US4613896A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods and apparatus for avoiding moire in color scanners for graphic art
Assignee: Dainippon Screen Manufacturing Co Ltd
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Filing: 1985-01-02
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Granted: 1986-09-23
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Expires: 2005-01-02
Abstract
Abstract Methods and apparatus for avoiding moire occurring in color scanning for graphic art, wherein light rays from a color original are passed through a pick-up lens, and prior to starting the color scanning, are modulated by means of a low-pass filter, which modulated rays are branched into two optical paths, on one of the paths a lattice plane is provided so as to project the modulated rays thereon, the lattice plane being beforehand selected in accordance with various conditions for scanning. A possible moire on the lattice plane is observed thereby to adjust the low-pass filter by replacement or displacement until the moire disappears on the lattice plane. Finally the light rays from the color original are modulated by the selected low-pass filter.
Inventors
- 👤 Nobuhiro Takita
- 👤 Yosuke Shimamoto
- 👤 Hiroichi Tada
- 👤 Yutaka Tamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:36
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/024; H04N1/028; G; G02; G02B; G02B26/00; G02B26/08; G02B26/10; H04N1/029; H04N1/40; H04N1/409
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
91 words
A method for avoiding the occurrence of moire in color scanners for graphic art, the method comprising: modulating light rays from the color original through a pick-up lens by means of a low pass filter, prior to starting the color scanning; projecting the modulated rays on a lattice plane; adjusting the low-pass filter through observation of the moire appearing on the lattice plane until the moire disappears thereon; and obtaining signals for recording the picture on the color original by light rays from the color original through the adjusted low-pass filter.
Claim 2
Independent Claim
91 words
A method for avoiding the occurrence of moire in color scanners for graphic art, the method comprising: modulating light rays from the color original through a pick-up lens by means of a low pass filter, prior to starting the color scanning; projecting the modulated rays on a lattice plane; adjusting the low-pass filter through observation of the moire appearing on the lattice plane until the moire disappears thereon; and obtaining signals for recording the picture on the color original by light rays from the color original through the adjusted low-pass filter.
Claim 3
Independent Claim
90 words
An apparatus for avoiding the occurrence of moire in color scanners for graphic art of the type having a plurality of apertures and spectrofilters, the apparatus comprising: an adjustable low-pass filter interposed between a pick-up lens and an aperture; a light branching lens for branching off light rays from the low-pass filter into first and second optical paths; a lattice plane located in the first optical path; and a plurality of light receivers in the second optical path in a number corresponding to the number of the apertures and spectrofilters.
Claim 4
Independent Claim
90 words
An apparatus for avoiding the occurrence of moire in color scanners for graphic art of the type having a plurality of apertures and spectrofilters, the apparatus comprising: an adjustable low-pass filter interposed between a pick-up lens and an aperture; a light branching lens for branching off light rays from the low-pass filter into first and second optical paths; a lattice plane located in the first optical path; and a plurality of light receivers in the second optical path in a number corresponding to the number of the apertures and spectrofilters.
Claim 5
Dependent Claim
19 words
An apparatus as set forth in claim 2, further comprising a restricting lens located ahead of the lattice plane.
Claim 6
Dependent Claim
80 words
An apparatus as set forth in claim 2 or 3, wherein the low-pass filter has at least several vapor-filmed parts located widely on one face thereof, the total area of the vapor-filled parts being approximately equal to half the entire area of the face on which they are located, and the vapor-filmed parts having an optical characteristic such that the light rays passing therethrough are differentiated by half waves from those passing through the non-vapor-filmed parts of said one face.
Claim 7
Dependent Claim
13 words
An apparatus as set forth in claim 4, wherein the aperture is elliptical.
Claim 8
Dependent Claim
54 words
An apparatus as set forth in claim 2 or 3, wherein the low-pass filter has at least several diffusing parts located widely on one face thereof, the diffusing parts allowing light rays passing therethrough to diffuse more widely than those passing through the parts of said one face not having diffusing parts located thereon.
Claim 9
Dependent Claim
13 words
An apparatus as set forth in claim 6, wherein the aperture is elliptical.
Claim 10
Dependent Claim
34 words
An apparatus as set forth in claim 2 or 3, wherein the low-pass filter has transparent parts and light modulating parts arranged alternately as well as convergently toward one point in a radial manner.
Claim 11
Dependent Claim
35 words
An apparatus as set forth in claim 8, wherein the total area of the light modulating parts is approximately equal to half of the entire area of the face on which both parts are provided.
Claim 12
Dependent Claim
16 words
An apparatus as set forth in claim 9, wherein the light modulating parts are made vapor-filming.
Claim 13
Dependent Claim
20 words
An apparatus as set forth in claim 9, wherein the light modulating parts are made of a light diffusing substance.
Claim 14
Dependent Claim
17 words
An apparatus as set forth in claim 8, wherein the light modulating parts are made by vapor-filming.
Claim 15
Dependent Claim
20 words
An apparatus as set forth in claim 8, wherein the light modulating parts are made of a light diffusing substance.
Claim 16
Dependent Claim
15 words
An apparatus as set forth in claim 2 or 3, wherein the aperture is elliptical.
Claim 17
Dependent Claim
17 words
An apparatus as set forth in claim 2 wherein the low pass filter is adjustable by replacement.
Claim 18
Dependent Claim
24 words
An apparatus as set forth in claim 2 wherein the low pass filter is adustable by altering its displacement with respect to the aperture.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-09-22 | 1990-03-24 | 1990-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-22 | 1994-03-24 | 1994-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-22 | 1998-03-24 | 1998-09-23 | $7700.00 | Window Closed / Lapsed |