CN106791293B

CN106791293B - Optical system

Info

Publication number: CN106791293B
Application number: CN201611034868.9A
Authority: CN
Inventors: 诸益炜; 尚洁阳; 盛亚茗; 张平华; 马斯颖
Original assignee: Jiaxing Zhongrun Optical Technology Co Ltd
Current assignee: Jiaxing Zhongrun Optical Technology Co Ltd
Priority date: 2016-11-23
Filing date: 2016-11-23
Publication date: 2023-08-18
Anticipated expiration: 2036-11-23
Also published as: WO2018095163A1; CN106791293A

Abstract

An optical system comprises a first lens group G1 and a second lens group G2, wherein the optical axes of the two lens groups are completely overlapped, the angle of view of the first lens group G1 is smaller than 60 degrees, and the angle of view of the second lens group G2 is larger than 90 degrees; from the object side along the optical axis direction, all lenses of the front section of the first lens group G1 and the front section of the second lens group G2 are shared, and all lenses of the rear section of the first lens group G1 and the rear section of the second lens group G2 are semicircular; the lens at the rear section of the first lens group G1 keeps a semicircular lens below the horizontal plane where the optical axis is positioned, and the semicircular part above the horizontal plane is completely removed; the lens at the rear section of the second lens group G2 keeps a semicircular lens above the horizontal plane where the optical axis is positioned, and the semicircular part below the horizontal plane is completely removed; the semicircular lenses at the rear sections of the two lens groups are assembled in the same lens cone.

Description

Optical system

Technical Field

The present invention relates to an optical system.

Background

In recent years, with the increasing number of automobiles and the rapid development of unmanned technology, the requirements of people on driving safety are also increasing. In the past, the safety of the automobile only depends on the judgment of a driver, and once the driver is not concentrated or does not notice various environmental changes around the automobile in time, driving accidents are easy to occur. With the continuous development of optical lenses, people start to utilize various vehicle-mounted optical lenses to assist drivers in understanding and judging driving environments. At present, in some high-end front-end automobile driving systems, an advanced driving assistance system (Advanced Driver Assistant System) is adopted, so that automobile driving safety is enabled to enter a new man-machine interaction era.

The advanced driving assistance system, abbreviated as ADAS, is an active safety technology that uses various sensors mounted on a vehicle to collect environmental data inside and outside the vehicle at a first time, and performs technologies such as identification, detection and tracking of static and dynamic objects, so that a driver can perceive possible danger in the fastest time to draw attention and improve safety. In the past, such systems were limited to the high-end market, and in recent years, the rapid growth of the ADAS system market is gradually going into the mid-end market. At the same time, many low technology applications are more common in the field of entry level passenger cars, and new opportunities and strategies are created for system deployment by improved new sensor technologies.

The ADAS system mainly comprises a positioning module, a detection module, a communication module, a control module and the like. The positioning module and the module receive GPS satellite signals through a GPS receiver and calculate longitude and latitude coordinates, speed, time and other information of the vehicle; the detection module is used for observing the conditions of the whole automobile and two sides of a road in real time by utilizing an optical lens arranged around the automobile; the communication module can send the detected related information and transmit the driving information in real time between automobiles which are close to each other; the control module can make active control when an accident happens, so that the accident is avoided.

In the detection module of the ADAS system, the detection module is most commonly composed of a lens, an image sensor, an image processor, a screen and the like. The method comprises the steps of collecting driving environment information around the automobile through a lens, imaging the driving environment information into an image sensor, forming a 360-degree imaging network around the automobile through a plurality of lenses matched with a plurality of image sensors, processing and analyzing the images through an image processor, and displaying the images on a screen for a driver to know and judge the surrounding environment of the automobile. If the automatic driving technology is combined, the key information can be directly read from the image to carry out automatic driving process analysis. In the detection module, the most important is the performance of the lens. An optical lens with excellent performance can provide richer detail information, greatly improve the overall performance of the detection module, and enable the ADAS system to have higher and more comprehensive safety and universality.

All detection modules of ADAS systems on the market at present are provided with an image sensor by a lens with a single field angle, so that each image sensor can only image at a single angle. In one lens, different angles of view have different characteristics, taking an optical lens directly in front of the vehicle as an example: the large angle of view corresponds to a wider field of view, as if the naked human eye looks directly, more objects in front of the vehicle from the near end to the far end can be seen, however, each object is very small, and detailed information cannot be presented; the small angle of view corresponds to a narrower field of view, as observed by a human telescope, only a small number of objects in a small range of angles in front of the vehicle can be seen, however, each object is correspondingly enlarged on the screen, so that more detailed information is presented for information analysis by a driver or an automatic driving system. Therefore, in all the test modules of the ADAS system at present, the automobile should be equipped with at least two lenses in a certain fixed direction (front direction): one tele lens to receive the remote detail information and one wide angle lens to receive the overall environment information (see fig. 1).

Two-lens ADAS systems are adopted, two sets of image sensors and image processors are matched at present, bridging is needed between the two sets of systems, and information is synchronized and processed. So that a certain time difference is generated from the acquisition of the lens image to the rendering of the information available on the screen, which causes the information to be delayed. In the high-speed driving process of the automobile, the driving risk caused by information delay can be greatly improved, so that the ADAS system has certain safety risk.

Meanwhile, more than two lenses are matched with more than two sets of image sensors, image processors and screens, so that the cost of a detection module becomes very expensive, and an ADAS system is still in a high-end automobile driving system at present and is not popularized in the field of middle-low-end automobiles.

Disclosure of Invention

The present invention has been made to overcome the above-mentioned drawbacks of the prior art, and provides an optical system having high detection performance while achieving miniaturization and low cost.

An optical system, characterized in that: comprising the following steps: the optical axes of the first lens group G1 and the second lens group G2 are completely overlapped, wherein the angle of view of the first lens group G1 is smaller than 60 degrees, and the angle of view of the second lens group G2 is larger than 90 degrees;

the first lens group G1 and the second lens group G2 satisfy the following formula:

TTL1-TTL2 of 0.01 mm-0.01 mm (formula 1)

Wherein: from the object side along the optical axis direction, TTL1 is a distance from the center of the front surface of the first lens L11 of the first lens group G1 to the first image plane T1 of the first lens group G1; TTL2 is the distance from the center of the front surface of the first lens L21 of the second lens group G2 to the second image plane T2 of the second lens group G2;

the first lens group G1 is divided into a front section and a rear section by the first aperture STP1, the second lens group G2 is divided into a front section and a rear section by the second aperture STP2, and the following formula is satisfied:

-SS 1-SS2 of 0.03mm or less and 0.03mm or less; (2)

SS3-SS1 is more than or equal to 0.1mm; (3)

Wherein: SS1 is a distance from the center of the front surface of the first lens L11 of the first lens group G1 to the first diaphragm STP1 from the object side in the optical axis direction; SS2 is the distance from the center of the front surface of the first lens L21 of the second lens group G2 to the second diaphragm STP 2; SS3 is the distance from the center of the front surface of the first lens L21 of the second lens group G2 to the center of the front surface of the first lens of the second lens group G2 located behind the stop STP 2;

all lenses of the front section of the first lens group G1 and the front section of the second lens group G2 are shared, and all lenses of the rear section of the first lens group G1 and the rear section of the second lens group G2 are semicircular; the lens at the rear section of the first lens group G1 keeps a semicircular lens above the horizontal plane where the optical axis is positioned, and the semicircular part below the horizontal plane is completely removed; the lens at the rear section of the second lens group G2 keeps a semicircular lens below the horizontal plane where the optical axis is positioned, and the semicircular part above the horizontal plane is completely removed; the semicircular lenses of the rear sections of the two lens groups are assembled in the same lens barrel, the lens of the rear section of the first lens group is positioned above the horizontal plane with the optical axis as a boundary, and the lens of the rear section of the second lens group is positioned below the horizontal plane with the optical axis as a boundary (see figure 3). Further, the first image plane T1 of the first lens group G1 and the second image plane T2 of the second lens group G2 are located on the same image sensor P.

The working principle of the invention is that light rays passing through two lens groups of an optical system can show two semicircles on an image plane (see figure 4): the light rays are imaged into a semicircle on the first image plane T1 after passing through the front section shared by the two lens groups and the rear section of the first lens group G1; the light rays are imaged into a semicircle on the second image plane T2 after passing through the front section shared by the two lens groups and the rear section of the second lens group G2. Because the total optical lengths TTL of the two lens groups are very close, the image plane positions of the two lens groups are very close and even the same in the case of sharing at least all lenses of the front section. When the rectangular image sensor is placed at the positions of the image surfaces of the two lens groups to receive images (if the image surfaces of the two lens groups are not overlapped, the rectangular image sensor is placed at the middle position of the two image surfaces), the upper half part of the rectangular image sensor is used for semi-circle imaging of the first lens group G1, and the lower half part of the rectangular image sensor is used for semi-circle imaging of the second lens group G2. Through the optical system, one lens can have two angles of view, and after light reaches the sensor through the lens, two pictures with different angles can be displayed on a screen (see figure 2): the upper half of the screen shows the real-time state of the tele lens, and the lower half of the screen shows the real-time state of the wide-angle lens. In addition, the two lens groups of the invention are insensitive to optical back focus by using more complex design methods such as positive and negative lens compensation and the like during design. For the lens insensitive to optical back focus, even if the position of the image surface is offset by a certain amount, the image quality is not greatly influenced, so that even if a certain interval exists between the image surfaces of the two lens groups, the same image sensor is used for receiving images at a certain position between the image surfaces of the two lens groups, high-quality images and rich information can be obtained, and the problems of image quality reduction and image information loss caused by assembly problems are improved.

The invention realizes that one lens has two angles of view simultaneously by adopting an innovative optical design and structure combination mode, and the screen can display two pictures with different angles after light reaches the sensor through the lens. In addition, the lens of the invention is insensitive to optical back focus by utilizing methods such as positive and negative lens compensation and the like during design; even if the position of the image plane of the lens insensitive to the optical back focus shifts by a certain amount, the lens does not have great influence on the image quality. Therefore, even if a certain interval exists between the two lens group image surfaces, the same image sensor is used for receiving images at a certain position between the two lens group image surfaces, and high-quality images and rich information can be obtained, so that the problems of image quality reduction, image information loss and the like caused by assembly are solved. In addition, the AA focusing automatic assembly process is matched, the assembly position of the image sensor is accurately positioned, the yield is greatly improved, the production cost is effectively reduced, and mass production is realized.

Meanwhile, the single lens has two angles of view, and the two detection requirements of long focus and wide angle can be realized by only one lens, one set of image sensor and an image processor for detection in a certain direction of the automobile, so that the cost of a detection system is greatly reduced.

In summary, the invention has the advantages of miniaturization, low cost, mass production and the like while ensuring that the detection module of the ADAS system has high detection performance. In addition, the invention can be widely applied to the fields of specific security monitoring, image detection, intelligent home furnishing and the like.

Drawings

FIG. 1 is a schematic diagram of a screen of a conventional on-board ADAS system, with pictures distributed on two different display screens;

FIG. 2 is a schematic diagram of a screen display of the present invention, with pictures on the same display screen;

FIG. 3 is a schematic view of the optical structure of the present invention;

FIG. 4 is a schematic representation of the imaging results of the present invention;

fig. 5 is an MTF diagram of the first lens group G1 in the embodiment;

FIG. 6 is a diagram showing aberrations of the first lens group G1 with respect to d-line in the embodiment;

fig. 7 is an MTF diagram of the second lens group G2 in the embodiment;

fig. 8 is a diagram showing aberrations of the second lens group G2 with respect to the d-line in the embodiment.

Detailed Description

The technical scheme of the invention is further described below with reference to the accompanying drawings.

Referring to fig. 2-8:

an optical system, characterized in that: comprising the following steps: the optical axes of the first lens group G1 and the second lens group G2 are completely overlapped, wherein the angle of view of the first lens group G1 is 50 degrees, and the angle of view of the second lens group G2 is 100 degrees;

TTL1-TTL2＝0

SS1-SS2＝0；

SS3-SS1＝3.15mm；

wherein: SS1 is a distance from the center of the front surface of the first lens L11 of the first lens group G1 to the first diaphragm STP1 from the object side in the optical axis direction; SS2 is the distance from the center of the front surface of the first lens L21 of the second lens group G2 to the second diaphragm STP 2; SS3 is the distance from the center of the front surface of the first lens L21 of the second lens group G2 to the center of the front surface of the first lens L25 of the second lens group G2 located behind the stop STP 2;

the first lens group G1 is composed of seven lenses, and includes, in order from an object side to an image side: the lens consists of a first lens L11 with negative focal power, a second lens L12 with negative focal power, a third lens L13 with positive focal power, a fourth lens L14 with negative focal power, a diaphragm, a glued lens L15/L16 with positive focal power and a seventh lens L17 with positive focal power.

The second lens group G2 is composed of eight lenses, and includes, in order from the object side to the image side: the lens comprises a first lens L21 with negative focal power, a second lens L22 with negative focal power, a third lens L23 with positive focal power, a fourth lens L24 with negative focal power, a diaphragm, a fifth lens L25 with positive focal power, a glued lens L26/L27 with negative focal power and an eighth lens L28 with positive focal power.

The front section of the first lens group G1 and the diaphragm of the second lens group G2 are shared by all lenses of the front section, and all lenses of the rear section of the first lens group G1 and the rear section of the second lens group G2 are semicircular; the lens at the rear section of the first lens group G1 keeps a semicircular lens above the horizontal plane where the optical axis is positioned, and the semicircular part below the horizontal plane is completely removed; the lens at the rear section of the second lens group G2 keeps a semicircular lens below the horizontal plane where the optical axis is positioned, and the semicircular part above the horizontal plane is completely removed; the semicircular lenses of the rear sections of the two lens groups are assembled in the same lens barrel, the lens of the rear section of the first lens group is positioned above the horizontal plane where the optical axis is positioned as a limit, and the lens of the rear section of the second lens group is positioned below the horizontal plane where the optical axis is positioned as a limit.

Table 1 is the structural parameters of the first lens group G1.

Table 2 is the structural parameters of the second lens group G2.

TABLE 1

TABLE 2

Surface serial number	Surface type	Radius of curvature	Thickness of (L)	Refractive index	Abbe number
						S1	Spherical surface	23.087	1.00	1.78	45.7
S2	Spherical surface	7.884	6.04
						S3	Spherical surface	15.863	1.40	1.72	56.2
S4	Spherical surface	7.451	2.79
						S5	Spherical surface	15.885	2.20	1.48	70.1
S6	Spherical surface	INF	1.08
						S7	Spherical surface	9.876	2.00	1.95	51.4
S8	Spherical surface	5.881	2.01
						Diaphragm	Spherical surface	INF	3.15
S10	Spherical surface	12.178	3.97	1.91	35.2
						S11	Spherical surface	-9.933	1.21
S12	Spherical surface	-17.929	1.09	1.92	18.0
						S13	Spherical surface	5.715	3.58	1.48	70.1
S14	Spherical surface	-7.072	0.67
						S15	Spherical surface	10.716	5.41	1.83	42.0
S16	Spherical surface	-112.39	5.30
						Image plane	Spherical surface

The first image plane T1 of the first lens group G1 and the second image plane T2 of the second lens group G2 are located on the same image sensor P. According to this embodiment, the person skilled in the art can change the parameters, the angle of view of the first lens group G1 can take other values smaller than 60 °, and the angle of view of the second lens group G2 can take other values larger than 90 °, so as to realize a similar embodiment.

The embodiments described in the present specification are merely examples of implementation forms of the inventive concept, and the scope of protection of the present invention should not be construed as being limited to the specific forms set forth in the embodiments, and the scope of protection of the present invention and equivalent technical means that can be conceived by those skilled in the art based on the inventive concept.

Claims

1. An optical system, characterized in that: comprising the following steps: the optical axes of the first lens group G1 and the second lens group G2 are completely overlapped, wherein the angle of view of the first lens group G1 is smaller than 60 degrees, and the angle of view of the second lens group G2 is larger than 90 degrees;

TTL1-TTL2 of 0.01 mm-0.01 mm (formula 1)

-SS 1-SS2 of 0.03mm or less and 0.03mm or less; (2)

SS3-SS1 is more than or equal to 0.1mm; (3)

all lenses of the front section of the first lens group G1 and the front section of the second lens group G2 are shared, and all lenses of the rear section of the first lens group G1 and the rear section of the second lens group G2 are semicircular; the lens at the rear section of the first lens group G1 keeps a semicircular lens above the horizontal plane where the optical axis is positioned, and the semicircular part below the horizontal plane is completely removed; the lens at the rear section of the second lens group G2 keeps a semicircular lens below the horizontal plane where the optical axis is positioned, and the semicircular part above the horizontal plane is completely removed; the semicircular lenses of the rear sections of the two lens groups are assembled in the same lens barrel, the lens of the rear section of the first lens group is positioned above the horizontal plane where the optical axis is positioned as a limit, and the lens of the rear section of the second lens group is positioned below the horizontal plane where the optical axis is positioned as a limit.

2. An optical system as claimed in claim 1, wherein: the first image plane T1 of the first lens group G1 and the second image plane T2 of the second lens group G2 are located on the same image sensor P.