TW202309583A - Zoom lens - Google Patents

Abstract

A zoom lens includes a zoom lens group, a focus lens group, a first driving mechanism, a second driving mechanism, and a first photointerrupter. After the completion of the focus action, the position of the zoom lens group and the corresponding position of the focus lens group can be in a rectangular coordinate plane to form a corresponding curve. Wherein the first photointerrupter is provided with a position corresponding to a position of the zoom lens group, the position of the zoom lens group being a point of the corresponding curve at a projection point on the horizontal axis, the point of the corresponding curve meets one of the following conditions: (1)0.1 ≤ S ≤ 5.7, (2)-5.7 ≤ S ≤ -0.1, where S is the slope of the point of the corresponding curve.

Description

zoom lens

The present invention relates to a zoom lens, and more particularly to a zoom lens with a photointerrupter.

In recent years, security cameras have been widely used in security monitoring. Whether in homes, businesses, government agencies, or even general public places, security cameras have become an indispensable monitoring tool for personal safety and property protection. Generally speaking, security cameras can monitor the dynamics of a monitoring environment to keep track of the occurrence of special events. Therefore, when a special event occurs, the user can detect the occurrence of the event through the security camera, or the security camera can automatically notify the user, so that the user can deal with the special event immediately.

In the prior art, the lens module included in the security camera can be divided into various forms such as a fixed-focus lens or a zoom lens. Among them, because the structure of the fixed-focus lens is relatively simple, it has the advantages of small size, light weight, good image quality, and relatively cheap price, and is widely used by ordinary consumers, but it has the disadvantage of being unable to change the focal length at will, resulting in Users will be subject to certain restrictions when using security cameras with fixed-focus lenses. In addition, even if a security camera with a zoom lens is used to allow users to adjust the focal length according to their own needs, as high-pixel security cameras are developed, it often happens that the zooming accuracy of the zoom lens is not correspondingly improved. The image quality of the pixel security camera cannot be used to its maximum effect, which further affects the quality of the image capture of the security camera due to the lack of zoom precision of the zoom lens. Therefore, how to provide a way to achieve high zoom precision is a problem that manufacturers need to solve.

Other purposes and advantages of the present invention can be further understood from the technical features disclosed in the embodiments of the present invention.

An embodiment of the present invention provides a zoom lens, including a zoom lens group, a focus lens group, a first driving mechanism, a second driving mechanism and a first photointerrupter. The zoom lens group and the focus lens group are provided with the same optical axis. The first driving part can drive the zoom lens group to move along the optical axis, and the second driving part can drive the focus lens group to move along the optical axis. Wherein, after the zoom lens finishes focusing, the position of the zoom lens group and the position of the corresponding focusing lens group can form a corresponding curve on a rectangular coordinate plane. The rectangular coordinate plane takes the position of the zoom lens group at the wide-angle end as the origin, and the zoom lens group The direction moving along the optical axis from the wide-angle end to the telephoto end is the positive direction of the horizontal axis of the Cartesian coordinate plane, the relative distance between the position of the zoom lens group and the position of the wide-angle end of the zoom lens group is the horizontal axis coordinate, and the position of a focus reference line is the Cartesian coordinate Point 0 on the vertical axis of the plane, the direction in which the focus lens group moves from the position of the focus reference line to the wide-angle end of the focus lens group along the optical axis is the positive direction of the vertical axis of the Cartesian coordinate plane, and the relative distance between the position of the focus lens group and the position of the focus reference line is Coordinates on the vertical axis, wherein the first photointerrupter is provided with a placement position, corresponding to a position of the zoom lens group, the position of the zoom lens group is a projection point of a point on the corresponding curve on the horizontal axis, corresponding to this point of the curve Satisfy one of the following conditions: (1) 0.1≦S≦5.7, (2) -5.7≦S≦-0.1, S is the slope of the point of the corresponding curve.

An embodiment of the present invention provides a zoom lens, including a zoom lens group, a focus lens group, a first driving mechanism, a second driving mechanism and a first photointerrupter. The zoom lens group and the focus lens group are provided with the same optical axis. The first driving part can drive the zoom lens group to move along the optical axis, and the second driving part can drive the focus lens group to move along the optical axis. Wherein, after the zoom lens finishes focusing, the position of the zoom lens group and the position of the corresponding focusing lens group can form a corresponding curve on a rectangular coordinate plane. The rectangular coordinate plane takes the position of the zoom lens group at the wide-angle end as the origin, and the zoom lens group The direction moving along the optical axis from the wide-angle end to the telephoto end is the positive direction of the horizontal axis of the Cartesian coordinate plane, the relative distance between the position of the zoom lens group and the position of the wide-angle end of the zoom lens group is the horizontal axis coordinate, and the position of a focus reference line is the Cartesian coordinate Point 0 on the vertical axis of the plane, the direction in which the focus lens group moves from the position of the focus reference line to the wide-angle end of the focus lens group along the optical axis is the positive direction of the vertical axis of the Cartesian coordinate plane, and the relative distance between the position of the focus lens group and the position of the focus reference line is Coordinates on the vertical axis, where the corresponding curve has an inflection point with a slope of 0, the projection point of the inflection point on the horizontal axis is C, the point of the zoom lens group at the telephoto end corresponding to the horizontal axis is A10, and point C on the horizontal axis The distance to point A10 is equally divided into 10 equal parts, and the 9 equal points are respectively set as A1, A2..., A8, A9, A1 is closest to point C, and the distance from point C to the origin on the horizontal axis is divided into equal parts 10 equal divisions, and 9 equal division points are respectively set as B1, B2..., B8, B9, B9 is closest to point C, wherein the first photointerrupter is provided with a placement position corresponding to a position of the zoom lens group, The position of the zoom lens group satisfies one of the following conditions: (1) between point A1 and point A9, (2) between point B1 and point B9.

An embodiment of the present invention provides a zoom lens, including a zoom lens group, a focus lens group, a first stepping motor, a second stepping motor and a first photointerrupter. The zoom lens group and the focus lens group are provided with the same optical axis. The first stepping motor can drive the zoom lens group to move along the optical axis, and the second stepping motor can drive the focusing lens group to move along the optical axis. Wherein, after the zoom lens finishes focusing, the position of the zoom lens group and the position of the corresponding focusing lens group can form a corresponding curve on a rectangular coordinate plane. The rectangular coordinate plane takes the position of the zoom lens group at the wide-angle end as the origin, and the zoom lens group The direction moving along the optical axis from the wide-angle end to the telephoto end is the positive direction of the horizontal axis of the Cartesian coordinate plane, the relative distance between the position of the zoom lens group and the position of the wide-angle end of the zoom lens group is the horizontal axis coordinate, and the position of a focus reference line is the Cartesian coordinate Point 0 on the vertical axis of the plane, the direction in which the focus lens group moves from the position of the focus reference line to the wide-angle end of the focus lens group along the optical axis is the positive direction of the vertical axis of the Cartesian coordinate plane, and the relative distance between the position of the focus lens group and the position of the focus reference line is Coordinates on the vertical axis, where the corresponding curve has an inflection point with a slope of 0, the projection point of the inflection point on the horizontal axis is C, and the first stepping motor drives the zoom lens group at the position of the inflection point to the direction of the telephoto end in full steps Move one step forward, the projection point corresponding to the horizontal axis on the corresponding curve is H1, and the second stepping motor drives the focus lens group to move one step in full steps in the direction of the inflection point at the telephoto end, which corresponds to The projection point of the horizontal axis is I1. The first stepping motor drives the zoom lens group to move one step in the direction of the wide-angle end at the position of the inflection point. Its projection point on the horizontal axis corresponding to the corresponding curve is J1. The second step The motor drives the focusing lens group at the wide-angle end position toward the inflection point to move one step in full steps. Its projection point on the corresponding horizontal axis of the corresponding curve is L1, and the first photointerrupter has a placement position corresponding to At a position of the zoom lens group, the position of the zoom lens group satisfies one of the following conditions: (1) between point H1 and point I1, (2) between point J1 and point L1.

With the design of the embodiment of the present invention, the zoom lens can have high zooming precision through the limitation of the placement positions of the photo-interrupters of the zoom lens group and the focus lens group. Therefore, a zoom lens design with good zoom precision and better imaging quality can be provided.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail together with the accompanying drawings.

The foregoing and other technical contents, features and effects of the present invention will be clearly presented in the following detailed descriptions of multiple embodiments with reference to the drawings. The directional terms mentioned in the following embodiments, such as "upper", "lower", "front", "rear", "left", "right", etc., are only referring to the directions of the attached drawings. Accordingly, the directional terms are used to illustrate, not to limit, the invention. In addition, the terms "first" and "second" used in the following embodiments are used to identify the same or similar components, and are not used to limit the components. In addition, the following embodiments only further illustrate the projection device and the display system, and those skilled in the art can apply the connection system to any desired situation according to actual needs.

An embodiment of the present invention proposes a camera device using a zoom lens. FIG. 1 shows a schematic structural diagram of a camera device 10 according to an embodiment of the present invention. As the imaging device 10 , for example, a security camera, a digital camera, a smart phone, a drone, and the like. The imaging device 10 includes a zoom lens 1, a filter 7 disposed on the image side of the zoom lens 1, an image sensor 8 that receives an image generated by the zoom lens 1, and a microprocessor that performs arithmetic processing on the output signal from the image sensor 8. device 4, a zoom lens group control module 5 for zooming (zoom) of the zoom lens 1, and a focus lens group control module 6 for performing focus (focus) of the zoom lens 1. In Fig. 1, it is shown that the zoom lens 1 is composed of the first lens group G1 to the fifth lens group G5, but the zoom lens of the present invention is not limited thereto, and may also be composed of two mirror groups, three mirror groups or It can be composed of other lens groups as long as it has a zoom lens group and a focus lens group at the same time. The number of lenses included in the zoom lens group can be single or multiple, and the number of lenses included in the focusing lens group can be single or multiple, which is not limited in the present invention. The image sensor 8 is, for example, a CCD (Charge Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor), or the like. It should be noted that FIG. 1 only shows one image sensor 8 , but the imaging device of the present invention is not limited thereto, and may also be a so-called 3-board imaging device having three image sensors.

FIG. 2 shows a schematic cross-sectional view of the zoom lens 1 according to an embodiment of the present invention. The zoom lens 1 includes a first lens group G1, a second lens group G2, a third lens group G3, a fourth lens group G4, and a fifth lens group G5. The second lens group G2 (zoom lens group) moves along the optical axis 20 for zooming, and the position of the wide-angle end (wide) of the zoom lens group G2 is used as a zoom reference line 42 . The fourth lens group G4 (focusing lens group) moves along the direction of the optical axis 20 for focusing, and a mechanism (not shown) is used as the focusing reference line 44, and the directions of the arrows X and -X are consistent with the light The axis 20 is in the same direction. The direction of the arrow X is the direction in which the zoom lens group G2 moves from the wide-angle end to the telephoto end (tele), and the direction of the arrow -X is the direction in which the zoom lens group G2 moves from the telephoto end to the wide-angle end. The first lens group G1, the third lens group G3 and the fifth lens group G5 are fixed on the frame (not shown in the figure).

The driving mechanism 22 drives the zoom lens group G2 to move along the optical axis 20 for zooming, and the driving mechanism 24 drives the focusing lens group G4 to move along the optical axis 20 for focusing. As the drive elements 22 and 24, for example, stepping motors, voice coil motors, piezoelectric elements, and the like are used. In this embodiment, the driving parts 22 and 24 are stepping motors. It should be noted that stepping motors can be divided into full-stepping, half-stepping and micro-stepping. Align the tooth slots of the stator, so the distance of each movement of the full-step motor is a multiple of one step, and the half-step is to move the tooth slot of the rotor to the middle of the two slots of the stator, so the half-step motor The distance of each movement is a complex multiple of 1/2 steps, and micro-stepping uses current and magnetic technology to achieve finer positioning and segmentation (resolution) by electronic segmentation. In this embodiment, although a full-step motor is used, it is not limited thereto, and a half-step or micro-step motor may also be used.

The switch between the light-shielding state and the light-transmitting state caused by the movement of the light-shielding portion 222 disposed on the zoom lens group G2 along the optical axis 20 is detected by the photo-interrupter 32 to confirm the position of the zoom lens group G2. In the same way, the switch between the light-shielding state and the light propagation state caused by the movement of the light-shielding portion 242 arranged in the focusing lens group G4 along the direction of the optical axis 20 is detected by the photo-interrupter 34, so as to confirm the function of the focusing lens group G4. Location.

FIG. 3 shows a schematic diagram of the corresponding curve 60 drawn by the position of the zoom lens group and the corresponding position of the focus lens group on the Cartesian coordinate plane 50 after the zoom lens 1 according to an embodiment of the present invention is in focus. Cartesian coordinate plane 50 takes the position of the zoom lens group G2 at the wide-angle end (wide) as the origin O, and the direction in which the zoom lens group G2 moves from the wide-angle end to the telephoto end (tele) is the positive direction of the horizontal axis (X axis). In the direction (+X), the abscissa coordinates the relative distance between the position of the zoom lens group G2 and the position of the wide-angle end. Take the position of the focus reference line 44 in Figure 2 as 0 point on the vertical axis (Y axis), take the moving direction of the focus lens group G4 from the reference line to the wide-angle end as the positive direction (+Y) of the vertical axis, and use the focus lens The relative distance between the position of group G4 and the position of the reference line is the coordinate on the vertical axis. Table 1 shows the values of several coordinate points K1-K7 on the Cartesian coordinate plane 50 after the focusing is completed, taking the position of the zoom lens group and the corresponding position of the focusing lens group. FIG. 3 also marks the approximate positions of K1 to K7 on the corresponding curve 60 . Table I Horizontal axis (mm) Longitudinal axis (mm) Remark K1 0 8.68 Zoom lens group wide-angle end Focus lens group wide-angle end K2 7.08 7.74 K3 16.23 5.77 K4 28.22 1.87 inflection point K5 30.51 2.75 K6 32.65 6.09 K7 33.25 7.60 Zoom lens group telephoto end Focus lens group telephoto end

In order to make the zoom lens have high zooming precision, an embodiment of the present invention achieves this by restricting the placement positions of the zoom lens group and the photo interrupter of the zoom lens group. Please refer to Figure 2, Figure 3 and Figure 4 at the same time, the corresponding curve 60 has an inflection point K4 with a slope of 0, the projection point of the inflection point K4 on the horizontal axis is C, and the zoom lens group G2 corresponds to the horizontal position K7 at the telephoto end A point on the axis is A10. Divide the distance from point C to point A10 on the horizontal axis into 10 equal parts, and set the 9 equal points as A1, A2..., A8, A9 respectively. A1 is closest to point C. The distance from point C on the axis to the origin is equally divided into 10 equal parts, and the 9 equal parts are respectively set as B1, B2..., B8, B9, and B9 is closest to point C, among which the photointerrupter of zoom lens group G2 The placement position of 32 corresponds to the position of the zoom lens group, which is between point A1 and point A9, or between point B1 and point B9. The better one can be between point A2 and point A8, or between point B2 and point B8. The better one can be between point A3 and point A7, or between point B3 and point B7. It should be noted that the placement position of the photo-interrupter 32 of the zoom lens group G2 corresponds to the position of the zoom lens group, which means that the positions of the photo-interrupter 32 and the zoom lens group G2 in the direction of the arrow X are the same.

Similarly, please refer to Figure 2, Figure 3 and Figure 4 at the same time, the corresponding curve 60 has an inflection point K4 with a slope of 0, the projection point of the inflection point K4 on the vertical axis is D, and the focusing lens group G4 is at the telephoto end The point corresponding to the vertical axis of K7 is E10, and the distance from point D to point E10 on the vertical axis is divided into 10 equal parts, and the 9 equal points are respectively set as E1, E2..., E8, E9, and E1 is closest to point D , the point of the focus lens group G4 at the wide-angle end position K1 corresponding to the vertical axis is F10, and the distance from point D to point F10 on the vertical axis is divided into 10 equal parts, and the 9 equal points are respectively set as F1, F2..., F8, F9, and F1 are closest to point D, where the placement position of the photointerrupter 34 of the focusing lens group G4 corresponds to the position of the focusing lens group, between point E1 and point E9, or between point F1 and point F9 between points. The better one can be between point E2 and point E8, or between point F2 and point F8. The better one can be between point E3 and point E7, or between point F3 and point F7. It should be noted that the placement position of the photo-interrupter 34 of the focus lens group G4 corresponds to the position of the focus lens group, which means that the positions of the photo-interrupter 34 and the focus lens group G4 in the direction of the arrow X are the same.

Please refer to Fig. 2, Fig. 3 and Fig. 5 at the same time, the corresponding curve 60 has an inflection point K4 with a slope of 0, the projection point of the inflection point K4 on the horizontal axis is C, and the driving mechanism (first stepping motor) 22 At the inflection point K4 position, drive the zoom lens group G2 in the direction of the telescopic end K7 to move one step in a full step (full step) mode, and its projection point on the corresponding horizontal axis of the corresponding curve 60 is H1, and the driving mechanism (second step The motor) 24 drives the focusing lens group G4 to move one step in a full-step manner in the direction of the inflection point K4 at the position of the telephoto end K7. The motor) 22 drives the zoom lens group G2 in the direction of the wide-angle end K1 at the position of the inflection point K4 to move one step in a full-step manner. ) 24 at the position of wide-angle end K1 to drive the focus lens group G4 to move in a full-step manner in the direction of the inflection point K4, and the projection point on the corresponding horizontal axis of the corresponding curve 60 is L1, wherein the photointerrupter of the zoom lens group G2 The placement position of 32 corresponds to the position of the zoom lens group, which is between the H1 point and the I1 point, or between the J1 point and the L1 point. It should be noted that the placement position of the photo-interrupter 32 of the zoom lens group G2 corresponds to the position of the zoom lens group, which means that the positions of the photo-interrupter 32 and the zoom lens group G2 in the direction of the arrow X are the same.

Similarly, please refer to Fig. 2, Fig. 3 and Fig. 5 at the same time, the corresponding curve 60 has an inflection point K4 with a slope of 0, and the projection point of the inflection point K4 on the vertical axis is D, and the driving mechanism (the first step The motor) 22 drives the zoom lens group G2 in the direction of the telescopic end K7 at the position of the inflection point K4 to move one step in a full step manner, and its projection point on the corresponding vertical axis of the corresponding curve 60 is H2, and the driving mechanism (No. Two stepping motors) 24 drive the focus lens group G4 to move one step in a full-step manner in the direction of the inflection point K4 at the position of the telephoto end K7. A stepping motor) 22 drives the zoom lens group G2 in the direction of the wide-angle end K1 at the position of the inflection point K4 to move one step in a full-step manner, and its projection point on the corresponding vertical axis of the corresponding curve 60 is J2, and the driving mechanism (the second The stepping motor) 24 drives the focus lens group G4 to move in a full-step manner in the direction of the inflection point K4 at the position of the wide-angle end K1, and the projection point corresponding to the vertical axis of the corresponding curve 60 is L2, wherein the light of the focus lens group G4 The placement position of the interrupter 34 corresponds to the position of the focusing lens group, which is between the H2 point and the I2 point, or between the J2 point and the L2 point. It should be noted that the placement position of the photo-interrupter 34 of the focus lens group G4 corresponds to the position of the focus lens group, which means that the positions of the photo-interrupter 34 and the focus lens group G4 in the direction of the arrow X are the same.

In addition, the placement positions of the photo-interrupter 32 of the zoom lens group G2 and the photo-interrupter 34 of the focus lens group G4 are all limited by the driving parts (stepping motors) moving one step in full steps, The present invention is not limited thereto. Preferably, the driving parts (stepping motors) can be used to move two steps in full steps to determine the positions of points H1, H2, I1, I2, J1, J2, L1 and L2. More preferably, the position of points H1, H2, I1, I2, J1, J2, L1, and L2 can be determined by using a driving component (stepping motor) to move three steps in a full-step manner.

The placement positions of the photo-interrupter 32 of the zoom lens group G2 and the photo-interrupter 34 of the focus lens group G4 can also be limited by using the slope S corresponding to the curve 60 . Please refer to FIG. 2 and FIG. 3 at the same time. The placement position of the photointerrupter 32 corresponds to a position of the zoom lens group G2. This position of the zoom lens group G2 is the projection point of a point corresponding to the curve 60 on the horizontal axis, corresponding to The point of the curve 60 satisfies 0.1≦S≦5.7 or -5.7≦S≦-0.1, and S is the slope corresponding to the point of the curve 60 . Preferably, the point corresponding to the curve 60 satisfies 0.1≦S≦4.7 or -4.7≦S≦-0.1. More preferably, the point corresponding to the curve 60 satisfies 0.1≦S≦2.7 or -0.56≦S≦-0.1. It should be noted that the placement position of the photo-interrupter 32 of the zoom lens group G2 corresponds to the position of the zoom lens group, which means that the positions of the photo-interrupter 32 and the zoom lens group G2 in the direction of the arrow X are the same. Similarly, please refer to FIG. 2 and FIG. 3 at the same time. The placement position of the photointerrupter 34 corresponds to a position of the focusing lens group G4, and this position of the focusing lens group G4 is the projection of a point corresponding to the curve 60 on the vertical axis. point, the point corresponding to the curve 60 satisfies 0.1≦S≦5.7 or -5.7≦S≦-0.1, and S is the slope of the point corresponding to the curve 60 . Preferably, the point corresponding to the curve 60 satisfies 0.1≦S≦4.7 or -4.7≦S≦-0.1. More preferably, the point corresponding to the curve 60 satisfies 0.1≦S≦2.7 or -0.56≦S≦-0.1. It should be noted that the placement position of the photo-interrupter 34 of the focus lens group G4 corresponds to the position of the focus lens group, which means that the positions of the photo-interrupter 34 and the focus lens group G4 in the direction of the arrow X are the same.

According to the design of the above-mentioned embodiment, the zoom lens can have high zooming precision through the limitation of the placement positions of the photo-interrupters of the zoom lens group and the focus lens group. Therefore, a zoom lens design with good zoom precision and better imaging quality can be provided.

It should be noted that the parameters listed in Table 1 are for illustrative purposes only and do not limit the present invention. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Anyone skilled in this art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be determined by the scope of the attached patent application. In addition, any embodiment or scope of claims of the present invention does not necessarily achieve all the objectives or advantages or features disclosed in the present invention. In addition, the abstract and the title are only used to assist the search of patent documents, and are not used to limit the scope of rights of the present invention.

1: zoom lens 4: Microprocessor 5: Zoom lens group control module 6: Focusing lens group control module 7: Filter 8: Image sensor 10: camera device 20: optical axis 22, 24: Drive parts (stepping motor) 222, 242: shading part 32, 34: Photointerrupter 42:Zoom reference line 44: Focus reference line 50: Cartesian coordinate plane 60: Corresponding curve A1-A9, B1-B9: equal points E1-E9, F1-F9: equal points A10: The point corresponding to the horizontal axis at the telephoto end of the zoom lens group E10: The point corresponding to the vertical axis at the telephoto end of the focusing lens group F10: The point corresponding to the vertical axis at the wide-angle end of the focusing lens group C, D: projection point G1, G3, G5: lens group G2: zoom lens group (lens lens group) G4: Focusing mirror group (lens mirror group) K1-K7: coordinate points H1, H2, I1, I2, J1, J2, L1, L2: projection point X, -X: Arrow

FIG. 1 shows a schematic configuration diagram of an imaging device according to an embodiment of the present invention.

FIG. 2 shows a schematic cross-sectional structure diagram of a zoom lens according to an embodiment of the present invention.

FIG. 3 shows a schematic diagram of corresponding curves drawn by the position of the zoom lens group and the corresponding position of the focus lens group on the Cartesian coordinate plane after the zoom lens according to an embodiment of the present invention is focused.

FIG. 4 shows a schematic view of the restrictions on placement positions of the photo-interrupters of the zoom lens group and the focus lens group of the zoom lens according to an embodiment of the present invention.

FIG. 5 is a schematic view showing the restricted positions of the photo-interrupters of the zoom lens group and the focus lens group of the zoom lens according to an embodiment of the present invention.

1: zoom lens

20: optical axis

22, 24: Drive parts (stepping motor)

222, 242: shading part

32, 34: Photointerrupter

42:Zoom reference line

44: Focus reference line

G1, G3, G5: lens group

G2: zoom lens group (lens lens group)

G4: Focusing mirror group (lens mirror group)

Claims (8)

A zoom lens comprising: A zoom lens group and a focus lens group, the zoom lens group and the focus lens group are provided with the same optical axis; A first driving mechanism and a second driving mechanism, the first driving mechanism can drive the zoom lens group to move along the optical axis, and the second driving mechanism can drive the focusing lens group to move along the optical axis; A first photointerrupter, wherein after the zoom lens finishes focusing, the position of the zoom lens group and the corresponding position of the focus lens group can form a corresponding curve on a Cartesian coordinate plane, and the Cartesian coordinate plane is based on the zoom The lens group is set as an origin at the wide-angle end position, and the direction that the zoom lens group moves along the optical axis from the wide-angle end to the telescopic end is a positive direction of a horizontal axis of the Cartesian coordinate plane. The relative distance of the wide-angle end position of the group is the abscissa coordinate, and a focus reference line position is set as a vertical axis 0 point of the Cartesian coordinate plane, and the focus lens group is moved from the focus reference line position to the focus lens group wide-angle end The moving direction of the optical axis is the positive direction of the longitudinal axis of the Cartesian coordinate plane, and the relative distance between the position of the focusing lens group and the position of the focusing reference line is the coordinate of the longitudinal axis, wherein the first photointerrupter is provided with a placement Position, corresponding to a position of the focusing lens group, the position of the focusing lens group is a projection point of a point of the corresponding curve on the vertical axis, and the point of the corresponding curve satisfies one of the following conditions: (1) 0.1 ≦S≦2.7, (2)-0.56≦S≦-0.1, S is the slope of the corresponding curve at this point. The zoom lens as described in claim 1, wherein the zoom lens further includes a second photo-interrupter, wherein the second photo-interrupter is provided with a placement position corresponding to a position of the zoom lens group, the zoom The position of the lens group is a projection point of the point of the corresponding curve on the horizontal axis. The zoom lens as described in claim 1, wherein the corresponding curve has an inflection point with a slope of 0, a projection point of the inflection point on the vertical axis is D, and the focusing lens group corresponds to the longitudinal position at the telephoto end One point on the axis is E10, divide the distance from point D to point E10 on the vertical axis into 10 equal parts, and set the 9 equal points as E1, E2..., E8, E9 respectively, and E1 is closest to point D , the point of the focus lens group at the wide-angle end corresponding to the vertical axis is F10, and the distance from the point D to the F10 point on the vertical axis is divided into 10 equal parts, and the 9 equal points are respectively set as F1 and F2 ..., F8, F9, F1 is closest to the point D, where the position of the focusing lens group meets one of the following conditions: (1) between point E1 and point E9, (2) between point F1 and point F9 between. The zoom lens as described in claim 3, wherein the zoom lens further includes a second photointerrupter, wherein when the position of the focusing lens group is between E1 and E9, the inflection point is at the horizontal A projected point on the axis is C, and the point of the zoom lens group at the telephoto end corresponding to the horizontal axis is A10. The distance from point C to point A10 on the horizontal axis is divided into 10 equal parts, and 9 equal parts The points are respectively set as A1, A2..., A8, A9, A1 is closest to the point C, the second photointerrupter is provided with a placement position corresponding to a position of the zoom lens group, and the zoom lens group of the The location is between point A1 and point A9. The zoom lens as described in claim 3, wherein the zoom lens further includes a second photointerrupter, wherein when the position of the focusing lens group is between F1 and F9, the inflection point is at the horizontal A projection point of the axis is C, and the distance from the point C on the horizontal axis to the origin is divided into 10 equal parts, and the 9 equal parts are respectively set as B1, B2..., B8, B9, and B9 is the closest to the Point C, wherein the second photointerrupter has a placement position corresponding to a position of the zoom lens group, and the position of the zoom lens group is between point B1 and point B9. The zoom lens as described in Claim 1, wherein the first driving mechanism is a first stepping motor and the second driving mechanism is a second stepping motor, and the first stepping motor can drive the zoom lens The group moves along the optical axis, the second stepping motor can drive the focusing lens group to move along the optical axis, the corresponding curve has an inflection point with a slope of 0, and the inflection point is at a projected point of the vertical axis is D, the first stepping motor drives the zoom lens group to move one step in a full step in the direction of the telescopic end at the position of the inflection point, which corresponds to a projected point of the vertical axis on the corresponding curve is H2, the second stepping motor drives the focus lens group to move one step in a full step in the direction of the inflection point at the telephoto end position, and a projected point on the corresponding curve corresponding to the vertical axis is I2, the first The stepper motor drives the zoom lens group to move one step in a full-step manner at the position of the inflection point toward the wide-angle end, and a projected point corresponding to the vertical axis on the corresponding curve is J2, and the second stepper motor At the wide-angle end position, the focus lens group is driven to move one step in a full step in the direction of the inflection point, and a projected point on the corresponding curve corresponding to the vertical axis is L2, wherein the position of the focus lens group satisfies the following conditions One: (1) between point H2 and point I2, (2) between point J2 and point L2. The zoom lens as described in Claim 6, wherein the zoom lens further includes a second photointerrupter, wherein when the position of the focusing lens group is between H2 and I2, the inflection point is at the horizontal A projection point of the axis is C, and the first stepping motor drives the zoom lens group to move one step in a full step in the direction of the telescopic end at the position of the inflection point, which corresponds to a projection of the horizontal axis on the corresponding curve The point is H1, the second stepping motor drives the focus lens group to move one step in a full step in the direction of the inflection point at the telephoto end position, and a projected point on the corresponding curve corresponding to the horizontal axis is I1, wherein The second photointerrupter has a placement position corresponding to a position of the zoom lens group, and the position of the zoom lens group is between point H1 and point I1. The zoom lens as described in Claim 6, wherein the zoom lens further includes a second photointerrupter, wherein when the position of the focusing lens group is between J2 and L2, the inflection point is at the horizontal A projection point of the axis is C, and the first stepping motor drives the zoom lens group to move one step in a full step in the direction of the wide-angle end at the position of the inflection point, which corresponds to a projection point of the horizontal axis on the corresponding curve is J1, the second stepping motor drives the focusing lens group to move one step in a full step in the direction of the inflection point at the wide-angle end position, and a projected point on the corresponding curve corresponding to the horizontal axis is L1, wherein the The second photointerrupter has a placement position corresponding to a position of the zoom lens group, and the position of the zoom lens group is between point J1 and point L1.

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