WO2022226957A1

WO2022226957A1 - An ultra-wide-angle lens optical system

Info

Publication number: WO2022226957A1
Application number: PCT/CN2021/091258
Authority: WO
Inventors: Sota Miyatani; Takuya Anzawa
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2021-04-30
Filing date: 2021-04-30
Publication date: 2022-11-03
Also published as: CN117222930A

Abstract

An ultra-wide-angle lens optical system consists of a front lens (L1), a non-planar prism (L2), and a rear lens group (L3, L4, L5, L6, L7). The non-planar prism (L2) has non-planar surfaces on both the object side and the imaging side. The non-planar prism (L2) is configured to bend the optical path by 90 o.

Description

AN ULTRA-WIDE-ANGLE LENS OPTICAL SYSTEM

FIELD OF THE DISCLOSURE

The present disclosure relates to an image pickup lens that forms an object image for a solid-state image sensor such as a CCD or CMOS sensor, and more particularly to an ultra-wide-angle lens for a CCD or CMOS sensor used for a portable device such as a smartphone, a game machine, a PC, an IP camera, a home appliance, an automobile, etc. It also relates to an ultra-wide-angle lens and a photographing device mounted on an unmanned aircraft or the like.

BACKGROUND OF THE DISCLOSURE

With the popularization of smartphones in recent years, the needs for imaging lenses have diversified, and it is desired to improve the optical performance such as a wider angle of view-angle, higher telephoto performance, and larger -diameter (higher NA) while maintaining the size of an imaging module that is directly affected by the product size. Nowadays, when multi-camera systems have become mainstream, the role of ultra-wide-angle lenses plays a major role in measuring differentiation in smartphone products since ultra-wide-angle lenses are suitable for shooting landscapes, buildings, self, indoors, macro photography, etc. Here, the ultra-wide angle refers to a half angle of view of approximately 45° or more.

As an example of such an ultra-wide-angle lens module, Japanese Patent Publication No. 2018072716A discloses an optical system composed of six lenses including a negative lens L1 and a positive lens L2. Here, with respect to the terms used in the present invention, unless otherwise specified, the positive/negative of a lens refers to the positive/negative of the focal length of a lens near the optical axis.

However, an imaging lens as described in Japanese Patent Publication No. 2018072716A has a large distortion, i.e., -10%to -30%. In ultra-wide-angle imaging optics, distortion is often sacrificed in order to ensure both a sufficiently small total optical length and imaging performance, which is of course not desirable for users who perceive a large distortion as a defect by the camera. In addition, there are many cameras that perform digital processing to correct this distortion problem, but as a result, such digital processing reduces the ultra-wide-angle of view and reduces the image quality to undermine the benefits of the ultra-wide-angle lens resulting in a loss of competitiveness as a camera.

An ultra-wide-angle imaging optical system that satisfactorily corrects this distortion is published in Japanese Patent Publication P2018-25794A. However, the total optical length of the optical system becomes 25 mm or more in order to correct the distortion, which leads to an increase in product size and cannot meet the needs for the recent mobile devices with a very thin thickness.

In order to shorten a total optical length of the optical system, it has been considered to bend the optical path by using a prism. Although the total optical length is shortened by using a prism, there is a problem that the thickness is increased by the amount that the front lens is pushed aside. An ultra-wide-angle lens that can solve the above-mentioned problems is required.

Therefore, there is a need for an ultra-wide-angle lens optical system that can solve the above-mentioned problems for a CCD or CMOS sensor used for a portable device such as a smartphone, a game machine, a PC, an IP camera, a home appliance, an automobile, etc.

SUMMARY OF THE DISCLOSURE

The present invention mitigates and/or obviates the afore-mentioned disadvantages.

The primary objective of the present disclosure is to provide an ultra-wide-angle lens optical system to provide a short TTL, a thinner thickness, and a high quality image with less distortion. By using an ultra-wide-angle lens optical system of this disclosure, it can be installed in thin products while suppressing distortion to the extent that high image quality can be obtained despite the ultra-wide-angle lens.

According to a first aspect, an ultra-wide-angle lens optical system is provided. The ultra-wide-angle lens optical system consists of a front lens, a non-planar prism, and a rear lens group. The non-planar prism has non-planar surfaces on both the object side and the imaging side and configured to bend the optical path by 90°. Since the non-planar prism has power, the front lens can be arranged very close to the non-planar prism to minimize the distance between the front surface of the front lens and the non-planar prism, i.e., the optical axis of the rear lens group.

Therefore, both thickness and TTL of the optical module can be smaller than that of an ordinary optical module using a regular prism since it enables the configuration such that the front sphere protrudes slightly from the maximum diameter of the rear group of the lens system.

According to one aspect of the present ultra-wide-angle lens optical system comprising, form the object side to the image side, a first lens, a non-planar prism, and a rear group of lenses, wherein ω is half angle of view of the ultra-wide-angle lens optical system, f is the focal length of the ultra-wide-angle lens optical system, and f1 is the focal length of the first lens, it satisfies the following conditions:

(i) 50 ≤ ω ≤ 75, more preferably 55 ≤ ω ≤ 70; and

(ii) -3.9 ≤ f1 /f ≤ -0.8, more preferably -2.8 ≤ f1 /f ≤ -1.3

The condition (ii) defines the range in which the ultra-wide-angle lens optical system can appropriately control the area of light flux incident on the non-planar prism while achieving the field of view defined by condition (i) .

According to one aspect of the present ultra-wide-angle lens optical system as claimed in claim 1, wherein f2 is the focal length of the non-planar prism, it satisfies the following conditions:

(iii) 2 ≤ f2 /f ≤ 9.5, more preferably 3 ≤ f2 /f ≤ 7.5

The condition (iii) defines the range of power of the non-planar prism for satisfactorily correcting distortion and coma aberration, achieving miniaturization, and ensuring a sufficient amount of peripheral light.

According to one aspect of the present ultra-wide-angle lens optical system as claimed in any of the previous claims, wherein f (G_rear) is the focal length of the rear group, it satisfies the following conditions:

(iv) 1.3 ≤ f (G_rear) /f ≤ 3.3, more preferably 1.6 ≤ f (G_rear) /f ≤ 2.5

The condition (iv) defines the range for effectively achieving good correction of curvature of field and shortening of the optical overall length (TTL) .

According to one aspect of the present the ultra-wide-angle lens optical system as claimed in any of the previous claims, wherein TTL is that total length of the optical path from an imaging surface to the front surface of the first lens, it satisfies the following conditions:

(v) 6 ≤ TTL /f ≤ 16, more preferably 7.6 ≤ TTL /f ≤ 14

The conditions (v) defines an optical overall length condition suitable for sufficiently reducing distortion and then satisfactorily correcting coma and curvature of field.

According to one aspect of the present ultra-wide-angle lens optical system as claimed in any of the previous claims, wherein sag_L2S2 is the amount of sag on the back surface of the non-planar prism L2, when the direction toward the imaging surface is positive and the direction toward the object is negative and rad_L2S2 is the optical effective radius of the image side of the non-planar prism L2, it satisfies the following conditions:

(vi) -0.15 ≤ sag_L2S2 /rad_L2S2 ≤ 0.1, more preferably -0.1 ≤ sag_L2S2 /rad_L2S2 ≤0.05

The conditions (vi) keeps it possible to inject a light ray into the lens group G_rear with an appropriate angle of the light ray emitted from the image side surface of the non-planar prism L2.

According to a second aspect, a camera is provided. The camera comprises the ultra-wide-angle lens optical system provided in the first aspect and an image sensor. The ultra-wide-angle lens optical system is configured to input light, which is used to carry image data, to the image sensor; and the image sensor is configured to display an image according to the image data.

According to a third aspect, a terminal is provided. The terminal comprises a camera, which is the camera provided in the second aspect, and a Graphic Processing Unit (GPU) . The GPU is connected to the camera. The camera is configured to obtain image data and input the image data into the GPU, and the CPU is configured to process the image data received from the camera. The terminal can be applied to small cameras for mobile devices such as mobile phones and tablets.

The present disclosure will be presented in further detail from the following descriptions with accompanying drawings, which show, for purpose of illustration only, the preferred embodiments in accordance with the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure can be better understood from the following detailed description of non-limiting embodiments thereof, and on examining the accompanying drawings, in which:

FIG 1-1 shows a cross-sectional illustration of an optical lens system in accordance with a first embodiment of the present disclosure.

FIG 1-2 shows a longitudinal spherical aberration of the optical lens system in accordance with the first embodiment of the present disclosure.

FIG 1-3 shows an astigmatic field of the optical lens system in accordance with the first embodiment of the present disclosure.

FIG 1-4 shows a distortion of the optical lens system in accordance with the first embodiment of the present disclosure.

FIG 2-1 shows a cross-sectional illustration of an optical lens system in accordance with a second embodiment of the present disclosure.

FIG 2-2 shows a longitudinal spherical aberration of the optical lens system in accordance with the second embodiment of the present disclosure.

FIG 2-3 shows an astigmatic field of the optical lens system in accordance with the second embodiment of the present disclosure.

FIG 2-4 shows a distortion of the optical lens system in accordance with the second embodiment of the present disclosure.

FIG 3-1 shows a cross-sectional illustration of an optical lens system in accordance with a third embodiment of the present disclosure.

FIG 3-2 shows a longitudinal spherical aberration of the optical lens system in accordance with the third embodiment of the present disclosure.

FIG 3-3 shows an astigmatic field of the optical lens system in accordance with the third embodiment of the present disclosure.

FIG 3-4 shows a distortion of the optical lens system in accordance with the third embodiment of the present disclosure.

FIG 4 shows an implementation of the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following embodiments of the ultra-wide-angle lens optical system of the present disclosure will be described referring to the figures and the optical data. This lens system can be applied to cameras for mobile devices such as a mobile-phones and tablets. In addition, the present optical system consists of a front lens, a non-planner prism, and a rear lens group consisting of five lenses. The rear lens of group may consist of less or more than five lenses.

The non-planar prism has non-planar surfaces on both an object side and an image side such that the front lens can be arranged very close to the non-planar prism in order to minimize the distance between the front surface of the front lens and the optical axis of the rest of the lenses. Therefore, both thickness and TTL of the optical module can be smaller than an ordinary optical module using a regular prism since it enables the configuration that the front sphere protrudes slightly from the maximum diameter of the rear group of lens system.

As a result, the following embodiments of the ultra-wide-angle lens optical system of the present disclosure can achieve both high image quality with substantially little distortion and compactness.

First Embodiment

FIG 1-1 shows a cross-sectional illustration of an optical lens system in accordance with a first embodiment of the present disclosure. The optical lens system comprises, from the object side, a first lens L1 with a positive refractive index, a non-planar prism L2 with a positive refractive index and which bends the optical path by 90°, and a rear group of the lens system (G_rear) composed of a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a seventh lens L7. In addition, the term “stop” stands for an iris surface, which is arranged between the non-planar prism L2 and the third lens L3. An optical filter IR such as an infrared cut filter or a cover glass is arranged between the L7 lens and the imaging surface. Note that this filter IR can be omitted.

Table 1-1 shows the radius of curvature, the thickness or separation for each of the optical surfaces at center, and the refractive index of the d line, and the Abbe number with respect to the d line for each of the lens elements of the optical lens system in accordance with a first embodiment.

Table 1-1

It should be also noted that the surface with *indicates that the surface is an aspherical surfaces so that all surfaces of each optical elements in the first embodiment are aspherical surfaces. Only the fifth lens L5 is made of an optical glass material while the others are made of plastic material in the first embodiments.

Table 1-2 shows the aspheric coefficients for each of the lens elements of the optical lens system in accordance with a first embodiment., wherein numbers 2, 4, …, 20 represent the higher order aspheric coefficients. The equation of the aspheric surface profiles is expressed as follows:

wherein:

z: the distance (sag amount) in the optical axis direction from the apex of the lens surface;

H: the height in the direction perpendicular to the optical axis direction;

c: paraxial curvature at the apex of the lens (reciprocal of radius of curvature) ;

Y: the distance from a point on the curve of the aspheric surface to the optical axis;

k: the conic coefficient; and

Ai: the aspheric coefficient of order i.

Table 1-2

ASPHERICAL COEFFICIENTS

FIG 1-2 shows the spherical aberration diagram which shows the amount of aberration for each wavelength of the F line (486.1 nm) , d line (587.6 nm) , and C line (656.3 nm) with solid lines.

FIG 1-3 shows the astigmatism diagram, the amount of d-line aberration on the sagittal image plane S is shown by a solid line, and the amount of d-line aberration on the tangential image plane T is shown by a broken line.

FIG 1-4 shows the distortion diagram shows the amount of aberration on the d-line with a solid line.

It can be seen from the diagrams that each aberration is satisfactorily corrected. Further, with respect to the term used in the present invention, the refractive power refers to the refractive power in the paraxial axis (near the optical axis) .

Second Embodiment

FIG 2-1 shows a cross-sectional illustration of an optical lens system in accordance with a second embodiment of the present disclosure. The optical lens system comprises, from the object side, a first lens L1 with a negartive refractive index, a non-planar prism L2 with a positive refractive index and which bends the optical path by 90°, and a rear group of the lens system (G_rear) composed of a third lens L3, a forth lens L4, a fifth lens L5, a sixth lens L6, and a seventh lens L7. In addition, the term “stop” stands for an iris surface, which is arranged between the non-planner prism L2 and the third lens L3. An optical filter IR such as an infrared cut filter or a cover glass is arranged between the L7 lens and the imaging surface. Note that this filter IR can be omitted.

Table 1-2 shows the radius of curvature, the thickness or separation for each of the optical surfaces at center, and the refractive index of the d line, and the Abbe number with respect to the d line for each of the lens elements of the optical lens system in accordance with a second embodiment.

Table 2-1

It should be also noted that the surface with *indicates that the surface is an aspherical surfaces so that all surfaces except the non-planar prism L2 are composed of aspherical surfaces in the second embodiment, and L2 is composed of double-sided spherical surfaces. All optical elements are made of plastic material in the second embodiments.

Table 2-2 shows the aspheric coefficients for each of the lens elements of the optical lens system in accordance with a second embodiment, wherein numbers 2, 4, …, 20 represent the higher order aspheric coefficients. The aspheric coefficients are given as mentioned above.

Table 2-2

ASPHERICAL COEFFICIENTS

FIG 2-2 shows the spherical aberration diagram which shows the amount of aberration for each wavelength of the F line (486.1 nm) , d line (587.6 nm) , and C line (656.3 nm) with solid lines.

FIG 2-3 shows the astigmatism diagram, the amount of d-line aberration on the sagittal image plane S is shown by a solid line, and the amount of d-line aberration on the tangential image plane T is shown by a broken line.

FIG 2-4 shows the distortion diagram shows the amount of aberration on the d-line with a solid line.

Third Embodiment

FIG 3-1 shows a cross-sectional illustration of an optical lens system in accordance with a thirdt embodiment of the present disclosure. The optical lens system comprises, from the object side, a first lens L1 with a negative refractive index, a non-planar prism L2 with a positive refractive index and which bends the optical path by 90°, and a rear group of the lens system (G_rear) composed of a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, and a seventh lens L7. In addition, the term “stop” stands for an iris surface, which is arranged between the non-planar prism L2 and the third lens L3. An optical filter IR such as an infrared cut filter or a cover glass is arranged between the L7 lens and the imaging surface. Note that this filter IR can be omitted.

Table 3-1 shows the radius of curvature, the thickness or separation for each of the optical surfaces at center, and the refractive index of the d line, and the Abbe number with respect to the d line for each of the lens elements of the optical lens system in accordance with a third embodiment.

Table 3-1

It should be also noted that the surface with *indicates that the surface is an aspherical surfaces so that all surfaces of each optical elements in the third embodiment are aspherical surfaces. All optical elements are made of plastic material.

Table 3-2 shows the aspheric coefficients for each of the lens elements of the optical lens system in accordance with a third embodiment, wherein numbers 2, 4, …, 20 represent the higher order aspheric coefficients. The aspheric coefficients are given as mentioned above.

Table 3-2

ASPHERICAL COEFFICIENTS

FIG 3-2 shows the spherical aberration diagram which shows the amount of aberration for each wavelength of the F line (486.1 nm) , d line (587.6 nm) , and C line (656.3 nm) with solid lines.

FIG 3-3 shows the astigmatism diagram, the amount of d-line aberration on the sagittal image plane S is shown by a solid line, and the amount of d-line aberration on the tangential image plane T is shown by a broken line.

FIG 3-4 shows the distortion diagram, which shows the amount of aberration on the d-line with a solid line.

As shown in the optical data above, the ultra-wide-angle lens optical system of the present disclosure can achieve both high image quality with substantially little distortion and compactness. The ultra-wide-angle lens in these embodiments obtains a preferable effect by satisfying the following conditions:

(i) 50 ≤ ω ≤ 75

Where ω is half angle of view.

(ii) -3.9 ≤ f1 /f ≤ -0.8

Where f is the focal length of the ultra-wide-angle lens optical system, and f1 is the focal length of the first lens L1.

(iii) 2 ≤ f2 /f ≤ 9.5

Where f is the focal length of the ultra-wide-angle lens optical system, and f2 is the focal length of the non-planar prism L2.

(iv) 1.3 ≤ f (G_rear) /f ≤ 3.3

Where f is the focal length of the ultra-wide-angle lens optical system, and f (G_rear) is the focal length of the rear group G_rear.

(v) 6 ≤ TTL /f ≤ 16

Where f is the focal length of the ultra-wide-angle lens optical system, and TTL is that total length of the optical path from the imaging surface to the surface S1 of the first lens L1.

(vi) -0.15 ≤ sag_L2S2 /rad_L2S2 ≤ 0.1

Where sag_L2S2 is the amount of sag on the S2 surface of the non-planner prism L2, when the direction toward the imaging surface is positive and the direction toward the object is negative and rad_L2S2 is the optical effective radius of the S2surface of the non-planar prism L2.

The condition (i) defines the range of field of view for ultra-wide-angle lens. If it falls below this lower limit, large distortion, which has been a problem as mentioned above, occurs. Further, even if the configuration of the present invention is used, it becomes difficult to correct the distortion aberration generated when the upper limit is exceeded in a well-balanced manner together with the coma aberration and the curvature of field. Specifically, the resolution performance deteriorates due to an excessive increase in the power of the non-planar prism. From this viewpoint, the following range is more preferable.

(i) -2: 55 ≤ ω ≤ 70

The condition (ii) defines the range in which the ultra-wide-angle lens optical system can appropriately control the area of light flux incident on the non-planar prism while achieving the field of view defined by condition (i) . If it falls below the lower limit, the prism thickness becomes large, and a thickness such that it can be mounted on a thin product cannot be achieved. If the upper limit is exceeded, the prism thickness becomes smaller, but coma aberration and spherical aberration occur due to the sudden bending of light rays by the first lens, and good resolution performance cannot be obtained. From this viewpoint, the following range is more preferable.

(ii) -2: -2.8 ≤ f1 /f ≤ -1.3

The condition (iii) defines the range of power of the non-planar prism for satisfactorily correcting distortion and coma aberration, achieving miniaturization, and ensuring a sufficient amount of peripheral light. If this upper limit is exceeded, the power of the non-planar prism will be weakened, and the effect will be the same as that of a right-angle prism that has been usually used. If it falls below the lower limit, the power of the non-planar prism becomes excessively strong and the resolution performance deteriorates. From this viewpoint, the following range is more preferable.

(iii) -2: 3 ≤ f2 /f ≤ 7.5

Regarding peripheral light, it is known that as the field of view increases, the amount of peripheral light decreases due to the cosine fourth power law. One way to improve this issue is to generate distortion, which distorts the image as described above. Another method for improving peripheral light is to increase the vignetting factor. This means that the thickness of the luminous flux incident on the first lens L1 is made thicker than the central luminous flux. This enlargement of the peripheral luminous flux prevents a decrease in the amount of peripheral light. Regarding the content of the present invention, this vignetting factor can be maximized by observing the conditions (ii) and (iii) , leading to the result that the amount of peripheral light can be secured.

The condition (iv) defines the range for effectively achieving good correction of curvature of field and shortening of the optical overall length (TTL) . By satisfying this range, the curvature of field can be satisfactorily corrected and the total optical length can be shortened. If it exceeds the upper limit, the total optical length becomes longer, and if it falls below the lower limit, curvature of field occurs and the resolution performance deteriorates. From this viewpoint, the following range is more preferable.

(iv) -2: 1.6 ≤ f (G_rear) /f ≤ 2.5

The conditions (v) defines an optical overall length condition suitable for sufficiently reducing distortion and then satisfactorily correcting coma and curvature of field. Exceeding the upper limit will lead to an increase in the size of the lens module. The space is not infinite even though it is bent and lowered. If it falls below the lower limit, the above-mentioned aberration correction becomes insufficient and the resolution performance deteriorates. From this viewpoint, the following range is more preferable.

(v) -2: 7.6 ≤ TTL /f ≤ 14

The conditions (vi) keeps it possible to inject a light ray into the lens group G_rear with an appropriate angle of the light ray emitted from the image side surface of the non-planar prism L2. If it deviates from this range, it becomes difficult to maintain an ultra-wide-angle and aberration correction. Further, within this range, the ease of manufacturing the non-planar prism and the ease of assembling the front group and the rear group can be improved. From this viewpoint, the following range is more preferable.

(vi) -2: -0.1 ≤ sag_L2S2 /rad_L2S2 ≤ 0.05

With the ultra-wide-angle lens optical system of the present invention, the distortion can be maintained very low (less than 5%) despite the ultra-wide-angle. Further, it also enables the first lens L1 to be arranged close to the non-planar prism L2, in other word, to keep the thickness of the ultra-wide-angle lens module very small. Therefore, he ultra-wide-angle lens optical system of the present invention can be used in many mobile devices to provide both an ultra-wide angle and preferable image quality.

Further, a camera is provided. The camera in the present disclosure comprises the ultra-wide-angle lens optical system of the present disclosure and an image sensor. The ultra-wide-angle lens optical system is configured to input light, which is used to project an image to the image sensor; and the image sensor is configured to convert the image into a digital image data. Such a camera is preferable for installation in a mobile device.

FIG. 4 shows a terminal 1000 disclosed in the present disclosure. The terminal 1000 comprises cameras 100 provided in the above implementations and a Graphic Processing Unit (GPU) 200. The camera 100 is configured to convert an image through an ultra-wide-angle lens optical system of the present disclosure to digital image data and input the digital image data into the GPU 200, and the GPU 200 is configured to process the image data received from the camera.

In FIG. 4 terminal comprises two cameras 100. However, the terminal may comprise a single camera or two or more cameras and it (or they) could be connected to the single GPU 200. The terminal 1000 can be applied to a high resolution mobile device camera such as a mobile phone camera because of its ultra-wide-angle, high image quality and compactness.

In the present disclosure, the ultra-wide angle here refers to a half angle of view of approximately 45° or more.

Although the lens system according to the present disclosure can be applied especially to mobile phone cameras, it can also be applied to cameras in any mobile device such as a smartphone, a game machine, a PC, an IP camera, a home appliance, an automobile, etc.

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

Claims

An ultra-wide-angle lens optical system comprising, form the object side to the image side, a first lens, a non-planner prism, and a rear group of lenses, wherein ω is half angle of view of the ultra-wide-angle lens optical system, f is the focal length of the ultra-wide-angle lens optical system, and f1 is the focal length of the first lens, it satisfy the following conditions:

(i) 50 ≤ ω ≤ 75, more preferably 55 ≤ ω ≤ 70; and

(ii) -3.9 ≤ f1 /f ≤ -0.8, more preferably -2.8 ≤ f1 /f ≤ -1.3
The ultra-wide-angle lens optical system as claimed in claim 1, wherein f2 is the focal length of the non-planner prism, it satisfy the following conditions:

(iii) 2 ≤ f2 /f ≤ 9.5, more preferably 3 ≤ f2 /f ≤ 7.5
The ultra-wide-angle lens optical system as claimed in any of the previous claims, wherein f (G_rear) is the focal length of the rear group, it satisfy the following conditions:

(iv) 1.3 ≤ f (G_rear) /f ≤ 3.3, more preferably 1.6 ≤ f (G_rear) /f ≤ 2.5
The ultra-wide-angle lens optical system as claimed in any of the previous claims, wherein TTL is that total length of the optical path from an imaging surface to the front surface of the first lens, it satisfy the following conditions:

(v) 6 ≤ TTL /f ≤ 16, more preferably 7.6 ≤ TTL /f ≤ 14
The ultra-wide-angle lens optical system as claimed in any of the previous claims, wherein sag_L2S2 is the amount of sag on the back surface of the non-planner prism, when the direction toward the imaging surface is positive and the direction toward the object is negative and rad_L2S2 is the optical effective radius of the image side of the non-planner prism, it satisfy the following conditions:

(vi) -0.15 ≤ sag_L2S2 /rad_L2S2 ≤ 0.1, more preferably -0.1 ≤ sag_L2S2 /rad_L2S2 ≤0.05
The ultra-wide-angle lens optical system as claimed in any of the previous claims, wherein the rear group is consist of five lenses.
A camera comprising the ultra-wide-angle lens optical system as claimed in any of the previous claims, further comprising an image sensor, wherein the ultra-wide-angle lens optical system is configured to project an image onto the image sensor, and the image sensor is configured to convert the image into digital image data.
A terminal comprising the camera according to claim 7 and a Graphic Processing Unit (GPU) , wherein the GPU is connected with the camera to receive and process the digital image.