CN117850005A - Zoom optical system and image pickup apparatus - Google Patents

Abstract

The embodiment of the application provides a zoom optical system and an image acquisition device, wherein the zoom optical system is sequentially provided with a first lens group, a second lens group, a diaphragm, a third lens group, a fourth lens group, a fifth lens group and a photosensitive element from an object direction to an image side; the second lens group, the third lens group and the fourth lens group are zoom lens groups, and the fifth lens group is a focusing lens group; the focal power of the second lens group and the fifth lens group is negative, the focal length of the zooming optical system is changed between 35.5 mm and 257.4 mm, and the focal length of the zooming optical system at the long focal end is increased; the focal length ft of the zoom optical system at the telephoto end and the total optical length TTL of the zoom optical system satisfy: 1.2 And the TTL/ft is more than or equal to 0.9, so that the length from a short focal end to a long focal end of the zoom lens system is reduced, the volume of the zoom lens system is further reduced, and the zoom lens system with long focal length and small volume is realized.

Description

Zoom optical system and image pickup apparatus

Technical Field

The present application relates to the field of optical imaging technology, and in particular, to a zoom optical system and an image capturing apparatus.

Background

At present, the existing optical system cannot realize long focal length while the volume is small due to the volume and cost limitation, but the existing small-volume zoom optical system is smaller in focal length when being positioned at a long focal end, and cannot meet the requirements of wide shooting range and long shooting distance.

Disclosure of Invention

An object of an embodiment of the present application is to provide a zoom optical system and an image pickup apparatus to realize a small-volume long-focal-length zoom optical system. The specific technical scheme is as follows:

in a first aspect, embodiments provide a zoom optical system provided with a first lens group, a second lens group, a stop, a third lens group, a fourth lens group, a fifth lens group, and a photosensitive element in order from an object to an image; wherein the second lens group, the third lens group, and the fourth lens group are variable magnification lens groups, and the fifth lens group is a focusing lens group;

the optical power of the first lens group, the third lens group and the fourth lens group is positive, and the optical power of the second lens group and the fifth lens group is negative;

the relative positions of the diaphragm and the third lens group are unchanged, and the second lens group, the third lens group, the fourth lens group and the fifth lens group can move back and forth along the optical axis direction so as to enable visible light to be imaged on the photosensitive element;

wherein a focal length f1 of the first lens group, a focal length f2 of the second lens group, a focal length f3 of the third lens group, a focal length f4 of the fourth lens group, and a focal length f5 of the fifth lens group satisfy: -0.25 is more than or equal to f2/f1 is more than or equal to-0.4; 0.8 More than or equal to f3/f1 is more than or equal to 0.6;0.9 More than or equal to f4/f1 is more than or equal to 0.75; -1 is more than or equal to f5/f1 is more than or equal to-1.5; the focal length ft of the zooming optical system at the long focal end and the focal length fw of the zooming optical system at the short focal end satisfy the following conditions: the ft/fw is more than or equal to 7.2, and the zoom range of the zoom optical system is 35.5 mm-257.4 mm; the focal length ft of the zooming optical system at the long focal end and the total optical length TTL of the zooming optical system meet the following conditions: 1.2 And the TTL/ft is more than or equal to 0.9.

In one possible embodiment, when the zoom optical system is at a short focal end and the zoom optical system is at a long focal end, a moving distance m1 of the second lens group, a moving distance m2 of the third lens group, and a moving distance m3 of the fourth lens group satisfy:

in one possible embodiment, the range of movement of the second lens group is 0 to 20.5 mm when the zoom optical system is at the short focal end to when the zoom optical system is at the long focal end.

In one possible embodiment, the range of movement of the third lens group is 0 to 82.9 millimeters when the zoom optical system is at the short focal end to when the zoom optical system is at the long focal end.

In one possible embodiment, the range of movement of the fourth lens group is 0 to 83.8 mm when the zoom optical system is at the short focal end to when the zoom optical system is at the long focal end.

In one possible embodiment, the range of movement of the fifth lens group is 0 to 72.3 mm when the zoom optical system is at the short focal end to when the zoom optical system is at the long focal end.

In one possible implementation manner, the first lens group comprises a first lens, a second lens, a third lens and a fourth lens which are sequentially arranged along the image side of the object direction, wherein the first lens is a spherical lens with negative focal power and concave surface facing the image side, the second lens is a biconvex spherical lens with positive focal power, the third lens is a spherical lens with negative focal power and concave surface facing the image side, and the fourth lens is a meniscus spherical lens with positive focal power and convex surface facing the object side; and is also provided with

The second lens group comprises a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens which are sequentially arranged along an image side in an object direction, wherein the fifth lens is a spherical lens with negative focal power and a concave surface facing the image side, the sixth lens is a biconcave spherical lens with negative focal power, the seventh lens is a biconvex spherical lens with positive focal power, the eighth lens is a biconcave spherical lens with negative focal power, and the ninth lens is a biconvex spherical lens with positive focal power; the image surface of the eighth lens is glued with the object surface of the ninth lens; and is also provided with

The third lens group comprises a tenth lens, an eleventh lens, a twelfth lens and a thirteenth lens which are sequentially arranged along the image space in the object direction, wherein the tenth lens is a biconvex spherical lens with positive focal power, the eleventh lens is a spherical lens with negative focal power and a concave surface facing the object space, and the twelfth lens is a spherical lens with negative focal power and a concave surface facing the image space; the thirteenth lens is a meniscus spherical lens with positive focal power and a convex surface facing the object; the image surface of the twelfth lens is glued with the object surface of the thirteenth lens; and is also provided with

The fourth lens group comprises a fourteenth lens, a fifteenth lens and a sixteenth lens, wherein the fourteenth lens is a biconvex spherical lens with positive focal power, the fifteenth lens is a biconcave spherical lens with negative focal power, and the sixteenth lens is a meniscus spherical lens with positive focal power and a convex surface facing an object side; the image surface of the fourteenth lens is glued with the object surface of the fifteenth lens; and is also provided with

The fifth lens group comprises a seventeenth lens, an eighteenth lens and a nineteenth lens which are sequentially arranged along an image space in an object direction, wherein the seventeenth lens is a spherical lens with negative focal power and a concave surface facing the image space, the eighteenth lens is a biconvex spherical lens with positive focal power, and the nineteenth lens is a spherical lens with negative focal power and a concave surface facing the image space.

In one possible embodiment, the zoom optical system further includes a filter located between the fifth lens group and the photosensitive element.

In one possible embodiment, the diagonal dimension of the photosensitive element is 25.6 millimeters.

In a second aspect, embodiments of the present application provide an image capturing apparatus comprising a zoom optical system according to the first aspect

The beneficial effects of the embodiment of the application are that:

the zoom optical system provided by the embodiment of the application adopts a structure that three zoom lens groups and one focusing lens group are matched with each other, and the diaphragm is arranged on the third lens group and moves along with the zoom lens groups, so that the focal length of the zoom optical system can be changed between 35.5 mm and 257.4 mm, and the focal length of the zoom optical system when the zoom optical system is positioned at a long focal end is increased. And, the focal length ft when the zoom lens system is at the telephoto end and the total optical length TTL of the zoom lens system satisfy: 1.2 And the TTL/ft is more than or equal to 0.9, so that the length from a short focal end to a long focal end of the zoom lens system is reduced, the volume of the zoom lens system is further reduced, and the zoom lens system with long focal length and small volume is realized.

Of course, not all of the above-described advantages need be achieved simultaneously in practicing any one of the products or methods of the present application.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following description will briefly introduce the drawings that are required to be used in the embodiments or the description of the prior art, and it is obvious that the drawings in the following description are only some embodiments of the present application, and other embodiments may also be obtained according to these drawings to those skilled in the art.

Fig. 1 is a schematic diagram of a zoom optical system according to an embodiment of the present application;

FIG. 2 is an exemplary diagram of a zoom optical system according to an embodiment of the present application at a short focal length;

FIG. 3 is an exemplary diagram of a zoom optical system provided by an embodiment of the present application at an intermediate end;

fig. 4 is an exemplary diagram of a zoom optical system provided in an embodiment of the present application when at the tele end.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present application. Based on the embodiments herein, a person of ordinary skill in the art would be able to obtain all other embodiments based on the disclosure herein, which are within the scope of the disclosure herein.

As shown in fig. 1, the present embodiment provides a zoom optical system provided with a first lens group 1, a second lens group 2, a stop 6, a third lens group 3, a fourth lens group 4, a fifth lens group 5, and a photosensitive element 8 in order from an object side image side; wherein the second lens group 2, the third lens group 3 and the fourth lens group 4 are variable magnification lens groups, and the fifth lens group 5 is a focusing lens group;

the optical powers of the first lens group 1, the third lens group 3, and the fourth lens group 4 are positive, and the optical powers of the second lens group 2 and the fifth lens group 5 are negative;

during zooming of the zooming optical system, the position of the first lens group 1 is fixed, the relative position of the diaphragm 6 and the third lens group 3 is unchanged, and the second lens group 2, the third lens group 3, the fourth lens group 4 and the fifth lens group 5 can move back and forth along the optical axis direction so as to enable visible light to image on the photosensitive element;

wherein, the focal length f1 of the first lens group 1, the focal length f2 of the second lens group 2, the focal length f3 of the third lens group 3, the focal length f4 of the fourth lens group 4, and the focal length f5 of the fifth lens group 5 satisfy: -0.25 is more than or equal to f2/f1 is more than or equal to-0.4; 0.8 More than or equal to f3/f1 is more than or equal to 0.6;0.9 More than or equal to f4/f1 is more than or equal to 0.75; -1 is more than or equal to f5/f1 is more than or equal to-1.5; the focal length ft when the zoom optical system is at the telephoto end and the focal length fw when the zoom optical system is at the short-focal end satisfy: the ft/fw is more than or equal to 7.2, and the zoom range of the zoom optical system is 35.5 mm-257.4 mm.

The length of the zoom optical system at the long focal end is longer than that at the short focal end, and if the volume of the zoom optical system at the long focal end is small, the zoom optical system is a small-volume zoom optical system. It is to be understood that the small volume in this application refers to the small volume relative to existing zoom optical systems, and is not a limitation on the volume of the zoom optical system. The criteria for small volume may depend on the actual needs of the user, and illustratively, in one possible embodiment, may be considered as: the zoom optical system is a small-volume zoom optical system when the ratio of the total optical length of the zoom optical system to the focal length of the zoom optical system at the telephoto end is less than 1.2, and in another possible embodiment, it can also be considered that: the zoom optical system is a small-volume zoom optical system when a ratio of an optical total length of the zoom optical system to a focal length of the zoom optical system at a telephoto end is less than 1. In yet another possible embodiment, it can also be considered that: when the ratio of the length of the zoom optical system to the focal length of the zoom optical system at the telephoto end is less than 1 and the focal length of the zoom optical system at the telephoto end is greater than 100 mm, the zoom optical system is a small-volume zoom optical system.

Since the focal length ft of the zoom optical system at the telephoto end and the total optical length TTL of the zoom optical system in the embodiment of the present application satisfy: 1.2 And the ratio of TTL/ft is more than or equal to 0.9, so that the zoom optical system in the embodiment of the application is a small-volume zoom optical system.

Wherein the diaphragm 6 is used to control the size of the incident beam.

The object side refers to the side close to the object, and the image side refers to the side close to the image plane. The lens generally has an image plane, which refers to the surface of the lens that is close to the object, and an object plane, which refers to the surface that can be imaged by the lens. The variable magnification lens group refers to a lens group in which magnification can be continuously adjusted within a certain range.

According to the embodiment of the application, the structure that three zoom lens groups and one focusing lens group are matched with each other is adopted, and the diaphragm is arranged on the third lens group and moves along with the zoom lens groups, so that the focal length of the zoom optical system can be changed between 35.5 mm and 257.4 mm, and the focal length of the zoom optical system at a long focal end is increased. And, the focal length ft when the zoom lens system is at the telephoto end and the total optical length TTL of the zoom lens system satisfy: 1.2 And the TTL/ft is more than or equal to 0.9, so that the length from a short focal end to a long focal end of the zoom lens system is reduced, the volume of the zoom lens system is further reduced, and the zoom lens system with long focal length and small volume is realized.

It is understood that the zoom range of the zoom optical system is 35.5 mm to 257.4 mm, and 7.2 times zooming can be achieved. In one possible implementation manner, the horizontal view angle range of the zoom optical system is 5 ° (long focal end) to 36.7 ° (short focal end), the shooting range is wide, when the zoom optical system is at the short focal end, even if the shooting distance is 1.5 meters, the zoom optical system can clearly shoot a picture, and when the zoom optical system is at the long focal end, even if the shooting distance is 3 meters, the zoom optical system can clearly shoot a picture, so the zoom optical system in the embodiment of the application can be suitable for various environments, for example, the zoom optical system needs to be used in a machine vision system of an automatic guiding robot, but is limited by the volume of the automatic guiding robot, and the space capable of placing the zoom optical system is often limited, and at this time, the zoom optical system provided by the application can be used. As another example, some cameras require taking close-up pictures with long focal length and taking panoramic pictures with short focal length, limited cameras themselves have limited space and are difficult to accommodate common zoom optical systems, and these cameras can take pictures using the zoom optical systems provided herein.

The short focal end and the long focal end are two states of the zooming optical system, the zooming optical system can be positioned at the short focal end or the long focal end by adjusting the positions of the lens groups, and the zooming optical system can be positioned at other states, such as the middle end. The short focal end is also called a wide-angle end, the angle of view of the variable-focus optical system is wider when the variable-focus optical system is positioned at the short focal end, and the amount of information contained in imaging is large; the long focal end is also called a telephoto end, the angle of view of the variable-focus optical system is narrow when the variable-focus optical system is positioned at the long focal end, a distant object can be pulled up, and the information content in the imaged image is less; the intermediate end is a state when the zoom optical system is interposed between the long focal end and the short focal end. The initial state of the zoom optical system is at the short focal end.

Since most of the zoom optical systems at present generally employ a 1/2.8 inch, 1/1.8 inch, 1/1.2 inch element as a photosensitive element due to its volume limitation, and since the above-described element itself has a poor low-light effect and a small monitoring range, resulting in poor photographing effect, in order to improve photographing effect, in one possible embodiment, a photosensitive element 8 having a diagonal size of 25.6 mm may be employed.

Taking the example that the photosensitive element 8 adopts Super35 (a size specification of the photosensitive element) with a diagonal size of 25.6 mm as the CCD (Charge Coupled Device ), the zoom optical system in the embodiment of the application can realize a large target surface, the pixel size is 2.9 micrometers, and the low illumination effect is improved due to the large-size pixels, so that the CCD of the Super35 is better than the CCD with 1/2.8 inch, 1/1.8 inch and 1/1.2 inch, the central resolution of the zoom optical system is higher than 172lp/mm (line pair/mm), and the peripheral 0.8H (80% diagonal position) resolution is higher than 125lp/mm. This can achieve a resolution of 8K (1600 ten thousand pixels) compared with the conventional lenses with resolutions of 720P, 1080P, 4M, and 4K.

In one possible embodiment, each lens group is disposed in a lens barrel with a fixed length, and by adjusting each lens group, each lens group moves along a lens barrel wall in the lens barrel to realize zooming of the optical system, compared with the prior art that each lens group is driven to move by adjusting the length of the lens barrel, the overall length of the zooming optical system is effectively reduced.

For convenience of description, the position of the second lens group 2 when the zoom optical system is at the short focal end is denoted as x1, the position of the third lens group 3 is denoted as x2, the position of the fourth lens group 4 is denoted as x3, the position of the second lens group 2 when the zoom optical system is at the long focal end is denoted as y1, the position of the third lens group 3 is denoted as y2, and the position of the fourth lens group 4 is denoted as y3.

The distance by which the second lens group 2 moves is |x1-y1| (hereinafter, denoted as m 1), the distance by which the third lens group 3 moves is |x2-y2| (hereinafter, denoted as m 2), and the distance by which the fourth lens group 4 moves is |x3-y3| (hereinafter, denoted as m 3) in the process of changing the zoom optical system from the short focal end to the long focal end.

In one possible embodiment, the focal lengths of m1, m2, m3 and the lens group need to satisfy certain constraints, and the following constraints need to be satisfied, by way of example:

as shown in fig. 2, 3 and 4, fig. 2 is a schematic view when the zoom optical system is at the short focal end, fig. 3 is a schematic view when the zoom optical system is at the intermediate end, fig. 4 is a schematic view when the zoom optical system is at the long focal end, the second lens group 2 moves toward the image side gradually away from the first lens group when the zoom optical system is changed from the short focal end to the long focal end, and the third lens group 3, the fourth lens group 4 and the fifth lens group 5 all move toward the first lens group 1 gradually close to the first lens group.

In one possible embodiment, when the zoom optical system zooms from the short focal end to the long focal end, the movement range of the second lens group 2 is 0 to 20.5 mm, the movement range of the third lens group 3 is 0 to 82.9 mm, the movement range of the fourth lens group 4 is 0 to 83.8 mm, and the movement range of the fifth lens group 5 is 0 to 72.3 mm.

The moving range of the lens group is 0 to the maximum movable distance, and the maximum movable distance refers to the maximum displacement of the lens group along the optical axis to the object space when the zoom optical system is at the short focal end and the zoom optical system is at the long focal end. For example, when the zoom optical system is currently in the initial state, i.e. in the short focal end, and the zoom optical system is zoomed to the long focal end, the second lens group 2 is adjusted to move toward the image side along the optical axis S, and the maximum distance of movement of the second lens group 2 is 20.5 mm.

With the present embodiment, the second lens group 2, the third lens group 3, the fourth lens group 4, and the fifth lens group 5 move back and forth along the optical axis, and since the stop 6 is fixed on the third lens group 3, the fourth lens group 4 moves and focuses with the movement of the second lens group 2, the third lens group 3, so that the focal length of the zoom optical system varies between 35.5 mm and 257.4 mm.

In a specific embodiment, as shown in fig. 2, the lenses included in each lens group shown in fig. 2 are first described in the following, and specific parameters of each lens may be referred to in tables 1 and 2 below, which are not repeated herein.

The first lens group 1 includes a first lens 11, a second lens 12, a third lens 13 and a fourth lens 14 sequentially disposed along an image space in an object direction, wherein the first lens 11 is a spherical lens with negative focal power and a concave surface facing the image space, the second lens 12 is a biconvex spherical lens with positive focal power, the third lens 13 is a spherical lens with negative focal power and a concave surface facing the image space, and the fourth lens 14 is a meniscus spherical lens with positive focal power and a convex surface facing the object space.

Wherein the second lens group 2 includes: the fifth lens 21, the sixth lens 22, the seventh lens 23, the eighth lens 24 and the ninth lens 25 are sequentially arranged along the image side in the object direction, wherein the fifth lens 21 is a spherical lens with negative focal power and a concave surface facing the image side, the sixth lens 22 is a biconcave spherical lens with negative focal power, the seventh lens 23 is a biconvex spherical lens with positive focal power, the eighth lens 24 is a biconcave spherical lens with negative focal power, and the ninth lens 25 is a biconvex spherical lens with positive focal power; the image plane of the eighth lens 24 is cemented with the object plane of the ninth lens 25.

Wherein the third lens group 3 includes: a tenth lens 31, an eleventh lens 32, a twelfth lens 33, and a thirteenth lens 34 sequentially arranged along an image side in an object direction, wherein the tenth lens 31 is a biconvex spherical lens with positive optical power, the eleventh lens 32 is a spherical lens with negative optical power and a concave surface facing the object side, and the twelfth lens 33 is a spherical lens with negative optical power and a concave surface facing the image side; the thirteenth lens 34 is a meniscus spherical lens with positive power and convex surface facing the object; the image plane of the twelfth lens 33 is cemented with the object plane of the thirteenth lens 34.

The fourth lens group 4 includes a fourteenth lens 41, a fifteenth lens 42 and a sixteenth lens 43, wherein the fourteenth lens 41 is a biconvex spherical lens with positive focal power, the fifteenth lens 42 is a biconcave spherical lens with negative focal power, and the sixteenth lens 43 is a meniscus spherical lens with positive focal power and a convex surface facing the object side; the image plane of the fourteenth lens 41 is cemented with the object plane of the fifteenth lens 42;

the fifth lens group 5 includes a seventeenth lens 51, an eighteenth lens 52 and a nineteenth lens 53, which are sequentially disposed along an image side in an object direction, wherein the seventeenth lens 51 is a spherical lens having negative optical power and a concave surface facing the image side, the eighteenth lens 52 is a biconvex spherical lens having positive optical power, and the nineteenth lens 53 is a spherical lens having negative optical power and a concave surface facing the image side.

The biconcave spherical lens is a spherical lens with a thinner center and a thicker edge and negative focal power, the biconvex spherical lens is a spherical lens with a thicker center and a thinner edge and positive focal power, and the meniscus spherical lens is a lens with a thinner edge and two sides protruding towards the same side.

It will be appreciated that the biconvex spherical lens may be a convex lens with both sides of the lens protruding significantly toward the outside, such as the second lens 12 in fig. 2, with both the image surface and the object surface protruding toward the outside, or a convex lens with only one side protruding significantly toward the outside and the other side being relatively flat, such as the seventh lens 23 in fig. 2, with the object surface protruding toward the outside and the image surface being relatively flat; the biconcave spherical lens may be a concave lens with both centers of two surfaces significantly recessed toward the inside of the lens, for example, the sixth lens 22 in fig. 2 is a biconcave spherical lens with both object and image surfaces recessed toward the inside of the lens, or a concave lens with only the center of one surface significantly recessed toward the inside of the lens and the other surface relatively flat, for example, the eighth lens 24 in fig. 2 is a biconcave spherical lens with its object surface significantly recessed toward the inside of the lens and the image surface relatively flat.

The two lenses are glued by gluing them with transparent glue or by fixing them as one piece using existing means.

By adopting the embodiment of the application, nineteen glass spherical lenses, namely the first lens 11 to the nineteenth lens 53, are used, so that the cost and the complexity of the production process are reduced, and chromatic aberration of a zooming optical system can be eliminated and balanced by matching the lenses after being glued.

The lenses included in each lens group in fig. 2 have been described above, and it is to be understood that the zoom optical system shown in fig. 2 includes not only the first lens group to the fifth lens group, but also the diaphragm 6, the optical filter 7, and the photosensitive element 8, where the diaphragm 6 and the photosensitive element 8 have been described above, and will not be described herein. The filter 7 in the zoom optical system shown in fig. 2 will be described below.

The optical filter 7 is located between the fifth lens group 5 and the photosensitive element 8, and the optical filter 7 is used for eliminating infrared rays and correcting incident light rays. In one possible embodiment, the filter 7 is a quartz filter that uses an adapted physical polarization to maintain the direct portion of the incident light and reflect the oblique portion.

In the zoom optical system shown in fig. 2, by providing the optical filter 7 between the fifth lens group 5 and the photosensitive element 8, light outside the desired wavelength band can be filtered, and interference of light outside the desired wavelength band can be avoided.

The detailed parameters of each lens, aperture stop, and optical filter in the zoom optical system shown in fig. 2 will be described below, referring to table 1, each of the surface numbers 1, 2, and 3 … … in table 1 corresponds to the surface numbered P1, P2, and P3 … … in fig. 2, and the image surface in table 1 is the surface on which the photosensitive element 8 images.

Table 1 parameters of each lens

If the surface indicated by the surface number in table 1 is an object surface, for example, the surface indicated by the surface number 1 in table 1, that is, P1 in fig. 2, indicates the object surface of the first lens 11; the plane with the plane number 3, i.e. P3 in fig. 2, represents the object plane of the second lens 12; the plane with the plane number 19, i.e., P19 in fig. 2, represents the object plane of the tenth lens 31, and the thickness refers to the center thickness of the lens where the object plane is located. If the plane indicated by the plane number is an image plane, for example, the plane indicated by the plane number 2 in table 1, that is, P2 in fig. 2, indicates the image plane of the first lens 11; the plane No. 17, i.e., P17 in fig. 2, represents the image plane of the ninth lens 25; the plane with the plane number 30, i.e. P30 in fig. 2, represents the image plane of the sixteenth lens 43, and the thickness refers to the distance between the image plane and the object plane of the lens next adjacent to the lens where the image plane is located.

If two adjacent lenses are cemented together, the same reference numeral is used to denote the cemented object plane and the image plane, for example, the image plane of the eighth lens 24 is cemented with the object plane of the ninth lens 25, and the reference numeral P16 denotes both the image plane of the eighth lens 24 and the object plane of the ninth lens 25. For the bonding of two adjacent lenses, the same numbers are used to denote the object plane and the image plane of the bonding, so the thickness is the center thickness of the lens where the object plane is located, for example, the plane with the plane number 24 in table 1, i.e., P24 in fig. 2, represents both the image plane of the twelfth lens 33 and the object plane of the thirteenth lens 34, and the corresponding thickness 3.0399 with the plane number 24 in table 1 means the center thickness of the thirteenth lens 34 is 3.0399mm.

In addition, BSC7 in table 1 is a material of an optical glass, since the refractive index and abbe number of the filter 7 are determined by the refractive index of BSC 7. Infinicity means Infinity, i.e., the face is a sphere with an infinite radius of curvature, i.e., the face can be considered a plane.

As is clear from the foregoing, in the present application, the second lens group 2, the third lens group 3, the fourth lens group 4, and the fifth lens group 5 are capable of moving back and forth in the optical axis direction, and the distances between the lens groups are different when the zoom optical system is at the short focal end, the intermediate end, and the long focal end, respectively, and as is clear from the foregoing explanation about the thicknesses, the thickness of the image plane of the lens closest to the image side in each lens group is a variable value, that is, the plane with the plane numbers 8, 17, 25, 30, 36. In table 1, D (1), D (2), D (3), D (4), and D (5) are used to refer to the thicknesses of these 5 surfaces, respectively.

The values of D (1) to D (5) are shown in Table 2 below:

table 2 optical parameters

	Short focal point	Intermediate end	Long focal end
				Focal length f (mm)	35.5	121.2	257.4
F# (mm)	2.2	3.8	4.5
				Image height (mm)	25.8	25.8	25.8
D(1)(mm)	1.429	10.296	22.74
				D(2)(mm)	105.333	28.245	0.852
D(3)(mm)	1.207	26.755	1.2
				D(4)(mm)	17.526	20.620	28.168
D(5)(mm)	3.988	43.565	76.523

Taking D (1) as an example, table 2 shows: the value of D (1) is 1.429mm when the zoom optical system is at the short focal end, 10.296mm when the zoom optical system is at the middle end, and 22.74mm when the zoom optical system is at the long focal end. Also, table 2 shows parameters other than D (1) to D (5) different when the zoom optical system is at the short focal end, the intermediate end, and the long focal end, including the focal length F, the f# and the image height.

Corresponding to the aforementioned zoom optical system, the embodiment of the present application also provides an image capturing apparatus including the aforementioned zoom optical system. Since the image pickup apparatus includes the zoom optical system as described above, the technical effects that can be achieved by the aforementioned zoom optical system can be achieved.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

In this specification, each embodiment is described in a related manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments.

The foregoing description is only of the preferred embodiments of the present application and is not intended to limit the scope of the present application. Any modifications, equivalent substitutions, improvements, etc. that are within the spirit and principles of the present application are intended to be included within the scope of the present application.

Claims (10)

1. The zooming optical system is characterized in that a first lens group, a second lens group, a diaphragm, a third lens group, a fourth lens group, a fifth lens group and a photosensitive element are arranged in sequence from an object direction to an image side; wherein the second lens group, the third lens group, and the fourth lens group are variable magnification lens groups, and the fifth lens group is a focusing lens group;

the optical power of the first lens group, the third lens group and the fourth lens group is positive, and the optical power of the second lens group and the fifth lens group is negative;

the relative positions of the diaphragm and the third lens group are unchanged, and the second lens group, the third lens group, the fourth lens group and the fifth lens group can move back and forth along the optical axis direction so as to enable visible light to be imaged on the photosensitive element;

wherein a focal length f1 of the first lens group, a focal length f2 of the second lens group, a focal length f3 of the third lens group, a focal length f4 of the fourth lens group, and a focal length f5 of the fifth lens group satisfy: -0.25 is more than or equal to f2/f1 is more than or equal to-0.4; 0.8 More than or equal to f3/f1 is more than or equal to 0.6;0.9 More than or equal to f4/f1 is more than or equal to 0.75; -1 is more than or equal to f5/f1 is more than or equal to-1.5; the focal length ft of the zooming optical system at the long focal end and the focal length fw of the zooming optical system at the short focal end satisfy the following conditions: the ft/fw is more than or equal to 7.2, and the zoom range of the zoom optical system is 35.5 mm-257.4 mm; the focal length ft of the zooming optical system at the long focal end and the total optical length TTL of the zooming optical system meet the following conditions: 1.2 And the TTL/ft is more than or equal to 0.9.

2. The zoom optical system according to claim 1, wherein a moving distance m1 of the second lens group, a moving distance m2 of the third lens group, and a moving distance m3 of the fourth lens group when the zoom optical system is at a short focal end to when the zoom optical system is at a long focal end satisfy:

3. the zoom optical system according to claim 1, wherein the range of movement of the second lens group is 0 to 20.5 mm when the zoom optical system is at a short focal end to when the zoom optical system is at a long focal end.

4. The zoom optical system according to claim 1, wherein a range of movement of the third lens group is 0 to 82.9 mm when the zoom optical system is at a short focal end to when the zoom optical system is at a long focal end.

5. The zoom optical system according to claim 1, wherein a range of movement of the fourth lens group is 0 to 83.8 mm when the zoom optical system is at a short focal end to when the zoom optical system is at a long focal end.

6. The zoom optical system according to claim 1, wherein a range of movement of the fifth lens group is 0 to 72.3 mm when the zoom optical system is at a short focal end to when the zoom optical system is at a long focal end.

7. The zoom optical system according to any one of claims 1 to 2, wherein the first lens group includes a first lens, a second lens, a third lens, and a fourth lens which are disposed in order along an object direction image side, wherein the first lens is a spherical lens having negative optical power and concave surface toward the image side, the second lens is a biconvex spherical lens having positive optical power, the third lens is a spherical lens having negative optical power and concave surface toward the image side, and the fourth lens is a meniscus spherical lens having positive optical power and convex surface toward the object side; and is also provided with

The second lens group comprises a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens which are sequentially arranged along an image side in an object direction, wherein the fifth lens is a spherical lens with negative focal power and a concave surface facing the image side, the sixth lens is a biconcave spherical lens with negative focal power, the seventh lens is a biconvex spherical lens with positive focal power, the eighth lens is a biconcave spherical lens with negative focal power, and the ninth lens is a biconvex spherical lens with positive focal power; the image surface of the eighth lens is glued with the object surface of the ninth lens; and is also provided with

The third lens group comprises a tenth lens, an eleventh lens, a twelfth lens and a thirteenth lens which are sequentially arranged along the image space in the object direction, wherein the tenth lens is a biconvex spherical lens with positive focal power, the eleventh lens is a spherical lens with negative focal power and a concave surface facing the object space, and the twelfth lens is a spherical lens with negative focal power and a concave surface facing the image space; the thirteenth lens is a meniscus spherical lens with positive focal power and a convex surface facing the object; the image surface of the twelfth lens is glued with the object surface of the thirteenth lens; and is also provided with

The fourth lens group comprises a fourteenth lens, a fifteenth lens and a sixteenth lens, wherein the fourteenth lens is a biconvex spherical lens with positive focal power, the fifteenth lens is a biconcave spherical lens with negative focal power, and the sixteenth lens is a meniscus spherical lens with positive focal power and a convex surface facing an object side; the image surface of the fourteenth lens is glued with the object surface of the fifteenth lens; and is also provided with

The fifth lens group comprises a seventeenth lens, an eighteenth lens and a nineteenth lens which are sequentially arranged along an image space in an object direction, wherein the seventeenth lens is a spherical lens with negative focal power and a concave surface facing the image space, the eighteenth lens is a biconvex spherical lens with positive focal power, and the nineteenth lens is a spherical lens with negative focal power and a concave surface facing the image space.

8. The zoom optical system of claim 7, further comprising a filter between the fifth lens group and the photosensitive element.

9. The zoom optical system of claim 1, wherein the diagonal dimension of the photosensitive element is 25.6 millimeters.

10. An image capturing device, characterized in that the image capturing device comprises a zoom optical system according to any one of claims 1 to 9.