US6587224B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image reading apparatus that can correct chromatic aberration caused by optical system and chromatic aberration correction method
Assignee: Minolta Co Ltd
•
Filing: 1999-09-14
•
Granted: 2003-07-01
•
Expires: 2019-09-14
Abstract
Abstract In order to correct chromatic aberration accurately and read out a document original properly, an image reader apparatus includes a chromatic aberration correction chart, a CCD linear sensor, and a correction processing unit. A chromatic aberration correction chart includes a high reflectance portion and a low reflectance portion lower than the high reflectance portion. A CCD linear sensor receives light reflected from the chromatic aberration correction chart. A correction processing unit corrects chromatic aberration of image data according to a light receiving position in the photoelectric conversion unit receiving light of a first wavelength included in the reflected light from the chromatic aberration correction chart and a light receiving position in the photoelectric conversion unit receiving light of a second wavelength included in the reflected light from the chromatic aberration correction chart.
Inventors
- 👤 Takayuki Nabeshima
- 👤 Makoto Kumagai
- 👤 Satoshi Iwasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:33
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/48; H04N1/56; H04N1/58; H04N2201/00; H04N2201/04; H04N2201/0402; H04N2201/044
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
108 words
An image reading apparatus comprising: a chromatic aberration correction chart including a high reflectance portion and a low reflectance portion lower in reflectance than said high reflectance portion, a photoelectric conversion unit which receives light reflected from said chromatic aberration correction chart, and a correction processor which corrects chromatic aberration of image data according to a light receiving position in said photoelectric conversion unit receiving light of a first wavelength included in the reflected light from said chromatic aberration correction chart and a light receiving position in said photoelectric conversion unit receiving light of a second wavelength included in the reflected light from said chromatic aberration correction chart.
Claim 2
Dependent Claim
108 words
An image reading apparatus comprising: a chromatic aberration correction chart including a high reflectance portion and a low reflectance portion lower in reflectance than said high reflectance portion, a photoelectric conversion unit which receives light reflected from said chromatic aberration correction chart, and a correction processor which corrects chromatic aberration of image data according to a light receiving position in said photoelectric conversion unit receiving light of a first wavelength included in the reflected light from said chromatic aberration correction chart and a light receiving position in said photoelectric conversion unit receiving light of a second wavelength included in the reflected light from said chromatic aberration correction chart.
Claim 3
Dependent Claim
22 words
The image reading apparatus according to claim 1 , further comprising a light source emitting light to said chromatic aberration correction chart.
Claim 4
Dependent Claim
25 words
The image reading apparatus according to claim 2 , further comprising a shading correction plate to correct variation in distributed light of said light source.
Claim 5
Dependent Claim
40 words
The image reading apparatus according to claim 1 , wherein said chromatic aberration correction chart has said high reflectance portion and said low reflectance portion arranged alternately in an arrangement direction of light receiving elements of said photoelectric conversion unit.
Claim 6
Dependent Claim
33 words
The image reading apparatus according to claim 1 , wherein said correction processing unit determines a light receiving position by comparing an output of said photoelectric conversion unit with a predetermined reference value.
Claim 7
Dependent Claim
28 words
The image reading apparatus according to claim 1 , wherein said photoelectric conversion unit includes a filter separating respective light of said first wavelength and said second wavelength.
Claim 8
Dependent Claim
29 words
The image reading apparatus according to claim 1 , wherein said chromatic aberration correction chart has a distinct boundary between said high reflectance portion and said low reflectance portion.
Claim 9
Dependent Claim
36 words
The image reading apparatus according to claim 7 , wherein said correction processing unit detects light receiving positions of the light of said first wavelength and said second wavelength included in light reflected from said boundary.
Claim 10
Dependent Claim
109 words
A chromatic aberration correction method of an image reading apparatus, comprising the steps of: receiving light reflected from a chromatic aberration correction chart including a high reflectance portion and a low reflectance portion lower in reflectance than said high reflectance portion, detecting a first light receiving position in a photoelectric conversion unit receiving light of a first wavelength included in light reflected from said high reflectance portion and a second light receiving position in said photoelectric conversion unit receiving light of a second wavelength included in light reflected from said high reflectance portion, and correcting chromatic aberration of image data according to said first and second light receiving positions.
Claim 11
Dependent Claim
109 words
A chromatic aberration correction method of an image reading apparatus, comprising the steps of: receiving light reflected from a chromatic aberration correction chart including a high reflectance portion and a low reflectance portion lower in reflectance than said high reflectance portion, detecting a first light receiving position in a photoelectric conversion unit receiving light of a first wavelength included in light reflected from said high reflectance portion and a second light receiving position in said photoelectric conversion unit receiving light of a second wavelength included in light reflected from said high reflectance portion, and correcting chromatic aberration of image data according to said first and second light receiving positions.
Claim 12
Dependent Claim
38 words
The chromatic aberration correction method of an image reading apparatus according to claim 9 , wherein said detecting step determines a light receiving position by comparing an output of said photoelectric conversion unit with a predetermined reference value.
Claim 13
Dependent Claim
77 words
A reading apparatus comprising: a light source, a correction chart including portions formed in different density, an optical system which focuses light from said light source reflected at said correction chart, a light receiving unit which receives light focused by said optical system, separated into light of predetermined wavelengths, and a processor which corrects chromatic aberration caused by said optical system based on a difference between data of respective separated lights obtained by said light receiving unit.
Claim 14
Dependent Claim
77 words
A reading apparatus comprising: a light source, a correction chart including portions formed in different density, an optical system which focuses light from said light source reflected at said correction chart, a light receiving unit which receives light focused by said optical system, separated into light of predetermined wavelengths, and a processor which corrects chromatic aberration caused by said optical system based on a difference between data of respective separated lights obtained by said light receiving unit.
Claim 15
Dependent Claim
24 words
The reading apparatus according to claim 11 , further comprising a shading correction plate to correct variation in distributed light of said light source.
Claim 16
Dependent Claim
37 words
The reading apparatus according to claim 11 , wherein said correction chart has a high density portion and a low density portion arranged alternately in an arrangement direction of light receiving elements of said light receiving unit.
Claim 17
Dependent Claim
30 words
The reading apparatus according to claim 11 , wherein said processor determines a light receiving position by comparing an output of said light receiving unit with a predetermined reference value.
Claim 18
Dependent Claim
26 words
The reading apparatus according to claim 11 , wherein said correction chart has a distinct boundary between the high density portion and the low density portion.
Claim 19
Dependent Claim
32 words
The reading apparatus according to claim 15 , wherein said processor detects light receiving positions of light of a first wavelength and a second wavelength included in light reflected from said boundary.
References Cited (Backward Citations)
US4731661A
Cited
US4943155A
Cited
US5168373A
Cited
US5691827A
Cited
JPH04280574A
Cited
JPH05122542A
Cited
US6320668B1
Cited
US6421146B1
Cited
US6205244B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2006-06-30 | 2006-12-30 | 2007-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-06-30 | 2010-12-30 | 2011-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-06-30 | 2014-12-30 | 2015-07-01 | $7700.00 | Window Closed / Lapsed |