CN1690833A - Automatic focusing method for digital camera - Google Patents
Automatic focusing method for digital camera Download PDFInfo
- Publication number
- CN1690833A CN1690833A CN 200410026999 CN200410026999A CN1690833A CN 1690833 A CN1690833 A CN 1690833A CN 200410026999 CN200410026999 CN 200410026999 CN 200410026999 A CN200410026999 A CN 200410026999A CN 1690833 A CN1690833 A CN 1690833A
- Authority
- CN
- China
- Prior art keywords
- digital camera
- imaging
- image sensing
- lens combination
- sensing chip
- 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.)
- Pending
Links
Images
Landscapes
- Automatic Focus Adjustment (AREA)
- Focusing (AREA)
- Studio Devices (AREA)
Abstract
The invention provides an auto focusing method for digital camera and comprises following steps: supply a digital camera; determine mechanical movement range of drive device by over view domain focal depth; select drive device fit to the precision of mechanical movement and corresponding signal process unit and drive chip; use drive device to drive lens group or video sensing chip to right focusing position. The method improves focusing precision, convenient and saves time.
Description
[technical field]
The invention relates to a kind of automatic focusing method, especially a kind of auto focusing method for digital camera that is used for.
[background technology]
Continuous development along with digital technology, digital camera is by people's widespread use, mobile phone and PDA (Personal Digital Assistant in recent years particularly, personal digital assistant) etc. portable electron device is also fast to high-performance, the multifunction direction develops, digital camera becomes the key that develops the mobile multimedia technology with combining of these portable electron devices, the digital camera volume that combines with this portable electron device is less and simple in structure, therefore adopt focuses structure more, the focal length that is its lens combination is constant, the distance of its lens combination and image sensor remains unchanged, the patent No. of Granted publication on the 5th is that 01202112.1 Chinese patent has disclosed a kind of camera lens module that focuses structure as Dec calendar year 2001, and the image sensing chip in this camera lens module is positioned at the focal position of its lens combination.According to the lens imaging principle, be positioned at when thing under the situation of infinite distant place (object distance is more than or equal to 50 times of focal length), imaging surface is positioned on the focal plane.Therefore, above-mentioned tight shot module can not influence image quality when being used to take remote scenery, but it is when taking closely scenery, because object distance is less, image distance increases, and causes imaging surface and focal plane not at grade, therefore causes the imaging on the focal plane unintelligible.For improving this kind situation, just need to adjust image distance, the i.e. distance of lens combination and image sensing chip.China Intellectual Property Office is that No. 02220115 Chinese patent has disclosed a kind of camera lens module of adjusting image distance in the patent No. of Granted publication on the 26th February in 2003, and this camera lens module mainly comprises camera lens, focusing ring, elastic device and pedestal.Wherein camera lens and focusing ring be by threads engaged, is connected by elastic device between focusing ring and the pedestal, is provided with regulating tank below this focusing ring, and pedestal is provided with the salient point that matches with regulating tank.Pull focusing ring, it is rotated with respect to pedestal, because the salient point of pedestal contacts with the varying mesa of the focusing groove of focusing ring, drive camera lens and do rectilinear motion, thereby change the spacing of lens combination and image sensing chip along optical axis direction.Pause on only can be in the regulating tank different table top of the rotation of the focusing ring of this camera lens module, promptly only can segmentation focus, thereby influence focusing accuracy, in addition, need constantly to change the spacing of lens combination and image sensing chip in the focusing process, when judging that with the method for range estimation image is the most clear, take, thus, time and effort consuming not only, and because the accuracy that the subjectivity of range estimation and can not guaranteeing is focused.
In view of this, provide a kind of convenient and time-saving, what the focusing degree of accuracy was high is used for auto focusing method for digital camera in fact for necessary.
[summary of the invention]
The object of the present invention is to provide one to be used for auto focusing method for digital camera, this method is convenient and time-saving, and focusing degree of accuracy height.
For realizing purpose of the present invention, the invention provides a kind of auto focusing method for digital camera, it may further comprise the steps: a digital camera is provided, and it comprises: lens combination, image sensing chip, distance measuring equipment, signal processing unit, chip for driving and drive unit; Measure fixture under situation, through the panorama field depth of focus of lens combination imaging on image sensing chip; Utilize this panorama field depth of focus to determine the mechanical mobile accuracy scope of this drive unit; Selection is suitable for drive unit and the corresponding signal process unit and the chip for driving of this machinery mobile accuracy; Utilize this distance measuring equipment to measure object distance, and this object distance information is sent to signal processing unit, after signal processing unit is made respective handling, produce control signal; This control signal is sent to chip for driving, and this chip for driving is according to its received control signal accessory drive; This drive unit drives this lens combination or image sensing chip moves to correct focusing position.
The invention has the beneficial effects as follows: the present invention utilizes optical means to determine the mechanical focusing precision and the focusing parameter of drive unit, improved focusing accuracy effectively, control influences the spacing of induction chip and lens combination to utilize distance measuring equipment to cooperate automatically with signal processor, thereby reaches the purpose of convenient and time-saving automatic focusing.
[description of drawings]
Fig. 1 is an object distance when being infinity, the MTF curve map of lens combination imaging point on the axle of image sensing chip.
Fig. 2 is an object distance when being infinity, lens combination on image sensing chip from the MTF of imaging shaft point curve map (0.5 visual field, 0.6 visual field, 0.7 visual field, 0.8 visual field).
Fig. 3 A is an object distance when being infinity, and lens combination of the present invention is at the MTF of imaging point on image sensing chip curve map (on the axle, 0.5 visual field, 0.6 visual field, 0.7 visual field, 0.8 visual field).
Fig. 3 B is an object distance when being 2.00m, and lens combination of the present invention is at the MTF of imaging point on image sensing chip curve map (on the axle, 0.5 visual field, 0.6 visual field, 0.7 visual field, 0.8 visual field).
Fig. 3 C is an object distance when being 0.40m, and lens combination of the present invention is at the MTF of imaging point on image sensing chip curve map (on the axle, 0.5 visual field, 0.6 visual field, 0.7 visual field, 0.8 visual field).
Fig. 3 D is an object distance when being 0.20m, and lens combination of the present invention is at the MTF of imaging point on image sensing chip curve map (on the axle, 0.5 visual field, 0.6 visual field, 0.7 visual field, 0.8 visual field).
[embodiment]
The digital camera that is suitable for auto focusing method for digital camera of the present invention comprises: lens combination, image sensing chip, distance measuring equipment, signal processing unit, chip for driving and drive unit.This distance measuring equipment can be measured the spacing of the captured scenery of lens combination and this digital camera, it is object distance, this signal processing unit utilizes the information of the measured object distance of distance measuring equipment, carry out calculation process, produce control signal, and this control signal is sent to chip for driving, this chip for driving drives this lens combination according to its received control signal accessory drive or image sensing chip moves to correct focusing position, thereby finishes auto-focus process.
This distance measuring equipment can be one to be assemblied in the range sensor in the picture window, and its similar is in infrared ambulator, and it can be run into the ultrared mistiming of returning after the subject with receiving by measuring the emission infrared ray, calculates object distance.
This drive unit can be solenoid valve or step motor.
The focal length of the lens combination of being tested in the present embodiment is 4.815mm, and the resolution of image sensing chip is the 1280*960=1.23 mega pixel, and pixel size is 3.18um, and resolution is 160lp/mm, and imaging highly is 2.543mm.Utilize the optics simulation software can simulate incident ray, and measure the parameters of this imaging through the imaging situation on image sensing chip after the lens combination.
Auto focusing method for digital camera of the present invention may further comprise the steps:
At first utilize the optics method of emulation to determine the mechanical mobile accuracy of the drive unit of digital camera, to guarantee focusing accuracy.Determine that mechanical mobile accuracy may further comprise the steps: utilize the optics simulation software, when measuring the object distance infinity, resolution is 160lp/mm (LinePairs/Millimeter, line is right/millimeter) time, MTF (the Modulation Transfer Function of this lens combination imaging point on the axle on the image sensing chip, modulation transfer function) curve map, as shown in Figure 1, its transverse axis is an image planes side-play amount (unit: mm); The mtf value of the last imaging point of this axle was greater than 0.3 o'clock as seen from the figure, and this lens combination depth of focus on the axle of imaging on the image sensing chip is-0.01mm to 0.029mm; This resolution is in order to specify image quality, and it can change according to different image quality demands, and the resolution height of healing then becomes picture element higher; Mtf value is an important parameter of weighing image quality, and it can change according to different image quality demands, and the mtf value height of healing then becomes picture element higher, and mtf value is greater than 0.3 demand that can satisfy general image quality.When measuring the object distance infinity, resolution is 80lp/mm, lens combination on image sensing chip from the MTF of imaging shaft point curve map (should be positioned at 0.5 visual field, 0.6 visual field, 0.7 visual field, 0.8 visual field) from the imaging shaft point, as shown in Figure 2, its transverse axis is an image planes side-play amount (unit: mm), be positioned at as seen from the figure 0.8 visual field from the mtf value of imaging shaft point greater than 0.3 o'clock, lens combination on image sensing chip imaging from the axle depth of focus be-0.024mm to 0.01mm.Wherein 0.5 visual field, 0.6 visual field, 0.7 visual field, 0.8 visual field refer to that image height is the imaging point of 0.5*2.543mm=1.272mm, 0.6*2.543mm=1.526mm, 0.7*2.543mm=1.781mm, 0.8*2.543mm=2.035mm.This goes up depth of focus and the depth of focus that is the panorama field imaging of lens combination on image sensing chip from the intersection of axle depth of focus, promptly-and 0.01mm to 0.01mm.Because imaging surface need not to be positioned at the optimal imaging point, as long as and be positioned at its focal depth range, therefore, the mechanical mobile accuracy of this drive unit be less than the panorama field depth of focus 1/2nd, be 0.01mm, just can guarantee that imaging surface is positioned at focal depth range, thereby guarantee focusing accuracy.
Detection changes the focusing result that the spacing of image sensing chip and lens combination is focused with the mechanical mobile accuracy less than 0.01mm, measure object distance respectively for infinitely great through optics emulation, 1.00m, 0.60m, 0.20m the time the MTF curve map of imaging point (this imaging point is positioned on the axle, 0.5 visual field, 0.6 visual field, 0.7 visual field, 0.8 the visual field), as Fig. 3 A, 3B, 3C, shown in the 3D, its transverse axis is the resolution (unit: lp/mm) of imaging, as known in the figure, when resolution is 160lp/mm, the mtf value of imaging point greater than 0.4 (greater than 0.3) on the axle, when resolution is 80lp/mm, from the mtf value of imaging shaft point greater than 0.4 (greater than 0.3), thereby object distance is infinitely great to the situation of 20m as can be known, and the quality of imaging has all reached the appointment requirement.
Select mechanical mobile accuracy to be less than the drive unit and the signal processing unit and the chip for driving that are suitable for this drive unit of 0.01mm.
In the shooting process, the distance measuring equipment of digital camera is measured object distance automatically, this object distance information is sent to signal processing unit, after signal processing unit is made respective handling, produce control signal, and this control signal is sent to chip for driving, this chip for driving drives this lens combination according to its received control signal accessory drive or image sensing chip moves to correct focusing position, thereby finish auto-focus process, can guarantee the image quality of captured scenery.
Claims (10)
1. auto focusing method for digital camera, it is characterized in that: it may further comprise the steps:
One digital camera is provided, and it comprises: lens combination, image sensing chip, distance measuring equipment, signal processing unit, chip for driving and drive unit;
Measure fixture under situation, through the panorama field depth of focus of lens combination imaging on image sensing chip;
Utilize this panorama field depth of focus to determine the mechanical mobile accuracy scope of this drive unit;
Selection is suitable for drive unit and the corresponding signal process unit and the chip for driving of this machinery mobile accuracy;
Utilize this distance measuring equipment to measure object distance, and this object distance information is sent to signal processing unit, after signal processing unit is made respective handling, produce control signal;
This control signal is sent to chip for driving, and this chip for driving is according to its received control signal accessory drive;
This drive unit drives this lens combination or image sensing chip moves to correct focusing position.
2. auto focusing method for digital camera as claimed in claim 1 is characterized in that: described mechanical mobile accuracy is less than 1/2nd of this panorama field depth of focus.
3. auto focusing method for digital camera as claimed in claim 2 is characterized in that: described measuring method through lens combination panorama field depth of focus of imaging on image sensing chip may further comprise the steps:
Test out certain fixture apart from the time, when first resolution is designated value, through lens combination MTF curve map of imaging point on the axle on the image sensing chip;
Determine when mtf value that axle is gone up imaging point is positioned at specified scope by this mtf value curve map of going up imaging point, this lens combination imaging on the image sensing chip spool on depth of focus;
Test out certain fixture apart from the time, when second resolution is designated value, through lens combination on image sensing chip from the MTF of imaging shaft point curve map;
Determine when the mtf value from imaging shaft point is positioned at specified scope from the MTF of imaging shaft point curve map by this, this lens combination on image sensing chip imaging from the axle depth of focus;
This is gone up depth of focus and is panorama field depth of focus with lap from the axle depth of focus.
4. auto focusing method for digital camera as claimed in claim 3 is characterized in that: the resolution of the image sensing chip of described digital camera is the 1280*960=1.23 mega pixel, and this pixel size is 3.18um, and resolution is 160lp/mm.
5. auto focusing method for digital camera as claimed in claim 4 is characterized in that: the designated value of described first resolution is 160lp/mm, and the designated value of second resolution is 80lp/mm.
6. auto focusing method for digital camera as claimed in claim 5 is characterized in that: described axle is gone up the specified scope of mtf value of imaging point for greater than 0.3, is greater than 0.3 from the specified scope of the mtf value of imaging shaft point.
7. auto focusing method for digital camera as claimed in claim 3 is characterized in that: described fixture is apart from being infinity.
8. auto focusing method for digital camera as claimed in claim 3 is characterized in that: describedly be positioned at 0.8 visual field from the imaging shaft point.
9. auto focusing method for digital camera as claimed in claim 1 is characterized in that: the drive unit of described digital camera is a step motor.
10. auto focusing method for digital camera as claimed in claim 1 is characterized in that: the drive unit of described digital camera is a solenoid valve.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410026999 CN1690833A (en) | 2004-04-20 | 2004-04-20 | Automatic focusing method for digital camera |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410026999 CN1690833A (en) | 2004-04-20 | 2004-04-20 | Automatic focusing method for digital camera |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1690833A true CN1690833A (en) | 2005-11-02 |
Family
ID=35346356
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200410026999 Pending CN1690833A (en) | 2004-04-20 | 2004-04-20 | Automatic focusing method for digital camera |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1690833A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100533245C (en) * | 2006-05-23 | 2009-08-26 | 鸿富锦精密工业（深圳）有限公司 | Real-time automatic focusing method |
| CN100582851C (en) * | 2007-12-04 | 2010-01-20 | 鸿富锦精密工业（深圳）有限公司 | Focus system and method for promoting resolving power of optical lens |
| CN102662293A (en) * | 2012-05-21 | 2012-09-12 | 信利光电(汕尾)有限公司 | Close-range focusing device and method |
| CN103188499A (en) * | 2011-12-27 | 2013-07-03 | 鸿富锦精密工业（深圳）有限公司 | 3D imaging module and 3D imaging method |
| CN104469168A (en) * | 2014-12-29 | 2015-03-25 | 信利光电股份有限公司 | Shooting module and automatic focusing method thereof |
| CN106657982A (en) * | 2016-11-16 | 2017-05-10 | 信利光电股份有限公司 | Image pickup module set image definition calibration method and apparatus |
| WO2018019011A1 (en) * | 2016-07-29 | 2018-02-01 | 广东欧珀移动通信有限公司 | Macro shooting processing method and apparatus, and terminal device |
| CN110954554A (en) * | 2019-12-16 | 2020-04-03 | 广州量子激光智能装备有限公司 | Online burr detecting system |
| CN110987959A (en) * | 2019-12-16 | 2020-04-10 | 广州量子激光智能装备有限公司 | Online burr detection method |
-
2004
- 2004-04-20 CN CN 200410026999 patent/CN1690833A/en active Pending
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100533245C (en) * | 2006-05-23 | 2009-08-26 | 鸿富锦精密工业（深圳）有限公司 | Real-time automatic focusing method |
| CN100582851C (en) * | 2007-12-04 | 2010-01-20 | 鸿富锦精密工业（深圳）有限公司 | Focus system and method for promoting resolving power of optical lens |
| CN103188499A (en) * | 2011-12-27 | 2013-07-03 | 鸿富锦精密工业（深圳）有限公司 | 3D imaging module and 3D imaging method |
| CN103188499B (en) * | 2011-12-27 | 2016-05-04 | 鸿富锦精密工业（深圳）有限公司 | 3D imaging modules and 3D formation method |
| CN102662293A (en) * | 2012-05-21 | 2012-09-12 | 信利光电(汕尾)有限公司 | Close-range focusing device and method |
| CN102662293B (en) * | 2012-05-21 | 2015-06-24 | 信利光电股份有限公司 | Close-range focusing device and method |
| CN104469168A (en) * | 2014-12-29 | 2015-03-25 | 信利光电股份有限公司 | Shooting module and automatic focusing method thereof |
| WO2018019011A1 (en) * | 2016-07-29 | 2018-02-01 | 广东欧珀移动通信有限公司 | Macro shooting processing method and apparatus, and terminal device |
| CN106657982A (en) * | 2016-11-16 | 2017-05-10 | 信利光电股份有限公司 | Image pickup module set image definition calibration method and apparatus |
| CN110954554A (en) * | 2019-12-16 | 2020-04-03 | 广州量子激光智能装备有限公司 | Online burr detecting system |
| CN110987959A (en) * | 2019-12-16 | 2020-04-10 | 广州量子激光智能装备有限公司 | Online burr detection method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109451244B (en) | Automatic focusing method and system based on liquid lens | |
| US9860434B2 (en) | Auto-focus in low-profile folded optics multi-camera system | |
| CN105430279B (en) | Camera fast automatic focusing method and device | |
| US20170223256A1 (en) | Image capturing terminal and image capturing method | |
| EP3151536A1 (en) | Image capturing terminal and image capturing method | |
| CN103149789A (en) | Image modulation transfer function (MTF) evaluation-based module motor curve testing method | |
| CN101034240A (en) | Automatic focusing method used for testing camera module group | |
| US20130271454A1 (en) | Interactive Screen Viewing | |
| EP3154251A1 (en) | Application programming interface for multi-aperture imaging systems | |
| CN102590218A (en) | Device and method for detecting micro defects on bright and clean surface of metal part based on machine vision | |
| CN108600638B (en) | Automatic focusing system and method for camera | |
| JPS6398615A (en) | Automatic focus adjusting method | |
| US9055237B1 (en) | Projection autofocus | |
| TW201400964A (en) | Enhanced image processing with lens motion | |
| CN104469169A (en) | Phase ranging camera shooting module and automatic focusing method thereof | |
| CN1690833A (en) | Automatic focusing method for digital camera | |
| CN1892401A (en) | Multi-stage automatic focusing method according to time-frequency domain catched by iris picture | |
| CN105592258B (en) | Auto focusing method and device | |
| CN101718912A (en) | Digitalized detail visualizer of industrial X-ray negative with variable zooming ratio | |
| RU2389050C1 (en) | Automatic focusing method | |
| CN113923358A (en) | Online automatic focusing method and system in flying shooting mode | |
| CN106060376A (en) | Display control apparatus, display control method, and image capturing apparatus | |
| CN106154688A (en) | A kind of method and device of auto-focusing | |
| CN1862305A (en) | Image sensing module multi-point focusing detecting method and apparatus thereof | |
| TW200536386A (en) | An method for auto-adjusting the focus of the digital camera |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |