Low refractive index internal focusing lens unit and optical system thereof

Abstract

An internal focusing lens unit combined with a main imaging lens comprises: at least one positive lens group (G1) and at least one negative lens group (G2). The main imaging lens can be used as a single lens. The internal focusing lens unit is placed within the flange distance between the main imaging lens and the imaging sensor surface, and provides a focusing function when focusing from infinity (INF) to minimum object distance (MOD) by moving the negative lens group (G2) toward the imaging sensor surface to focus at a closer object distance, and vice versa. The excellent optical performance of the main imaging lens is substantially unaffected by the placement of the internal focusing lens unit within the flange distance between the main imaging lens and the imaging sensor surface.

Description

Technical Field

[0001] The present disclosure relates to an optical system, and more particularly to a focusing system of a camera. Background Art

[0002] There are several generally known focusing methods for focusing lenses. Among these methods, there are mainly two generally known methods for focusing telephoto lenses. One of the two methods is the "whole group extension" method, which moves the entire lens group by focusing. In this method, the total length of the lens (TTL) is changed. The other method is the "internal focus" method, which focuses by moving one or more lens groups within the lens system without changing the TTL. The "whole group extension" method is generally used in mobile devices such as mobile phones and tablets due to its advantages of simple structure and high productivity, while the internal focus system is generally used in still cameras and video cameras due to its advantage of fixed TTL. On the other hand, the internal focus system requires a more complex mechanical and optical structure due to the need to move part of the optical system within the lens system. Since the product precision increases the impact of optical performance, the demand for higher precision manufacturing technology makes mass production very difficult.

[0003] Therefore, due to the advantages of internal focusing lens fixed TTL, there has been a demand for its application in mobile devices such as mobile phones and tablets. However, due to the complexity of internal focusing lens in assembly and structure, its introduction in mobile devices has stagnated.

[0004] For the "whole group extension" method, since the optical elements move as a whole, focusing has less impact on optical performance, making mass production simpler. However, since this method changes TTL, it is not optimal for miniaturization, especially for telephoto lenses, because the entire optical system of a telephoto lens usually has a longer stroke than a wide-angle lens and requires a longer focal length. The focusing stroke is related to its focal length, and a telephoto lens must extend the lens for a longer focusing stroke to focus from infinity (INF) to the minimum object distance (MOD). Therefore, it is not preferred to apply the "whole group extension" method to small cameras for mobile devices, especially for telephoto lenses. In addition, there is another problem with the "whole group extension" method. When focusing on a subject at a close point, the extension amount becomes particularly large. In addition, the entire lens system, including the focus drive, needs to be assembled and inspected, which causes problems in mass production.

[0005] For example, the refractive index of the internal focusing type lens in the prior art is too high to reduce the sensitivity to manufacturing errors to improve mass productivity, resulting in an excessively long focusing stroke.

[0006] Existing integrated "extended" optical systems offer better mass production, but the change in TTL during focusing makes miniaturization difficult. This is a significant problem, as the TTL extension is significant (especially when focusing on a close-up subject).

[0007] Therefore, there is a need for an internal lens focusing system for a small camera telephoto lens for mobile devices (such as mobile phones and tablets) that requires a simple structure and high productivity. There is also a need for an internal lens focusing system with a short MOD, which is difficult to achieve in a compact size on mobile devices using a conventional "whole group extension" type focusing mechanism. Summary of the Invention

[0008] The present invention mitigates and / or eliminates the above-mentioned disadvantages.

[0009] The main purpose of the focusing system of the present disclosure is to provide a low-refractive-index internal focusing lens unit and its optical system to provide fixed TTL, short MOD and high productivity.

[0010] The low-refractive-index internal focusing lens unit, also referred to as the focusing lens unit, has a very low refractive index as its entire optical unit according to the present disclosure, and includes at least one positive lens group and at least one negative lens group, wherein the negative lens group is configured to move toward the imaging sensor surface when focusing from INF to MOD, and vice versa. Sometimes, at least one positive lens group of the focusing lens unit can also be configured to move toward the object side to compensate for interfering aberrations that may occur during focusing. It is assumed that the low-refractive-index internal focusing lens unit according to the present invention can be used with an imaging lens, wherein the imaging lens is the main lens unit of the optical system. By inserting the low-refractive-index internal focusing lens unit according to the present disclosure within the flange distance between the main imaging lens and the image sensor surface, a focusing function is provided to the main imaging lens to provide an internal focusing function to the optical system while maintaining the optical performance of the main imaging lens.

[0011] According to one aspect of the present low-refractive-index internal focusing lens unit, when the magnification of the negative lens group of the focusing lens unit is β (the negative lens group is configured to move during focusing), it satisfies the relationship:

[0012] (i) 0.5≦|1-β^2|≦3.5, more preferably 0.7≦|1-β^2|≦3.0

[0013] Satisfying condition (i) keeps the amount of focus stroke small enough to miniaturize the optical system and prevents the error sensitivity of the moving focus lens unit from becoming too strong, which would be disadvantageous in terms of manufacturing and mass production.

[0014] According to one aspect of the present low-refractive-index internal focusing lens unit, when the half-diagonal length of the image sensor of the optical system used with the present focusing lens unit is IMH and the focal length of the focusing lens unit is Ff, it satisfies the relationship:

[0015] (ii) |Ff| / IMH≧10, more preferably |Ff| / IMH≧17

[0016] Satisfying condition (ii) prevents the refractive index of the focusing unit from becoming too large relative to the sensor size, which would make it unsuitable for miniaturization and would lead to deterioration in manufacturing error sensitivity and mass productivity due to its substantial impact on the performance of the main imaging lens.

[0017] According to one aspect of the present low-refractive-index internal focusing lens unit, when the focal length of the main imaging lens used in combination is Fmain and the focal length of the focusing lens unit is Ff, it satisfies the relationship:

[0018] (iii) Ff / Fmain≦0.55, more preferably Ff / Fmain≦0.4

[0019] Satisfying condition (iii) avoids the deterioration of manufacturing and mass productivity caused by the excessive refractive index of the focusing lens unit, and avoids the reduction of the versatility of the optical system due to significant changes in the performance of the main imaging lens when the focusing lens unit is combined with the main imaging lens.

[0020] According to one aspect of the present low refractive index internal focusing lens unit, when the maximum optical effective diameter of the lens in the focusing lens unit is And when the distance between the opposing lens surfaces (the opposing lens surfaces are close together at the INF lens position) between different lens groups of the focusing lens unit is Dmin, it satisfies the relationship:

[0021] (iv) More preferably

[0022] Satisfying condition (iv) keeps the influence of the focusing lens unit on the main imaging lens small enough to maintain the optical performance of the main imaging lens.

[0023] According to one aspect of the present low-refractive-index internal focusing lens unit, the opposing lens surfaces (close together at the INF lens position) between different lens groups of the focusing lens unit have substantially corresponding surfaces. When the surface shape (sag value, SAG (Surface Sag)) of the object-side surface of the opposing lens surface is Sob(h) (which is defined by the lens diameter height h), and the surface shape (SAG value) of the image-side surface of the opposing lens surface is Sim(h), the two satisfy the following relationship:

[0024] (v) 0.5 < |Sob(h) / Sim(h)| < 2.0, more preferably, 0.5 < |Sob(h) / Sim(h)| < 1.8, even more preferably, 0.6 < |Sob(h) / Sim(h)| < 1.7

[0025] According to one aspect of the present low - refractive - index internal focusing lens unit, the radius of the object - side surface of the above - mentioned opposite surface is Rob, and the radius of the imaging - side surface of the above - mentioned opposite surface is Rim, which satisfies the following relationship:

[0026] (vi) 0.5 < Rob / Rim < 2.0

[0027] Satisfying conditions (v) and (vi) avoids the situation that when the two surfaces are close, it is difficult to approximate them as a single lens unit with low aberration because the surface shapes of the above - mentioned opposite surfaces are too different from each other, thus making it difficult to maintain the optical specifications of the main imaging lens.

[0028] According to a second aspect, a low - refractive - index internal lens focusing system is provided. The low - refractive - index internal lens focusing system includes the low - refractive - index internal focusing lens unit of the present disclosure and a main imaging lens. Since the low - refractive - index internal focusing lens unit provides a focusing function for the main imaging lens, the lens elements of the main imaging lens are fixed without a focusing unit. Further, during the lens performance inspection process, various inspections can be performed only on the main imaging lens that is independent of the focusing lens unit, which is helpful for manufacturing. On the other hand, by focusing with such a focusing lens unit, it is possible to avoid changing the TTL and avoid increasing the total lens length. An internal focusing method can be adopted, where the total length remains unchanged and the MOD is short. Further, since the focusing lens unit according to the present invention has a very low refractive index, it has a very small impact on the optical performance of the main imaging lens. Therefore, it can keep the sensitivity to manufacturing errors at a very low level, thus achieving a high manufacturing rate and mass production.

[0029] According to a third aspect, a camera is provided. The camera includes a low - refractive - index internal lens focusing system and an imaging sensor. The low - refractive - index internal lens focusing system is configured to input light rays to the imaging sensor, where the light rays are used to carry image data; and the imaging sensor is configured to convert the image into digital image data.

[0030] According to a fourth aspect, a terminal is provided. The terminal (such as a mobile phone or tablet computer) includes at least one camera (provided in the third aspect) and a graphics processing unit (GPU). The GPU is connected to the camera. The camera is configured to acquire image data and input the image data to the GPU, which is configured to process the image data received from the camera.

[0031] The present disclosure will appear in more detail from the following description taken in conjunction with the accompanying drawings, which show preferred embodiments according to the present disclosure for illustrative purposes only. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present disclosure may be better understood from the following detailed description of non-limiting embodiments and by examination of the accompanying drawings, in which:

[0033] Figure 1-1 1 is a cross-sectional view of an optical lens system at an INF lens position according to a first embodiment of the present disclosure.

[0034] Figure 1-2 1 shows a cross-sectional view of an optical lens system at a MOD lens position according to a first embodiment of the present disclosure.

[0035] Figure 1-3 A comparison of longitudinal spherical aberrations between a main imaging lens and a combination of the main imaging lens and the focusing lens unit according to the first embodiment of the present disclosure is shown.

[0036] Figure 1-4 Shown is an astigmatism field comparison between a main imaging lens and a combination of the main imaging lens and the focusing lens unit according to the first embodiment of the present disclosure.

[0037] Figure 1-5 A distortion comparison between a main imaging lens and a combination of the main imaging lens and the focus lens unit according to the first embodiment of the present disclosure is shown.

[0038] Figure 2-1 A cross-sectional view of an optical lens system at an infinity lens position according to a second embodiment of the present disclosure is shown.

[0039] Figure 2-2 1 shows a cross-sectional view of an optical lens system at a MOD lens position according to a second embodiment of the present disclosure.

[0040] Figure 2-3 A comparison of longitudinal spherical aberrations between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a second embodiment of the present disclosure is shown.

[0041] Figure 2-4Shown is an astigmatism field comparison between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a second embodiment of the present disclosure.

[0042] Figure 2-5 A distortion comparison between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a second embodiment of the present disclosure is shown.

[0043] Figure 3-1 1 shows a cross-sectional view of an optical lens system at an infinity lens position according to a third embodiment of the present disclosure.

[0044] Figure 3-2 1 shows a cross-sectional view of an optical lens system at a MOD lens position according to a third embodiment of the present disclosure.

[0045] Figure 3-3 A comparison of longitudinal spherical aberrations between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a third embodiment of the present disclosure is shown.

[0046] Figure 3-4 Shown is an astigmatism field comparison between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a third embodiment of the present disclosure.

[0047] Figure 3-5 A distortion comparison between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a third embodiment of the present disclosure is shown.

[0048] Figure 4-1 1 shows a cross-sectional view of an optical lens system at an infinity lens position according to a fourth embodiment of the present disclosure.

[0049] Figure 4-2 1 shows a cross-sectional view of an optical lens system at a MOD lens position according to a fourth embodiment of the present disclosure.

[0050] Figure 4-3 A comparison of longitudinal spherical aberrations between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a fourth embodiment of the present disclosure is shown.

[0051] Figure 4-4 Shown is an astigmatism field comparison between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a fourth embodiment of the present disclosure.

[0052] Figure 4-5 A distortion comparison between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a fourth embodiment of the present disclosure is shown.

[0053] Figure 5-1 1 is a cross-sectional view of an optical lens system at an infinity lens position according to a fifth embodiment of the present disclosure.

[0054] Figure 5-2 1 shows a cross-sectional view of an optical lens system at a MOD lens position according to a fifth embodiment of the present disclosure.

[0055] Figure 5-3 A comparison of longitudinal spherical aberrations between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a fifth embodiment of the present disclosure is shown.

[0056] Figure 5-4 Shown is an astigmatism field comparison between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a fifth embodiment of the present disclosure.

[0057] Figure 5-5 A distortion comparison between a main imaging lens and a combination of the main imaging lens and a focus lens unit according to a fifth embodiment of the present disclosure is shown.

[0058] Figure 6-1 1 is a cross-sectional view of an optical lens system at an infinity lens position according to a sixth embodiment of the present disclosure.

[0059] Figure 6-2 1 shows a cross-sectional view of an optical lens system at a MOD lens position according to a sixth embodiment of the present disclosure.

[0060] Figure 6-3 A comparison of longitudinal spherical aberrations between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a sixth embodiment of the present disclosure is shown.

[0061] Figure 6-4 Shown is an astigmatism field comparison between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a sixth embodiment of the present disclosure.

[0062] Figure 6-5 A distortion comparison between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a sixth embodiment of the present disclosure is shown.

[0063] Figure 7-1 1 is a cross-sectional view of an optical lens system at an infinity lens position according to a seventh embodiment of the present disclosure.

[0064] Figure 7-2 1 shows a cross-sectional view of an optical lens system at a MOD lens position according to a seventh embodiment of the present disclosure.

[0065] Figure 7-3 A comparison of longitudinal spherical aberrations between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a seventh embodiment of the present disclosure is shown.

[0066] Figure 7-4Shown is an astigmatism field comparison between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a seventh embodiment of the present disclosure.

[0067] Figure 7-5 A distortion comparison between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a seventh embodiment of the present disclosure is shown.

[0068] Figure 8-1 1 is a cross-sectional view of an optical lens system at an infinity lens position according to an eighth embodiment of the present disclosure.

[0069] Figure 8-2 1 shows a cross-sectional view of an optical lens system at a MOD lens position according to an eighth embodiment of the present disclosure.

[0070] Figure 8-3 A comparison of longitudinal spherical aberrations between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to an eighth embodiment of the present disclosure is shown.

[0071] Figure 8-4 Shown is an astigmatism field comparison between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to an eighth embodiment of the present disclosure.

[0072] Figure 8-5 A distortion comparison between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to an eighth embodiment of the present disclosure is shown.

[0073] Figure 9-1 1 is a cross-sectional view of an optical lens system at an infinity lens position according to a ninth embodiment of the present disclosure.

[0074] Figure 9-2 1 is a cross-sectional view of an optical lens system at a MOD lens position according to a ninth embodiment of the present disclosure.

[0075] Figure 9-3 A comparison of longitudinal spherical aberration between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a ninth embodiment of the present disclosure is shown.

[0076] Figure 9-4 Shown is an astigmatism field comparison between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a ninth embodiment of the present disclosure.

[0077] Figure 9-5 A distortion comparison between a main imaging lens and a combination of the main imaging lens and a focusing lens unit according to a ninth embodiment of the present disclosure is shown.

[0078] Figure 10 An embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0079] The following embodiments will describe the low refractive index internal lens focusing system of the present invention in conjunction with the accompanying drawings and optical data. The lens system can be applied to small cameras of mobile devices (such as mobile phones and tablets). In addition, the optical system includes a main imaging lens and a focusing lens unit. The following embodiments describe the combination of a main imaging lens with good optical performance and the focusing lens unit of the present invention. However, when the focusing unit is inserted into the flange distance between the main imaging lens and the imaging sensor surface to provide focusing function for the main imaging lens, since the focusing unit has a very low refractive index and does not affect the optical performance of the main imaging unit, the focusing unit can be used with various general-purpose main imaging lenses.

[0080] Therefore, the main lens unit and the focusing lens unit can be inspected separately, and productivity is improved. The low-refractive-index internal lens focusing system makes it easier for optical designers to select or design the main imaging lens.

[0081] The low-refractive-index internal lens focusing system also enables a short minimum object distance (MOD) and a fixed total track length (TTL), which are desirable features for telephoto lenses, particularly those used in small cameras in mobile devices such as mobile phones and tablets.

[0082] First embodiment

[0083] Figure 1-1 A cross-sectional view of an optical lens system at infinity is shown according to a first embodiment of the present disclosure. The main imaging lens comprises lens elements ML1, ML2, ML3, and ML4, and the focusing unit comprises lens elements FL1, FL2, and FL3. In this embodiment, the focusing lens unit comprises a first positive lens group consisting of FL1, and a second negative lens group consisting of FL2 and FL3.

[0084] Figure 1-2 FIG2 shows a cross-sectional view of an optical lens system at a MOD lens position according to a first embodiment of the present disclosure. The opposing lens surfaces between FL1 and FL2 substantially have corresponding surfaces.

[0085] Figure 1-1 and Figure 1-2 The focus lens unit's lens elements FL2 and FL3 are moved together toward the image direction for focusing at a closer object distance, and toward the object direction for focusing at a farther object distance. Therefore, the focusing mechanism is easier to design.

[0086] Table 1-1 shows the radius of curvature (r) and thickness or spacing (d) of each optical surface, and the refractive index (N), Abbe number (v), and effective diameter of each lens element of the low-refractive-index internal lens focusing system of the first embodiment. The term "Stop" refers to the aperture surface.

[0087] Table 1-1

[0088]

[0089] Table 1-2 shows the aspheric coefficients of each optical surface of the low refractive index internal lens focusing system, where the numbers 2, 4, ..., 10 represent higher-order aspheric coefficients. The formula for the aspheric profile is as follows:

[0090]

[0091] in:

[0092] X: The height of a point on the aspheric surface at a distance Y from the optical axis to the tangent plane relative to the vertex of the aspheric surface;

[0093] Y: the distance from a point on the aspheric curve to the optical axis;

[0094] k: cone coefficient;

[0095] Ai: aspheric coefficient of order i.

[0096] Table 1-2

[0097] Aspheric coefficient

[0098]

[0099] Figure 1-3 The longitudinal spherical aberration comparison between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the first embodiment of the present disclosure is shown. This comparison shows that the aberration of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0100] Figure 1-4 The astigmatism field comparison between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the first embodiment of the present disclosure is shown. This comparison shows that the astigmatism field of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0101] Figure 1-5 A comparison of the distortion between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the first embodiment of the present disclosure is shown. This comparison shows that the distortion of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0102] Second embodiment

[0103] Figure 2-1 A cross-sectional view of an optical lens system at infinity is shown according to a second embodiment of the present disclosure. The main imaging lens includes lens elements ML1, ML2, ML3, ML4, and ML5, and the focusing unit includes lens elements FL1, FL2, and FL3. In this embodiment, the focusing lens unit comprises a first positive lens group consisting of FL1 and FL2, and a second negative lens group consisting of FL3.

[0104] Figure 2-2 FIG2 shows a cross-sectional view of an optical lens system at a MOD lens position according to a second embodiment of the present disclosure. The opposing lens surfaces between FL2 and FL3 substantially have corresponding surfaces.

[0105] Figure 2-1 and Figure 2-2 This shows that only the lens element FL3 of the focus lens unit is moved toward the image side to focus at a shorter focal length, and toward the object side to focus at an infinite focal length. Therefore, the focusing mechanism is easier to design.

[0106] Table 2-1 shows the radius of curvature (r) and thickness or spacing (d) of each optical surface, and the refractive index (N), Abbe number (v), and effective diameter of each lens element of the low-refractive-index internal lens focusing system of the second embodiment.

[0107] Table 2-1

[0108]

[0109]

[0110] Table 2-2 shows the aspheric coefficients of each optical surface of the low-refractive-index internal lens focusing system, where the numbers 2, 4, ..., 10 represent higher-order aspheric coefficients.

[0111] Table 2-2

[0112] Aspheric coefficient

[0113]

[0114] Figure 2-3 The longitudinal spherical aberration comparison between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the second embodiment of the present disclosure is shown. This comparison shows that the aberration of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0115] Figure 2-4A comparison of the astigmatism field between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the second embodiment of the present disclosure is shown. This comparison shows that the astigmatism field of the main imaging lens alone is barely affected by the added focusing lens unit.

[0116] Figure 2-5 The distortion comparison between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the second embodiment of the present disclosure is shown. This comparison shows that the distortion of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0117] Third embodiment

[0118] Figure 3-1 A cross-sectional view of an optical lens system at infinity is shown according to a third embodiment of the present disclosure. The main imaging lens comprises lens elements ML1, ML2, ML3, ML4, and ML5, and the focusing unit comprises lens elements FL1, FL2, and FL3. In this embodiment, the focusing lens unit comprises a first positive lens group consisting of FL1 and FL2, and a second negative lens group consisting of FL3.

[0119] Figure 3-2 FIG2 shows a cross-sectional view of an optical lens system at a MOD lens position according to a third embodiment of the present disclosure. The opposing lens surfaces between FL2 and FL3 substantially have corresponding surfaces.

[0120] Figure 3-1 and Figure 3-2 This shows that only the lens element FL3 of the focus lens unit is moved toward the image side to focus at a shorter focal length, and toward the object side to focus at an infinite focal length. Therefore, the focusing mechanism is easier to design.

[0121] Table 3-1 shows the radius of curvature (r) and thickness or spacing (d) of each optical surface, and the refractive index (N), Abbe number (v), and effective diameter of each lens element of the low-refractive-index internal lens focusing system of the third embodiment.

[0122] Table 3-1

[0123]

[0124] Table 3-2 shows the aspheric coefficients of each optical surface of the low-refractive-index internal lens focusing system, where the numbers 2, 4, ..., 10 represent higher-order aspheric coefficients.

[0125] Table 3-2

[0126] Aspheric coefficient

[0127]

[0128] Figure 3-3 The longitudinal spherical aberration comparison between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the third embodiment of the present disclosure is shown. This comparison shows that the aberration of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0129] Figure 3-4 The astigmatism field comparison between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the third embodiment of the present disclosure is shown. This comparison shows that the astigmatism field of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0130] Figure 3-5 A comparison of the distortion of the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the third embodiment of the present disclosure is shown. This comparison shows that the distortion of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0131] Fourth embodiment

[0132] Figure 4-1 A cross-sectional view of an optical lens system according to a fourth embodiment of the present disclosure at the infinity lens position is shown. The main imaging lens comprises lens elements ML1, ML2, ML3, and ML4, and the focusing unit comprises lens elements FL1, FL2, and FL3. In this embodiment, the focusing lens unit comprises a first positive lens group consisting of FL1 and FL2, and a second negative lens group consisting of FL3.

[0133] Figure 4-2 FIG2 shows a cross-sectional view of an optical lens system at a MOD lens position according to a fourth embodiment of the present disclosure. The opposing lens surfaces between FL2 and FL3 substantially have corresponding surfaces.

[0134] Figure 4-1 and Figure 4-2 This shows that only the lens element FL3 of the focus lens unit is moved toward the image side to focus at a shorter focal length, and toward the object side to focus at an infinite focal length. Therefore, the focusing mechanism is easier to design.

[0135] Table 4-1 shows the radius of curvature (r) and thickness or spacing (d) of each optical surface, and the refractive index (N), Abbe number (v), and effective diameter of each lens element of the low-refractive-index internal lens focusing system of the fourth embodiment.

[0136] Table 4-1

[0137]

[0138] Table 4-2 shows the aspheric coefficients of each optical surface of the low-refractive-index internal lens focusing system, where the numbers 2, 4, ..., 10 represent higher-order aspheric coefficients.

[0139] Table 4-2

[0140] Aspheric coefficient

[0141]

[0142]

[0143] Figure 4-3 A comparison of longitudinal spherical aberration between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the fourth embodiment of the present disclosure is shown. This comparison shows that the aberration of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0144] Figure 4-4 A comparison of the astigmatism field between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the fourth embodiment of the present disclosure is shown. This comparison shows that the astigmatism field of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0145] Figure 4-5 FIG4 shows a comparison of the distortion of the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the fourth embodiment of the present disclosure. The comparison shows that the distortion of the main imaging lens alone is hardly affected by the newly added focusing lens unit.

[0146] Fifth embodiment

[0147] Figure 5-1 A cross-sectional view of an optical lens system according to a fifth embodiment of the present disclosure at the infinity lens position is shown. The main imaging lens comprises lens elements ML1, ML2, ML3, and ML4, and the focusing unit comprises lens elements FL1, FL2, and FL3. In this embodiment, the focusing lens unit comprises a first positive lens group consisting of FL1, a second negative lens group consisting of FL2, and a third positive lens group consisting of FL3.

[0148] Figure 5-2 FIG2 shows a cross-sectional view of an optical lens system at a MOD lens position according to a fifth embodiment of the present disclosure. The opposing lens surfaces between FL1 and FL2 substantially have corresponding surfaces.

[0149] Figure 5-1 and Figure 5-2 This shows that only the lens element FL2 of the focus lens unit is moved toward the image side to focus at a shorter focal length, and toward the object side to focus at an infinite focal length. Therefore, the focusing mechanism is easier to design.

[0150] Table 5-1 shows the radius of curvature (r) and thickness or spacing (d) of each optical surface, and the refractive index (N), Abbe number (v), and effective diameter of each lens element of the low-refractive-index internal lens focusing system of the fifth embodiment.

[0151] Table 5-1

[0152]

[0153] Table 5-2 shows the aspheric coefficients of each optical surface of the low-refractive-index internal lens focusing system, where the numbers 2, 4, ..., 10 represent higher-order aspheric coefficients.

[0154] Table 5-2

[0155] Aspheric coefficient

[0156]

[0157] Figure 5-3 A comparison of longitudinal spherical aberration between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the fifth embodiment of the present disclosure is shown. This comparison shows that the aberration of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0158] Figure 5-4 The astigmatism field comparison between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the fifth embodiment of the present disclosure is shown. This comparison shows that the astigmatism field of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0159] Figure 5-5 A comparison of the distortion of the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the fifth embodiment of the present disclosure is shown. This comparison shows that the distortion of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0160] Sixth embodiment

[0161] Figure 6-1 A cross-sectional view of an optical lens system according to a sixth embodiment of the present disclosure at the infinity lens position is shown. The main imaging lens includes lens elements ML1, ML2, ML3, and ML4, and the focusing unit includes lens elements FL1, FL2, and FL3. In this embodiment, the focusing lens unit comprises a first positive lens group consisting of FL1, and a second negative lens group consisting of FL2 and FL3.

[0162] Figure 6-2 FIG2 shows a cross-sectional view of an optical lens system at a MOD lens position according to a sixth embodiment of the present disclosure. The opposing lens surfaces between FL1 and FL2 substantially have corresponding surfaces.

[0163] Figure 6-1 and Figure 6-2 The focus lens unit only moves lens elements FL2 and FL3 toward the image side to focus at a shorter focal length, and toward the object side to focus at infinity. This makes the focusing mechanism easier to design.

[0164] Table 6-1 shows the radius of curvature (r) and thickness or spacing (d) of each optical surface, and the refractive index (N), Abbe number (v), and effective diameter of each lens element of the low-refractive-index internal lens focusing system of the sixth embodiment.

[0165] Table 6-1

[0166]

[0167]

[0168] Table 6-2 shows the aspheric coefficients of each optical surface of the low-refractive-index internal lens focusing system, where the numbers 2, 4, ..., 10 represent higher-order aspheric coefficients.

[0169] Table 6-2

[0170] Aspheric coefficient

[0171]

[0172] Figure 6-3 The longitudinal spherical aberration comparison between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the sixth embodiment of the present disclosure is shown. This comparison shows that the aberration of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0173] Figure 6-4 The astigmatism field comparison between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the sixth embodiment of the present disclosure is shown. This comparison shows that the astigmatism field of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0174] Figure 6-5 A comparison of the distortion of the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the sixth embodiment of the present disclosure is shown. This comparison shows that the distortion of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0175] Seventh embodiment

[0176] Figure 7-1A cross-sectional view of an optical lens system according to a seventh embodiment of the present disclosure at the infinity lens position is shown. The main imaging lens includes lens elements ML1, ML2, ML3, ML4, and ML5, and the focusing unit includes lens elements FL1, FL2, and FL3. In the focusing lens unit of this embodiment, the first positive lens group is composed of FL1, the second negative lens group is composed of FL2, and the third negative lens group is composed of FL3.

[0177] Figure 7-2 FIG2 shows a cross-sectional view of an optical lens system at a MOD lens position according to a seventh embodiment of the present disclosure. The opposing lens surfaces between FL1 and FL2 substantially have corresponding surfaces.

[0178] Figure 7-1 and Figure 7-2 The focus mechanism is designed to be easier to design by moving only the lens element FL1 of the focus lens unit toward the image side to focus at a shorter focal length and toward the object side to focus at infinity.

[0179] Table 7-1 shows the radius of curvature (r) and thickness or spacing (d) of each optical surface, and the refractive index (N), Abbe number (v), and effective diameter of each lens element of the low-refractive-index internal lens focusing system of the seventh embodiment.

[0180] Table 7-1

[0181]

[0182] Table 7-2 shows the aspheric coefficients of each optical surface of the low-refractive-index internal lens focusing system, where the numbers 2, 4, ..., 10 represent higher-order aspheric coefficients.

[0183] Table 7-2

[0184] Aspheric coefficient

[0185]

[0186] Figure 7-3 The longitudinal spherical aberration comparison between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the seventh embodiment of the present disclosure is shown. This comparison shows that the aberration of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0187] Figure 7-4 The astigmatism field comparison between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the seventh embodiment of the present disclosure is shown. This comparison shows that the astigmatism field of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0188] Figure 7-51 shows a comparison of the distortion between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the seventh embodiment of the present disclosure. This comparison shows that the distortion of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0189] Eighth embodiment

[0190] Figure 8-1 A cross-sectional view of an optical lens system at infinity is shown according to an eighth embodiment of the present disclosure. The main imaging lens comprises lens elements ML1, ML2, ML3, ML4, and ML5, and the focusing unit comprises lens elements FL1, FL2, and FL3. In this embodiment, the focusing lens unit comprises a first positive lens group consisting of FL1 and FL2, and a second negative lens group consisting of FL3.

[0191] Figure 8-2 FIG2 shows a cross-sectional view of an optical lens system at a MOD lens position according to an eighth embodiment of the present disclosure. The opposing lens surfaces between FL2 and FL3 substantially have corresponding surfaces.

[0192] Figure 8-1 and Figure 8-2 This shows that only the lens element FL2 of the focus lens unit is moved toward the image side to focus at a shorter focal length, and toward the object side to focus at an infinite focal length. Therefore, the focusing mechanism is easier to design.

[0193] Table 8-1 shows the radius of curvature (r) and thickness or spacing (d) of each optical surface, and the refractive index (N), Abbe number (v), and effective diameter of each lens element of the low-refractive-index internal lens focusing system of the eighth embodiment.

[0194] Table 8-1

[0195]

[0196] Table 8-2 shows the aspheric coefficients of each optical surface of the low-refractive-index internal lens focusing system, where the numbers 2, 4, ..., 10 represent higher-order aspheric coefficients.

[0197] Table 8-2

[0198] Aspheric coefficient

[0199]

[0200]

[0201] Figure 8-3The longitudinal spherical aberration comparison between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the eighth embodiment of the present disclosure is shown. This comparison shows that the aberration of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0202] Figure 8-4 The astigmatism field comparison between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the eighth embodiment of the present disclosure is shown. This comparison shows that the astigmatism field of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0203] Figure 8-5 A comparison of the distortion of the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the eighth embodiment of the present disclosure is shown. This comparison shows that the distortion of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0204] Ninth embodiment

[0205] Figure 9-1 A cross-sectional view of an optical lens system according to a ninth embodiment of the present disclosure at the infinity lens position is shown. The main imaging lens includes lens elements ML1, ML2, ML3, and ML4, and the focusing unit includes lens elements FL1, FL2, FL3, and FL4. In the focusing lens unit of this embodiment, the first positive lens group is composed of FL1, the second negative lens group is composed of FL2, the third positive lens group is composed of FL3, and the fourth negative lens group is composed of FL4.

[0206] Figure 9-2 FIG2 shows a cross-sectional view of an optical lens system according to a ninth embodiment of the present disclosure at the MOD lens position. The opposing lens surfaces between FL1 and FL2 substantially correspond to each other. The opposing lens surfaces between FL3 and FL4 also substantially correspond to each other.

[0207] Figure 9-1 and Figure 9-2 The focus mechanism can be designed more easily by moving only the lens elements FL2 and FL3 of the focus lens unit in opposite directions to focus to a shorter focal length or to focus to infinity.

[0208] Table 9-1 shows the radius of curvature (r) and thickness or spacing (d) of each optical surface, and the refractive index (N), Abbe number (v), and effective diameter of each lens element of the low-refractive-index internal lens focusing system of the ninth embodiment.

[0209] Table 9-1

[0210]

[0211]

[0212] Table 9-2 shows the aspheric coefficients of each optical surface of the low-refractive-index inner lens focusing system, where the numbers 2, 4, ..., 10 represent higher-order aspheric coefficients.

[0213] Table 9-2

[0214] Aspheric coefficient

[0215]

[0216] Figure 9-3 A comparison of longitudinal spherical aberration between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the ninth embodiment of the present disclosure is shown. This comparison shows that the aberration of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0217] Figure 9-4 The astigmatism field comparison between the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the ninth embodiment of the present disclosure is shown. This comparison shows that the astigmatism field of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0218] Figure 9-5 1 shows a comparison of the distortion of the main imaging lens and the combination of the main imaging lens and the focusing lens unit according to the ninth embodiment of the present disclosure. This comparison shows that the distortion of the main imaging lens alone is hardly affected by the added focusing lens unit.

[0219] As shown in the optical data, the main imaging lens and the focusing unit are arranged in the low-refractive-index internal lens focusing system according to the present disclosure, and the two can be checked independently of each other. Only one or a pair of lenses in the focusing lens unit is moved to focus the lens system without changing the TTL, which greatly simplifies the focusing mechanism. In addition, the focusing lens unit does not affect the performance of the main imaging lens. In other words, the focusing lens unit can provide a focus adjustment function for various main imaging lenses without causing deterioration in the imaging quality of the main imaging lens. The low-refractive-index internal focusing lens unit (also referred to as the focusing lens unit) described in the present invention has a very low refractive index and includes at least one positive lens combined with at least one negative lens group. In the process of focusing from infinity to MOD, the negative lens group moves toward the imaging sensor surface to focus at a closer object distance, and vice versa. The above advantages can be achieved when the following formula is satisfied:

[0220] (i):0.5≦|1-β^2|≦3.5

[0221] Where β is the magnification of the negative lens group of the focusing lens unit,

[0222] (ii):|Ff| / IMH≧10

[0223] Where Ff is the focal length of the focusing lens unit and IMH is the half-diagonal length of the imaging sensor.

[0224] (iii):|Ff / Fmain|≦0.55

[0225] Where Fmain is the focal length of the combined main imaging lens.

[0226] (iv)

[0227] where Dmin is the distance between the different lens groups of the focusing lens unit relative to the lens surface, which are close together at the INF lens position, It is the maximum optically effective diameter of the lens in the focusing lens unit.

[0228] (v): 0.5 <abs[Sob(h) / Sim(h)]<2.0

[0229] Among them, the relative lens surfaces between different lens groups of the focusing lens unit (the relative lens surfaces are close together at the INF lens position) basically have corresponding surfaces, Sob(h) is the surface shape (SAG amount) of the object side surface of the relative lens surface, which is defined by the lens diameter height h, and Sim(h) is the surface shape (SAG amount) of the imaging side of the relative surface.

[0230] (vi): 0.5 <Rob / Rim<2.0

[0231] Where Rob is the radius of the object-side surface relative to the lens surface, and Rim is the radius of the imaging-side surface relative to the lens surface.

[0232] Condition (i) keeps the amount of focus stroke small enough to miniaturize the optical system and prevents the error sensitivity of the moving focus lens unit from becoming too strong, which is disadvantageous in terms of manufacturing and mass production. Accordingly, the following ranges are more preferred:

[0233] (i) -2: 0.7 ≦ |1-β^2| ≦ 3.0

[0234] Condition (ii) prevents the refractive index of the focusing unit from becoming too large relative to the sensor size. Such a large refractive index would make it unsuitable for miniaturization and would substantially affect the performance of the main imaging lens, leading to deterioration in sensitivity to manufacturing errors and deterioration in mass productivity. Therefore, the following ranges are more preferred:

[0235] (ii)-2: Preferably, |Ff| / IMH≧17

[0236] Condition (iii) avoids deterioration of manufacturing and mass productivity caused by an overly high refractive index of the focusing lens unit, and avoids a reduction in the versatility of the optical system due to a significant change in the performance of the main imaging lens when the focusing lens unit is combined with the main imaging lens. Accordingly, the following range is more preferable:

[0237] (iii)-2: |Ff / Fmain|≦0.4

[0238] Condition (iv) keeps the influence of the focusing lens unit on the main imaging lens small enough to maintain the optical performance of the main imaging lens. Accordingly, the following range is more preferable:

[0239] (iv)-2:

[0240] Condition (v) keeps the relative lens surfaces close enough to each other. When the relative lens surfaces between different lens groups of the focusing lens unit (which are close together at the INF lens position) differ too much to be approximated as a single lens unit with low aberration when the two surfaces are close to each other, it becomes difficult to maintain the optical performance of the main imaging lens. Accordingly, the following range is more preferable:

[0241] (v)-2: 0.5 < abs[Sob(h) / Sim(h)] < 1.8, or even

[0242] (v)-3: 0.6 < abs[Sob(h) / Sim(h)] < 1.7

[0243] With the low refractive index internal focusing lens unit of the present invention, the main imaging lens does not need to have a focusing optical function, which results in a compact design and inexpensive mass production. Further, during the lens performance inspection process, various inspections can be performed only on the main imaging lens independent of the focusing lens unit, which helps in manufacturing. On the other hand, by focusing with such a focusing lens unit, it is possible to avoid changing the TTL and avoid increasing the total lens length. An internal focusing method can be adopted, where the total length remains unchanged and the MOD is short. Further, since the focusing lens unit according to the present invention has a very low refractive index, it has a very small influence on the optical performance of the main imaging lens. Therefore, it can keep the sensitivity to manufacturing errors at a very low level, thus achieving a high manufacturing rate and mass production.

[0244] Furthermore, a camera is provided. The camera of the present disclosure includes the low-refractive-index internal lens focusing system of the present disclosure and an imaging sensor. The low-refractive-index internal lens focusing system is configured to input light for projecting an image onto the imaging sensor; and the imaging sensor is configured to convert the image into digital image data. The camera has a fixed TTL, which is preferred for installation in a mobile device.

[0245] Figure 10 FIG2 shows a terminal 1000 disclosed in the present disclosure. The terminal 1000 includes the camera 100 provided in the above embodiment, and a graphics processing unit (GPU) 200. The camera 100 is configured to convert an image into digital image data through the low-refractive-index internal lens system of the present disclosure, and input the digital image data to the GPU 200. The GPU 200 is configured to process the image data received from the camera.

[0246] exist Figure 10 In the embodiment, the terminal 1000 includes two cameras 100. However, the terminal may include a single camera or two or more cameras, and these cameras may be connected to at least one GPU 200. The camera 100 can be applied as a high-resolution mobile device camera, such as a mobile phone camera, due to its high imaging quality, fixed TTL, and high productivity.

[0247] Those skilled in the art will appreciate that high productivity is difficult in mass production of internal lens focusing systems for fixed TTLs. The present disclosure satisfies these dual requirements by satisfying the above relationship.

[0248] In the present disclosure, the term "low refractive index" should be understood to satisfy the relationship |Ff / Fmain|≦0.55, where Ff is the focal length of the internal focusing lens unit and Fmain is the focal length of the main imaging lens, both used in combination.

[0249] While the lens system of the present disclosure may be particularly applicable to mobile phone cameras, it may also be applicable to cameras of any mobile device, such as tablet-type devices and wearable devices.

[0250] Although the preferred embodiments of the present disclosure have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the disclosure as disclosed in the accompanying claims.

Claims

1. An internal focusing lens unit combined with a main imaging lens, comprising: at least one positive lens group and at least one negative lens group; wherein the main imaging lens may be used as a separate lens group, and the internal focusing lens unit is placed within the flange distance between the main imaging lens and the imaging sensor surface, and provides a focusing function by moving the negative lens group toward the imaging sensor surface to focus at a closer object distance when focusing from infinity INF to minimum object distance MOD, and vice versa; The internal focusing lens unit satisfies the following relationship: |Ff| / IMH≧10; wherein Ff is the focal length of the internal focusing lens unit, and IMH is the half-diagonal length of the imaging sensor; The internal focusing lens unit satisfies the following relationship: |Ff / Fmain|≦0.55; where Fmain is the focal length of the main imaging lens.

2. The internal focusing lens unit according to claim 1, wherein: The following relationship is satisfied: ； in is the magnification of the negative lens group of the inner focusing lens unit.

3. The internal focusing lens unit according to claim 2, wherein: The following relationship is satisfied: 。 4. The internal focusing lens unit according to claim 1, wherein: The following relationship is satisfied: |Ff| / IMH≧17.

5. The internal focus lens unit according to claim 1, wherein: The following relationship is satisfied: |Ff / Fmain|≦0.

4.

6. The internal focusing lens unit according to any one of claims 1 to 5, wherein: The following relationship is satisfied: ； where Dmin is the distance between the opposing lens surfaces of the different lens groups of the internal focusing lens unit in the INF lens position, is the maximum optically effective diameter of the internal focusing lens unit.

7. The internal focusing lens unit according to claim 6, wherein: The following relationship is satisfied: 。 8. The internal focusing lens unit according to any one of claims 1 to 7, wherein: The opposing lens surfaces between different lens groups of the internal focusing lens unit substantially have corresponding surfaces, and the following relationship is satisfied: 0.5 <abs[Sob(h) / Sim(h)]<2.0; Among them, Sob(h) is the sag amount of the surface shape of the object side surface of the opposite lens surface, which is defined by the lens diameter height h, and Sim(h) is the SAG amount of the surface shape of the imaging side of the opposite lens surface.

9. The internal focus lens unit according to claim 8, wherein: The following relationship is satisfied: 0.5 <abs[Sob(h) / Sim(h)]<1.8。 10. The internal focusing lens unit according to claim 9, wherein: The following relationship is satisfied: 0.6 <abs[Sob(h) / Sim(h)]<1.7。 11. The internal focus lens unit according to any one of claims 1 to 10, wherein: The following relationship is satisfied: 0.5 <Rob / Rim<2.0; The relative lens surfaces between different lens groups of the focusing lens unit basically have corresponding surfaces, and the radius of the object side surface of the relative lens surfaces is Rob, and the radius of the imaging side surface of the relative lens surfaces is Rim.

12. An internal lens focusing system comprising: main imaging lens; Internal focusing lens unit; The main imaging lens can be used as a separate lens group; the internal focusing lens unit includes at least one positive lens group and at least one negative lens group; the internal focusing lens unit is located within the flange distance between the main imaging lens and the imaging sensor surface to provide a focusing function for the main imaging lens, and when focusing from infinity INF to minimum object distance MOD, the negative lens group is moved toward the imaging sensor surface to focus at a closer object distance, and vice versa; The internal lens focusing system satisfies the following relationship: |Ff| / IMH≧10; wherein Ff is the focal length of the internal focusing lens unit, and IMH is the half-diagonal length of the imaging sensor; The internal lens focusing system satisfies the following relationship: |Ff / Fmain|≦0.55; where Fmain is the focal length of the main imaging lens.

13. The internal lens focusing system of claim 12, wherein: Satisfies the following relationship: ； in is the magnification of the negative lens group of the inner focusing lens unit.

14. The internal lens focusing system of claim 13, wherein: Satisfies the following relationship: 。 15. The internal lens focusing system of claim 12, wherein: The following relationship is satisfied: |Ff| / IMH≧17.

16. The internal lens focusing system of claim 12, wherein: The following relationship is satisfied: |Ff / Fmain|≦0.

4.

17. The internal lens focusing system according to any one of claims 12 to 16, wherein the following relationship is satisfied: ； where Dmin is the distance between the opposing lens surfaces of the different lens groups of the internal focusing lens unit in the INF lens position, is the maximum optically effective diameter of the internal focusing lens unit.

18. The internal lens focusing system of claim 17, wherein the following relationship is satisfied: 。 19. The internal lens focusing system according to any one of claims 12 to 18, wherein the following relationship is satisfied: 0.5 <abs[Sob(h) / Sim(h)]<2.0; in, Sob(h) is the sag amount of the surface shape of the object side surface of the opposing lens surface, which is defined by the lens diameter height h, and Sim(h) is the SAG amount of the surface shape of the image side surface of the opposing lens surface.

20. The internal lens focusing system of claim 19, wherein the following relationship is satisfied: 0.5 <abs[Sob(h) / Sim(h)]<1.8。 21. The internal lens focusing system of claim 20, wherein the following relationship is satisfied: 0.6 <abs[Sob(h) / Sim(h)]<1.7。 22. The internal lens focusing system of any one of claims 12 to 21, wherein: The following relationship is satisfied: 0.5 <Rob / Rim<2.0; The relative lens surfaces between different lens groups of the internal focusing lens unit basically have corresponding surfaces, and the radius of the object side surface of the relative lens surfaces is Rob, and the radius of the imaging side surface of the relative lens surfaces is Rim.

23. A camera comprising: An internal lens focusing system according to any one of claims 12 to 22; Imaging sensors; Wherein, the internal lens focusing system is configured to project an image onto the imaging sensor, and the imaging sensor is configured to convert the image into digital image data.

24. A terminal comprising: at least one camera according to claim 23, and a graphics processing unit GPU, The GPU is connected to the at least one camera to receive and process the digital image data.

Images