Patent EP0213891A2 successfully refreshed from Google Patents.
EP0213891A2
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EP
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Image processing apparatus
Assignee: Canon Inc
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Filing: 1986-08-20
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Granted: —
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Expires: 2006-08-20
Abstract
Abstract There is disclosed an image processing apparatus in which plural image signals are generated for modulating plural light beams for obtaining different colours. In order to avoid unpleasant moire pattern on a reproduced image, the plural image signals are generated with mutually different screen angles by comparing the signals, in the generation thereof, with different analogue pattern signals having mutually different characteristics for the colours, e.g. different phases or frequencies.
Inventors
- 👤 Yuji Nishigaki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 22:58
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/52
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
103 words
An image processing apparatus comprising: image signal generating means for generating first and second colour image signals; and pulse-width modulated signal generating means for processing said first and second colour image signals, generated by said image signal generating means, respectively with first and second analogue pattern signals to generate first and second pulse-width modulated signals for modulating a beam; wherein said first and second analog pattern signals are generated in response to a synchronization signal associated with said beam, and have mutually different characteristics in order to obtain mutually different characteristics in the reproduced image to be formed with said analog pattern signals.
Claim 2
Dependent Claim
103 words
An image processing apparatus comprising: image signal generating means for generating first and second colour image signals; and pulse-width modulated signal generating means for processing said first and second colour image signals, generated by said image signal generating means, respectively with first and second analogue pattern signals to generate first and second pulse-width modulated signals for modulating a beam; wherein said first and second analog pattern signals are generated in response to a synchronization signal associated with said beam, and have mutually different characteristics in order to obtain mutually different characteristics in the reproduced image to be formed with said analog pattern signals.
Claim 3
Dependent Claim
38 words
An apparatus according to claim 1, wherein said first and second analogue pattern signals have mutually different phases in order to obtain mutually different screen angles in the reproduced image to be formed with said analog pattern signals.
Claim 4
Dependent Claim
42 words
An apparatus according to claim 1 or 2, wherein said first and second analog pattern signals have mutually different repeating periods in order to obtain mutually different numbers of lines in the reproduced image to be formed with said analog pattern signals.
Claim 5
Independent Claim
56 words
An apparatus according to any preceding claim, wherein said first and second analog pattern signals are first and second triangular signals and said pulse-width modulated signal generating means comprises comparator means for comparing said first and second image signals respectively with said first and second triangular signals to generate said first and second pulse-width modulated signals.
Claim 6
Independent Claim
60 words
An apparatus according to any preceding claim, further comprising reference clock signal generating means for generating a reference clock signal, and screen clock generating means for dividing the frequency of said reference clock signal in response to said synchronization signal to generate first and second screen clock signals to be used for generating said first and second analog pattern signals.
Claim 7
Dependent Claim
44 words
An apparatus according to claim 5, further comprising image clock signal generating means for dividing the frequency of said reference clock signal in response to said synchronization signal to generate first and second image clock signals for transferring said first and second image signals.
Claim 8
Independent Claim
22 words
An apparatus according to any preceding claim, wherein said first and second image signals are respectively associated with first and second colours.
Claim 9
Independent Claim
57 words
An apparatus according to any preceding claim, further comprising image forming means for modulating a laser beam according to said first and second pulse-width modulated signals to form an image on a recording medium, said image forming means comprising synchronization signal generating means for generating said sychronization signal by detecting the scanning position of said laser beam.
Claim 10
Dependent Claim
35 words
An image processing apparatus, in which first and second colour image signals are processed with first and second varying reference signals, respectively, of mutually different characteristics to produce first and second processed colour image signals.
Claim 11
Dependent Claim
35 words
An image processing apparatus, in which first and second colour image signals are processed with first and second varying reference signals, respectively, of mutually different characteristics to produce first and second processed colour image signals.
Claim 12
Dependent Claim
25 words
An apparatus as claimed in claim 9. wherein the reference signals are of the same frequency but not in phase, or are of different frequencies.
References Cited (Backward Citations)
US4040094A
Cited
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