US5430288A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for setting the sharpness of an optical imaging system
Assignee: Heidelberger Druckmaschinen AG
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Filing: 1993-08-31
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Granted: 1995-07-04
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Expires: 2013-08-31
Abstract
Abstract A method and apparatus for setting sharpness of an optical image system by step-by-step adjustment of the distance between a subject and an objective until a maximum is achieved for respectively identified sharpness values of the objective.
Inventors
- 👤 Rainer Schielke
- 👤 Holger Suhr
- 👤 Udo Wurdemann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:41
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
194 words
A method for setting sharpness of an optical imaging system by step-by-step adjustment of a distance between a subject and an objective until a maximum is achieved for respectively identified sharpness values of the subject, comprising the steps of: determining sharpness values from a sum of square differences of image signal values in a line of neighboring pixels, and identifying an initial sharpness value at a prescribed distance between the subject and the objective; varying the prescribed distance by respective steps in both adjustment directions and identifying first and second sharpness values corresponding to varied first and second distances; determining a mathematical curve formed by the initial, first, and second sharpness values, said mathematical curve defining sharpness values over distances defined within a range of adjustment between the subject and the objective; determining a function and coefficients of the function defining the curve; identifying a maximum sharpness value as an apex point on the curve and a corresponding maximum sharpness value distance between the subject and the objective corresponding to the apex point; and adjusting the objective to the distance corresponding to the maximum sharpness value corresponding to the apex point on the curve.
Claim 2
Independent Claim
194 words
A method for setting sharpness of an optical imaging system by step-by-step adjustment of a distance between a subject and an objective until a maximum is achieved for respectively identified sharpness values of the subject, comprising the steps of: determining sharpness values from a sum of square differences of image signal values in a line of neighboring pixels, and identifying an initial sharpness value at a prescribed distance between the subject and the objective; varying the prescribed distance by respective steps in both adjustment directions and identifying first and second sharpness values corresponding to varied first and second distances; determining a mathematical curve formed by the initial, first, and second sharpness values, said mathematical curve defining sharpness values over distances defined within a range of adjustment between the subject and the objective; determining a function and coefficients of the function defining the curve; identifying a maximum sharpness value as an apex point on the curve and a corresponding maximum sharpness value distance between the subject and the objective corresponding to the apex point; and adjusting the objective to the distance corresponding to the maximum sharpness value corresponding to the apex point on the curve.
Claim 3
Dependent Claim
70 words
A method according to claim 1 wherein, following the identifying of the first and second sharpness values, carrying out a check to see whether the first and second sharpness values are lower than the initial sharpness value, and given non-satisfaction thereof, again varying the distance by a smaller step width in both adjustment directions and determining new first and second sharpness values and then continuing with the subsequent method steps.
Claim 4
Dependent Claim
88 words
A method according to claim 1 wherein following identifying the distance corresponding to the apex point and the corresponding maximum sharpness value, carrying out a check to see whether the first and second sharpness values at the first and second distances and the initial sharpness value are lower than the corresponding maximum sharpness value and, given non-satisfaction thereof, aborting the method and triggering an abort indication, and if the initial sharpness value is not lower than the corresponding maximum sharpness value, then continuing subsequent steps of the method.
Claim 5
Dependent Claim
34 words
A method according to claim 1 wherein, given an image original as said subject, acquiring image signal values for identification of said sharpness values by point-by-point and line-by-line optoelectronic scanning of the image original.
Claim 6
Dependent Claim
40 words
A method according to claim 1 including the step of providing the subject as an image original and utilizing only image signal values of a section of a scanned line of an image original for calculation of the sharpness values.
Claim 7
Dependent Claim
14 words
A method according to claim 5 wherein said section is approximately 512 pixels long.
Claim 8
Dependent Claim
19 words
A method according to claim 5 wherein said section is approximately 15 mm long given an opaque image original.
Claim 9
Dependent Claim
19 words
A method according to claim 5 wherein said section is approximately 10 mm long given a transparency image original.
Claim 10
Dependent Claim
37 words
A method according to claim 1 including the steps of providing said subject as a color original and employing a color signal of a red channel for calculation of the sharpness values when scanning the color original.
Claim 11
Dependent Claim
26 words
A method according to claim 1 including the step of utilizing only more-significant bits of the digitized image signal values for calculation of the sharpness values.
Claim 12
Dependent Claim
28 words
A method according to claim 1 including the step of undertaking a scanning of the subject with an imaging system given a small diaphragm of the imaging system.
Claim 13
Dependent Claim
27 words
A method according to claim 1 including the step of scanning the subject with an imaging system given a minimum depth of field of the imaging system.
Claim 14
Dependent Claim
32 words
A method according to claim 1 including the step of scanning the subject with an imaging system and varying a focusing condition of the imaging system with at least one stepping motor.
Claim 15
Dependent Claim
30 words
A method according to claim 1 including the step of scanning the subject with an imaging system and varying a focusing condition of the imaging system with a piezo drive.
Claim 16
Dependent Claim
38 words
A method according to claim 1 including the step of scanning the subject with I, an imaging system and presetting a focusing condition of the imaging system to an initial value before calculation of said initial sharpness value.
Claim 17
Dependent Claim
20 words
A method according to claim 15 including the step of calculating said initial value in a separate work preparation device.
Claim 18
Dependent Claim
80 words
A method according to claim 1 including the steps of providing said subject as an image original; before actual scanning of the image original, determining approximate maximum sharpness values at various locations of the image original; storing coordinate values of corresponding focusing conditions for the approximate sharpness values; and for actual scanning of the image original, automatically setting a focusing condition using the stored coordinate values when an original region around a corresponding location of the image original is scanned.
Claim 19
Dependent Claim
16 words
A method according to claim 1 wherein said curve is of at least a second order.
Claim 20
Dependent Claim
15 words
A method according to claim 18 wherein said curve is of a third higher order.
Claim 21
Independent Claim
162 words
A method for setting sharpness of an optical imaging system by step-by-step adjustment of a distance between a subject and an objective until a maximum is achieved for respectively identified sharpness values of the subject, comprising the steps of: determining sharpness values from a sum of square differences of image signal values in a line of neighboring pixels, and identifying an initial sharpness value at a prescribed distance between the subject and the objective; varying the prescribed,distance by steps in both adjustment directions and identifying sharpness values; determining a mathematical curve formed by the sharpness values, said mathematical curve defining sharpness values over varying distances between the subject and the objective; identifying a maximum sharpness value as an apex point on the curve and a corresponding maximum sharpness value distance between the subject and the objective corresponding to the apex point; and adjusting the objective to the distance corresponding to the maximum sharpness value corresponding to the apex point on the curve.
Claim 22
Independent Claim
162 words
A method for setting sharpness of an optical imaging system by step-by-step adjustment of a distance between a subject and an objective until a maximum is achieved for respectively identified sharpness values of the subject, comprising the steps of: determining sharpness values from a sum of square differences of image signal values in a line of neighboring pixels, and identifying an initial sharpness value at a prescribed distance between the subject and the objective; varying the prescribed,distance by steps in both adjustment directions and identifying sharpness values; determining a mathematical curve formed by the sharpness values, said mathematical curve defining sharpness values over varying distances between the subject and the objective; identifying a maximum sharpness value as an apex point on the curve and a corresponding maximum sharpness value distance between the subject and the objective corresponding to the apex point; and adjusting the objective to the distance corresponding to the maximum sharpness value corresponding to the apex point on the curve.
Claim 23
Independent Claim
238 words
An apparatus for setting sharpness of an optical imaging system by step-by-step adjustment of a distance between a subject and an objective until a maximum is achieved for respectively identified sharpness values of the; subject, comprising: an optical imaging system having an objective; an adjustment unit for the objective for adjusting a distance between the objective and the subject; an opto-electronic scanner head; a first signal processing circuit connected to the scanner head for identifying sharpness values from sums of square differences of image signal values in a line of neighboring pixels; a second signal processing circuit connected to the first signal processing circuit and to the adjustment unit; and said second signal processing circuit comprising means for identifying a starting sharpness value for a given prescribed distance between the subject and the objective; means for identifying first and second distances determined by varying from said prescribed distance by a first step width in both adjustment directions and identifying corresponding first and second sharpness values; means for determining a mathematical curve from said initial and first and second sharpness values, said curve representing sharpness values as a function of distances within a range of adjustment of said objective relative to said subject; means for identifying a function of said curve and coefficients thereof; and means for determining an apex point of said curve corresponding to a maximum sharpness and a corresponding distance between the subject and the objective.
Claim 24
Independent Claim
238 words
An apparatus for setting sharpness of an optical imaging system by step-by-step adjustment of a distance between a subject and an objective until a maximum is achieved for respectively identified sharpness values of the; subject, comprising: an optical imaging system having an objective; an adjustment unit for the objective for adjusting a distance between the objective and the subject; an opto-electronic scanner head; a first signal processing circuit connected to the scanner head for identifying sharpness values from sums of square differences of image signal values in a line of neighboring pixels; a second signal processing circuit connected to the first signal processing circuit and to the adjustment unit; and said second signal processing circuit comprising means for identifying a starting sharpness value for a given prescribed distance between the subject and the objective; means for identifying first and second distances determined by varying from said prescribed distance by a first step width in both adjustment directions and identifying corresponding first and second sharpness values; means for determining a mathematical curve from said initial and first and second sharpness values, said curve representing sharpness values as a function of distances within a range of adjustment of said objective relative to said subject; means for identifying a function of said curve and coefficients thereof; and means for determining an apex point of said curve corresponding to a maximum sharpness and a corresponding distance between the subject and the objective.
Claim 25
Dependent Claim
22 words
An apparatus according to claim 21 wherein said means for determining said curve determines a curve of at least a second order.
Claim 26
Dependent Claim
23 words
An apparatus according to claim 22 wherein said means for determining said mathematical curve determines a curve of at least a third order.
Claim 27
Independent Claim
211 words
An apparatus for setting sharpness of an optical imaging system by step-by-step adjustment of a distance between a subject and an objective until a maximum is achieved for respectively identified sharpness values of the subject, comprising: an optical imaging system having an objective; an adjustment unit for the objective for adjusting a distance between the objective and the subject; an opto-electronic scanner head; a first signal processing circuit connected to the scanner head for identifying sharpness values from sums of square differences of image signal values in a line of neighboring pixels; a second signal processing circuit connected to the first signal processing circuit and to the adjustment unit; and said second signal processing circuit comprising means for identifying a starting sharpness value for a given prescribed distance between the subject and the objective; means for identifying distances determined by varying from said prescribed distance by a step width in both adjustment directions and identifying sharpness values; means for determining a mathematical curve from said sharpness values, said curve representing sharpness values as a function of distances of said objective relative to said subject image original; and means for determining an apex point of said curve corresponding to a maximum sharpness and a corresponding distance between the subject and the objective.
Claim 28
Independent Claim
211 words
An apparatus for setting sharpness of an optical imaging system by step-by-step adjustment of a distance between a subject and an objective until a maximum is achieved for respectively identified sharpness values of the subject, comprising: an optical imaging system having an objective; an adjustment unit for the objective for adjusting a distance between the objective and the subject; an opto-electronic scanner head; a first signal processing circuit connected to the scanner head for identifying sharpness values from sums of square differences of image signal values in a line of neighboring pixels; a second signal processing circuit connected to the first signal processing circuit and to the adjustment unit; and said second signal processing circuit comprising means for identifying a starting sharpness value for a given prescribed distance between the subject and the objective; means for identifying distances determined by varying from said prescribed distance by a step width in both adjustment directions and identifying sharpness values; means for determining a mathematical curve from said sharpness values, said curve representing sharpness values as a function of distances of said objective relative to said subject image original; and means for determining an apex point of said curve corresponding to a maximum sharpness and a corresponding distance between the subject and the objective.
References Cited (Backward Citations)
GB545437A
Cited
DE2234448A1
Cited
US4010479A
Cited
US4083056A
Cited
US4203031A
Cited
US4183642A
Cited
US4284335A
Cited
US4255028A
Cited
US4291958A
Cited
US4641942A
Cited
DE3141182A1
Cited
US4641865A
Cited
US4660094A
Cited
DE3340647A1
Cited
DE3634609A1
Cited
US4902101A
Cited
US4883951A
Cited
US4937620A
Cited
US4908645A
Cited
US4974002A
Cited
EP0347010A1
Cited
US4948940A
Cited
US5083150A
Cited
EP0404523A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-07-03 | 1999-01-02 | 1999-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-07-03 | 2003-01-02 | 2003-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-07-03 | 2007-01-02 | 2007-07-04 | $7700.00 | Window Closed / Lapsed |