Telescopic four-group continuous zoom optical lens, imaging component and mobile phone

Abstract

The present invention discloses a telescopic four-group continuous zoom optical lens, an imaging component and a mobile phone. The telescopic four-group continuous zoom optical lens comprises a lens body, the lens body comprises a lens barrel, a zoom lens group and a compensation lens group; the zoom lens group comprises a first lens group, a second lens group and a third lens group, the compensation lens group comprises a fourth lens group, the lens body is movably arranged, an aperture is arranged on the third lens group, the aperture is fixed relative to the third lens group so as to be driven by the third lens group, the focal length f1 of the first lens group, the focal length f2 of the second lens group, the focal length f3 of the third lens group, the focal length f4 of the fourth lens group, and the distance d between the first lens group and the second lens group at the wide-angle end w12 , the distance d between the first lens group and the second lens group at the telephoto end t12 , the distance d between the third lens group and the fourth lens group at the wide angle end w34 , the distance d between the third lens group and the fourth lens group at the telephoto end t34 , satisfying the following relationship: #imgabs0# and #imgabs1# The present invention helps to enrich the application scenarios of optical lenses.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lenses, and in particular to a telescopic four-group continuous zoom optical lens, an imaging component and a mobile phone. Background Art

[0002] Optical lenses are essential components in machine vision systems, which directly affect the quality of imaging and the implementation and effect of algorithms. Optical lenses can be divided into fixed-focus lenses and zoom lenses based on focal length. Fixed-focus lenses are widely used as mobile phone lenses due to their low production costs.

[0003] With the continuous development of mobile phone camera lens related technologies, consumers have higher and higher requirements for the performance of mobile phone lenses. The traditional fixed-focus mobile phone lens with digital zoom can no longer meet the growing consumer demand. Continuous optical zoom lenses have the ability to continuously zoom within a certain focal length range, which can achieve perfect imaging at different magnifications. Therefore, they have become the direction of efforts of major mobile phone lens manufacturers. However, the traditional continuous optical zoom lens solution cannot be directly migrated to mobile phones for application. The biggest obstacle lies in the size of the lens. The thickness of a general smartphone is less than 10mm, while the length of a traditional optical zoom lens is at least tens of millimeters. Therefore, applying optical zoom lenses to mobile phone cameras faces huge difficulties. Summary of the invention

[0004] The invention discloses a telescopic four-group continuous zoom optical lens, an imaging component and a mobile phone, aiming to solve the problem in the prior art that it is difficult to apply the optical zoom lens to mobile phone photography.

[0005] To achieve the above object, the present invention provides a telescopic four-group continuous zoom optical lens, comprising a lens body, wherein the direction from the object side to the image side along the optical axis of the lens body is from front to back;

[0006] The lens body comprises a lens barrel, and a variable power lens group and a compensating lens group arranged in the lens barrel; the variable power lens group comprises a first lens group with negative optical power, a second lens group with negative optical power and a third lens group with positive optical power, the compensating lens group comprises a fourth lens group with positive optical power, the first lens group, the second lens group, the third lens group and the fourth lens group are arranged in sequence from front to back, and are movably arranged in the front-to-back direction relative to the lens barrel, respectively, the third lens group is provided with an aperture stop, and the aperture stop is fixed relative to the third lens group so as to be driven by the third lens group to move in the front-to-back direction;

[0007] Wherein, the focal length of the first lens group is f 1 , the focal length of the second lens group is f 2 , the focal length of the third lens group is f 3, the focal length of the fourth lens group is f 4 The distance between the first lens group and the second lens group at the wide-angle end is d w12 The distance between the first lens group and the second lens group at the telephoto end is d t12 The distance between the third lens group and the fourth lens group at the wide-angle end is d w34 The distance between the third lens group and the fourth lens group at the telephoto end is d t34 , satisfying the following relationship:

[0008] and

[0009] Optionally, the aperture stop is arranged on the front side of the third lens group.

[0010] Optionally, the first lens group includes a first lens;

[0011] The second lens group includes a second lens and a third lens arranged in sequence from front to back;

[0012] The third lens group includes a fourth lens, a fifth lens and a sixth lens;

[0013] The fourth lens group includes a seventh lens;

[0014] Wherein, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all aspherical lenses.

[0015] Optionally, the lens body further includes a driving device, and the driving device is used to drive the first lens group, the second lens group, the third lens group and the fourth lens group to move in the front-rear direction respectively.

[0016] Optionally, the driving device comprises:

[0017] A CAM barrel driving mechanism is provided on the lens barrel and is used to drive the first lens group, the second lens group and the third lens group to move in the front-rear direction respectively; and

[0018] The VCM driving mechanism is arranged on the lens barrel and is used for driving the fourth lens group to move in the front-rear direction.

[0019] Optionally, when the first lens group, the second lens group, the third lens group and the fourth lens group move away from each other in the front-rear direction, the length of the lens body is 10.36-13.61 mm.

[0020] Optionally, when the first lens group, the second lens group, the third lens group and the fourth lens group move toward each other in the front-rear direction, the shortest optical length of the lens body is 7.1 mm-8.0 mm.

[0021] Optionally, when the first lens group, the second lens group, the third lens group and the fourth lens group move toward each other in the front-rear direction, the shortest optical length of the lens body is 7.1 mm.

[0022] The present invention also provides an imaging assembly, comprising a telescopic four-group continuous zoom optical lens, wherein the telescopic four-group continuous zoom optical lens comprises a lens body, and the direction from the object side to the image side along the optical axis of the lens body is from front to back;

[0023] The lens body comprises a lens barrel, and a variable power lens group and a compensating lens group arranged in the lens barrel; the variable power lens group comprises a first lens group with negative optical power, a second lens group with negative optical power and a third lens group with positive optical power, the compensating lens group comprises a fourth lens group with positive optical power, the first lens group, the second lens group, the third lens group and the fourth lens group are arranged in sequence from front to back, and are movably arranged in the front-to-back direction relative to the lens barrel, respectively, the third lens group is provided with an aperture stop, and the aperture stop is fixed relative to the third lens group so as to be driven by the third lens group to move in the front-to-back direction;

[0024] Wherein, the focal length of the first lens group is f 1 , the focal length of the second lens group is f 2 , the focal length of the third lens group is f 3 , the focal length of the fourth lens group is f 4 The distance between the first lens group and the second lens group at the wide-angle end is d w12 The distance between the first lens group and the second lens group at the telephoto end is d t12 The distance between the third lens group and the fourth lens group at the wide-angle end is d w34 The distance between the third lens group and the fourth lens group at the telephoto end is d t34 , satisfying the following relationship:

[0025] and

[0026] The present invention also provides a mobile phone, which includes the imaging component as described above.

[0027] In the technical solution provided by the present invention, the focal length of the lens body can be adjusted through the relative movement between the variable magnification lens group and the compensation lens group, thereby enriching the application scenarios of the lens body; when the lens body produces a phase difference and reduces the imaging clarity due to the relative movement between the variable magnification lens group and the compensation lens group, the third lens group and the fourth lens group in the compensation lens group can perform more accurate image plane compensation, thereby helping to improve the imaging clarity; the relative movement between the first lens group and the second lens group in the variable magnification lens group can achieve continuous zooming of the lens body, and combined with the above-mentioned relationship, it is possible to balance the imaging quality during continuous zooming and the size of the lens body, which is conducive to the application of the lens body in electronic devices with imaging functions and thin thickness such as mobile phones. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0029] Figure 1 A schematic structural diagram of an embodiment of a lens body (a state) provided by the present invention;

[0030] Figure 2 for Figure 1 A schematic diagram of the structure of the lens body (another state) described in ;

[0031] Figure 3 for Figure 1 MTF curve diagram of the lens body at the wide angle end;

[0032] Figure 4 for Figure 1 MTF curve at the telephoto end of the lens body described in .

[0033] Description of Figure Numbers

[0034] Label name Label name 100 First lens group 310 The fourth lens 110 First lens 320 Fifth lens 200 Second lens group 330 The sixth lens 210 Second lens 400 The fourth lens group 220 The third lens 410 Seventh lens 300 The third lens group 500 Aperture

[0035] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0038] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0039] Optical lenses are essential components in machine vision systems, which directly affect the quality of imaging and the implementation and effect of algorithms. Optical lenses can be divided into fixed-focus lenses and zoom lenses based on focal length. Fixed-focus lenses are widely used as mobile phone lenses due to their low production costs.

[0040] With the continuous development of mobile phone camera lens related technologies, consumers have higher and higher requirements for the performance of mobile phone lenses. The traditional fixed-focus mobile phone lens with digital zoom can no longer meet the growing consumer demand. Continuous optical zoom lenses have the ability to continuously zoom within a certain focal length range, which can achieve perfect imaging at different magnifications. Therefore, they have become the direction of efforts of major mobile phone lens manufacturers. However, the traditional continuous optical zoom lens solution cannot be directly migrated to mobile phones for application. The biggest obstacle lies in the size of the lens. The thickness of a general smartphone is less than 10mm, while the length of a traditional optical zoom lens is at least tens of millimeters. Therefore, applying optical zoom lenses to mobile phone cameras faces huge difficulties.

[0041] In view of this, the present invention provides a mobile phone, including an imaging component, wherein the imaging component includes a telescopic four-group continuous zoom optical lens. Figure 1 A schematic structural diagram of an embodiment of a lens body (a state) provided by the present invention; Figure 2 for Figure 1 A schematic diagram of the structure of the lens body (another state) described in ; Figure 3 for Figure 1 MTF curve diagram of the lens body at the wide angle end; Figure 4 for Figure 1 The MTF curve at the telephoto end of the lens body described in .

[0042] Specifically, the telescopic four-group continuous zoom optical lens provided by the present invention comprises a lens body, and the direction from the object side to the image side along the optical axis of the lens body is from front to back; the lens body comprises a lens barrel and a variable power lens group and a compensation lens group arranged in the lens barrel; the variable power lens group comprises a first lens group with negative optical power, a second lens group with negative optical power and a third lens group with positive optical power, the compensation lens group comprises a fourth lens group with positive optical power, the first lens group, the second lens group, the third lens group and the fourth lens group are arranged in sequence from front to back, and are movably arranged in the front-rear direction relative to the lens barrel, respectively, the third lens group is provided with an aperture stop, and the aperture stop is fixed relative to the third lens group so as to be driven by the third lens group to move in the front-rear direction;

[0043] Among them, the focal length of the first lens group is f 1 , the focal length of the second lens group is f 2 , the focal length of the third lens group is f 3 , the focal length of the fourth lens group is f 4 , the distance between the first lens group and the second lens group at the wide angle end is d w12 , the distance between the first lens group and the second lens group at the telephoto end is d t12 , the distance between the third lens group and the fourth lens group at the wide angle end is d w34 , the distance between the third lens group and the fourth lens group at the telephoto end is d t34 , satisfying the following relationship:

[0044] and

[0045] It should be noted that the zoom lens group is mainly responsible for zooming, and can achieve continuous zooming from the wide-angle end to the telephoto end of the lens body; the compensation lens group is mainly responsible for image plane compensation, and can compensate the image plane during the continuous zooming of the lens body to ensure the image quality of the lens body during continuous zooming. In addition, the zooming principle of the zoom lens group and the image plane compensation principle of the compensation lens group are already existing technologies and will not be described in detail here.

[0046] In the technical solution provided by the present invention, the focal length of the lens body can be adjusted through the relative movement between the variable magnification lens group and the compensation lens group, thereby enriching the application scenarios of the lens body; when the lens body produces a phase difference and reduces the imaging clarity due to the relative movement between the variable magnification lens group and the compensation lens group, the third lens group and the fourth lens group in the compensation lens group can perform more accurate image plane compensation, thereby helping to improve the imaging clarity; the relative movement between the first lens group and the second lens group in the variable magnification lens group can achieve continuous zooming of the lens body, and combined with the above-mentioned relationship, it is possible to balance the imaging quality during continuous zooming and the size of the lens body, which is beneficial to the application of the lens body in electronic devices with imaging functions and thin thickness, such as mobile phones.

[0047] As mentioned above, the third lens group is provided with an aperture, which is fixed relative to the third lens group so as to be driven by the third lens group to move in the front-rear direction. Specifically, in the technical solution of the present invention, the aperture is arranged at the front side of the third lens group. The aperture plays a role in limiting the light beam in the lens. Arranging the aperture at the front side of the third lens group can make its effect better and be more helpful for the imaging effect of the lens body.

[0048] Specifically, in the technical solution of the present invention, the first lens group includes a first lens; the second lens group includes a second lens and a third lens arranged in sequence from front to back; the third lens group includes a fourth lens, a fifth lens and a sixth lens; the fourth lens group includes a seventh lens; the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all aspherical lenses.

[0049] As mentioned above, the first lens group, the second lens group, the third lens group and the fourth lens group are arranged in sequence from front to back, and are movable relative to the lens barrel in the front-to-back direction. Specifically, when the first lens group, the second lens group, the third lens group and the fourth lens group move in the front-to-back direction to be close to each other, the shortest optical length of the lens body is 7.1mm-8.0mm. In this way, the continuous change of focal length can be achieved to obtain better photo and video effects.

[0050] It should be further explained that when the first lens group, the second lens group, the third lens group and the fourth lens group move toward each other in the front-rear direction, the shortest optical length of the lens body is 7.1 mm. The optical length of 7.1 mm makes the performance of the lens body better, and it is convenient to switch between long-range and close-range shooting, so as to achieve better shooting effect.

[0051] Furthermore, when the first lens group, the second lens group, the third lens group and the fourth lens group move away from each other in the front-back direction, the length of the lens body is 10.36-13.61 mm. The telescopic lens body is also more suitable for small electronic devices, making the lens body more retractable and adaptable, which helps to enrich the use scenarios and improve economic benefits.

[0052] In order to achieve higher telescopic accuracy and better telescopic effect of the lens, in the technical solution of the present invention, the lens body also includes a driving device, which is used to drive the first lens group, the second lens group, the third lens group and the fourth lens group to move forward and backward respectively.

[0053] Specifically, the driving device includes a CAM barrel driving mechanism and a VCM driving mechanism; the CAM barrel driving mechanism is arranged on the lens barrel to drive the first lens group, the second lens group and the third lens group to move in the front and rear directions respectively; the VCM driving mechanism is arranged on the lens barrel to drive the fourth lens group to move in the front and rear directions.

[0054] The CAM barrel driving mechanism is a mature technology and will not be described in detail here. Taking the first lens group 100 as an example, the CAM barrel driving mechanism is, for example, that the first lens group 100 is provided with a frame structure for supporting the lens in the first lens group 100, the frame structure is movably connected with a CAM barrel, a guide column is provided at the frame structure, the CAM barrel is provided with a CAM groove corresponding to the guide column, and the guide column is movably connected with the CAM groove, so as to realize the movement of the first lens group 100 relative to the lens barrel.

[0055] The VCM driving mechanism is also a mature technology and will not be described in detail here. The VCM driving mechanism is, for example, that the third lens group 300 is provided with a frame structure for supporting the lens in the third lens group 300, and the outer wall of the frame structure is provided with a first magnetic block and a long strip of position sensing magnetic sheet, and the long strip of position sensing magnetic sheet extends in the front-to-back direction; a VCM motor coil on the lens barrel that is opposite to the magnetic block and is used to drive the frame structure to move forward and backward, and a magnetoresistive sensor that is opposite to the position sensing magnetic sheet and is used to detect the position of the frame structure, and the VCM motor coil is provided with a coil groove facing forward and backward, and a second magnetic block is inserted and fixed in the coil groove, and the magnetic poles of the ends of the first magnetic block and the second magnetic block that are close to each other attract each other.

[0056] The specific data of the telescopic four-group continuous zoom mobile phone lens of this embodiment are given in Tables 1 to 4. In the table, S1 to S23 represent the surface number of each optical element, R represents the radius of curvature of the optical element, D represents the thickness or air gap of the optical element, Nd represents the d-light refractive index of the optical material used, Vd represents the d-light Abbe number of the optical material used, f' represents the focal length of the system, F-number is the system F number, ω is the system half field angle, D1 represents the variable spacing between the first lens group and the second lens group, D2 represents the variable spacing between the second lens group and the third lens group, D3 represents the variable spacing between the third lens group and the fourth lens group, and D4 represents the variable spacing between the fourth lens group and the filter.

[0057] All optical lenses used in the present invention are aspheric lenses. Table 4 shows the aspheric coefficients of all surfaces of the aspheric lenses, where K is the quadratic surface coefficient of the aspheric surface, and A4-A20 are even-order aspheric coefficients.

[0058] Table 1

[0059]

[0060]

[0061] Table 2

[0062] System focal length f' F-numberF-number Half field of view ω Wide-angle end 5.9 1.95 38.34 Telephoto 15 3 18

[0063] Table 3

[0064] D1 D2 D3 D4 Wide-angle end 4.17 6.43 9.46 9.46 Telephoto 0.38 1.41 9.89 4.32

[0065] Table 4

[0066]

[0067]

[0068] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A telescopic four-group continuous zoom optical lens, characterized in that: It includes a lens body, and the direction from the object side to the image side along the optical axis of the lens body is from front to back; The lens body comprises a lens barrel and a variable-power lens group and a compensation lens group arranged in the lens barrel; The variable power lens group includes a first lens group with negative optical power, a second lens group with negative optical power, and a third lens group with positive optical power; the compensation lens group includes a fourth lens group with positive optical power; the first lens group, the second lens group, the third lens group, and the fourth lens group are arranged in sequence from front to back, and are movably arranged in the front-to-back direction relative to the lens barrel; the third lens group is provided with an aperture stop, and the aperture stop is fixed relative to the third lens group so as to be driven by the third lens group to move in the front-to-back direction; The focal length of the first lens group is f1, the focal length of the second lens group is f2, the focal length of the third lens group is f3, the focal length of the fourth lens group is f4, and the distance between the first lens group and the second lens group at the wide-angle end is d w12 The distance between the first lens group and the second lens group at the telephoto end is d t12 The distance between the third lens group and the fourth lens group at the wide-angle end is d w34 The distance between the third lens group and the fourth lens group at the telephoto end is d t34 , satisfying the following relationship: and 2. The telescopic four-group continuous zoom optical lens according to claim 1, characterized in that: The aperture stop is disposed on the front side of the third lens group.

3. The telescopic four-group continuous zoom optical lens according to claim 1 or 2, characterized in that: The first lens group includes a first lens; The second lens group includes a second lens and a third lens arranged in sequence from front to back; The third lens group includes a fourth lens, a fifth lens and a sixth lens; The fourth lens group includes a seventh lens; Wherein, the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens and the seventh lens are all aspherical lenses.

4. The telescopic four-group continuous zoom optical lens according to claim 1 or 2, characterized in that: The lens body further includes a driving device, and the driving device is used to drive the first lens group, the second lens group, the third lens group and the fourth lens group to move in the front-rear direction respectively.

5. The telescopic four-group continuous zoom optical lens as claimed in claim 4, characterized in that: The driving device comprises: A CAM barrel driving mechanism is provided on the lens barrel and is used to drive the first lens group, the second lens group and the third lens group to move in the front-rear direction respectively; and The VCM driving mechanism is arranged on the lens barrel and is used for driving the fourth lens group to move in the front-rear direction.

6. The telescopic four-group continuous zoom optical lens according to claim 1, wherein: When the first lens group, the second lens group, the third lens group and the fourth lens group move away from each other in the front-rear direction, the length of the lens body is 10.36-13.61 mm.

7. The telescopic four-group continuous zoom optical lens according to claim 1, characterized in that: When the first lens group, the second lens group, the third lens group and the fourth lens group move toward each other in the front-rear direction, the shortest optical length of the lens body is 7.1 mm-8.0 mm.

8. The telescopic four-group continuous zoom optical lens as claimed in claim 7, characterized in that: When the first lens group, the second lens group, the third lens group and the fourth lens group move toward each other in the front-rear direction, the shortest optical length of the lens body is 7.1 mm.

9. An imaging assembly, characterized in that: It comprises a telescopic four-group continuous zoom optical lens as described in any one of claims 1 to 8.

10. A mobile phone, characterized in that: Comprising the imaging assembly of claim 9.

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