WO2022198418A1 - Optical system, photographic apparatus, gimbal, and movable platform - Google Patents

Abstract

An optical system, a photographic apparatus, a gimbal, and a movable platform, the optical system (100) comprising in sequence from the object side to the image side a first lens (101) having negative focal power, a second lens (102) having negative focal power, a third lens (103) having positive focal power, a fourth lens (104) having negative focal power, a fifth lens (105) having positive focal power, a sixth lens (106) having positive focal power, and a seventh lens (107) having negative focal power, and the optical system (100) satisfying the expression: -2≤f₇/E_FFL≤0, wherein f₇ is the focal length of the seventh lens (107) and E_FFL is the effective focal length of the optical system (100).

Description

Optical system, camera device, pan/tilt and movable platform technical field

The present application relates to the field of optical technology, and in particular, to an optical system, a photographing device using the optical system, a pan/tilt head, and a movable platform.

Background technique

With the development of photography technology, photographing devices (such as aerial cameras, action cameras or handheld cameras) also tend to be thinner and smaller. As a result, the optical system used in the photographing device must also be reduced in size and size under the market trend, but it is impossible to take into account the large image area when miniaturization is achieved.

SUMMARY OF THE INVENTION

Based on this, the embodiments of the present application provide an optical system, a photographing device, a pan-tilt head, and a movable platform. The optical system has a large field of view, can be adapted to an image sensor with a large image surface, and has a high resolution.

In a first aspect, an embodiment of the present application provides an optical system, the optical system comprising: sequentially arranged from the object side to the image side:

a first lens having positive refractive power;

a second lens having negative refractive power;

The third lens has positive refractive power;

a fourth lens with negative refractive power;

the fifth lens, with positive refractive power;

the sixth lens, with positive refractive power;

the seventh lens, with negative refractive power;

The optical system satisfies the following expression:

-2≤f ₇ /E _FFL ≤0

Wherein, f7 is the focal length of the _seventh lens, and E _FFL is the effective focal length of the optical system.

In a second aspect, an embodiment of the present application further provides a photographing device, the photographing device includes the optical system and the image sensor according to any one of the embodiments of the present application, and the optical system is configured between the photographed object and the image sensor. The optical path of the image sensor is used to image the photographed object on the image sensor.

In a third aspect, the present application further provides a pan/tilt head, the pan/tilt head is equipped with a photographing device, and the photographing device includes the optical system and the image sensor according to any one of the embodiments of the present application, and the optical system It is arranged in the optical path between the photographed object and the image sensor, and is used to image the photographed object on the image sensor.

In a fourth aspect, the present application further provides a movable platform, the movable platform includes a platform body and a photographing device, the photographing device is mounted on the platform body; the photographing device includes the The optical system and the image sensor according to any one of the above, wherein the optical system is arranged in an optical path between a photographed object and the image sensor, and is used for imaging the photographed object on the image sensor.

In the optical system, photographing device, pan-tilt and movable platform provided by the embodiments of the present application, the optical system can be installed on the photographing device, and the photographing device can be mounted on the pan-tilt or on the platform body of the movable platform. The optical system utilizes the specific parameter settings of the combination of seven lenses, which can realize the optical system with a large field of view, so as to adapt to large-sized image sensors (such as image sensors of 1 inch and above), and at the same time improve the imaging quality.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not limiting of the present application.

Description of drawings

In order to explain the technical solutions of the embodiments of the present application more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. For those of ordinary skill, other drawings can also be obtained from these drawings without any creative effort.

1 is a schematic structural diagram of an optical system provided by an embodiment of the present application;

2 is a schematic structural diagram of another optical system provided by an embodiment of the present application;

3 is a schematic structural diagram of another optical system provided by an embodiment of the present application;

4 is a schematic configuration diagram of an optical system provided by an embodiment of the present application;

5 is a schematic diagram of the effect of the field curvature of the optical system provided by the embodiment of the present application at an infinite object distance;

6 is a schematic diagram of the distortion effect of the optical system provided by the embodiment of the present application at an infinite object distance;

7 is a schematic structural diagram of a photographing device provided by an embodiment of the present application;

8 is a schematic structural diagram of a movable platform provided by an embodiment of the present application;

FIG. 9 is a schematic structural diagram of a handheld gimbal provided by an embodiment of the present application.

Description of main components and symbols:

100, optical system; 101, first lens; 102, second lens; 103, third lens, 104, fourth lens; 105, fifth lens; 106, sixth lens; 107, seventh lens, 108, filter Optical lens; 109. Protective lens;

200, a photographing device; 20, an image sensor; 22, a photographed object; 220, an image of the photographed object; 211, a display screen; 212, a photographing button;

300. Movable platform; 30. Platform body;

400. Hand-held PTZ; 40. Grip part; 41. PTZ body.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

Some embodiments of the present application will be described in detail below with reference to the accompanying drawings. The embodiments described below and features in the embodiments may be combined with each other without conflict.

It should also be understood that the terminology used in the specification of the application herein is for the purpose of describing particular embodiments only and is not intended to limit the application. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural unless the context clearly dictates otherwise.

It should also be further understood that, as used in this specification and the appended claims, the term "and/or" refers to and including any and all possible combinations of one or more of the associated listed items .

Please refer to FIG. 1 , which is a schematic structural diagram of an optical system provided by an embodiment of the present application. The optical system has a larger field of view, can be adapted to an image sensor with a large image surface, and can improve imaging quality.

As shown in FIG. 1, the optical system 100 includes a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, a sixth lens 106 and a The seventh lens 107 .

The first lens 101 has negative power, the second lens 102 has negative power, the third lens 103 has positive power, the fourth lens 104 has negative power, the fifth lens 105 has positive power, and the sixth lens 105 has positive power. The lens 106 has positive refractive power, and the seventh lens 107 has negative refractive power.

Wherein, the optical system 100 satisfies the following expression:

-2≤f ₇ /E _FFL ≤0 (1)

In Expression (1), f ₇ is the focal length of the seventh lens 107 , and E _FFL is the effective focal length of the optical system 100 . The optical system that satisfies the expression (1) is beneficial to the miniaturization of the optical system, and at the same time, it can match the image sensor with a large image plane, for example, it can match the image sensor of more than 1 inch, and also improve the imaging clarity of the optical system .

It should be noted that, in the embodiment of the present application, the lens of the optical system 100 adopts a wide spectrum design, which is beneficial to increase the color richness of the image, thereby improving the user experience. The broad spectrum design means that at least the working wavelength band of the optical system is within a preset wavelength range, such as 340nm-800nm or 300nm-700nm, and of course other ranges are also possible.

In addition, the optical system 100 can be used as an interchangeable lens, such as being detachably mounted on the lens of the photographing device, and the detachable method can be fixed, for example, by one or more connection methods among magnetic attraction, sticking, threading or snapping. connect.

The optical system provided by the above embodiment uses the combination of seven lenses to set specific parameters, so that the optical system can have a large field of view and can be adapted to large-sized image sensors (such as image sensors of 1 inch and above), and at the same time can be used. Get higher resolution images.

In some embodiments, in order to improve the imaging quality of the optical system, the optical system 100 can be further set to satisfy the following expression:

0.5≤f ₁₂₃ /E _FFL ≤3.5 (2)

In Expression (2), f ₁₂₃ is the combined focal length corresponding to the first lens 101, the second lens 102 and the third lens 103 as the combined lens, that is, it can be understood as the first lens 101, the second lens 102 and the third lens 103 is the effective focal length of the whole, and E _FFL is the effective focal length of the optical system 100 . The optical system satisfying the expression (2) can help to balance the optical power of the optical system, reduce the sensitivity of the optical optical system, and further improve the imaging quality of the optical system.

In some embodiments, in order to realize the miniaturization of the optical system product and improve the endurance of the photographing device using the optical system, the fourth lens 104 and the fifth lens 105 of the optical system 100 may also be defined as focusing lenses. The fourth lens 104 and the fifth lens 105 are used as focusing lenses, the focusing structure is simple and the weight is low. By adopting the single-group in-focus method for focusing, the lightness and thinness of the focusing group are realized, and close-up photography can be realized, which is beneficial to reduce the product cost. power consumption, thereby improving the battery life of the product.

In some embodiments, the optical system 100 can also be defined to satisfy the following expressions:

0.8≤|f ₄₅ /E _FFL |≤3 (3)

In Expression (3), f ₄₅ is the combined focal length corresponding to the fourth lens 104 and the fifth lens 105 as the combined lens, which can be understood as the effective focal length of the fourth lens 104 and the fifth lens 105 as a whole, and E _FFL is the optical Effective focal length of system 100. The optical system satisfying the expression (3) can realize the miniaturization of the optical system and at the same time improve the imaging quality of the optical system.

In some embodiments, the optical system 100 can also be defined to satisfy the following expressions:

0≤|D ₄₅ /E _FFL |≤0.2 (4)

In Expression (4), D ₄₅ is the travel amount on the optical axis of the fourth lens 104 and the fifth lens 105 as focusing lenses when focusing from an object at infinity to a close distance, and E _FFL is the effective amount of the optical system 100 focal length. The optical system satisfying the expression (4) can not only realize the single-group intra-focusing scheme, but also limit the travel amount of the focusing lens, thereby improving the imaging quality of the optical system during the focusing process.

In some embodiments, in order to improve the imaging quality of the optical system, the optical system 100 can be defined to satisfy the following expression:

In Expression (5), c ₃₁ is the radius of curvature of the object-side lens surface of the third lens 103 , and c ₃₂ is the radius of curvature of the image-side lens surface of the third lens 103 . The optical system satisfying Expression (5) is beneficial to balance the optical power of the optical system and reduce the sensitivity of the optical system.

In some embodiments, in order to realize the miniaturization of the optical system, the optical system 100 can also be defined to satisfy the following expression:

In Expression (6), c ₆₁ is the radius of curvature of the object-side lens surface of the sixth lens 106 , and c ₆₂ is the radius of curvature of the image-side lens surface of the sixth lens 106 . The optical system satisfying the expression (6) is beneficial to shorten the optical path difference, compress the volume of the lens, and is beneficial to the miniaturization of the lens.

In some embodiments, in order to achieve the imaging quality of the optical system, increase the field angle of the optical system, and at the same time improve the imaging quality of the optical system, the optical system 100 may also be limited to satisfy the following expression: 1.2≤T _tl /E _FFL ≤2 and/or, 1.25≤T _tl /(I _mgH *2)≤2.5; and/or, 20°≤H _FOV≤28 °; and/or,

0.1≤B _fl /T _tl ≤0.32 (7)

_Wherein , T is the distance on the optical axis from the object-side lens surface of the first lens 101 to the image sensor of the optical system 100, E _FFL is the effective focal length of the optical system 100, and 1 _mgh is the diagonal angle of the effective pixel area of the optical system 100 One half of the line, H _FOV is one half of the field of view in the diagonal direction of the image sensor of the optical system 100, and B _fl is the distance from the image side lens surface of the seventh lens 107 to the image sensor on the optical axis. distance.

In some embodiments, in order to improve the imaging quality of the optical system, the optical system 100 may also be limited to satisfy the following expression: F _no ≥ 2, in this expression, F _no represents a clear image from an object at infinity to the aperture below the imaging plane The opening aperture number of the optical system 100 when it is opened to the maximum.

In some embodiments, in order to improve the imaging quality of the optical system, the optical system 100 may also be defined to satisfy the following expression:

_60≤V6≤76 and _{1.5≤N6≤1.6} ; and/or, _19≤V3≤35 and 1.9≤N3≤2.1 ( ₈ )

In Expression (8), V6 is the dispersion coefficient of the _sixth lens 106, also referred to as the Abbe number, _N6 is the refractive index of the sixth lens 106, _V3 is the dispersion coefficient of the _third lens 103, N3 is the refractive index of the third lens 103 .

In some embodiments, in order to realize the miniaturization of the optical system, the first lens 101 and the second lens 102 may also be set as a cemented lens. By cementing the first lens 101 and the second lens 102, the stability of the optical system and the imaging quality can be improved.

In some embodiments, the optical system 100 includes a variable aperture and a mechanical shutter, and the variable aperture and the mechanical shutter are disposed between the third lens 103 and the fourth lens 104 . While achieving miniaturization, the optical system also reserves a space including a variable aperture and a mechanical shutter, that is, the distance between the third lens 103 and the fourth lens 104, thereby improving user experience, setting the variable aperture and The mechanical shutter can reduce the jelly effect of the optical system, thereby improving the imaging quality of the optical system.

In some embodiments, in order to improve the imaging quality of the optical system and realize the miniaturization of the optical system, some lenses of the optical system 100 may also be set as aspherical lenses, for example, the sixth lens 106 may be set as an aspherical lens.

In some embodiments, in order to reduce the weight of the optical system, some or all of the lenses of the optical system 100 may be limited to use glass lenses. For example, the sixth lens 106 is a glass material lens.

It should be noted that, in one embodiment of the present application, the sixth lens 106 is defined as a glass aspheric lens, the other lenses are spherical lenses, or the other lenses are plastic spherical lenses, and the sixth lens 106 is defined as a glass aspheric lens by defining the sixth lens 106 as a glass aspheric lens , that is, using an aspherical lens made of glass material can realize the miniaturization of the optical system and at the same time improve the imaging quality of the optical system.

In some embodiments, for further correction, one mirror surface of the aspherical lens or all aspherical lens surfaces may be high-order aspherical surfaces, and the high-order aspherical surfaces satisfy the following expression:

In expression (9), z is the rotational symmetry axis of the aspheric surface, c is the curvature of the center point; y is the radial coordinate, whose unit is the same as the unit length of the lens; k is the quadratic curve constant, a ₁ to a ₈ represent respectively The coefficients corresponding to each radial coordinate.

In some embodiments, in order to improve the imaging quality of the optical system, the optical system 100 can be defined to satisfy the expression: T ₆₁ ≥ 6 mm, where T ₆₁ is the object-side lens surface of the sixth lens 106 to the image sensor of the optical system 100 distance on the optical axis. By defining the distance from the sixth lens 106 to the position of the photosensitive sensor to be greater than or equal to 6 mm, sufficient space can be reserved to make the lens of the optical system and/or the filter lens farther away from the photosensitive element (photosensitive element of the image sensor), In order to effectively prevent dust and dirt problems, and then improve the imaging quality of the optical system.

In some embodiments, as shown in FIG. 2 , the optical system 100 further includes a filter lens 108 , and the filter lens 108 is disposed between the seventh lens 107 and the imaging plane IMA of the optical system 100 . Used to filter out some stray light, thereby improving image quality. Exemplarily, for example, the filter lens 108 includes an infrared filter lens (IR lens) for filtering out infrared light to eliminate chromatic aberration caused by infrared light, thereby improving the imaging quality of the optical system.

In some embodiments, as shown in FIG. 3 , the optical system 100 includes a protective lens 109, and the protective lens 109 is disposed between the filter lens 108 and the image sensor (imaging surface Ima) of the optical system 100 for protecting the optical system. The photosensitive element of the image sensor.

In addition, it should be noted that the size of the imaging surface of any optical system 100 provided in the embodiments of the present application is greater than or equal to 1 inch, thereby ensuring that the optical system 100 can be adapted to images of 1 inch and larger than 1 inch sensor.

The specific numerical configuration of the optical system is given below in conjunction with the accompanying drawings and the table. The surface numbers 1, 2, 3, 4, 6, 7, 8, 9... in the table represent the surface numbers in the optical system, respectively. Mirror surfaces and corresponding surfaces of the first lens 101 , the second lens 102 , the third lens 103 , the fourth lens 104 , the fifth lens 105 , the sixth lens 106 , the seventh lens 107 , the filter lens 108 and the protective lens 109 .

Specifically, as shown in FIG. 4 , the two lens surfaces of the first lens 101 are the surface F1 and the surface F2 respectively, the two lens surfaces of the second lens 102 are the surface F2 and the surface F3 respectively, and the two lens surfaces of the third lens 103 The lens surfaces are respectively the surface F4 and the surface F5, STO represents the diaphragm, the two lens surfaces of the fourth lens 104 are the surface F7 and the surface F8 respectively, the two lens surfaces of the fifth lens 105 are the surface F9 and the surface F10 respectively, The two lens surfaces of the six lenses 106 are the surface F11 and the surface F12 respectively, the two lens surfaces of the seventh lens 107 are the surface F13 and the surface F14 respectively, and the two mirror surfaces of the filter lens 108 are the surface F15 and the surface F16 respectively. The two mirror surfaces of the lens 109 are the surface F17 and the surface F18, respectively. The serial number of the surface corresponds to the serial number of the surface under Surf in Table 1.

In Table 1, the number of surfaces (Surf) represents the surface of the lens, the type represents the shape of the surface, "STANDRAD" represents a plane, "EVENASPH" represents an aspheric surface; the radius of curvature (Radius) represents the degree of curvature of the lens surface, which can be represented by R , the smaller the R value, the more curved the lens surface; the interval or thickness (Thickness), the interval is expressed as the separation distance between the lenses of the optical system on the optical axis, and the thickness is the central thickness of the lens; ND is the refractive index of the lens; VD Represents the dispersion coefficient of the lens, also known as the Abbe coefficient; "Infinity" represents the plane; STO represents the diaphragm surface, and IMA represents the image side.

In Table 2, Surf represents the number of faces, K is a quadratic curve constant, and "quadric terms" to "12th-order terms" indicate that a ₂ to a ₇ respectively indicate the coefficients corresponding to each radial coordinate.

In Table 3, T is the distance on the optical axis from the object-side lens surface of the first lens 101 of the optical system to the image sensor of the optical system, and 1 _mgh is the _half of the diagonal of the effective pixel area of the optical system One, H _FOV is one-half of the field of view in the diagonal direction of the image sensor of the optical system.

It should be noted that Table 1 shows the specific parameters of the optical system, which is referred to as Example 1.

Table 1 is the surface parameter data of the lens of the optical system of Example 1

Surf	Type	Radius	Thickness	ND	VD
OBJ	STANDARD	Infinity	Infinity
1	STANDARD	16.519	1.976	1.88	40.8
2	STANDARD	-73.169	0.500	1.76	27.5
3	STANDARD	8.410	0.356
4	STANDARD	10.174	1.265	2.00	30.1
5	STANDARD	23.920	3.656
STO	STANDARD	Infinity	3.924
7	STANDARD	-10.018	0.729	1.70	30.1
8	STANDARD	15296.290	0.295
9	STANDARD	44.643	2.270	1.88	40.8
10	STANDARD	-13.002	0.800
11	EVENASPH	18.504	4.200	1.59	67.0
12	EVENASPH	-26.350	2.630
13	STANDARD	-9.214	0.8	1.69	33.1
14	STANDARD	-105	4.7
15	STANDARD	Infinity	0.8	1.52	64.2
16	STANDARD		Infinity	0
17	STANDARD	Infinity	0.5	1.52	64.2
18	STANDARD	Infinity	0.104
IMA	STANDARD	Infinity	Infinity

Table 2 is the aspheric coefficient data of the optical system lens-surface of Example 1

Surf	K	4th term	6th term	8th term	10 times	12th term
11	1.339	6.72E-05	-1.12E-06	1.22E-06	-3.35E-08	4.14E-10
12	-81.692	-3.18E-04	1.99E-05	-5.85E-06	1.09E-07	-8.32E-10

Table 3 Relevant parameters of the optical system of Example 1

T tl	29.5mm
1 mgH	7.93mm
H FOV	22.5 degrees

FIG. 5 and FIG. 6 are the field curvature parameters and distortion parameters of the optical system of the example of Embodiment 1 at an infinite object distance (INF), respectively. The infinite object distance is that the incident light is parallel light, as can be seen from FIG. 5 and FIG. 6 , the optical system has better imaging effect, so it has higher imaging quality.

It should be noted that, according to Example 1 given above, one of the parameters can be changed and then optical design can be performed to obtain more different optical systems. It should also be noted that the length units involved in the embodiments of the present application are millimeters, such as focal length, thickness, and distance.

Please refer to FIG. 7 , which is a schematic structural diagram of a photographing apparatus provided by an embodiment of the present application. By using the optical system 100 provided by the embodiment of the present application, the imaging device 200 can increase the imaging area and use a larger-sized image sensor, such as a 1-inch image sensor, and can improve the imaging resolution, thereby improving the imaging device. 200 image quality.

Specifically, as shown in FIG. 7 , the photographing apparatus 200 includes an optical system 100 and an image sensor (not shown), and the optical system 100 is arranged in the optical path between the photographed object 22 and the image sensor. The optical system 100 adopts any one of the optical systems provided in the above embodiments, and the image sensor may be, for example, a CMOS sensor or a CCD sensor.

Specifically, the photographing apparatus 200 may also be an electronic device for photographing, including a mobile phone, a digital camera, a motion camera, a wearable device, and the like.

In some embodiments, as shown in FIG. 8 , the photographing device 200 may be a motion camera, including a display screen 211 and a photographing button 212 . The optical system 100 is used to image the photographed object 22 (such as a scene) on the image sensor of the photographing device 200; the display screen 211 is used to display the imaging, such as displaying the image 220 of the object to be photographed, and the display screen 211 may specifically be a touch display screen; The shooting button 212 is used to trigger shooting.

The photographing device in the above-mentioned embodiments uses the optical system provided by the embodiments of the present application, thereby increasing the field of view of the photographing device, adapting to the image sensor with a large image plane, improving the imaging quality of the photographing device, and at the same time. And realize the miniaturization of the product.

An embodiment of the present application further provides a pan/tilt head, the pan/tilt head is equipped with a photographing device, and the photographing device includes the optical system and the image sensor according to any one of the embodiments of the present application, and the optical system is configured in The optical path between the photographed object and the image sensor is used to image the photographed object on the image sensor.

Please refer to FIG. 8 , which is a schematic structural diagram of a movable platform provided by an embodiment of the present application. The movable platform is equipped with a photographing device to realize photographing.

As shown in FIG. 8 , the movable platform 300 includes a platform body 30 and a photographing device 200. The photographing device 200 is mounted on the platform body 30. The optical system 100 is configured in the optical path between the photographed object and the image sensor, and is used to image the photographed object on the image sensor.

Illustratively, the movable platform 300 includes any one of a drone, a robot, an unmanned vehicle, and a handheld gimbal.

Wherein, the aircraft includes an unmanned aerial vehicle, and the unmanned aerial vehicle includes a rotary-wing unmanned aerial vehicle, such as a quad-rotor unmanned aerial vehicle, a six-rotor unmanned aerial vehicle, an eight-rotored unmanned aerial vehicle, or a fixed-wing unmanned aerial vehicle. It is a combination of rotary-wing and fixed-wing drones, which is not limited here.

Among them, the robot can also be called an educational robot. It uses a Mecanum wheel omnidirectional chassis, and is equipped with multiple pieces of intelligent armor. Each intelligent armor has a built-in strike detection module, which can quickly detect physical strikes. At the same time, it also includes a two-axis gimbal, which can be rotated flexibly. With the launcher, it can accurately, steadily and continuously launch crystal bullets or infrared beams, and with ballistic light effects, it gives users a more realistic shooting experience.

For example, if the optical system is installed on the drone, since the optical system can increase the field of view of the lens, it can shoot a wide range of scenes, and can be adapted to an image sensor with a large imaging surface, and at the same time can improve the shooting device. Imaging quality, and the combination of multiple lenses makes the relative distance smaller, thereby reducing the volume of the optical system and realizing miniaturization and portability. Therefore, when the drone is used for aerial photography, better images can be captured by using the optical system, thereby improving the user's experience.

Please refer to FIG. 9. FIG. 9 shows the structure of a handheld pan/tilt provided by an embodiment of the present application. The handheld gimbal is equipped with a photographing device to realize photographing.

As shown in FIG. 9 , the handheld gimbal 400 includes a grip portion 40 , a gimbal body 41 and a photographing device 200 . The photographing device 200 is mounted on the gimbal body 41 , and the photographing device 200 is any one of the photographing devices provided in the above embodiments. , that is, it includes any one of the optical systems 100 provided in the above embodiments. The optical system 100 is configured in the optical path between the photographed object and the image sensor, and is used to image the photographed object on the image sensor.

It should be noted that the pan/tilt provided in the embodiments of the present application may be a two-axis pan/tilt or a three-axis pan/tilt, which is used for stabilization of the photographing device mounted on the pan/tilt.

It should also be noted that the photographing device can be integrated with the gimbal body, or can be detachably installed on the gimbal body, that is, the photographing device can be installed on the gimbal body when the user is using it, and the camera can be installed when not in use. The photographing device is detached from the head body for storage or carrying.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalents within the technical scope disclosed in the present application. Modifications or substitutions shall be covered by the protection scope of this application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (28)

1. An optical system, characterized in that, the optical system comprises: sequentially arranged from the object side to the image side:

   a first lens having positive refractive power;

   a second lens having negative refractive power;

   The third lens has positive refractive power;

   a fourth lens with negative refractive power;

   the fifth lens, with positive refractive power;

   the sixth lens, with positive refractive power;

   the seventh lens, with negative refractive power;

   The optical system satisfies the following expression:

   -2≤f ₇ /E _FFL ≤0

   Wherein, f7 is the focal length of the _seventh lens, and E _FFL is the effective focal length of the optical system.
2. The optical system according to claim 1, wherein the optical system satisfies the following expression:

   0.5≤f ₁₂₃ /E _FFL ≤3.5

   Wherein, f ₁₂₃ is the combined focal length corresponding to the first lens, the second lens and the third lens as combined lenses.
3. The optical system according to claim 1, wherein the optical system satisfies the following expression:

   0.8≤|f ₄₅ /E _FFL |≤3

   Wherein, f ₄₅ is the combined focal length corresponding to the fourth lens and the fifth lens as combined lenses.
4. The optical system according to claim 1, wherein the optical system satisfies the following expression:

   

   Wherein, c ₃₁ is the curvature radius of the object-side lens surface of the third lens, and c ₃₂ is the curvature radius of the image-side lens surface of the third lens.
5. The optical system according to claim 1, wherein the optical system satisfies the following expression:

   

   Wherein, c ₆₁ is the curvature radius of the object-side lens surface of the sixth lens, and c ₆₂ is the curvature radius of the image-side lens surface of the sixth lens.
6. The optical system according to claim 1, wherein the fourth lens and the fifth lens serve as focus lenses.
7. The optical system according to claim 1, wherein the optical system satisfies the following expression:

   0≤|D ₄₅ /E _FFL |≤0.2

   Wherein, D ₄₅ is the travel amount on the optical axis of the fourth lens and the fifth lens as focusing lenses when focusing from an infinity object to a close object.
8. The optical system according to claim 1, wherein the optical system satisfies the following expression:

   1.2≤T _tl /E _FFL ≤2

   Wherein, T _t1 is the distance on the optical axis from the object-side lens surface of the first lens to the image sensor of the optical system.
9. The optical system according to claim 1, wherein the optical system satisfies the following expression:

   F _no ≥2

   Among them, F _no represents the open aperture number of the optical system when the infinity object is clearly imaged to the aperture under the imaging plane when the aperture is opened to the maximum.
10. The optical system according to claim 1, wherein the optical system satisfies the following expression:

    1.25≤T _tl /(I _mgH *2)≤2.5; and/or

    20°≤H _FOV≤28 °; and/or

    0.1≤B _fl /T _tl ≤0.32

    _Wherein , T is the distance on the optical axis from the object-side lens surface of the first lens to the image sensor of the optical system, and 1 _mgh is one-half of the diagonal of the effective pixel area of the optical system, H _FOV is half of the field of view in the diagonal direction of the image sensor of the optical system, and B _fl is the distance on the optical axis from the image-side lens surface of the seventh lens to the image sensor.
11. The optical system according to claim 1, wherein the optical system satisfies the following expression:

    60≤V ₆ ≤76 and 1.5≤N ₆ ≤1.6

    Wherein, V ₆ is the dispersion coefficient of the sixth lens, and N ₆ is the refractive index of the sixth lens.
12. The optical system according to claim 1, wherein the optical system satisfies the following expression:

    19≤V ₃ ≤35 and 1.9≤N ₃ ≤2.1

    Wherein, V ₃ is the dispersion coefficient of the third lens, and N ₃ is the refractive index of the third lens.
13. The optical system according to claim 1, wherein the first lens and the second lens are cemented lenses.
14. The optical system according to claim 1, wherein the optical system comprises a variable aperture and a mechanical shutter, and the variable aperture and the mechanical shutter are provided between the third lens and the fourth lens.
15. The optical system according to claim 1, wherein some of the lenses of the optical system are aspherical lenses.
16. The optical system according to claim 15, wherein the sixth lens is an aspherical lens.
17. The optical system according to claim 1, wherein some or all of the lenses of the optical system are made of glass.
18. The optical system according to claim 17, wherein the sixth lens is a glass material lens.
19. The optical system according to any one of claims 1 to 18, wherein the optical system satisfies the following expression:

    T _6l ≥ 6mm

    Wherein, T ₆₁ is the distance on the optical axis from the object-side lens surface of the sixth lens to the image sensor of the optical system.
20. The optical system according to any one of claims 1 to 18, wherein the imaging surface size of the optical system is greater than or equal to 1 inch, and the optical system can be adapted to image sensors of 1 inch and greater than 1 inch .
21. The optical system according to any one of claims 1 to 18, wherein the optical system further comprises a filter sheet, and the filter sheet is arranged between the seventh lens and the imaging surface of the optical system between.
22. The optical system of claim 21, wherein the filter comprises an infrared filter lens.
23. The optical system according to claim 21, wherein the optical system comprises a protective lens, the protective lens is disposed between the filter lens and the image sensor of the optical system, and is used to protect the image The light-sensitive element of the sensor.
24. A photographing device, characterized in that, the photographing device comprises the optical system and the image sensor according to any one of claims 1 to 23, the optical system is arranged in the optical path between the photographed object and the image sensor, and uses for imaging the photographed object on the image sensor.
25. A pan/tilt head, characterized in that, the pan/tilt head is equipped with a photographing device, and the photographing device includes the optical system and the image sensor according to any one of claims 1 to 23, and the optical system is arranged between the photographed object and the image sensor. The optical path of the image sensor is used to image the photographed object on the image sensor.
26. The pan/tilt according to claim 25, wherein the pan/tilt comprises a hand-held pan/tilt, the hand-held pan/tilt comprises a holding part and a pan/tilt body disposed on the holding part, the pan/tilt The imaging device is mounted on the main body.
27. A movable platform, characterized in that the movable platform comprises a platform body and a photographing device, the photographing device is mounted on the platform body; An optical system and an image sensor are provided, wherein the optical system is configured in the optical path between the photographed object and the image sensor, and is used to image the photographed object on the image sensor.
28. The movable platform of claim 27, wherein the movable platform comprises a drone or a robot.

Images