US4682216A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color image picture forming process and apparatus which improves the quality of the black portions of the picture
Assignee: Canon Inc
•
Filing: 1984-03-01
•
Granted: 1987-07-21
•
Expires: 2004-03-01
Abstract
Abstract Color image picture forming process and apparatus can provide a picture with smooth shadow portions without false contours. When a black component of a color picture data is smaller than a predetermined value, the black component is expressed by using the combination of cyan, magenta and yellow colorants. When the black component is larger than the predetermined value, it is expressed by alternately using the black colorant and the three colorant combination. In another embodiment, picture quality can be enhanced by using a black colorant having a higher density than the cyan, magenta and yellow colorants.
Inventors
- 👤 Takashi Sasaki
- 👤 Nobuaki Sakurada
- 👤 Hideaki Kawamura
- 👤 Jiro Moriyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:46
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/46; H04N1/56; H04N1/60; H04N1/6016; H04N1/6022; B; B41; B41M; B41M1/00; B41M1/14; B41M1/18; H04N1/50
Claims Analysis
Total Claims: 58
Claim 1
Independent Claim
98 words
A color image picture forming process comprising the steps of: forming dots of colorants of four colors of cyan, magenta, yellow and black; a first expression step of expressing black in the picture using the cyan, magenta and yellow colorants; a second expression step of expressing black in the picture using the black colorant; selecting said first expression step when a black component of color image picture data is smaller than a predetermined value; and selecting said first and second expression steps in a mutually exclusive alternating manner when the black component is larger than the predetermined value.
Claim 2
Dependent Claim
98 words
A color image picture forming process comprising the steps of: forming dots of colorants of four colors of cyan, magenta, yellow and black; a first expression step of expressing black in the picture using the cyan, magenta and yellow colorants; a second expression step of expressing black in the picture using the black colorant; selecting said first expression step when a black component of color image picture data is smaller than a predetermined value; and selecting said first and second expression steps in a mutually exclusive alternating manner when the black component is larger than the predetermined value.
Claim 3
Dependent Claim
46 words
A color image picture forming process according to claim 1, further comprising the step of selecting a second predetermined value which is larger than the first-mentioned predetermined value and selecting only said second expression step when the black component is larger than the second predetermined value.
Claim 4
Dependent Claim
33 words
A color image picture forming process according to claim 1, wherein in said dot forming step, the dots of colorants of the respective colors are formed on a recording paper using ink-jet heads.
Claim 5
Dependent Claim
21 words
A color image picture forming process according to claim 3, further comprising the step of controlling the sizes of the dots.
Claim 6
Dependent Claim
32 words
A color image picture forming process according to claim 4, further comprising the step of controlling the amount of voltage applied to said ink-jet heads for controlling the sizes of the dots.
Claim 7
Dependent Claim
96 words
A color image picture forming process comprising the steps of: forming dots of colorants of four colors of cyan, magenta, yellow and black; a first expression step of expressing black in the picture using the cyan, magenta and yellow colorants; a second expression step of expressing black in the picture using the black colorant; selecting said first expression step when a black component of color image picture data is smaller than a predetermined value; and selecting said first and second expression steps alternately or at random when the black component is larger than the predetermined value.
Claim 8
Dependent Claim
96 words
A color image picture forming process comprising the steps of: forming dots of colorants of four colors of cyan, magenta, yellow and black; a first expression step of expressing black in the picture using the cyan, magenta and yellow colorants; a second expression step of expressing black in the picture using the black colorant; selecting said first expression step when a black component of color image picture data is smaller than a predetermined value; and selecting said first and second expression steps alternately or at random when the black component is larger than the predetermined value.
Claim 9
Dependent Claim
46 words
A color image picture forming process according to claim 6 further comprising the step of selecting a second predetermined value which is larger than the first-mentioned predetermined value and selecting only said second expression step when the black component is larger than the second predetermined value.
Claim 10
Dependent Claim
33 words
A color image picture forming process according to claim 6, wherein in said dot forming step, the dots of colorants of the respective colors ae formed on a recording paper using ink-jet heads.
Claim 11
Dependent Claim
21 words
A color image picture forming process according to claim 8, further comprising the step of controlling the sizes of the dots.
Claim 12
Dependent Claim
33 words
A color image picture forming process according to claim 9, further comprising the step of controlling the amount of voltage applied to said ink jet heads for controlling the sizes of the dots.
Claim 13
Dependent Claim
132 words
A color image picture forming apparatus comprising: dot forming means for forming dots of colorants of four colors consisting of three primary colors and black; detecting means for obtaining a black component from color image picture data; first processing means for processing the color image picture data to express black in the picture by combining dots of the three primary colors; second processing means for processing the color image picture data to express black in the picture using black dots; and selecting means for selecting either one or both of said first and second processing means in accordance with the magnitude of the black component, wherein said selecting means selects both said first and second processing means in a mutually exclusive alternating manner when the black component is in a predetermined range.
Claim 14
Dependent Claim
132 words
A color image picture forming apparatus comprising: dot forming means for forming dots of colorants of four colors consisting of three primary colors and black; detecting means for obtaining a black component from color image picture data; first processing means for processing the color image picture data to express black in the picture by combining dots of the three primary colors; second processing means for processing the color image picture data to express black in the picture using black dots; and selecting means for selecting either one or both of said first and second processing means in accordance with the magnitude of the black component, wherein said selecting means selects both said first and second processing means in a mutually exclusive alternating manner when the black component is in a predetermined range.
Claim 15
Dependent Claim
34 words
A color image picture forming apparatus according to claim 11, wherein said selecting means selects only said first processing means when the black component is smaller than a lower limit of the predetermined range.
Claim 16
Dependent Claim
34 words
A color image picture forming apparatus according to claim 11, wherein said selecting means selects only said second processing means when the black component is larger than an upper limit of the predetermined range.
Claim 17
Dependent Claim
18 words
A color image picture forming apparatus according to claim 11, wherein said dot forming means includes ink-jet heads.
Claim 18
Dependent Claim
25 words
A color image picture forming apparatus according to claim 14, further comprising means for controlling the sizes of ink droplets discharged from said ink-jet heads.
Claim 19
Dependent Claim
20 words
A color image picture forming apparatus according to claim 11, further comprising means for controlling the sizes of the dots.
Claim 20
Dependent Claim
20 words
A color image picture forming apparatus according to claim 11, wherein said first processing means includes a three-color masking circuit.
Claim 21
Dependent Claim
20 words
A color image picture forming apparatus according to claim 11, wherein said second processing means includes a four-color masking circuit.
Claim 22
Dependent Claim
20 words
A color image picture forming apparatus according to claim 11, wherein the three primary colors are cyan, magenta and yellow.
Claim 23
Dependent Claim
132 words
A color image picture forming apparatus comprising: dot forming means for forming dots of colorants of four colors consisting of three primary colors and black; detecting means for obtaining a black component from color image picture data; first processing means for processing the color image picture data to express black in the picture by combining dots of the three primary colors; second processing means for processing the color image picture data to express black in the picture using black dots; and selecting means for selecting either one or both of said first and second processing means in accordance with the magnitude of the black component, wherein said selecting means selects both said first and second processing means in a mutually exclusive random manner when the black component is in a predetermined range.
Claim 24
Dependent Claim
132 words
A color image picture forming apparatus comprising: dot forming means for forming dots of colorants of four colors consisting of three primary colors and black; detecting means for obtaining a black component from color image picture data; first processing means for processing the color image picture data to express black in the picture by combining dots of the three primary colors; second processing means for processing the color image picture data to express black in the picture using black dots; and selecting means for selecting either one or both of said first and second processing means in accordance with the magnitude of the black component, wherein said selecting means selects both said first and second processing means in a mutually exclusive random manner when the black component is in a predetermined range.
Claim 25
Dependent Claim
29 words
A color image picture forming apparatus according to claim 20, wherein said selecting means includes a dither generator for the random selection of said first and second processing means.
Claim 26
Dependent Claim
34 words
A color image picture forming apparatus according to claim 20, wherein said selecting means selects only said first processing means when the black component is smaller than a lower limit of the predetermined range.
Claim 27
Dependent Claim
34 words
A color image picture forming apparatus according to claim 20, wherein said selecting means selects only said second processing means when the black component is larger than an upper limit of the predetermined range.
Claim 28
Dependent Claim
18 words
A color image picture forming apparatus according to claim 20, wherein said dot forming means includes ink-jet heads.
Claim 29
Dependent Claim
25 words
A color image picture forming apparatus according to claim 24, further comprising means for controlling the sizes of ink droplets discharged from said ink-jet heads.
Claim 30
Dependent Claim
19 words
A color image forming apparatus according to claim 20, further comprising means for controlling the sizes of the dots.
Claim 31
Dependent Claim
20 words
A color image picture forming apparatus according to claim 20, wherein said first processing means includes a three-color masking circuit.
Claim 32
Dependent Claim
20 words
A color image picture forming apparatus according to claim 20, wherein said second processing means includes a four-color masking circuit.
Claim 33
Dependent Claim
20 words
A color image picture forming apparatus according to claim 20, wherein the three primary colors are cyan, magenta and yellow.
Claim 34
Dependent Claim
106 words
A color image picture forming process comprising the steps of: forming dots of colorants consisting of three primary colors and black; a first expression step of expressing black in the picture by a combination of dots of the three primary colors; a second expression step of expressing black in the picture using black dots; and selecting either one or both of said first and second expression steps in accordance with the magnitude of a black component of color image picture data, wherein said first and second expression steps are both selected in a mutually exclusive alternating manner when the black component is in a predetermined range.
Claim 35
Dependent Claim
106 words
A color image picture forming process comprising the steps of: forming dots of colorants consisting of three primary colors and black; a first expression step of expressing black in the picture by a combination of dots of the three primary colors; a second expression step of expressing black in the picture using black dots; and selecting either one or both of said first and second expression steps in accordance with the magnitude of a black component of color image picture data, wherein said first and second expression steps are both selected in a mutually exclusive alternating manner when the black component is in a predetermined range.
Claim 36
Dependent Claim
36 words
A color image picture forming process according to claim 30, wherein in said selecting step, only said first expression step is selected when said the component is smaller than a lower limit of the predetermined range.
Claim 37
Dependent Claim
36 words
A color image picture forming process according to claim 30, wherein in said selecting step, only said second expression step is selected when the black component is larger than an upper limit of the predetermined range.
Claim 38
Dependent Claim
23 words
A color image picture forming process according to claim 30, wherein in said dot forming step, the dots are formed by ink-jet heads.
Claim 39
Dependent Claim
106 words
A color image picture forming process comprising the steps of: forming dots of colorants consisting of three primary colors and black; a first expression step of expressing black in the picture by a combination of dots of the three primary colors; a second expression step of expressing black in the picture using black dots; and selecting either one or both of said first and second expression steps in accordance with the magnitude of a black component of color image picture data, wherein said first and second expression steps are both selected in a mutually exclusive random manner when the black component is in a predetermined range.
Claim 40
Dependent Claim
106 words
A color image picture forming process comprising the steps of: forming dots of colorants consisting of three primary colors and black; a first expression step of expressing black in the picture by a combination of dots of the three primary colors; a second expression step of expressing black in the picture using black dots; and selecting either one or both of said first and second expression steps in accordance with the magnitude of a black component of color image picture data, wherein said first and second expression steps are both selected in a mutually exclusive random manner when the black component is in a predetermined range.
Claim 41
Dependent Claim
36 words
A color image picture forming process according to claim 34, wherein in said selecting step, only said first expression step is selected when the black component is smaller than a lower limit of the predetermined range.
Claim 42
Dependent Claim
36 words
A color image picture forming process according to claim 34, wherein in said selecting step, only said second expression step is selected when the black component is larger than an upper limit of the predetermined range.
Claim 43
Dependent Claim
23 words
A color image picture forming process according to claim 34, wherein in said dot forming step, the dots are formed by ink-jet heads.
Claim 44
Dependent Claim
116 words
A color image picture forming process comprising the steps of: forming dots of colorants of three primary colors and black; detecting a black component from color image picture data; combining the black component with a noise signal when the black component is larger than a first predetermined value, wherein the first predetermined value is 50% or more of the highest optical density expressible using the black colorant; expressing black in the picture using the three primary color colorants when the black component is smaller than a second predetermined value lower than the first predetermined value; and expressing black in the picture using the black colorant when the black component is larger than the second predetermined value.
Claim 45
Dependent Claim
116 words
A color image picture forming process comprising the steps of: forming dots of colorants of three primary colors and black; detecting a black component from color image picture data; combining the black component with a noise signal when the black component is larger than a first predetermined value, wherein the first predetermined value is 50% or more of the highest optical density expressible using the black colorant; expressing black in the picture using the three primary color colorants when the black component is smaller than a second predetermined value lower than the first predetermined value; and expressing black in the picture using the black colorant when the black component is larger than the second predetermined value.
Claim 46
Dependent Claim
28 words
A color image picture forming process according to claim 38, wherein in said combining step, the noise signal is superimposed on a signal representative of the black component.
Claim 47
Dependent Claim
27 words
A color image picture forming process according to claim 39, wherein in said combining step, said noise signal is generated in accordance with a predetermined dither pattern.
Claim 48
Dependent Claim
20 words
A color image picture forming process according to claim 38, wherein the three primary colors are cyan, magenta and yellow.
Claim 49
Dependent Claim
29 words
A color image picture forming process according to claim 38, wherein in said dot forming step, the dots of colorants of the respective colors are formed using ink-jet heads.
Claim 50
Dependent Claim
32 words
A color image picture forming process according to claim 38, further comprising the step of controlling the sizes of the dots in response to density levels of the color image picture data.
Claim 51
Dependent Claim
153 words
A color image picture forming apparatus comprising: dot forming means for forming dots of colorants of three primary colors and black; combining means for combining a dither signal with a black component signal obtained from color image picture data; means for inhibiting the operation of said combining means when the level of the black component signal is smaller than a first predetermined value, wherein the first predetermined value is 50% or more of the highest optical density expressible using the black colorant; first processing means for processing the color image data to express black in the picture by combining dots of the three primary colors when the black component is smaller than a second predetermined value lower than the first predetermined value; and second processing means for processing the color image data to express black in the picture by using black dots when the black component is larger than the second predetermined value.
Claim 52
Dependent Claim
153 words
A color image picture forming apparatus comprising: dot forming means for forming dots of colorants of three primary colors and black; combining means for combining a dither signal with a black component signal obtained from color image picture data; means for inhibiting the operation of said combining means when the level of the black component signal is smaller than a first predetermined value, wherein the first predetermined value is 50% or more of the highest optical density expressible using the black colorant; first processing means for processing the color image data to express black in the picture by combining dots of the three primary colors when the black component is smaller than a second predetermined value lower than the first predetermined value; and second processing means for processing the color image data to express black in the picture by using black dots when the black component is larger than the second predetermined value.
Claim 53
Dependent Claim
22 words
A color image picture forming apparatus according to claim 44, wherein the color image picture data comprises R, G and B signals.
Claim 54
Dependent Claim
26 words
A color image picture forming apparatus according to claim 45, further comprising detecting means for detecting the black component from the R, G and B signals.
Claim 55
Dependent Claim
21 words
A color image picture forming apparatus according to claim 44, wherein said combining means includes means for generating the dither signal.
Claim 56
Dependent Claim
19 words
A color image picture forming apparatus according to claim 47, wherein the amplitude of the dither signal changes regularly.
Claim 57
Dependent Claim
28 words
A color image picture forming apparatus according to claim 44, wherein said dot forming means includes ink-jet heads and said heads can vary the sizes of the dots.
Claim 58
Dependent Claim
20 words
A color image picture forming apparatus according to claim 44, further comprising means for controlling the sizes of the dots.
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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) | 1990-07-20 | 1991-01-19 | 1991-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-20 | 1995-01-19 | 1995-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-20 | 1999-01-19 | 1999-07-21 | $7700.00 | Window Closed / Lapsed |