Patent US4346402A successfully refreshed from Google Patents.
US4346402A
Expired / Lapsed
US
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Image-reproduction apparatus
Assignee: FFEI Ltd
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Filing: 1980-05-28
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Granted: 1982-08-24
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Expires: 2000-05-28
Abstract
Abstract A color scanner for the graphic arts of the kind in which three uncorrected color-component analogue signals from the scanner are converted into digital form and are applied to the inputs of a three-dimensional look-up table or read-only memory in which are stored corresponding color-corrected signal values for the three colors and, if desired, for black. Individual one-dimensional color-component look-up tables are interposed between the analogue-digital converter and the three-dimensional look-up table. The functions performed by the one-dimensional tables may include logarithmic conversion of the input signals, for example. Preferably, further individual one-dimensional look-up tables are inserted between the outputs of the three-dimensional table and a digital-analogue converter preceding an output scanner.
Inventors
- 👤 Peter C. Pugsley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:21
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/6027; H04N1/6016; H04N1/6022; H04N1/6025
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
145 words
A method for the production of colour-separated and colour-corrected images from a coloured original, including electro-optically scanning the original to produce uncorrected colour separation signals which are then converted into digital form, comprising the steps of: individually applying the uncorrected colour separation signals to separate first signal-varying means each including a digitally stored first look-up table, said first signal-varying means providing signals which have been modified substantially independently of one another; thereafter applying the modified uncorrected colour separation signals to a further signal-varying means including a digitally stored look-up table to obtain corrected colour separation signals, each of which is a function of two or more of the modified uncorrected colour separation signals; and from the corrected signals, deriving output signals for application to one or more output devices by means of which each colour corrected colour separation image is recorded on a recording medium.
Claim 2
Independent Claim
145 words
A method for the production of colour-separated and colour-corrected images from a coloured original, including electro-optically scanning the original to produce uncorrected colour separation signals which are then converted into digital form, comprising the steps of: individually applying the uncorrected colour separation signals to separate first signal-varying means each including a digitally stored first look-up table, said first signal-varying means providing signals which have been modified substantially independently of one another; thereafter applying the modified uncorrected colour separation signals to a further signal-varying means including a digitally stored look-up table to obtain corrected colour separation signals, each of which is a function of two or more of the modified uncorrected colour separation signals; and from the corrected signals, deriving output signals for application to one or more output devices by means of which each colour corrected colour separation image is recorded on a recording medium.
Claim 3
Dependent Claim
53 words
A method in accordance with claim 1, comprising applying each corrected colour separation signal obtained from the colour-correcting signal-varying means to an output signal-varying means including an individual digitally stored look-up table which further modifies the corrected colour separation signal applied thereto, the further modified signal being used to control the output device.
Claim 4
Dependent Claim
161 words
Apparatus for the production of colour-separated and colour-corrected images from a coloured original, including an electro-optical scanner for producing uncorrected colour separation signals corresponding to successively scanned elements of the original, comprising: a plurality of analogue-to-digital converters for individually converting the signals into digital form; a plurality of separate first signal-varying means, each including a digitally stored first look-up table, connected to individually receive the uncorrected colour separation signals, said first signal-varying means providing signals which have been modified substantially independently of one another; colour-correcting signal-varying means connected to receive the modified uncorrected colour separation signals, the colour-correcting signal-varying means including a digitally stored look-up table for providing colour-corrected colour separation signals, each of which is a function of two or more of the modified uncorrected colour separation signals; and means for deriving from the colour-corrected signals, output signals for application to one or more output devices by means of which each colour-corrected colour-separation image is recorded on a recording medium.
Claim 5
Dependent Claim
161 words
Apparatus for the production of colour-separated and colour-corrected images from a coloured original, including an electro-optical scanner for producing uncorrected colour separation signals corresponding to successively scanned elements of the original, comprising: a plurality of analogue-to-digital converters for individually converting the signals into digital form; a plurality of separate first signal-varying means, each including a digitally stored first look-up table, connected to individually receive the uncorrected colour separation signals, said first signal-varying means providing signals which have been modified substantially independently of one another; colour-correcting signal-varying means connected to receive the modified uncorrected colour separation signals, the colour-correcting signal-varying means including a digitally stored look-up table for providing colour-corrected colour separation signals, each of which is a function of two or more of the modified uncorrected colour separation signals; and means for deriving from the colour-corrected signals, output signals for application to one or more output devices by means of which each colour-corrected colour-separation image is recorded on a recording medium.
Claim 6
Dependent Claim
57 words
Apparatus in accordance with claim 3, further comprising a separate output signal-varying means for each corrected colour separation signal obtained from the colour-correcting signal-varying means, each output signal-varying means including an individually digitally stored look-up table which further modifies the corrected colour separation signal applied thereto, the further modified signal being used to control the output device.
Claim 7
Dependent Claim
18 words
Apparatus in accordance with claim 3 or 4, in which the look-up tables operate in an absolute mode.
Claim 8
Dependent Claim
18 words
Apparatus in accordance with claim 3 or 4, in which the look-up tables operate in an incremental manner.
Claim 9
Dependent Claim
39 words
Apparatus in accordance with claim 3 in which a number of bits used for the signal immediately following analogue-digital conversion is greater than the number of bits used for the signal at the output of the first look-up tables.
Claim 10
Dependent Claim
32 words
Apparatus in accordance with claim 4, in which the number of bits used at the input to the output look-up tables is smaller than the number of bits obtained at the output.
Claim 11
Dependent Claim
31 words
Apparatus in accordance with claim 3, in which the first look-up tables provide a linear-to-logarithmic transformation, converting the linear representation of transmittance or reflectance of the original to a density representation.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-08-23 | 1986-02-22 | 1986-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-23 | 1990-02-22 | 1990-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-23 | 1994-02-22 | 1994-08-24 | $7700.00 | Window Closed / Lapsed |