CN110275290B

CN110275290B - Relay lens design method for multi-camera imaging test

Info

Publication number: CN110275290B
Application number: CN201810209025.0A
Authority: CN
Inventors: 陆海雷
Original assignee: Shenzhen Long Ce Technology Co ltd
Current assignee: Shenzhen Long Ce Technology Co ltd
Priority date: 2018-03-14
Filing date: 2018-03-14
Publication date: 2022-07-05
Anticipated expiration: 2038-03-14
Also published as: CN110275290A

Abstract

The invention discloses a relay lens design method for multi-camera imaging test, which comprises the following steps: s1, the imaging system is arranged to comprise: the system comprises an illumination system, a test card, a camera module and a relay lens; the relay lens is deviated from the optical axis at the two sides of the diaphragm, and the deviation distance is greater than the distance between the adjacent cameras to be measured; s2, setting a lens group and an initial structure thereof, selecting a field angle and an entrance pupil diameter of the camera module, and optimizing distortion and axis offset according to concentricity to optimize imaging quality; s3, determining the structure of the lens group to complete the design of the relay lens, and solving the problems that the imaging quality is reduced when the existing relay lens design method for imaging test is used for testing a plurality of cameras, the in-situ parallel imaging and detection are realized, the working efficiency is low, more automatic focusing equipment is needed, and the utilization rate of the area of equipment and a production workshop is low.

Description

Relay lens design method for multi-camera imaging test

Technical Field

The invention relates to the field of optical imaging quality detection, in particular to a design method of a relay lens for multi-camera imaging test.

Background

The relay lens is used for simulating the far-focus imaging of the camera, so that the far-focus effect is shot in a short distance, and the relay lens is widely applied to the automatic focusing of the camera module and the imaging quality detection industries of the camera module, a mobile phone camera, a vehicle-mounted camera and the like.

In the imaging detection of the double cameras, a single-camera relay lens is adopted to carry out analog imaging by moving, switching and dividing twice. The detection process comprises the following steps: (1) the camera 1 moves to the relay lens position; (2) shooting an image 1; (3) processing the image 1 and evaluating the image quality 1; (4) the camera 1 moves away, and the camera 2 moves in; (5) shooting an image 2; (6) processing the image 2 and evaluating the image quality 2; (7) the camera 2 is removed. Completing a test cycle, namely processing the image 1, evaluating the image quality 1, moving the camera 1 away and moving the camera 2 in, but most processes are carried out in sequence, thus influencing the detection efficiency and being characterized by saving the equipment space;

in the multi-station automatic focusing, a single-shot relay lens is adopted. The detection process comprises the following steps: (1) the

cameras

1 and 2 are placed at the positions of the relay lenses; (2)

images

1, 2 are taken simultaneously; (3) processing the

images

1, 2; and (4) evaluating the

image quality

1 and 2. And a test cycle is completed, and because the two sets of tests adopt parallel processing, the test efficiency is higher, but the equipment occupies 2 times of space. (in the imaging detection, the parts occupying the space of the equipment are a test card and a plane light source, and the size of the parts is 600x600mm when the parts are small and 1000x1000mm when the parts are large.)

If an imaging detection system consisting of a relay lens is used, the homothetic parallel imaging and detection can be realized, and the working efficiency can be greatly improved. Meanwhile, the scheme can also replace multi-station single-camera automatic focusing, and even can expand to 3 to 4 camera modules for automatic focusing, so that automatic focusing equipment is greatly reduced, and the utilization rate of the area of equipment and a production workshop is improved.

However, in the conventional single-shot relay lens, the optical axes of the camera and the relay lens are not on the same axis, i.e. there is an eccentricity, in which case the imaging quality of the system will be seriously degraded, which is obviously not feasible.

Therefore, a design scheme of a relay lens with two cameras is needed, which can ensure the imaging quality and greatly reduce the automatic focusing equipment, thereby improving the utilization rate of the area of the equipment and the production workshop.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, the invention mainly aims to provide a design method of a relay lens for double-camera imaging test, and aims to solve the problems that the existing design method of the relay lens for imaging test can not realize in-situ parallel imaging and detection on the premise of ensuring imaging quality, the working efficiency is low, more automatic focusing equipment is needed, and the utilization rate of the equipment and the production workshop area is low.

In order to achieve the above object, the present invention provides a method for designing a relay lens for multi-camera imaging test, comprising the following steps:

s1, an imaging system is set, and the imaging system comprises: the system comprises an illumination system, a test card arranged at the front end of the illumination system, a camera module arranged at the front end of the test card and a relay lens arranged between the camera module and the test card;

the relay lens is deviated from the optical axis at the two sides of the diaphragm, and the deviation distance is greater than the distance between the adjacent cameras to be measured;

s2, setting a lens group and an initial structure thereof, selecting a field angle and an entrance pupil diameter of the camera module, and optimizing distortion and axis offset according to concentricity to optimize imaging quality;

s3 determining the structure of the lens set to complete the design of the relay lens.

In one embodiment, the imaging system is configured to include: setting the wavelength of light, setting the diameter of a diaphragm of an illumination system, setting the angle of view of a camera module, setting an object plane, setting an image plane and setting the distance between the object plane and the image plane.

The invention has the following beneficial effects:

the invention realizes the homothetic parallel imaging and detection by setting each parameter to achieve the imaging system that at least two cameras use one relay lens, thereby greatly improving the working efficiency, reducing the automatic focusing equipment and improving the utilization rate of the equipment and the area of a production workshop.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic flow chart of the present invention.

Fig. 2 is a schematic structural diagram of an imaging quality detection system of the present invention.

FIG. 3 is a schematic diagram showing the positional relationship between the relay lens and each station of the imaging quality detection system according to the present invention.

FIG. 4 is a test chart of MTF curve in the embodiment of the present invention.

Fig. 5 is a graph showing distortion characteristics in the embodiment of the present invention.

FIG. 6 is a Spot Diagram in an embodiment of the invention.

FIG. 7 is a graph of MTF vs Fields in an example of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.

Descriptions in this specification as relating to "first", "second", etc. are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit to any indicated technical feature or quantity. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature.

In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "connected," "secured," and the like are to be construed broadly, and for example, "secured" may be a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In addition, the technical solutions in the embodiments of the present invention may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination of technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

Example 1

Referring to fig. 1, a method for designing a relay lens for a multi-camera imaging test includes the following steps:

s1, an imaging system shown in figure 2 is arranged, and comprises: the test system comprises an illumination system 4, a test card 1 arranged at the front end of the illumination system 4, a camera module 2 arranged at the front end of the test card 1 and a relay lens 3 arranged between the camera module 2 and the test card 1;

referring to fig. 3, the camera module 2 is at least provided with two cameras, the relay lens 3 deviates from the optical axis 5 of the diaphragm at two sides, and the deviation distance is greater than the distance DBC between adjacent cameras to be measured;

s2, setting a lens group and an initial structure thereof, selecting a field angle FOV (field of view) of the camera module and an entrance pupil diameter of the camera module, and optimizing distortion and axis offset according to concentricity to optimize imaging quality;

and S3, taking data of the optimal imaging quality, recording the data and designing a relay lens structure.

Preferably, the imaging system is arranged to comprise: setting the wavelength of light, setting the diameter of a diaphragm of an illumination system, setting the view field angle of a camera module, setting an object plane, setting an image plane and setting the distance WDV between the object plane and the image plane.

According to the design method, the double-camera relay lens is designed, so that the optical axis is within a certain eccentric range, and excellent imaging quality can be still obtained.

The verification process is as follows:

setting the wavelengths of light rays 0.48613270, 0.58756180 and 0.65627250 um;

the field angle of the camera module is 106 degrees, and the diameter of the entrance pupil of the camera module is 2 mm;

taking the axis center offset (camera module baseline) as 17 mm;

the designed double-lens relay lens has the structure shown in figure 3;

the optical indices are shown in the following table:

as shown in fig. 4 to 7 combined with the above table, it can be found by comparing with the conventional single quality detection system that the relay lens related by the design method achieves an imaging system in which at least two cameras use one relay lens by setting parameters, and realizes in-situ parallel imaging and detection without affecting the imaging quality, thereby greatly improving the working efficiency, reducing the number of auto-focusing devices, and improving the utilization ratio of the areas of the devices and the production workshops.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A design method of a relay lens for multi-camera imaging test is characterized by comprising the following steps:

s1, an imaging system is set, and the imaging system comprises: the system comprises an illumination system, a test card arranged at the front end of the illumination system, a camera module arranged at the front end of the test card and a relay lens arranged between the camera module and the test card; the setting imaging system includes: setting light wavelength, setting the diameter of a diaphragm of the illumination system, setting the view field angle of the camera module, setting an object plane, setting an image plane and setting the distance between the object plane and the image plane;

s2, setting a camera lens group and an initial structure thereof, selecting a view field angle and an entrance pupil diameter of the camera module, and optimizing distortion and axis offset according to concentricity to optimize imaging quality;

and S3, determining the structure of the relay lens group to complete the design of the relay lens.