CN1900807A - Optical device - Google Patents

Optical device Download PDF

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Publication number
CN1900807A
CN1900807A CNA2006101056688A CN200610105668A CN1900807A CN 1900807 A CN1900807 A CN 1900807A CN A2006101056688 A CNA2006101056688 A CN A2006101056688A CN 200610105668 A CN200610105668 A CN 200610105668A CN 1900807 A CN1900807 A CN 1900807A
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CN
China
Prior art keywords
step position
condenser lens
focusing
scope
depth
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Granted
Application number
CNA2006101056688A
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Chinese (zh)
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CN100510938C (en
Inventor
斋藤恭造
加藤正志
京谷升一
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Alps Alpine Co Ltd
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Alps Electric Co Ltd
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Publication of CN1900807A publication Critical patent/CN1900807A/en
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Publication of CN100510938C publication Critical patent/CN100510938C/en
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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
    • G02B7/28—Systems for automatic generation of focusing signals
    • G02B7/36—Systems for automatic generation of focusing signals using image sharpness techniques, e.g. image processing techniques for generating autofocus signals
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
    • G02B7/02—Mountings, adjusting means, or light-tight connections, for optical elements for lenses
    • G02B7/04—Mountings, adjusting means, or light-tight connections, for optical elements for lenses with mechanism for focusing or varying magnification
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B13/00—Viewfinders; Focusing aids for cameras; Means for focusing for cameras; Autofocus systems for cameras
    • G03B13/32—Means for focusing
    • G03B13/34—Power focusing
    • G03B13/36—Autofocus systems

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Automatic Focus Adjustment (AREA)
  • Studio Devices (AREA)
  • Focusing (AREA)

Abstract

The invention provides an optical device achieving the shortening of time taken to control automatic focusing. The optical device is equipped with: an imaging device 2 receiving transmitted light through a focusing lens 1 and outputting an imaging signal; an arithmetic calculation means 4 arithmetically calculating a focus evaluated value on the basis of the imaging signal from the imaging device 2; and a driving means 3 moving the focusing lens 1 to a predetermined step position in an optical axis direction according to the focus evaluated value. The focusing lens 1 has a focusing distance range set within the range of the depth of field at each step position, and the step position of the focusing lens by the driving means 3 is set so that the focusing distance range of the focusing lens 1 at such a step position is not overlapped on the focusing distance range of the focusing lens 1 at a step position separate by two steps.

Description

Optical devices
Technical field
The present invention relates to have the optical devices of the photographic optical system of carrying out automatic focusing, relate in particular to a kind of by making lens step (step) position according to the rules move the optical devices that carry out automatic focusing.
Background technology
All the time, as the automatic focusing mode in the optical devices such as camera, known have so-called contrast (contrast) mode.This mode is by imaging apparatus subject to be made a video recording, utilize the image pickup signal in the regulation zone of this imaging apparatus to decide focal position, and become the position of peak value by finding out the focus evaluated value corresponding with the contrast in regulation zone, detect focal position.
For automatic focusing, be used in the lens that are imaged on imaging apparatus by step motor and move along optical axis, find out the position that focus evaluated value becomes peak value by the so-called control method of climbing.The control of climbing is to make lens when optical axis moves, and comes the computing focus evaluated value by the step position of each regulation, and therefrom finding out becomes the step of peak position.Optical devices as carry out automatic focusing by such method for example have the device of being enumerated in patent documentation 1 and the patent documentation 2.
[patent documentation 1] TOHKEMY 2003-307669 communique
[patent documentation 2] TOHKEMY 2003-315665 communique
In existing automatic focusing,, improved focusing accuracy by fine select the step position that lens are moved as far as possible.Fig. 8 represents the progression of the control of climbing in the existing optical devices.The transverse axis of this figure is represented the step position, and the longitudinal axis is represented focus evaluated value, and the step position is divided into 35 parts till from No. 0 to No. 34, and No. 26 positions are peak.
As shown in Figure 8, at first, focus evaluated value is asked in per No. 5 of step position.Focus evaluated value increases till the 5th grade, and focus evaluated value reduces in the 6th grade.Thus, at this moment can know from the 4th grade No. 20 to the 6th grade No. 30 and have peak value.Therefore, focus evaluated value is asked for to per No. 2 later in the 7th grade of No. 20 positions returning the 4th grade once more.
So because focus evaluated value increases till the 10th grade, focus evaluated value reduces in the 11st grade, so, turn back to the 10th grade No. 26 positions at the 12nd grade of place and determine peak value.Like this, be divided under 35 parts the situation 12 grades of maximum demands in the step position.
If in order to improve focusing accuracy, and with cutting apart of step position of several granulars, then can therefore make the progression that be used to find out the focus evaluated value peak value increase, for the control that determines lens position needs the time, cause the response variation thus.
Summary of the invention
The present invention is in view of above-mentioned problem, and its purpose is to provide a kind of can reduce the optical devices that automatic focusing is controlled the time that is spent.
In order to solve above-mentioned problem, optical devices involved in the present invention possess: imaging apparatus, the seeing through light and export image pickup signal of collectiong focusing lens; Arithmetical organ calculates the focus evaluated value that changes along with the focus state of above-mentioned condenser lens based on the image pickup signal from this imaging apparatus; And driving mechanism, according to the focus evaluated value that this arithmetical organ calculated, make described condenser lens move to the regulation step position of optical axis direction, it is characterized in that,
Described condenser lens has the focusing distance scope that is set in respectively in the field depth in each step position, the step position of the condenser lens of finishing by described driving mechanism, with the focusing distance scope of the condenser lens in this step position and the unduplicated mode of focusing distance scope of isolating the condenser lens in 2 grades the step position, set.
In addition, optical devices involved in the present invention, it is characterized in that, the step position of the condenser lens of finishing by described driving mechanism,, set in the mode that the scope below 10% repeats according to the focusing distance scope of condenser lens in the step position of the focusing distance scope of the condenser lens in this step position and adjacency.
And optical devices involved in the present invention is characterized in that, the focusing distance scope that described condenser lens had, field depth and back this two side of field depth before comprising.
According to the optical devices that the present invention relates to, by the step position of condenser lens is set with the focusing distance scope of the condenser lens in this step position and the unduplicated mode of focusing distance scope of isolating the condenser lens in 2 grades the step position, because by reducing the repetition of field depth, so, can cover (cover) desired focusing distance scope with less step position, thus, can reduce the time that automatic focusing control is spent.
And, according to optical devices involved in the present invention, by the step position of condenser lens is set in the mode that the scope below 10% repeats according to the focusing distance scope of condenser lens in the step position of the focusing distance scope of the condenser lens in this step position and adjacency, owing to can reduce the repetition of the focusing distance scope in each step position, so, can cover desired focusing distance scope with step position still less.
Description of drawings
Fig. 1 is the pie graph of the optical devices in the present embodiment.
Fig. 2 is the graph of a relation of the distance (L) of the relative condenser lens of distance (R) of expression condenser lens and imaging apparatus and subject.
Fig. 3 is the step position when being illustrated in step (step) position and being divided into 35 parts and the graph of a relation of focussing distance (A).
Fig. 4 is the figure of the relation between the expression step position and the depth of field.
Fig. 5 is expression condenser lens and the distance of imaging apparatus and the graph of a relation between the focussing distance.
Fig. 6 is the figure of progression of the control of climbing in the optical devices of expression present embodiment.
Fig. 7 is illustrated in the asynchronous condenser lens of setting value and the distance of imaging apparatus and the graph of a relation between the focussing distance that allows the blur circle diameter.
Fig. 8 is the figure of the progression of the control of climbing in the existing optical devices of expression.
Among the figure: 1-condenser lens, 2-imaging apparatus, 3-driving mechanism, 4-arithmetical organ.
Embodiment
With reference to accompanying drawing embodiments of the present invention are described in detail.Fig. 1 is the pie graph of the optical devices of present embodiment.As shown in the drawing, the optical devices in the present embodiment are to receive the mode that sees through light of GRIN Lens 1 to constitute by imaging apparatus 2.Imaging apparatus 2 is photo-electric conversion elements, is used to export the corresponding electric signal of light intensity of picture of going up the subject 5 of imaging with light receiving surface 2a, and it is made of CCD and cmos sensor.
And condenser lens 1 can move freely in the direction of optical axis 6 by driving mechanism 3.And, in imaging apparatus 2, being provided with arithmetical organ 4, this arithmetical organ 4 calculates the focus evaluated value that changes along with the focus state of condenser lens 1 based on image pickup signal.Driving mechanism 3 makes condenser lens 1 move along optical axis direction based on the focus evaluated value of 4 computings of arithmetical organ, and it is made of step motor.
Driving mechanism 3 is set a plurality of steps position in mobile range, condenser lens 1 can be configured in any one step position by driving mechanism 3.Imaging apparatus 2 is made a video recording to subject 5 when condenser lens 1 each mobile step position, and the image pickup signal in the regulation zone is sent to arithmetical organ 4.Received the arithmetical organ 4 of image pickup signal, based on contrast method computing focus evaluated value.
Driving mechanism 3 and then make condenser lens 1 move to the step position that the focus evaluated value that is calculated by arithmetical organ 4 becomes peak value.Utilize the so-called control of climbing as the control method that is used for this purpose.To narrate in the back for this control.
Fig. 2 represents the relation of the distance (L) of relative condenser lens 1 with the distance (R) of imaging apparatus 2 of condenser lens 1 and subject.If the focal length of condenser lens 1 is made as f, then satisfy the relation of (1/L)+(1/R)=1/f between L and the R.At this, if the focal distance f of the condenser lens of present embodiment 1 is 4.71mm, then L and R become relation as shown in Figure 2.Here, according to the mode that the scope of L from 0.1m to the infinity in the scope shown in this figure can focus on, condenser lens 1 is moved.
Step position when Fig. 3 is illustrated in step (step) position and is divided into 35 parts and the relation between the focusing distance (A).By making the step change in location, make the distance (R) of condenser lens 1 and imaging apparatus 2 change, follow in this A also to change.
Here, in imaging apparatus 2, the focusing distance scope certain that can imaging because of the depth of field is positioned at.Focusing distance shown in Figure 3 is to be used for making 1 of the subject that will photograph to be imaged as 1 distance at imaging apparatus 2.Under the situation longer of the distance till subject than this, because image space compares with imaging apparatus 2 and is positioned at the rear, so, on imaging apparatus 2, become circle with a certain size.In addition, under the short situation of the distance till subject, because image space compares with imaging apparatus 2 and is positioned at the place ahead, so, also on imaging apparatus 2, become circle with a certain size.But in fact,, have certain size etc., also can make the specialized range of the distance till the subject become the allowed band of focusing as the depth of field by pixel even the size of imaging is bigger than 1 in imaging apparatus 2.
The depth of field has: the distance till subject is than the distance shown in Figure 3 preceding depth of field (Lf) in short-term and the back depth of field (Lr) during than distance shown in Figure 3, and the two is respectively by following various expression.Here, L is the distance till the subject, and F is the f-number of lens, and f is the focal length of lens, and δ is the allowed band of the size of the imaging circle on the imaging apparatus 2, promptly allows the blur circle diameter.
[formula 1]
L f = R 2 δF f 2 + RδF
[formula 2]
L f = R 2 δF f 2 - RδF
Fig. 4 represent the step position and the depth of field that calculates by these formula between relation.In the present embodiment, the f-number of lens is set at 2.8, and the focal length of lens is set at 4.71mm, allows the blur circle diameter to be set at 7 μ m.As shown in Figure 4, the depth of field of the step position of the depth of field of each step position and adjacency has considerable part to repeat.And, also repeat away from the offside depth of field of putting in rank of two-stage to three grade.As mentioned above, because the scope of the depth of field is the allowed band that focuses on, so in the scope that the depth of field repeats, the step position of other of repetition also is in focus state.
For example, the field depth that No. 3, No. 0, field depth that No. 1, the step position and step position and No. 2, step position and step position is repeating in the scope shown in the hachure of Fig. 4, can be covered all by the field depth of No. 3, No. 0, step position and step position.In addition, the field depth that No. 2, the step position also can be covered all by the field depth of No. 3, No. 0, step position and step position.Therefore, No. 2, No. 1 and step position even without the step position, also can focus on these scopes for No. 3 by No. 0, step position or step position.
Like this, by the focusing distance scope of regulation being asked for the scope of the depth of field, reduce the repetition scope of the depth of field in each step position, and mode with the zone of the field depth that is not included in any step position, promptly set the step position, can carry out focusing with the step position of minimum across specialized range by the mode that covers whole specialized ranges.
Fig. 5 represents step position that the focusing distance scope till from 0.1mm to 100m is set.The transverse axis of getting this figure is the distance of condenser lens 1 and imaging apparatus 2.Between 2 dotted lines among the figure is the scope of the depth of field, to the focusing distance scope from 0.1mm to 100m, if set the step position in the mode that all can cover, then as shown in the figure, has determined 5 positions.In this embodiment, set in the approximate unduplicated mode of the depth of field in each step position, but also can set in the mode that repeats about 10%.No matter be any mode, all the unduplicated mode of the depth of field of isolating in 2 grades the step position with the relative depth of field of certain step position is set the step position.
By condenser lens 1 is set these 5 step positions, concerning from the focusing distance scope of 0.1mm to 100m, because any one of 5 step positions be included in the field depth, so can focus on.In addition, the scope that focusing 100m is above, because the distance of condenser lens 1 and imaging apparatus 2 is almost constant as shown in Figure 2, so, by utilizing the step position of long part of focusing distance, the state that can obtain roughly to focus on of covering.
Then, the control of climbing that is used to focus on is described.Fig. 6 represents the progression of the control of climbing in the optical devices of present embodiment.As shown in the figure, in the optical devices of present embodiment, the step position of condenser lens 1 is set at 5 places as described above, asks for focus evaluated value in turn No. 1 from the step position.In this embodiment, focus evaluated value increases till the 4th grade, locates focus evaluated value at the 5th grade and reduces.Therefore, owing to know that peak value is positioned at the 4th grade of place, so, turn back to the step position once more No. 4, finishing control.That is, at this moment in the 6th grade, focus.
In the example of Fig. 6, represented in the step position to locate to have the situation of peak value No. 4, but the position outside this exists under the situation of peak value and can focus with progression still less.That is, in this example, can maximum focus with 6 grades.In the example of existing optical devices shown in Figure 8, be the controls of climbing of 35 places with the step set positions, but 12 grades of maximum demands at this moment.Like this, the depth of field is set at the number of minimum, can reduces the progression that is used to focus, thus, can reduce the time that automatic focusing spends by considering the step position.
Permission blur circle diameter during about the calculating depth of field can be set according to the pixel size that constitutes imaging apparatus 2, is set at setting by allowing the blur circle diameter, has also determined the setting of step position.In the example of explanation before this, allow the blur circle diameter to be made as 7 μ m, below, the setting of the step position in the time of will being made as 15 μ m to permission blur circle diameter describes.Condenser lens 1 when Fig. 7 represents to allow the blur circle diameter to be made as 15 μ m and the distance of imaging apparatus 2 and the relation between the focusing distance.
Between 2 dotted lines shown in Figure 7 is field depth, concerning from the focusing distance scope of 0.1mm to 100m, if set the step position in the mode that all can cover, then determines 3 positions as shown in the figure like that.Like this, allow the blur circle diameter if under the big situation of the pixel that constitutes imaging apparatus 2, increase, the expanded range of the relative step position of the depth of field then, thus can cover the specialized range of focusing distance by step position still less.
So far embodiments of the present invention are illustrated, still, utilization of the present invention is not limited to this embodiment, can use in every way in the scope of its technological thought.

Claims (3)

1, a kind of optical devices possess: imaging apparatus, the seeing through light and export image pickup signal of collectiong focusing lens; Arithmetical organ calculates the focus evaluated value that changes along with the focus state of described condenser lens based on the image pickup signal from this imaging apparatus; And driving mechanism, according to the focus evaluated value that this arithmetical organ calculated, make described condenser lens move to the regulation step position of optical axis direction,
Described condenser lens has the focusing distance scope that is set in respectively in the field depth in each step position, the step position of the condenser lens of finishing by described driving mechanism, with the focusing distance scope of the condenser lens in this step position and the unduplicated mode of focusing distance scope of isolating the condenser lens in 2 grades the step position, set.
2, optical devices according to claim 1 is characterized in that,
The step position of the condenser lens of being finished by described driving mechanism, is set in the mode that the scope below 10% repeats according to the focusing distance scope of the condenser lens in the step position of the focusing distance scope of the condenser lens in this step position and adjacency.
3, according to each described optical devices in claim 1 or 2, it is characterized in that,
The focusing distance scope that described condenser lens had, this two side of scope of the scope of the depth of field and the back depth of field before comprising.
CNB2006101056688A 2005-07-19 2006-07-17 Optical device Expired - Fee Related CN100510938C (en)

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JP2005209004 2005-07-19
JP2005209004A JP2007025381A (en) 2005-07-19 2005-07-19 Optical device

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CN1900807A true CN1900807A (en) 2007-01-24
CN100510938C CN100510938C (en) 2009-07-08

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Cited By (5)

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CN101931751A (en) * 2009-06-24 2010-12-29 索尼公司 The method and the program of removable Machinery Ministry control device, the removable Machinery Ministry of control
CN102262332A (en) * 2010-05-28 2011-11-30 索尼公司 Focus control device, focus control method, lens system and focus lens driving method
CN103237173A (en) * 2013-04-28 2013-08-07 中国空间技术研究院 Adaptive quick focusing device and method for optical camera
CN105812623A (en) * 2014-12-30 2016-07-27 深圳超多维光电子有限公司 Microlens array imaging device and imaging method
WO2016161734A1 (en) * 2015-04-07 2016-10-13 中兴通讯股份有限公司 Autofocusing method and device

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KR101993670B1 (en) * 2016-03-17 2019-06-27 주식회사 이오테크닉스 Photographing method and object alignment method using the photographing method

Family Cites Families (7)

* Cited by examiner, † Cited by third party
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JPH0514794A (en) * 1991-07-08 1993-01-22 Kyocera Corp Electronic still camera
JP3345900B2 (en) * 1992-01-17 2002-11-18 カシオ計算機株式会社 Auto focus device
JPH0773341B2 (en) * 1993-02-12 1995-08-02 株式会社日立製作所 Automatic focusing device
JP2000330009A (en) * 1999-05-20 2000-11-30 Sharp Corp Automatic focusing device for digital camera, and digital camera equipped with same
JP4320843B2 (en) * 1999-05-31 2009-08-26 富士フイルム株式会社 Autofocus method, apparatus and storage medium
JP2001042207A (en) * 1999-07-29 2001-02-16 Olympus Optical Co Ltd Electronic camera
JP2002122776A (en) * 2000-10-17 2002-04-26 Sharp Corp Autofocus controller, digital still camera and digital video camera equipped with the same, autofocus control method and recording medium having autofocus control program recorded thereon

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101931751A (en) * 2009-06-24 2010-12-29 索尼公司 The method and the program of removable Machinery Ministry control device, the removable Machinery Ministry of control
CN102262332A (en) * 2010-05-28 2011-11-30 索尼公司 Focus control device, focus control method, lens system and focus lens driving method
CN103237173A (en) * 2013-04-28 2013-08-07 中国空间技术研究院 Adaptive quick focusing device and method for optical camera
CN105812623A (en) * 2014-12-30 2016-07-27 深圳超多维光电子有限公司 Microlens array imaging device and imaging method
CN105812623B (en) * 2014-12-30 2018-10-16 深圳超多维科技有限公司 Microlens array imaging device and imaging method
WO2016161734A1 (en) * 2015-04-07 2016-10-13 中兴通讯股份有限公司 Autofocusing method and device

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TW200710465A (en) 2007-03-16
CN100510938C (en) 2009-07-08
JP2007025381A (en) 2007-02-01
KR20070011133A (en) 2007-01-24
TWI300495B (en) 2008-09-01

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