			??A8	??-1.148E-05	??5.114E-07
??A10	??1.178E-06	??-1.005E-08
			??C1	??-7.912E-04
??C2	??-1.424E-04

Table 10A: the systems organization of the tenth embodiment

Aperture=8.4
					The curved surface numbering	Radius-of-curvature	Thickness	The flexion rate	Abbe number
Object plane	The plane	??239.96
					????1	The plane	??3.00	??1.517	??64.2
????2	The plane	??0.00
					????3	??15.41	??4.37	??1.773	??49.6
????4	??72.45	??1.27
					????5	??33.34	??2.50
????6	??5.73	??0.77	??1.525	??56.3
					Diaphragm	The plane	??1.17
????8	??-13.39	??2.50	??1.525	??56.3
					????9	??-5.73	??0.00
????10	The plane	??0.70	??1.497	??81.6
					????11	The plane	??25.63
Image planes	The plane	??-0.38

Table 10B: the asphericity coefficient of the tenth embodiment and diffraction coefficient

Aperture	????6	????9
			??K	??1.0311	??0.4683
??A4	??5.911E-04	??-1.700E-04
			??A6	??2.181E-04	??-1.837E-05

??A8	-3.950E-06	?1.082E-06
			??A10	-3.576E-06	?-1.198E-07
??C1	-2.829E-03
			??C2	-1.255E-04

Claims (10)

1. combined lens system is characterized in that: constituted with three tool refractive power lens, risen by the thing side, include:

First lens of tool positive refracting power, its material are plastics, and this first lens front surface is that convex surface, rear surface are concave surface, and its front and rear surfaces radius-of-curvature is respectively R1 and R2, and satisfy | R1|＜| the relation of R2|;

Second lens of tool negative refraction power, its material are plastics, and this second lens front surface is a convex surface, and its shape coefficient X2 is greater than 0.9; If this shape coefficient X:X=(R1+R2)/(R2-R1); When front surface is convex surface, R1＞0, when front surface is concave surface, R1＜0, when the rear surface is concave surface, R2＞0, when the rear surface is convex surface, R2＜0);

The 3rd lens of tool positive refracting power, its material are glass;

Plastic lens in the above-mentioned optical system is provided with the diffraction face;

Can be provided with aspheric surface on the plastic lens in above-mentioned optical system.

2. combined lens system as claimed in claim 1 is characterized in that: the rear surface of these second lens also can be a convex surface.

3. combined lens system as claimed in claim 2 is characterized in that: the shape coefficient X1 of these first lens can be greater than 2.0.

4. combined lens system as claimed in claim 1 is characterized in that: this first lens refracting power P1, and the second lens refracting power P2, the synthetic refracting power P12 of first and second lens can produce following relationship:

(P1/P2)＞-1.0

0＞(P12/P1)＞-0.8

This refracting power P1 P2, P12 satisfy above-mentioned relation.

5. combined lens system as claimed in claim 4 is characterized in that: the synthetic refracting power P12 of these first lens and second lens and diffraction grating refracting power Pd can produce following relationship:

0.2＞(Pd/P12)＞-0.4

This refracting power P12, Pd satisfy above-mentioned relation.

6. combined lens system as claimed in claim 5 is characterized in that: the synthetic refracting power P12 of these first lens and second lens, and the overall refracting power P of the 3rd lens refracting power P3 and optical system can produce following relationship:

0.05＞(P12/P3)＞-0.55

0.2＞(P12/P)＞-1.0

This refracting power P12, P3, P satisfy above-mentioned relation.

7. combined lens system is characterized in that: it is that lens by three tool refracting powers constitute, and is risen by the thing side, is in regular turn:

First lens of tool positive refracting power, its material are glass;

Second lens of tool negative refraction power, its material are plastics, and its rear surface is concave surface, and the shape coefficient X2 of these second lens is less than-0.9;

The 3rd lens of tool positive refracting power, its material are plastics, and the front surface of the 3rd lens is a concave surface, and the rear surface is a convex surface, and its shape coefficient X3 is between-1.0 to-20;

Plastic lens in the above-mentioned optical system is provided with the diffraction face;

Can be provided with aspheric surface on the plastic lens in above-mentioned optical system.

8. combined lens system as claimed in claim 7 is characterized in that: the front surface of these second lens can be convex surface.

9. combined lens system as claimed in claim 7 is characterized in that: this second lens refracting power P2, and the 3rd lens refracting power P3, and the synthetic refracting power P23 of second and third lens can produce following relationship:

(P3/P2)＞-1.0

0.3＞(P23/P3)＞-0.3

This refracting power P2, P3 and P23 satisfy above-mentioned relation.

10. combined lens system as claimed in claim 9 is characterized in that: these second lens and the 3rd lens synthesize refracting power P23, and the refracting power Pd of diffraction optical gate, can produce following relationship:

4.0＞(Pd/P23)＞-1.0

This refracting power P23 and Pd satisfy above-mentioned relation.

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