US4727436A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for producing a picture
Assignee: Canon Inc
•
Filing: 1986-12-23
•
Granted: 1988-02-23
•
Expires: 2006-12-23
Abstract
Abstract For reproducing a picture with a density gradient through printing, an overlapped region is provided in a high density dot reproduction range and a low density dot reproduction range. The switch-over between the high density dot at the overlapped region is conducted where the picture density sharply changes. This reduces the unfavorable perception of quality differences in a printed picture resulting from the switch-over between the high and low density dots.
Inventors
- 👤 Hideaki Kawamura
- 👤 Nobuaki Sakurada
- 👤 Yuichi Sato
- 👤 Yoshitaka Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:27
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40087
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
152 words
A method of producing a picture comprising a pictorial color image having areas of different light-reflecting properties which provide different optical reflection densities, the method comprising: providing dots having a plurality of optical reflection densities for representing areas of the picture having corresponding optical reflection densities; using a first kind of dot with a first concentration for representing areas of the picture having optical reflection densities less than an upper level; using a second kind of dot with a second concentration higher than said first concentration for representing areas of the picture having optical reflection densities greater than a lower level below said upper level; and changing over between said first and second kinds of dots in a region of the picture that has an optical reflection density between said upper and lower levels, wherein said change-over is conducted by detecting a sharp change in the optical reflection density of the picture.
Claim 2
Independent Claim
152 words
A method of producing a picture comprising a pictorial color image having areas of different light-reflecting properties which provide different optical reflection densities, the method comprising: providing dots having a plurality of optical reflection densities for representing areas of the picture having corresponding optical reflection densities; using a first kind of dot with a first concentration for representing areas of the picture having optical reflection densities less than an upper level; using a second kind of dot with a second concentration higher than said first concentration for representing areas of the picture having optical reflection densities greater than a lower level below said upper level; and changing over between said first and second kinds of dots in a region of the picture that has an optical reflection density between said upper and lower levels, wherein said change-over is conducted by detecting a sharp change in the optical reflection density of the picture.
Claim 3
Dependent Claim
31 words
A method according to claim 1, wherein the picture is produced by the first kind of dots in the portions thereof having a lower optical reflection density than said lower level.
Claim 4
Dependent Claim
31 words
A method according to claim 1, wherein the picture is produced by the second kind of dots in the portions thereof having a higher optical reflection density than said upper level.
Claim 5
Dependent Claim
24 words
A method according to claim 1, wherein said detection is made by differentiating a signal representing the optical reflection density level of the picture.
Claim 6
Dependent Claim
44 words
A method according to claim 1, wherein said dots are provided by ink droplets discharged from an ink jet head corresponding to each kind of dot and the optical reflection densities of the dots are varied by changing the size of the ink droplets.
Claim 7
Dependent Claim
38 words
A method according to claim 1, wherein said dots have a plurality of colors, with respect to at least one color among said plurality of colors a plurality of optical reflection densities is used to form the picture.
Claim 8
Dependent Claim
20 words
A method according to claim 6, wherein said dots are provided in four colors of cyan, magenta, yellow, and black.
Claim 9
Independent Claim
204 words
A method of producing a picture comprising a pictorial color image having areas of different light-reflecting properties which provide different optical reflection densities, the method comprising the steps of: providing dots having a plurality of optical reflection densities for representing areas of the picture having corresponding optical reflection densities; setting a density overlapping region wherein the optical reflection densities of the picture can be represented by at least two kinds of dots having high and low concentrations that provide ranges of optical reflection densities that overlap with each other; producing areas of the picture by using said low concentration dots when the area has a lower optical reflection density level than the lower limit of said density overlapping region; producing areas of the picture by using said high concentration dots when the area has a higher optical reflection density level than the upper limit of said density overlapping region; producing areas of the picture using one of either said high or low concentration dots when the area has an intermediate optical reflection density level within said density overlapping region; and changing over between using high concentration dots and low concentration dots when the optical reflection density level sharply changes in said density overlapping region.
Claim 10
Independent Claim
204 words
A method of producing a picture comprising a pictorial color image having areas of different light-reflecting properties which provide different optical reflection densities, the method comprising the steps of: providing dots having a plurality of optical reflection densities for representing areas of the picture having corresponding optical reflection densities; setting a density overlapping region wherein the optical reflection densities of the picture can be represented by at least two kinds of dots having high and low concentrations that provide ranges of optical reflection densities that overlap with each other; producing areas of the picture by using said low concentration dots when the area has a lower optical reflection density level than the lower limit of said density overlapping region; producing areas of the picture by using said high concentration dots when the area has a higher optical reflection density level than the upper limit of said density overlapping region; producing areas of the picture using one of either said high or low concentration dots when the area has an intermediate optical reflection density level within said density overlapping region; and changing over between using high concentration dots and low concentration dots when the optical reflection density level sharply changes in said density overlapping region.
Claim 11
Dependent Claim
27 words
A method according to claim 8, wherein said change-over step is conducted by detecting the portion where the optical reflection density level of the picture sharply changes.
Claim 12
Dependent Claim
24 words
A method according to claim 9, wherein said detection is made by differentiating a signal representing the optical reflection density level of the picture.
Claim 13
Dependent Claim
44 words
A method according to claim 8, wherein said dots are provided by ink droplets discharged from an ink jet head corresponding to each kind of dot and the optical reflection densities of the dots are varied by changing the size of the ink droplets.
Claim 14
Dependent Claim
38 words
A method according to claim 8, wherein said dots have a plurality of colors, with respect to at least one color among said plurality of colors a plurality of optical reflection densities is used to form the picture.
Claim 15
Dependent Claim
20 words
A method according to claim 12, wherein said dots are provided in four colors of cyan, magenta, yellow, and black.
Claim 16
Dependent Claim
129 words
Apparatus for producing a picture comprising a pictorial color image having areas of different light-reflecting properties which provide different optical reflection densities, the apparatus comprising: means for providing dots having a plurality of optical reflection densities for representing areas of the picture having corresponding optical reflection densities by using at least two kinds of dots with different concentrations; means for detecting regions of the picture having an intermediate optical reflection density between two levels and areas of the picture in the regions wherein the optical reflection density changes at least by a predetermined amount from one area to an adjacent area; and means for controlling said dot-providing means to change over from one said kind of dot to another said kind of dot in response to said detecting means.
Claim 17
Dependent Claim
129 words
Apparatus for producing a picture comprising a pictorial color image having areas of different light-reflecting properties which provide different optical reflection densities, the apparatus comprising: means for providing dots having a plurality of optical reflection densities for representing areas of the picture having corresponding optical reflection densities by using at least two kinds of dots with different concentrations; means for detecting regions of the picture having an intermediate optical reflection density between two levels and areas of the picture in the regions wherein the optical reflection density changes at least by a predetermined amount from one area to an adjacent area; and means for controlling said dot-providing means to change over from one said kind of dot to another said kind of dot in response to said detecting means.
Claim 18
Dependent Claim
33 words
Apparatus according to claim 14, wherein said detection means detects the where the density optical reflection level sharply changes by differentiating a density signal representing the optical reflection density level of the picture.
Claim 19
Dependent Claim
36 words
Apparatus according to claim 14 wherein said dot-producing means includes an ink jet head corresponding to each kind of dot for discharging ink droplets of different sizes to vary the optical reflection densities of the dots.
Claim 20
Dependent Claim
16 words
Apparatus according to claim 14, wherein said dot-producing means forms dots having a plurality of colors.
Claim 21
Dependent Claim
17 words
Apparatus according to claim 17, wherein said dot-producing means forms dots of cyan, magenta, yellow, and black.
Claim 22
Dependent Claim
170 words
Apparatus for producing a picture having areas of different light-reflecting properties which provide different optical reflection densities, the apparatus comprising: means for providing dots having a plurality of optical reflection densities for representing areas of the picture having corresponding optical reflection densities by using at least two kinds of dots with different concentrations; means for detecting regions of the picture having an intermediate optical reflection density between two levels and areas of the picture in the regions wherein the optical reflection density changes at least by a predetermined amount from one area to an adjacent area, wherein said detection means detects said areas by second-order differentiating a density signal representing the optical reflection density level of the picture and by comparing the second-order differential value with a predetermined value to detect where the optical reflection density level of the picture sharply changes; and means for controlling said dot-providing means to change over from one said kind of dot to another said kind of dot in response to said detecting means.
Claim 23
Dependent Claim
170 words
Apparatus for producing a picture having areas of different light-reflecting properties which provide different optical reflection densities, the apparatus comprising: means for providing dots having a plurality of optical reflection densities for representing areas of the picture having corresponding optical reflection densities by using at least two kinds of dots with different concentrations; means for detecting regions of the picture having an intermediate optical reflection density between two levels and areas of the picture in the regions wherein the optical reflection density changes at least by a predetermined amount from one area to an adjacent area, wherein said detection means detects said areas by second-order differentiating a density signal representing the optical reflection density level of the picture and by comparing the second-order differential value with a predetermined value to detect where the optical reflection density level of the picture sharply changes; and means for controlling said dot-providing means to change over from one said kind of dot to another said kind of dot in response to said detecting means.
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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) | 1991-02-22 | 1991-08-24 | 1992-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-22 | 1995-08-24 | 1996-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-22 | 1999-08-24 | 2000-02-23 | $7700.00 | Window Closed / Lapsed |