CN103293635B - Imaging lens - Google Patents

A kind of imaging lens, it includes from thing side to imaging surface successively：One has the first lens of positive light coke, one has the second lens of negative power, one have the 3rd lens of positive light coke, one have the 4th lens of positive light coke, the 5th lens and an imaging surface with negative power.Described imaging lens meet following condition：D/TTL>0.94；Wherein, D is maximum imaging circular diameter on imaging surface；TTL is the length of whole imaging lens.Meet the imaging lens of above-mentioned condition, there is the little high-resolution of length, the image quality of low aberration.

Imaging lens

Technical field

The present invention relates to a kind of imaging technique, more particularly, to a kind of imaging lens.

Background technology

Day with intelligent mobile phone is also popularized, and consumer starts to thirst for, and mobile phone is in addition to feature is complete, and needs energy Possesses compact feature, to be convenient for carrying.Therefore, the compact of mobile phone limits the sky placing camera module Between, and then the imaging lens of needs " low length " and " exiting surface effective diameter is little ", can with the cumulative volume guaranteeing camera module To reach minimum.

Pick up ten thousand pixels currently used for hundred ginsengs one of on mobile phone（13M）The imaging lens of above camera module, meeting mostly Using autofocus motor（Auto Focus Actuator）Come to drive imaging lens move, allow shooting photo from distant view end （Infinitely great）To close shot end（100mm）Can be clear, this is because consumer wishes that the landscape that mobile phone can photograph shines （Distant view end）, and the personage that again can photograph shines and major part shines（Middle scape end）, or even business card identification use can be done（Close shot end, leads to The distance of often business card identification is about 100mm）, it is therefore desirable to the imaging lens of " far and near scape image quality is taken into account ".

Content of the invention

In view of this it is necessary to offer is a kind of has the little high-resolution of length, the imaging lens of low aberration.

A kind of imaging lens, it includes from thing side to imaging surface successively：One has the first lens of positive light coke, one has Second lens of negative power, one have the 3rd lens of positive light coke, one have the 4th lens of positive light coke, one have negative 5th lens of focal power and an imaging surface.Described imaging lens meet following condition：D/TTL>0.94；Wherein, D is imaging surface Upper maximum imaging circular diameter；TTL is the length of whole imaging lens.

Meet the imaging lens of above-mentioned condition, there is the little high-resolution of length, the image quality of low aberration.

Brief description

The structural representation of the imaging lens that Fig. 1 provides for the present invention.

The spherical aberration performance diagram at distant view end for the imaging lens that Fig. 2 provides for first embodiment of the invention.

The curvature of field performance diagram at distant view end for the imaging lens that Fig. 3 provides for first embodiment of the invention.

The distortion performance curve chart at distant view end for the imaging lens that Fig. 4 provides for first embodiment of the invention.

The modulation transfer function (MTF) characteristic curve at distant view end for the imaging lens that Fig. 5 provides for first embodiment of the invention Figure.

The spherical aberration performance diagram at close shot end for the imaging lens that Fig. 6 provides for first embodiment of the invention.

The curvature of field performance diagram at close shot end for the imaging lens that Fig. 7 provides for first embodiment of the invention.

The distortion performance curve chart at close shot end for the imaging lens that Fig. 8 provides for first embodiment of the invention.

The modulation transfer function (MTF) characteristic curve at close shot end for the imaging lens that Fig. 9 provides for first embodiment of the invention Figure.

The spherical aberration performance diagram at distant view end for the imaging lens that Figure 10 provides for second embodiment of the invention.

The curvature of field performance diagram at distant view end for the imaging lens that Figure 11 provides for second embodiment of the invention.

The distortion performance curve chart at distant view end for the imaging lens that Figure 12 provides for second embodiment of the invention.

The modulation transfer function (MTF) characteristic curve at distant view end for the imaging lens that Figure 13 provides for second embodiment of the invention Figure.

The spherical aberration performance diagram at close shot end for the imaging lens that Figure 14 provides for second embodiment of the invention.

The curvature of field performance diagram at close shot end for the imaging lens that Figure 15 provides for second embodiment of the invention.

The distortion performance curve chart at close shot end for the imaging lens that Figure 16 provides for second embodiment of the invention.

The modulation transfer function (MTF) characteristic curve at close shot end for the imaging lens that Figure 17 provides for second embodiment of the invention Figure.

Main element symbol description

Following specific embodiment will further illustrate the present invention in conjunction with above-mentioned accompanying drawing.

Specific embodiment

Below in conjunction with accompanying drawing, the present invention is described in further detail.

Refer to Fig. 1, a kind of imaging lens 100 that the present invention provides, it includes from thing side successively to imaging surface：One tool Have the first lens L1 of positive light coke, one have the second lens L2 of negative power, one there is the 3rd saturating of positive light coke Mirror L3, one have the 4th lens L4 of positive light coke, one there is the 5th lens L5 of negative power, an optical filter 10 and Imaging surface 20.

Described first lens L1 includes a first surface S1 and protruding towards thing side to institute successively from thing side to image side State the second surface S2 of imaging surface 20 protrusion.

Described second lens L2 includes a 3rd surface S3 and protruding towards object side successively from thing side to image side The 4th surface S4 to described second lens L2 inner recess.

Described 3rd lens L3 from thing side to image side include successively one towards object side protrude the 5th surface S5 and to The 6th surface S6 that described imaging surface 20 side is protruded.

Described 4th lens L4 includes the 7th table to described 4th lens L4 inner recess successively from thing side to image side The 8th surface S8 that face S7 and protrudes to described imaging surface 20 side.

Described 5th lens L5 includes the 9th table to described 5th lens L5 inner recess successively from thing side to image side Face S9 and one is to the tenth surface S10 of described 5th lens L5 inner recess.

Described optical filter 10 includes the 11st surface S11 near thing side and close described one-tenth successively from thing side to image side 12nd surface S12 of image planes 20.Described optical filter 10 is used for filtering the Infrared in the light of the 5th lens L5.

Described imaging lens 100 also include a diaphragm 30.Described diaphragm 30 is located at described first lens L1 and the second lens Between L2, symmetrical with respect to diaphragm 30 to ensure the overall structure of imaging lens 100, it is effectively reduced the shadow of coma (coma) Ring；Limit the luminous flux of light entrance the second lens L2 through the first lens L1 simultaneously, and allow after the second lens L2 Light cone is more symmetrical, so that the coma of imaging lens 100 is revised.

In present embodiment, light is incident to after the first lens L1 from thing side, and successively again through described diaphragm 30, second Described imaging surface 20 is imaged in after lens L2, the 3rd lens L3, the 4th lens L4, the 5th lens L5 and optical filter 10.Can manage Solution, can be by arranging image sensor (not shown), such as Charged Coupled Device (CCD) or complementary metal oxide semiconductors (CMOS) (CMOS), sentence composition one imaging system in described imaging surface 20.

Described imaging lens 100 satisfy the following conditional expression：

(1)D/TTL>0.94；

Wherein, D is the maximum imaging circular diameter on described imaging surface 20；TTL is the length of whole imaging lens 100.

In imaging lens 100 conditional provided by the present invention, conditional (1) limits the overall length of imaging lens 100.

Described imaging lens 100 can satisfy the following conditional expression further：

(2)D/L>1.21；

Wherein L is the effective diameter of the exiting surface of the tenth surface S10.

Conditional（2）, limit the exiting surface effective diameter of described imaging lens 100, make the total of described imaging lens 100 Diameter less than maximum imaging circular diameter, and can reach minimum.

Described imaging lens 100 can satisfy the following conditional expression further：

(3) Z/Y>0；

Wherein, Z is the difference with the center thickness of described 4th lens L4 for the curved surface transverse height of described 8th surface S8, Y Curved surface for described 8th surface S8 longitudinally height.

Conditional（3）It is ensured that described 4th lens L4 is easy to ejection formation so that the plastics being injected by monolateral cast gate are permissible It is accessible to to side, and then allow the core shift sensitivity of described imaging lens 100 to diminish.

Described imaging lens 100 can satisfy the following conditional expression further：

（4）R31/F3>R11/F1>0；

（5）R12/F1<R32/F3<0；

Wherein, R11 is the radius of curvature of the first surface S1 of described first lens L1；R12 is described first lens L1 The radius of curvature of second surface S2；R31 is the radius of curvature of the 5th surface S5 of described 3rd lens L3；R32 is the described 3rd The radius of curvature of the 6th surface S6 of lens L3；F1 is the focal length of described first lens L1；F3 is Jiao of described 3rd lens L3 Away from.

Conditional（4）With（5）So that imaging lens 100 have good astigmat correction effect.

Described imaging lens 100 can satisfy the following conditional expression further：

(6) R51/F5<R52/F5<0；

Wherein, R51 is the radius of curvature of the 9th surface S9 of described 5th lens L5；R52 is described 5th lens L5 The radius of curvature of the tenth surface S10；F5 is the focal length of described 5th lens L5.

Conditional（6）So that the core shift sensitivity of imaging lens 100 diminishes.

Wherein, described first surface S1, second surface S2, the 3rd surface S3, the 4th surface S4, the 5th surface S5, the 6th Surface S6, the 7th surface S7, the 8th surface S8, the 9th surface S9 and the tenth surface S10 are all aspheric surfaces, and meet aspheric Face type formula：

Wherein, z is that the position being h in height along optical axis direction is made with reference to the shift value away from optical axis with surface vertices, and c is bent Rate radius, h is lens height, and K is circular cone fixed number（Coin Constant）, Ai is asphericity coefficients (the i-th order of i time Aspherical Coefficient）.

By by table 1, table 2, table 3（Refer to hereafter）Data substitute into above-mentioned expression formula, the present invention first can be obtained real Apply the aspherical shape of each lens surface in the imaging lens 100 of mode.In addition, by substituting into the data of table 5, table 6, table 7 Above-mentioned expression formula, would know that the aspherical shape of each lens surface in the imaging lens 100 of second embodiment of the invention.

Show respectively in following each table by the optical surface of object end to the image end sequential, wherein, i represents from the beginning of thing side I-th lens surface；Agreement F/No is the F-number of imaging lens 100；2 ω are the angle of visual field of imaging lens 100；Ri represents The radius of curvature of i-th lens surface starting from thing side；Di represents i-th lens surface starting from thing side to i+1 Axial distance between lens surface；Ni represents the refractive index of i-th lens surface starting from thing side；Vi represents from the beginning of thing side I-th lens surface Abbe number；Ki represents the quadratic curvature of i-th lens surface starting from thing side.

First embodiment

Each optical module of the imaging lens 100 that first embodiment of the invention is provided meets table 1 to the condition of table 3.

Table 1

Table 2

Table 3

Table 4

In present embodiment, D=5.867mm；TTL=5.48mm；Z=0.137mm；Y=1.45mm; L=4.47mm；F1= 3.32mm；F3=7.99mm；F5=-2.57mm.

At distant view end, the spherical aberration of imaging lens 100 of first embodiment, the curvature of field, distortion, MTF are respectively as Fig. 2 to Fig. 5 Shown.Specifically, five shown in Fig. 2 curve is respectively and is directed to F line (wavelength be 486 nanometers (nm)), and (wavelength is d line 588nm), C line (wavelength is 654nm), e line (wavelength is 546), g line (wavelength is 436nm), and the aberration value curve observed. By this five curves can be seen that the imaging lens 100 of first embodiment to visible ray (wave-length coverage 400nm-700nm it Between) aberration value that produces controls in the range of -0.05mm ~ 0.05mm.As shown in figure 3, curve T and S is respectively meridianal curvature of field (tangential field curvature) characteristic curve and Sagittal field curvature (sagittal field curvature) characteristic Curve.The meridianal curvature of field value of this imaging lens 100 and Sagittal field curvature value are controlled in -0.05mm ~ 0.05mm model as seen from Figure 3 In enclosing.Further, the curve shown in Fig. 4 is the distortion performance curve of imaging lens 100, as shown in Figure 4, this imaging lens 100 optical distortion amount is controlled in the range of -2.00% ~ 2.00%.As shown in figure 5, in 1/2 frequency（Nyquist frequency）Under the conditions of（1/2 frequency (half frequency) of present embodiment is 224lp/mm）, the MTF of central vision>55% (as curve Shown in mc), the MTF of 0.8 visual field>40% (as shown in curve mp), remaining visual field between central vision and 0.8 visual field MTF, then between 40% ~ 55% (as shown in curve mt).

At close shot end, the spherical aberration of imaging lens 100 of first embodiment, the curvature of field, distortion, MTF are respectively as Fig. 6 to Fig. 9 Shown.Specifically, five shown in Fig. 6 curve is respectively and is directed to F line (wavelength be 486 nanometers (nm)), and (wavelength is d line 588nm), C line (wavelength is 654nm), e line (wavelength is 546), g line (wavelength is 436nm), and the aberration value curve observed. By this five curves can be seen that the imaging lens 100 of first embodiment to visible ray (wave-length coverage 400nm-700nm it Between) aberration value that produces controls in the range of -0.05mm ~ 0.05mm.As shown in fig. 7, curve T and S is respectively meridianal curvature of field (tangential field curvature) characteristic curve and Sagittal field curvature (sagittal field curvature) characteristic Curve.The meridianal curvature of field value of this imaging lens 100 and Sagittal field curvature value are controlled in -0.05mm ~ 0.05mm model as seen from Figure 3 In enclosing.Further, the curve shown in Fig. 8 is the distortion performance curve of imaging lens 100, as shown in Figure 8, this imaging lens 100 optical distortion amount is controlled in the range of -2.00% ~ 2.00%.As shown in figure 9, in 1/2 frequency（Nyquist frequency）Under the conditions of（1/2 frequency (half frequency) of present embodiment is 224lp/mm）, the MTF of central vision>42% (as curve Shown in mc), the MTF of 0.8 visual field>14% (as shown in curve mp), remaining visual field between central vision and 0.8 visual field MTF, then between 14% ~ 42% (as shown in curve mt).

Second embodiment

Each optical module of the imaging lens 100 that second embodiment of the invention is provided meet table 5, table 6, table 7 and The condition of table 8.

Table 5

Table 6

Table 7

Table 8

In present embodiment, D=5.867mm；TTL=5.66mm；Z=0.121mm；Y=1.44mm; L=4.42mm；F1= 3.55mm；F3=7.78mm；F5=-2.63mm.

At distant view end, the spherical aberration of described imaging lens 100, the curvature of field, distortion, MTF are respectively as shown in Figure 10 to Figure 13.Specifically Ground, five shown in Figure 10 curve is respectively and is directed to F line (wavelength is 486 nanometers (nm)), d line (wavelength is 588nm), C line (ripple A length of 654nm), e line (wavelength is 546), g line (wavelength is 436nm), and the aberration value curve observed.By this five curves Can be seen that the aberration that the imaging lens 100 of second embodiment produce to visible ray (wave-length coverage is between 400nm-700nm) Value controls in the range of -0.05mm ~ 0.05mm.As shown in figure 11, curve T and S is respectively meridianal curvature of field (tangential Field curvature) characteristic curve and Sagittal field curvature (sagittal field curvature) characteristic curve.By Figure 11 Can be seen that the meridianal curvature of field value of this imaging lens 100 and Sagittal field curvature value are controlled in the range of -0.05mm ~ 0.05mm.Enter one Step ground, the curve shown in Figure 12 is the distortion performance curve of imaging lens 100, as shown in Figure 12, the one-tenth of this second embodiment Optical distortion amount as camera lens 100 is controlled in the range of -2.00% ~ 2.00%.As shown in figure 13, in 1/2 frequency（Nyquist frequency）Under the conditions of（1/2 frequency (half frequency) of present embodiment is 224lp/mm）, the MTF of central vision>55% (as curve Shown in mc), the MTF of 0.8 visual field>40% (as shown in curve mp), remaining visual field between central vision and 0.8 visual field MTF, then between 40% ~ 55% (as shown in curve mt).

At close shot end, the spherical aberration of described imaging lens 100 of second embodiment, the curvature of field, distortion, MTF are respectively as Figure 14 To shown in Figure 17.Specifically, five shown in Figure 14 curve is respectively and is directed to F line (wavelength is 486 nanometers (nm)), d line (wavelength For 588nm), C line (wavelength is 654nm), e line (wavelength is 546), g line (wavelength is 436nm), and the aberration value observed is bent Line.(wave-length coverage is in 400nm-700nm to visible ray to can be seen that the imaging lens 100 of first embodiment by this five curves Between) aberration value that produces controls in the range of -0.05mm ~ 0.05mm.As shown in figure 15, curve T and S is respectively meridianal curvature of field (tangential field curvature) characteristic curve and Sagittal field curvature (sagittal field curvature) characteristic Curve.The meridianal curvature of field value of this imaging lens 100 and Sagittal field curvature value are controlled in -0.05mm ~ 0.05mm as seen from Figure 15 In the range of.Further, the curve shown in Figure 16 is the distortion performance curve of the imaging lens 100 of second embodiment, by scheming 16 understand, the optical distortion amount of the imaging lens 100 of second embodiment is controlled in the range of -2.00% ~ 2.00%.As figure Shown in 17, in 1/2 frequency（Nyquist frequency）Under the conditions of（1/2 frequency (half frequency) of present embodiment is 224lp/mm）, in The MTF of heart visual field>42% (as shown in curve mc), the MTF of 0.8 visual field>14% (as shown in curve mp), remaining is between central vision And 0.8 visual field between visual field MTF, then between 14% ~ 42% (as shown in curve mt).

Meet the imaging lens of above-mentioned condition, there is the little high-resolution of length, the image quality of low aberration.

In addition, those skilled in the art can also do other changes in present invention spirit, certainly, these are according to the present invention The change that spirit is done, all should be included within scope of the present invention.