CN114025090B - Camera focusing mode and device based on MTF value - Google Patents
Camera focusing mode and device based on MTF value Download PDFInfo
- Publication number
- CN114025090B CN114025090B CN202111295858.1A CN202111295858A CN114025090B CN 114025090 B CN114025090 B CN 114025090B CN 202111295858 A CN202111295858 A CN 202111295858A CN 114025090 B CN114025090 B CN 114025090B
- Authority
- CN
- China
- Prior art keywords
- camera
- lens
- focus
- mtf value
- mapping relation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000013507 mapping Methods 0.000 claims abstract description 19
- 238000001514 detection method Methods 0.000 claims description 5
- 238000000034 method Methods 0.000 claims description 5
- 238000012360 testing method Methods 0.000 description 6
- 238000003384 imaging method Methods 0.000 description 4
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000000007 visual effect Effects 0.000 description 2
- 238000004891 communication Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/60—Control of cameras or camera modules
- H04N23/67—Focus control based on electronic image sensor signals
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N17/00—Diagnosis, testing or measuring for television systems or their details
- H04N17/002—Diagnosis, testing or measuring for television systems or their details for television cameras
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/60—Control of cameras or camera modules
- H04N23/695—Control of camera direction for changing a field of view, e.g. pan, tilt or based on tracking of objects
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Health & Medical Sciences (AREA)
- Biomedical Technology (AREA)
- General Health & Medical Sciences (AREA)
- Lens Barrels (AREA)
Abstract
The invention provides a camera focusing mode based on an MTF value, which relates to the technical field of camera focus debugging and comprises the following steps: s1, constructing a mapping relation table between an actual shooting distance a and a compensation rotation angle b; s2, adjusting the focus of the camera; and S3, performing rotation of the compensation angle on the basis of adjusting the focus of the camera. According to the camera focusing mode based on the MTF value, a relay lens is not needed, so that the original debugging equipment is provided with a space for installing a manipulator, the debugging efficiency can be improved, the production automation is improved, and the focusing mode is simple, reliable and accurate.
Description
Technical Field
The invention relates to the technical field of camera focus debugging, in particular to a camera focusing mode and device based on an MTF value.
Background
The MTF value (modulation transfer function) is a numerical value for comprehensively evaluating the contrast and resolution of a lens. The MTF value characterizes a single point modulation value on the lens, and multiple points on the lens are generally selected to measure the MTF value for comprehensive evaluation, and since the thickness of the lens is not uniform or radian exists, the chart (lens test chart) placed at the imaging position of the lens is planar, so that the MTF values tested on the chart by different test points on the lens may be different. If the MTF value of the center point is maximum, the MTF value of the edge is correspondingly reduced, so that the middle of final imaging is clear, and the edge is blurred.
In order to make the definition of all positions in the imaging picture consistent, it is generally necessary to fine-tune after the MTF of the center point of the lens on the chart reaches a certain qualified value, so as to achieve the best effect. The ideal solution is to proceed within the nominal focal length of the camera module, but the far focus distance often reaches several meters, at which distance the test case needs to be large, which is obviously impractical. In the prior art, a test device with a relay lens is generally used for analog measurement, and the actual distance between the lens and the char is shortened by the relay lens. However, due to the arrangement of the relay lens, no redundant space is reserved for installing the manipulator, so that the feeding, discharging and rotating of the camera module are completed manually, and the automatic production is not facilitated.
Disclosure of Invention
Therefore, the invention aims to overcome the defects of the prior art, thereby providing a camera focusing mode based on an MTF value, and a relay lens is not needed, so that the original debugging equipment is provided with a space for installing a manipulator, the debugging efficiency can be improved, and the production automation is improved.
In order to achieve the above object, the present invention provides a camera focusing method based on an MTF value, including the following steps:
s1, constructing a mapping relation table; a mapping relation table is constructed between the actual shooting distance a and the compensation rotation angle b required by the camera after the focus is adjusted according to preset parameters of a lens in the camera in advance, and the mapping relation table is input into debugging equipment;
s2, adjusting a focus; the lens is preliminarily screwed into a lens seat of the camera so that the lens seat and the lens seat are connected, the camera is placed in a fixer arranged on focusing equipment, the lens is screwed to rotate, and an MTF value is used for judging an alignment focus;
s3, compensating the angle; inputting the value of the actual shooting distance a into a control panel of the debugging equipment, searching a compensation rotation angle b corresponding to the actual shooting distance a from a pre-constructed mapping relation table by the debugging equipment, judging an alignment focus by using an MTF value, and driving a manipulator to automatically screw a lens to rotate according to the value of the compensation rotation angle b by the debugging equipment.
Further, the camera adjusts the focus in the debugging equipment and then compensates the rotation direction of the rotation angle b to be positive rotation or reverse rotation.
Further, in the step S1, a mapping relation table is constructed, the focal point of the camera is adjusted according to preset parameters of the camera, the distance between the camera and the target is correspondingly adjusted according to the actual shooting distance a required by the camera in the working environment, each detection point on the camera is mapped to the image definition on the target to be visually consistent everywhere through rotating the camera, and then the corresponding relation between the actual shooting distance a and the compensation rotation angle b of the camera after the focal point is adjusted is recorded.
The invention also provides a camera focusing device based on the MTF value, which comprises a frame, a short-distance target and a fixer, wherein the short-distance target is arranged above the frame, the target surface of the short-distance target is downward, the fixer is arranged right below the short-distance target and is used for fixing a camera, a backlight source is arranged above the short-distance target, and a manipulator is further arranged on the frame and can clamp a lens of the camera arranged on the fixer and drive the lens to rotate forwards or reversely.
Further, a control chip is arranged in the rack, a control panel is arranged on one side of the rack, the backlight source irradiates on the short-distance target, the control chip is used for calculating the MTF value of each detection point of the lens, which is mapped on the short-distance target, and the MTF value and the corresponding image are displayed from the control panel.
According to the camera focusing mode based on the MTF value, a relay lens is not needed, so that the original debugging equipment is provided with a space for installing a manipulator, the debugging efficiency can be improved, the production automation is improved, and the focusing mode is simple, reliable and accurate.
According to the camera focusing device based on the MTF value, through the method, a relay lens is not needed, so that the debugging equipment is provided with a space for installing a manipulator, the debugging efficiency can be improved, and the production automation is improved.
Detailed Description
It will be apparent that the described embodiments are some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
The camera comprises a lens, a lens seat and a main circuit board, wherein the lens seat is used for fixing the lens, external threads are arranged on the outer side of the lens, internal threads are arranged in the lens seat, the lens and the lens seat are fixed through threaded engagement, a lens is arranged on the lens, an image photosensitive element is arranged on the lens seat, and the camera is focused, namely the distance between the lens and the image photosensitive element is adjusted, so that an obtained image is clearer.
A camera focusing mode based on MTF value comprises the following steps:
s1, constructing a mapping relation table;
s2, adjusting a focus;
s3, compensating the angle;
in step S1, a mapping relation table is constructed in advance according to an actual shooting distance a possibly used by the camera in the application scene and a compensating rotation angle b required by the camera after the camera is adjusted to a focus, and the mapping relation table is input into the debugging device. The lenses with different focal lengths all need to construct a mapping relation table of the actual shooting distance a and the compensation rotation angle b corresponding to the step S1.
In the step S1, the focal point of the camera is adjusted according to the preset parameters of the lens, where the preset parameters mainly refer to the shooting distance corresponding to the focal length of the lens, and after the focal point is adjusted, the camera is in a state where the image is shot more clearly, but because the lens thickness is inconsistent, there is a situation that the visual sharpness of the imaging picture is inconsistent, and fine adjustment is needed again. The specific fine tuning process is to correspondingly adjust the distance between the lens and the target according to the actual shooting distance a required by the camera in the working environment, and make the definition of the image mapped onto the target by each detection point on the lens visually consistent everywhere by rotating the lens, and then record the corresponding relation between the actual shooting distance a and the compensation rotation angle b of the camera after the focus is adjusted. Changing the actual shooting distance to obtain different compensation rotation angles, and then constructing a mapping relation table corresponding to the different compensation rotation angles.
In step S2, the lens is first screwed into the lens mount of the camera so that the lens mount and the lens mount are engaged, the camera is placed in a holder provided on the focusing apparatus, and the position of the camera is fixed by the holder. The lens is screwed to rotate, and the MTF value is used for judging the alignment focus;
s3, compensating the angle; inputting the value of the actual shooting distance a into a control panel of the debugging equipment, searching a compensation rotation angle b corresponding to the actual shooting distance a from a pre-constructed mapping relation table by the debugging equipment, judging an alignment focus by using an MTF value, and driving a manipulator to automatically screw a lens to rotate according to the value of the compensation rotation angle b by the debugging equipment. The rotation direction of the compensation rotation angle b is positive rotation or reverse rotation after the focus of the camera is adjusted in the debugging equipment, namely, the compensation rotation angle can be realized by positive rotation or direction rotation after the focus of the camera is adjusted.
By fine tuning the camera module, the resolution of the image shot by the camera is consistent in visual sense, and a relay lens is not required to be arranged, so that enough space is available above the camera for installing a manipulator, the debugging process is completed by controlling the manipulator, the efficiency can be improved, the labor is reduced, and the automatic production is facilitated.
In this embodiment, the lens focal length as a test example is 4mm. In the step S1, a mapping relation table is constructed, and according to multiple tests and adjustment, the following mapping relation table of the actual shooting distance a and the compensation rotation angle b is obtained:
the compensation rotation angle b is the rotation angle of the camera after the focus is adjusted in the debugging equipment, and the rotation direction is positive rotation or reverse rotation.
The embodiment also provides a camera focusing device based on MTF value, including frame, short distance target and fixer, the short distance target sets up in the top of frame to the target surface of short distance target is downward, the fixer sets up under the short distance target, the fixer is used for fixed camera, the top of short distance target is provided with the backlight, still be provided with the manipulator in the frame, the camera lens of camera can be placed on the fixer in the centre gripping to drive the forward or reverse rotation of camera lens.
The control chip is arranged in the frame, a control panel is arranged on one side of the frame, the backlight source irradiates on the short-distance target, the MTF value of each detection point of the lens, which is mapped on the short-distance target, is calculated through the control chip, and the MTF value and the corresponding image are displayed from the control panel.
It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the invention.
Claims (2)
1. The camera focusing mode based on the MTF value is characterized by comprising the following steps:
s1, constructing a mapping relation table; a mapping relation table is constructed between the actual shooting distance a and the compensation rotation angle b required by the camera after the focus is adjusted according to preset parameters of a lens in the camera in advance, and the mapping relation table is input into debugging equipment; when a mapping relation table is constructed, the focus of the camera is adjusted according to preset parameters of the camera, the distance between the camera and the target is correspondingly adjusted according to the actual shooting distance a required by the camera in a working environment, the camera is rotated to enable the image definition of each detection point on the camera to be mapped to the target to be consistent everywhere visually, and then the corresponding relation between the actual shooting distance a and the compensation rotation angle b of the camera after the focus is adjusted is recorded;
s2, adjusting a focus; the lens is preliminarily screwed into a lens seat of the camera so that the lens seat and the lens seat are connected, the camera is placed in a fixer arranged on focusing equipment, the lens is screwed to rotate, and an MTF value is used for judging an alignment focus;
s3, compensating the angle; inputting the value of the actual shooting distance a into a control panel of the debugging equipment, searching a compensation rotation angle b corresponding to the actual shooting distance a from a pre-constructed mapping relation table by the debugging equipment, judging an alignment focus by using an MTF value, and driving a manipulator to automatically screw a lens to rotate according to the value of the compensation rotation angle b by the debugging equipment.
2. The camera focusing method based on the MTF value according to claim 1, wherein the rotation direction of the camera compensating the rotation angle b after the camera adjusts the focus in the debugging device is either normal rotation or reverse rotation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111295858.1A CN114025090B (en) | 2021-11-04 | 2021-11-04 | Camera focusing mode and device based on MTF value |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111295858.1A CN114025090B (en) | 2021-11-04 | 2021-11-04 | Camera focusing mode and device based on MTF value |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114025090A CN114025090A (en) | 2022-02-08 |
| CN114025090B true CN114025090B (en) | 2024-03-19 |
Family
ID=80060674
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111295858.1A Active CN114025090B (en) | 2021-11-04 | 2021-11-04 | Camera focusing mode and device based on MTF value |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114025090B (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR19990039780A (en) * | 1997-11-14 | 1999-06-05 | 전주범 | How to adjust auto focus of digital camera |
| KR20070060250A (en) * | 2005-12-08 | 2007-06-13 | 삼성전기주식회사 | Apparatus for focusing and method of auto-focusing of camera module |
| CN102662293A (en) * | 2012-05-21 | 2012-09-12 | 信利光电(汕尾)有限公司 | Close-range focusing device and method |
| CN103984199A (en) * | 2014-05-30 | 2014-08-13 | 爱佩仪光电技术（深圳）有限公司 | Adjustment and application method for tilting compensation control of lens of automatic focusing camera module |
| CN105549174A (en) * | 2014-10-23 | 2016-05-04 | 奥林巴斯株式会社 | Photographing device and control method for photographing device |
| CN106501917A (en) * | 2016-12-07 | 2017-03-15 | 歌尔科技有限公司 | A kind of camera lens auxiliary focus adjustment method and device |
| WO2020248609A1 (en) * | 2019-06-11 | 2020-12-17 | 杭州海康微影传感科技有限公司 | Method, apparatus and imaging device for focusing, and computer-readable storage medium |
| CN113055553A (en) * | 2019-12-26 | 2021-06-29 | 晋城三赢精密电子有限公司 | Automatic focusing test method and device for camera module |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI412810B (en) * | 2006-09-01 | 2013-10-21 | Hon Hai Prec Ind Co Ltd | Focusing mechanism and method of using the same |
| JP2017211450A (en) * | 2016-05-24 | 2017-11-30 | オリンパス株式会社 | Imaging apparatus and focus adjustment method |
-
2021
- 2021-11-04 CN CN202111295858.1A patent/CN114025090B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR19990039780A (en) * | 1997-11-14 | 1999-06-05 | 전주범 | How to adjust auto focus of digital camera |
| KR20070060250A (en) * | 2005-12-08 | 2007-06-13 | 삼성전기주식회사 | Apparatus for focusing and method of auto-focusing of camera module |
| CN102662293A (en) * | 2012-05-21 | 2012-09-12 | 信利光电(汕尾)有限公司 | Close-range focusing device and method |
| CN103984199A (en) * | 2014-05-30 | 2014-08-13 | 爱佩仪光电技术（深圳）有限公司 | Adjustment and application method for tilting compensation control of lens of automatic focusing camera module |
| CN105549174A (en) * | 2014-10-23 | 2016-05-04 | 奥林巴斯株式会社 | Photographing device and control method for photographing device |
| CN106501917A (en) * | 2016-12-07 | 2017-03-15 | 歌尔科技有限公司 | A kind of camera lens auxiliary focus adjustment method and device |
| WO2020248609A1 (en) * | 2019-06-11 | 2020-12-17 | 杭州海康微影传感科技有限公司 | Method, apparatus and imaging device for focusing, and computer-readable storage medium |
| CN113055553A (en) * | 2019-12-26 | 2021-06-29 | 晋城三赢精密电子有限公司 | Automatic focusing test method and device for camera module |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114025090A (en) | 2022-02-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101833599B1 (en) | Device and method for detecting optical-axis offset of lens in apparatus | |
| KR101306289B1 (en) | Method of inspecting plat panel | |
| US8339464B2 (en) | Universal test system for controlling a plurality of parameters concerning the operation of a device for presenting optoelectronic information of various types | |
| CN109348129B (en) | Definition detection method and system for fixed-focus camera | |
| CN107063646B (en) | Method and device for determining effective focal length of lens by adopting camera and virtual reality headset | |
| US20110285857A1 (en) | Optical testing apparatus and testing method thereof | |
| US8581986B2 (en) | Method and apparatus for measuring the focus performance of a camera and lens combination | |
| CN102929074A (en) | Lens calibration system of employing imaging technology and calibration method thereof | |
| CN108646445B (en) | Defect detection device that self-adaptation is shaded | |
| US20060245748A1 (en) | Method and apparatus for testing and adjusting focus of an imaging device | |
| KR20170070296A (en) | Apparatus for inspecting camera module | |
| US10643350B1 (en) | Autofocus detecting device | |
| EP1628123A1 (en) | Testing of miniaturized cameras with electronic and/or optical zoom functions | |
| TWI489164B (en) | Method for adjusting focusing point with a 3d object and system thereof | |
| CN114025090B (en) | Camera focusing mode and device based on MTF value | |
| CN111044262A (en) | Near-to-eye display optical-mechanical module detection device | |
| CN110740255A (en) | Focusing apparatus and method | |
| CN108540793B (en) | Positioning and adjusting system of camera module | |
| WO2016182698A1 (en) | Adjustable lens mount | |
| US20080055696A1 (en) | Focusing mechanism for a lens module and focusing method for same | |
| CN106657982A (en) | Image pickup module set image definition calibration method and apparatus | |
| CN113959374B (en) | Image-based laser holder optical axis correction method and device | |
| CN115171625A (en) | Gamma correction method, device and storage medium for display panel | |
| US10908555B2 (en) | Imaging module, defocus testing device and method, and beam gating control method | |
| CN110275290B (en) | Relay lens design method for multi-camera imaging test |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |