TW202234112A - Optical imaging system, acquisition module and electronic device - Google Patents

Abstract

The invention provides an optical imaging system, an acquisition module, and an electronic device. From the object side to the image side, the optical imaging system sequentially includes a diaphragm, a first lens with the negative refractive power, and a second lens with the negative refractive power. The optical imaging system satisfies the following conditions: 25<v1-v2<26.5, the V1 is the dispersion coefficient of the first lens, the V2 is the dispersion coefficient of the second lens. The present invention can correct the chromatic aberration of the optical imaging system, to improve the imaging clarity of the optical imaging system and the imaging quality of the optical imaging system.

Description

Optical imaging system, imaging module and electronic device

The present application relates to the technical field of optical imaging, and in particular, to an optical imaging system, an imaging module and an electronic device.

An electronic device currently used, such as a bar code lens, consists of two lenses, which are sequentially arranged from the object side to the image side as an aperture, a first lens (Lens) and a second lens (Lens), These lenses are all glass lenses, with good optical performance, but high cost; while the choice of plastic lenses can reduce the cost, but the optical performance is poor, so that the imaging quality cannot meet the demand.

In view of the above situation, it is necessary to provide an optical imaging system, an imaging module and an electronic device to solve the above problems.

An embodiment of the present application provides an optical imaging system, which sequentially includes a diaphragm, a first lens with negative refractive power, and a second lens with negative refractive power from the object side to the image side, and the optical imaging system satisfies the following conditional formula : 25<v1-v2<26.5; wherein, v1 is the dispersion coefficient of the first lens, and v2 is the dispersion coefficient of the second lens.

When the dispersion coefficients of the first lens and the second lens in the above-mentioned optical imaging system satisfy the above relationship, the chromatic aberration of the optical imaging system can be effectively corrected, the imaging clarity of the optical imaging system can be improved, and the imaging quality of the optical imaging system can be improved.

The embodiments of the present application also provide an image capturing module, including: the above-mentioned optical imaging system; and a photosensitive element, and the photosensitive element is arranged on the image side of the optical imaging system.

The embodiments of the present application further provide an electronic device, including: a casing; and the above-mentioned imaging module, wherein the imaging module is mounted on the casing.

Referring to FIG. 1 , an embodiment of the present application proposes an optical imaging system 10 , which includes a diaphragm STO, a first lens L1 with negative refractive power, and a second lens L2 with negative refractive power in sequence from the object side to the image side. The first lens L1 has an object side S3 and an image side S4, and the second lens L2 has an object side S5 and an image side S6. The material of the first lens L1 and the second lens L2 may be plastic.

The optical imaging system satisfies the following conditional formula: 25<v1-v2<26.5; wherein, v1 is the dispersion coefficient of the first lens L1, and v2 is the dispersion coefficient of the second lens L2.

When the dispersion coefficients of the first lens L1 and the second lens L2 in the above-mentioned optical imaging system satisfy the above relationship, aberrations can be corrected effectively, the optical performance is better, and the imaging quality is better. In addition, the materials of the first lens L1 and the second lens L2 are both plastic, so the production cost is low.

In one embodiment, the optical imaging system 10 satisfies the conditional formula: 1.3<TL1/f<1.7; wherein, TL1 is the distance between the object side S3 of the first lens L1 and the imaging plane IMA of the optical imaging system 10 on the optical axis and f is the effective focal length of the optical imaging system 10 . When the above conditional expression is satisfied, it is beneficial to compress the total length of the optical imaging system 10 and can ensure better imaging quality.

In some embodiments, the optical imaging system 10 satisfies the conditional formula: 0.6<TL2/f<0.9; Wherein, TL2 is the distance on the optical axis from the object side S5 of the second lens L2 to the imaging surface IMA of the optical imaging system 10 , and f is the effective focal length of the optical imaging system 10 . When the above conditional expression is satisfied, it is beneficial to compress the total length of the optical imaging system 10 and can ensure better imaging quality.

In some embodiments, the optical imaging system 10 satisfies the relationship 1.4<Imgh/EPD<1.65; wherein, Imgh is half of the image height corresponding to the maximum angle of view of the optical imaging system 10, and EPD is the optical imaging system The entrance pupil diameter of the system 10 . By satisfying the above conditional formula, it is beneficial to ensure the improvement of the IMA brightness of the imaging surface during the imaging of a large target surface. When the upper limit of the conditional expression is exceeded, the diameter of the entrance pupil of the optical imaging system 10 is small, which reduces the beam width of the light beams entering the optical imaging system 10, which is not conducive to the improvement of the brightness of the imaging surface IMA; when the lower limit of the conditional expression is exceeded, the optical The imaging surface area of the imaging system 10 is small, which reduces the range of the field of view of the optical imaging system 10 .

In some embodiments, the optical imaging system 10 satisfies the relationship: 3<TTL/Imgh<4.5; Wherein, TTL is the total optical length of the optical imaging system 10 , and Imgh is half of the image height corresponding to the maximum angle of view of the optical imaging system 10 . Satisfying the above relational expression can make the optical imaging system 10 have ultra-thin characteristics and meet the requirement of miniaturization. However, when the TTL/Imgh does not satisfy the above-mentioned relational expression, the overall length of the optical imaging system 10 is large, which is not conducive to realizing the requirement of miniaturization.

In one embodiment, the optical imaging system 10 satisfies the conditional formula 16°/mm<FOV/f<24°/mm; wherein, FOV is the maximum field angle of the optical imaging system 10 , and f is the optical imaging system 10 effective focal length. In this way, it is possible to effectively control the optical imaging system 10 to achieve the purpose of shortening the overall length under the condition of satisfying an appropriate effective focal length, and to meet the requirement of the optical imaging system 10 being light and thin.

In one embodiment, the optical imaging system 10 satisfies the conditional formula: 0.05<T12/TTL<0.15; Wherein, T12 is the distance on the optical axis from the image side S3 of the first lens L1 to the object side S5 of the second lens L2 , and TTL is the total optical length of the optical imaging system 10 . When the above conditional expression is satisfied, it is beneficial to compress the total length of the optical imaging system 10 and can ensure better imaging quality.

In some embodiments, the optical imaging system 10 further includes a filter L3, the filter L3 has an object side S7 and an image side S8, the filter L3 is arranged on the image side of the second lens L2, and the filter L3 can be The infrared filter is used to filter out light in other wavelength bands such as visible light, and only allow infrared light to pass through, so that the optical imaging system 10 can also image in a dark environment and other special application scenarios. It can be understood that the material of the filter L3 can be plastic or glass.

In some embodiments, the optical imaging system 10 further includes a protective glass L4, which has an object side S9 and an image side S10 to prevent foreign objects such as water vapor or dust from entering the optical imaging system 10, thereby affecting the imaging quality.

first embodiment

Please continue to refer to FIG. 1 , the optical imaging system 10 in this embodiment includes a diaphragm STO from the object side to the image side, a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a light filter Sheet L3 and protective glass L4.

The object side S3 of the first lens L1 is a plane at the near optical axis, and the image side S4 of the first lens L1 is a convex surface at the near optical axis. The object side S5 of the second lens L2 is concave at the near optical axis, and the image side S6 of the second lens L2 is concave at the near optical axis.

When the optical imaging system 10 is used for imaging, the light emitted or reflected by the subject enters the optical imaging system 10 from the object side direction, and passes through the diaphragm STO, the first lens L1, the second lens L2, and the filter L3 in sequence and protective glass L4, and finally converge on the imaging surface IMA.

Table 1 shows the characteristics of the optical imaging system 10, f is the effective focal length of the optical imaging system 10, FOV is the field angle of the optical imaging system 10, the reference wavelength of the effective focal length, refractive index and Abbe number is 555nm, and the radius of curvature is 555 nm. , Thickness, net diameter and mechanical half diameter are in millimeters.

Table 1 first embodiment f=2.27mm, FOV=40.6 surface number Lens name surface type Radius of curvature thickness material refractive index Abbe number Net diameter Mechanical half diameter Conic factor OBJ Standard surface unlimited 80.000 31.384 31.374 0 S1 Standard surface unlimited 0.500 0.477 0.477 0 STO Standard surface unlimited 0.030 0.284 0.284 0 S3 first lens Aspherical 4.107 1.479 plastic 1.54 56.0 0.299 0.575 86.8 S4 Aspherical -0.561 0.314 0.575 0.575 -1.239 S5 second lens Aspherical -0.593 1.069 plastic 1.58 29.9 0.531 0.717 -0.303 S6 Aspherical -11.220 0.097 0.717 0.717 -1000 S7 filter Standard surface unlimited 0.100 Glass 1.52 64.2 0.736 0.756 0 S8 Standard surface unlimited 0.050 0.756 0.756 0 S9 protective glass Standard surface unlimited 0.400 Glass 1.52 64.2 0.772 0.853 0 S10 Standard surface unlimited 0.247 0.853 0.853 0 IMA Standard surface unlimited 0.931 0.931 0

Table 2 first embodiment surface K2 K4 K6 K8 K10 K12 S3 0.000E+00 -3.770E-01 -2.224E+00 2.688E+01 -1.787E+02 -2.121E+02 S4 0.000E+00 6.260E-01 -2.368E+00 4.056E+00 -3.345E+00 -2.510E-01 S5 0.000E+00 2.463E+00 -7.873E+00 2.225E+01 -3.514E+01 2.797E+01 S6 0.000E+00 5.920E-01 -1.536E+00 2.455E+00 -2.631E+00 1.648E+00

It should be noted that the object side surface and the image side surface of the first lens L1 and the second lens L2 of the optical imaging system 10 are both aspherical surfaces, and the conic constant k and aspherical surface coefficient corresponding to the surfaces of each aspherical surface are shown in Table 2. For these aspheric surfaces, the aspheric equation for the aspheric surface is:

Among them, Z represents the height parallel to the Z axis in the lens surface, r represents the radial distance from the vertex, c represents the curvature of the surface at the vertex, k represents the conic constant, K2, K4, K6, K8, K10, K12 represent respectively The aspheric coefficients of the corresponding orders of the 2nd, 4th, 6th, 8th, 10th, and 12th orders.

FIG. 2 is a data graph of the analog MTF versus field angle performance of the optical imaging system 10 in this embodiment. The abscissa represents the Y field offset angle, that is, the angle formed by the field of view of the optical system 100 relative to the optical axis, in degrees; the ordinate represents the OTF coefficient; S1 and T1 represent the curve at a spatial frequency of 57cyc/mm , S2 and T3 represent the curves at a spatial frequency of 114cyc/mm; and S1 and T1 represent the curves in the S direction and the T direction at a spatial frequency of 57cyc/mm, respectively; among them, the curves S1 and T1 are the curves at lower frequencies , which can reflect the contrast characteristics of the optical system 100 , while the curves S2 and T2 are curves at higher frequencies, which can reflect the resolution characteristics of the optical system 100 . S1 and T1 represent curves at a spatial frequency of 139 p/mm, which can reflect the contrast characteristics and resolution characteristics of the optical system 100 .

FIG. 3 is a field curvature graph and a distortion graph of the optical imaging system 10 in this embodiment from left to right, and the reference wavelength is 555 nm.

It can be seen from the curves in Fig. 2 and Fig. 3 that the curvature value of the sagittal field and the curvature value of the meridional field of the optical imaging system 10 are controlled between -0.1 mm and 0.1 mm, the lens is easier to manufacture and the manufacturing cost is reduced; the optical imaging system The distortion of 10 is controlled within 0-20%, that is, the distortion of the image formed by the optical imaging system 10 is small. Therefore, the optical imaging system 100 reflects a good value on the analog MTF, and the optical imaging system 10 has good imaging performance.

Second Embodiment

Referring to FIG. 4 , the optical imaging system 10 in this embodiment includes a diaphragm STO, a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, and a filter from the object side to the image side. L3 and protective glass L4.

The object side S3 of the first lens L1 is a plane at the near optical axis, and the image side S4 of the first lens L1 is a convex surface at the near optical axis. The object side S5 of the second lens L2 is concave at the near optical axis, and the image side S6 of the second lens L2 is concave at the near optical axis.

When the optical imaging system 10 is used for imaging, the light emitted or reflected by the subject enters the optical imaging system 10 from the object side direction, and passes through the diaphragm STO, the first lens L1, the second lens L2, and the filter L3 in sequence and protective glass L4, and finally converge on the imaging surface IMA.

Table 3 shows the characteristics of the optical imaging system 10 in this embodiment, f is the effective focal length of the optical imaging system 10, FOV is the field of view angle of the optical imaging system 10, and the reference wavelengths of the effective focal length, refractive index and Abbe number are 555nm, the unit of curvature radius, thickness, clear diameter and mechanical half diameter are all millimeters (mm).

table 3 Second Embodiment f=2.37mm, FOV=39.36 surface number Lens name surface type Radius of curvature thickness material refractive index Abbe number Net diameter Mechanical half diameter Conic factor OBJ Standard surface unlimited 80.000 30.33 30.33 0 S1 Standard surface unlimited 0.500 0.483 0.483 0 STO Standard surface unlimited 0.030 0.296 0.296 0 S3 first lens Aspherical 4.107 1.479 plastic 1.54 56.0 0.311 0.579 86.8 S4 Aspherical -0.561 0.314 0.579 0.579 -1.239 S5 second lens Aspherical -0.593 1.069 plastic 1.58 30.2 0.527 0.703 -0.303 S6 Aspherical 38.110 0.283 0.703 0.703 -1000 S7 filter Standard surface unlimited 0.100 Glass 1.52 64.2 0.778 0.799 0 S8 Standard surface unlimited 0.050 0.799 0.799 0 S9 protective glass Standard surface unlimited 0.400 Glass 1.52 64.2 0.815 0.900 0 S10 Standard surface unlimited 0.080 0.900 0.900 0 IMA Standard surface unlimited 0.927 0.927 0

Table 4 Second Embodiment surface K2 K4 K6 K8 K10 K12 S3 0.000E+00 -3.770E-01 -2.224E+00 2.688E+01 -1.787E+02 -2.121E+02 S4 0.000E+00 6.260E-01 -2.368E+00 4.056E+00 -3.345E+00 -2.510E-01 S5 0.000E+00 2.463E+00 -7.873E+00 2.225E+01 -3.514E+01 2.797E+01 S6 0.000E+00 5.920E-01 -1.536E+00 2.455E+00 -2.631E+00 1.648E+00

FIG. 5 is a graph of the analog MTF versus field angle performance data of the optical imaging system 10 . The abscissa represents the Y field offset angle, that is, the angle formed by the field of view of the optical system 100 relative to the optical axis, in degrees; the ordinate represents the OTF coefficient; S1 and T1 represent the curve at a spatial frequency of 57cyc/mm , S2 and T3 represent the curves at a spatial frequency of 114cyc/mm; and S1 and T1 represent the curves in the S direction and the T direction when the spatial frequency is 57cyc/mm; the curves S1 and T1 are the curves at a lower frequency, which can be Reflecting the contrast characteristics of the optical system 100 , the curves S2 and T2 are curves at higher frequencies, which can reflect the resolution characteristics of the optical system 100 . S1 and T1 represent curves at a spatial frequency of 139 p/mm, which can reflect the contrast characteristics and resolution characteristics of the optical system 100 .

FIG. 6 is a field curvature graph and a distortion graph of the optical imaging system 10 in the present embodiment from left to right, and the reference wavelength is 555 nm.

It can be seen from the curves in FIGS. 5 and 6 that the sag and meridional field curvature values of the optical imaging system 10 are controlled between -0.1 mm and 0.1 mm, which makes the lens production easier and reduces the production cost; the optical imaging system The distortion of 10 is controlled within 0-20%, that is, the distortion of the image formed by the optical imaging system 10 is small. Therefore, the optical imaging system 100 reflects a good value on the analog MTF, and the optical imaging system 10 has good imaging performance.

Third Embodiment

Referring to FIG. 7 , the optical imaging system 10 in this embodiment includes a diaphragm STO, a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, and a filter from the object side to the image side. L3 and protective glass L4.

The object side S3 of the first lens L1 is a plane at the near optical axis, and the image side S4 of the first lens L1 is a convex surface at the near optical axis. The object side S5 of the second lens L2 is concave at the near optical axis, and the image side S6 of the second lens L2 is concave at the near optical axis.

When the optical imaging system 10 is used for imaging, the light emitted or reflected by the subject enters the optical imaging system 10 from the object side direction, and passes through the diaphragm STO, the first lens L1, the second lens L2, and the filter L3 in sequence and protective glass L4, and finally converge on the imaging surface IMA.

Table 5 shows the characteristics of the optical imaging system 10 in this embodiment, f is the effective focal length of the optical imaging system 10, FOV is the field of view angle of the optical imaging system 10, and the reference wavelengths of the effective focal length, refractive index and Abbe number are 555nm, the unit of curvature radius, thickness, clear diameter and mechanical half diameter are all millimeters (mm).

table 5 Third Embodiment f=2.2mm, FOV=44.14 surface number Lens name surface type Radius of curvature thickness material refractive index Abbe number Net diameter Mechanical half diameter Conic factor OBJ Standard surface unlimited 80 34.423 34.423 0 S1 Standard surface unlimited 0.500 0.487 0.487 0 STO Standard surface unlimited 0.030 0.275 0.275 0 S3 first lens Aspherical 4.107 1.479 plastic 1.54 56.0 0.291 0.589 86.8 S4 Aspherical -0.561 0.314 0.589 0.589 -1.239 S5 second lens Aspherical -0.593 0.096 plastic 1.58 29.9 0.554 0.612 -0.186 S6 Aspherical -11.2 0.622 0.612 0.612 -5105.688 S7 filter Standard surface unlimited 0.100 Glass 1.52 64.2 0.764 0.780 0 S8 Standard surface unlimited 0.050 0.780 0.780 0 S9 protective glass Standard surface unlimited 0.400 Glass 1.52 64.2 0.792 0.859 0 S10 Standard surface unlimited 0.247 0.859 0.859 0 IMA Standard surface unlimited 0.929 0.929 0

Table 6 Third Embodiment surface K2 K4 K6 K8 K10 K12 S3 0.000E+00 -3.770E-01 -2.224E+00 2.688E+01 -1.787E+02 -2.121E+02 S4 0.000E+00 6.260E-01 -2.368E+00 4.056E+00 -3.345E+00 -2.510E-01 S5 0.000E+00 3.399E+00 -1.144E+01 2.084E+01 -1.695E+01 8.655E+01 S6 0.000E+00 1.075E+00 -4.800E+00 4.532E+00 7.575E+00 2.978E+00

FIG. 8 is a data graph of the analog MTF versus field angle performance of the optical imaging system 10 in this embodiment. The abscissa represents the Y field offset angle, that is, the angle formed by the field of view of the optical system 100 relative to the optical axis, in degrees; the ordinate represents the OTF coefficient; S1 and T1 represent the curve at a spatial frequency of 57cyc/mm, S2 and T3 represent the curves at a spatial frequency of 114cyc/mm; and S1 and T1 respectively represent the curves in the S direction and the T direction when the spatial frequency is 57cyc/mm; among them, the curves S1 and T1 are the curves at a lower frequency, which can be Reflecting the contrast characteristics of the optical system 100 , the curves S2 and T2 are curves at higher frequencies, which can reflect the resolution characteristics of the optical system 100 . S1 and T1 represent curves at a spatial frequency of 139 p/mm, which can reflect the contrast characteristics and resolution characteristics of the optical system 100 .

FIG. 9 is a field curvature graph and a distortion graph of the optical imaging system 10 in this embodiment from left to right, and the reference wavelength is 555 nm.

It can be seen from the curves in FIG. 8 and FIG. 9 that the curvature value of the sagittal field and the curvature value of the meridional field of the optical imaging system 10 are controlled between -0.1 mm and 0.1 mm, which makes the manufacture of the lens easier and reduces the manufacturing cost; the optical imaging system The distortion of 10 is controlled within 0-20%, that is, the distortion of the image formed by the optical imaging system 10 is small. Therefore, the optical imaging system 100 reflects a good value on the analog MTF, and the optical imaging system 10 has good imaging performance.

Embodiment 4

Referring to FIG. 10 , the optical imaging system 10 in this embodiment includes a diaphragm STO, a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, and a filter from the object side to the image side. L3 and protective glass L4.

The object side S3 of the first lens L1 is a plane at the near optical axis, and the image side S4 of the first lens L1 is a convex surface at the near optical axis. The object side S5 of the second lens L2 is concave at the near optical axis, and the image side S6 of the second lens L2 is concave at the near optical axis.

When the optical imaging system 10 is used for imaging, the light emitted or reflected by the subject enters the optical imaging system 10 from the object side direction, and passes through the diaphragm STO, the first lens L1, the second lens L2, and the filter L3 in sequence and protective glass L4, and finally converge on the imaging surface IMA.

Table 7 shows the characteristics of the optical imaging system 10 of this embodiment, f is the effective focal length of the optical imaging system 10, FOV is the field of view angle of the optical imaging system 10, and the reference wavelengths of the effective focal length, refractive index and Abbe number are 555nm, the unit of curvature radius, thickness, clear diameter and mechanical half diameter are all millimeters (mm).

Table 7 Fourth Embodiment f=1.99mm, FOV=46.16 surface number Lens name surface type Radius of curvature thickness material refractive index Abbe number Net diameter Mechanical half diameter Conic factor OBJ Standard surface unlimited 80.000 36.049 36.049 0 S1 Standard surface unlimited 0.500 0.471 0.471 0 STO Standard surface unlimited 0.030 0.248 0.248 0 S3 first lens Aspherical 4.107 1.220 plastic 1.54 56.0 0.265 0.524 86.8 S4 Aspherical -0.561 0.361 0.524 0.524 -1.239 S5 second lens Aspherical -0.593 0.261 plastic 1.58 29.9 0.512 0.585 -0.169 S6 Aspherical -11.2 0.334 0.585 0.585 -125600 S7 filter Standard surface unlimited 0.100 Glass 1.52 64.2 0.697 0.722 0 S8 Standard surface unlimited 0.050 0.722 0.722 0 S9 protective glass Standard surface unlimited 0.400 Glass 1.52 64.2 0.742 0.840 0 S10 Standard surface unlimited 0.247 0.840 0.840 0 IMA Standard surface unlimited 0.936 0.936 0

Table 8 Fourth Embodiment surface K2 K4 K6 K8 K10 K12 S3 0.000E+00 -4.330E-01 -3.347E+00 1.963E+01 -1.952E+02 2.066E+02 S4 0.000E+00 4.070E-01 -2.175E+00 4.056E+00 -4.395E+00 -1.512E+00 S5 0.000E+00 3.303E+00 -1.159E+01 2.205E+01 -1.170E+01 9.558E+01 S6 0.000E+00 1.305E+00 -4.620E+00 4.277E+00 6.487E+00 2.082E+00

FIG. 11 is a graph showing the performance of the optical imaging system 10 in the present embodiment by an analog MTF versus a viewing angle. The abscissa represents the Y field offset angle, that is, the angle formed by the field of view of the optical system 100 relative to the optical axis, in degrees; the ordinate represents the OTF coefficient; S1 and T1 represent the curve at a spatial frequency of 57cyc/mm, S2 and T3 represent the curves at a spatial frequency of 114cyc/mm; and S1 and T1 respectively represent the curves in the S direction and the T direction when the spatial frequency is 57cyc/mm; among them, the curves S1 and T1 are the curves at lower frequencies, which can be Reflecting the contrast characteristics of the optical system 100 , the curves S2 and T2 are curves at higher frequencies, which can reflect the resolution characteristics of the optical system 100 . S1 and T1 represent curves at a spatial frequency of 139 p/mm, which can reflect the contrast characteristics and resolution characteristics of the optical system 100 .

FIG. 12 is a field curvature graph and a distortion graph of the optical imaging system 10 in this embodiment from left to right, and the reference wavelength is 555 nm.

It can be seen from the curves in FIG. 11 and FIG. 12 that the sagittal field curvature and the meridional field curvature of the optical imaging system 10 are controlled between -0.1 mm and 0.1 mm, the lens is easier to manufacture and the manufacturing cost is reduced; the optical imaging system The distortion of 10 is controlled within 0-20%, that is, the distortion of the image formed by the optical imaging system 10 is small. Therefore, the optical imaging system 100 reflects a good value on the analog MTF, and the optical imaging system 10 has good imaging performance.

Table 9 shows the values of v1-v2, TL1/f, TL2/f, Imgh/EPD, TTL/Imgh, FOV/f, and T12/TTL in the optical imaging systems of the first to fourth embodiments.

Table 9 formula v1-v2 TL1/f TL2/f Imgh/EPD first embodiment 26.146 1.661 0.863 1.544 Second Embodiment 25.81 1.591 0.835 1.492 Third Embodiment 26.12 1.505 0.686 1.6 Fourth Embodiment 25.81 1.492 0.698 1.492 formula TTL/Imgh FOV/f T12/TTL first embodiment 4.307 17.885 0.082 Second Embodiment 4.318 16.608 0.083 Third Embodiment 3.795 20.064 0.094 Fourth Embodiment 3.409 23.196 0.105

Referring to FIG. 13 , the optical imaging system 10 of the embodiment of the present application can be applied to the imaging module 100 of the embodiment of the present application. The imaging module 100 includes the photosensitive element 20 and the optical imaging system 10 of any of the above embodiments. The photosensitive element 20 is provided on the image side of the optical imaging system 10 .

The photosensitive element 20 can be a complementary metal oxide semiconductor (MMOS, Complementary Metal Oxide Semiconductor) image sensor or a charge-coupled device (CCD, Charge-coupled Device).

In the above-mentioned optical imaging system in the image capturing module 100, when the dispersion coefficients of the first lens L1 and the second lens L2 satisfy the above relationship, aberrations can be corrected effectively, the optical performance is better, and the imaging quality is better. In addition, the materials of the first lens L1 and the second lens L2 are both plastic, and the production cost is low.

Referring to FIG. 14 , the imaging module 100 of the embodiment of the present application can be applied to the electronic device 200 of the embodiment of the present application. The electronic device 200 includes a casing 210 and an imaging module 100 , and the imaging module 100 is mounted on the casing 210 .

The electronic device 200 in the embodiment of the present application includes, but is not limited to, a driving recorder, a smart phone, a tablet computer, a notebook computer, an electronic book reader, a portable multimedia player (PMP), a portable phone, a video phone, a digital still camera, Mobile medical devices, wearable devices, smart doorbell detection devices, smart home appliance detection devices and other electronic devices that support imaging.

In the above-mentioned optical imaging system of the electronic device 200 , when the dispersion coefficients of the first lens L1 and the second lens L2 satisfy the above relationship, aberrations can be corrected effectively, and the optical performance is better and the imaging quality is better. In addition, the materials of the first lens L1 and the second lens L2 are both plastic, and the production cost is low.

To sum up, the present invention complies with the requirements of an invention patent, and a patent application can be filed in accordance with the law. However, the above descriptions are only preferred embodiments of the present invention, and for those who are familiar with the art of the present case, equivalent modifications or changes made in accordance with the spirit of the present invention should all be included within the scope of the following claims.

L1: first lens L2: Second lens L3: Filter L4: Protective glass STO: diaphragm IMA: Imaging plane S3, S5, S7, S9: Object side S4, S6, S8, S10: Like the side 10: Optical imaging system 20: Photosensitive element 100: Acquisition module 200: Electronics 210: Shell

FIG. 1 is a structural diagram of an optical imaging system according to a first embodiment of the present application.

FIG. 2 is a data diagram showing the performance of the optical imaging system according to the first embodiment of the present application with respect to the viewing angle by an analog MTF.

FIG. 3 is a field curvature and distortion curve diagram of the optical imaging system according to the first embodiment of the present application.

FIG. 4 is a structural diagram of an optical imaging system according to a second embodiment of the present application.

FIG. 5 is a graph showing the performance of the analog MTF versus the viewing angle of the optical imaging system according to the second embodiment of the present application.

FIG. 6 is a field curvature and distortion curve diagram of the optical imaging system according to the second embodiment of the present application.

FIG. 7 is a structural diagram of an optical imaging system according to a third embodiment of the present application.

FIG. 8 is a graph showing the performance of the analog MTF versus the viewing angle of the optical imaging system according to the third embodiment of the present application.

FIG. 9 is a field curvature and distortion curve diagram of the optical imaging system according to the third embodiment of the present application.

FIG. 10 is a structural diagram of an optical imaging system according to a third embodiment of the present application.

FIG. 11 is a graph showing the performance of the analog MTF versus the viewing angle of the optical imaging system according to the third embodiment of the present application.

FIG. 12 is a field curvature and distortion curve diagram of the optical imaging system according to the third embodiment of the present application.

FIG. 13 is a schematic structural diagram of an image capturing module according to an embodiment of the present application.

FIG. 14 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

none.

L1: first lens

L2: Second lens

L3: Filter

L4: Protective glass

STO: diaphragm

IMA: Imaging plane

S3, S5, S7, S9: Object side

S4, S6, S8, S10: Like the side

10: Optical imaging system

Claims (10)

An optical imaging system, which is improved by including a diaphragm, a first lens with negative refractive power, and a second lens with negative refractive power in sequence from the object side to the image side, the optical imaging system satisfies the following conditional formula: 25< v1-v2<26.5; wherein, v1 is the dispersion coefficient of the first lens, and v2 is the dispersion coefficient of the second lens. According to the optical imaging system of claim 1, the object side surface of the first lens is a plane at the near optical axis, and the image side surface of the first lens is a convex surface at the near optical axis; The side surface is concave at the near optical axis, and the image side surface of the second lens is concave at the near optical axis. The optical imaging system according to claim 1, wherein the optical imaging system satisfies the following conditional formula: 1.3<TL1/f<1.7; wherein, TL1 is from the object side of the first lens to the imaging plane of the optical imaging system The distance on the optical axis, f is the effective focal length of the optical imaging system. The optical imaging system according to claim 1, wherein the optical imaging system satisfies the following conditional formula: 0.6<TL2/f<0.9; wherein, TL2 is from the object side of the second lens to the imaging plane of the optical imaging system The distance on the optical axis, f is the effective focal length of the optical imaging system. The optical imaging system according to claim 1, wherein the optical imaging system satisfies the following relation: 1.4 < Imgh/EPD <1.65; wherein, Imgh is half of the image height corresponding to the maximum angle of view of the optical imaging system , EPD is the entrance pupil diameter of the optical imaging system. The optical imaging system according to claim 1, wherein the optical imaging system satisfies the following relation: 3<TTL/Imgh<4.5; wherein, TTL is the total optical length of the optical imaging system, and Imgh is the length of the optical imaging system. Half of the image height corresponding to the largest field of view. The optical imaging system according to claim 1, the optical imaging system satisfies the following conditional formula: 16°/mm <FOV/f<24°/mm; wherein, FOV is the maximum angle of view of the optical imaging system, f is the effective focal length of the optical imaging system. According to the optical imaging system of claim 1, the optical imaging system satisfies the following conditional formula: 0.05<T12/TTL<0.15; wherein, T12 is the distance between the image side of the first lens and the object side of the second lens. The distance on the optical axis, TTL is the total optical length of the optical imaging system. An imaging module, comprising: The optical imaging system of any one of claims 1 to 8; and A photosensitive element, the photosensitive element is arranged on the image side of the optical imaging system. An electronic device, comprising: the shell; and The imaging module according to claim 9, wherein the imaging module is mounted on the casing.

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