CA1304980C - Method of improving dot-on-dot graphics area-fill using an ink-jet device - Google Patents
Method of improving dot-on-dot graphics area-fill using an ink-jet deviceInfo
- Publication number
- CA1304980C CA1304980C CA000558642A CA558642A CA1304980C CA 1304980 C CA1304980 C CA 1304980C CA 000558642 A CA000558642 A CA 000558642A CA 558642 A CA558642 A CA 558642A CA 1304980 C CA1304980 C CA 1304980C
- Authority
- CA
- Canada
- Prior art keywords
- color
- swath
- printing
- printhead
- partial
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
- B41J2/01—Ink jet
- B41J2/21—Ink jet for multi-colour printing
- B41J2/2132—Print quality control characterised by dot disposition, e.g. for reducing white stripes or banding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
- B41M1/00—Inking and printing with a printer's forme
- B41M1/14—Multicolour printing
- B41M1/18—Printing one ink over another
Landscapes
- Engineering & Computer Science (AREA)
- Quality & Reliability (AREA)
- Ink Jet (AREA)
- Particle Formation And Scattering Control In Inkjet Printers (AREA)
- Ink Jet Recording Methods And Recording Media Thereof (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Perceived quality of printing dot-on-dot graphics area fill using an ink-jet device is improved by printing rows (30, 32, 34, 36, 38) of alternating colors, with each row offset from the preceeding row by a predetermined amount. In this manner, banding (22, 22'), which is per-ceived with prior art printing methods, is substantially reduced.
Perceived quality of printing dot-on-dot graphics area fill using an ink-jet device is improved by printing rows (30, 32, 34, 36, 38) of alternating colors, with each row offset from the preceeding row by a predetermined amount. In this manner, banding (22, 22'), which is per-ceived with prior art printing methods, is substantially reduced.
Description
- 13~980 METHOD OF IMP~OVIIJG DOT-OI~-DOT GRAPHICS AREA-FILL
USI~G A~ INK-JET DEVICE
1 TECHtJICAL FIELD
T~le present invelltion relates to ink-~et devlces for printing colors on a prlnt medlum, and, more partlcularly, to a method of improvlng the percel~ed quality of color graphicc thereorl.
BACKGROUI~D A~T
Ink-~et devlces flre droplets of lnk toward a print-lng medlum, 8uch as paper or mylar. Typlcal lnk-~et printheads comprlse at least one group of nozzles, called a primitive, through whlch the droplets of ink are flred.
For full color prlntlng, three primitlves are employed, with the nozzles of each fluldlcally connected to a reser-voir of a different color ink ~cyan, yellow, magenta).
The firing, or propelllng of lnk droplets, may be done by piezoelectric means or by reslstive heat~ng (thermal).
In green, red and blue soltd area-flll, the colors are generated by placlng one dot of a flrst color on top of anot~ler dot of a 6econd color, whlch produces the de-~ired t~llrd color (e.g., yellow on cyan creates greenJ.
In the normal prlnting mode, the dots are put down on each other ln the same pass of the prlnthead across the medium. When prlrltlng a block of area-fill, bands occur between swaths of prlnt rows, due to absorptlon of the ~304980 first color printed on the medium, which may be a specially coated paper used for color ink-jet printing.
The banding tends to reduce the perceived quality of the output.
Accordingly, a method of producing a substantially uniform block of color, without the perceived banding or at least with reduced perceived banding is desired.
DISCLOSURE OF INVENTION
In accordance with the invention, a method of forming dot-on-dot graphics area-fill with reduced perceived banding is provided. The method comprises overlapping a portion of one print row or print swath with a portion of another print row or print swath.
In particular, the invention provides a method of generating dot-on-dot graphics area fill on a print medium using an ink-jet device including at least one printhead having a set of primitives, each primitive comprising a plurality of nozzle~ one dot apart fluidically connected to a reservoir of a given colour, 0 the method comprising:
printing a first row of a first colour;
printing a second row of a second colour; and printing further rows of alternating first and second colours, each further row of each colour being 5 contiguous with the previous row of that colour;
characterised in that each row of the second colour is offset from its respective row of the first colour by a predetermined displacement toward the previous row of the first colour.
The offset printing may be done by moving either the print medium or the printhead relative to the other.
Also, primitives on the printhead may be staggered to achieve the desired effect.
B
USI~G A~ INK-JET DEVICE
1 TECHtJICAL FIELD
T~le present invelltion relates to ink-~et devlces for printing colors on a prlnt medlum, and, more partlcularly, to a method of improvlng the percel~ed quality of color graphicc thereorl.
BACKGROUI~D A~T
Ink-~et devlces flre droplets of lnk toward a print-lng medlum, 8uch as paper or mylar. Typlcal lnk-~et printheads comprlse at least one group of nozzles, called a primitive, through whlch the droplets of ink are flred.
For full color prlntlng, three primitlves are employed, with the nozzles of each fluldlcally connected to a reser-voir of a different color ink ~cyan, yellow, magenta).
The firing, or propelllng of lnk droplets, may be done by piezoelectric means or by reslstive heat~ng (thermal).
In green, red and blue soltd area-flll, the colors are generated by placlng one dot of a flrst color on top of anot~ler dot of a 6econd color, whlch produces the de-~ired t~llrd color (e.g., yellow on cyan creates greenJ.
In the normal prlnting mode, the dots are put down on each other ln the same pass of the prlnthead across the medium. When prlrltlng a block of area-fill, bands occur between swaths of prlnt rows, due to absorptlon of the ~304980 first color printed on the medium, which may be a specially coated paper used for color ink-jet printing.
The banding tends to reduce the perceived quality of the output.
Accordingly, a method of producing a substantially uniform block of color, without the perceived banding or at least with reduced perceived banding is desired.
DISCLOSURE OF INVENTION
In accordance with the invention, a method of forming dot-on-dot graphics area-fill with reduced perceived banding is provided. The method comprises overlapping a portion of one print row or print swath with a portion of another print row or print swath.
In particular, the invention provides a method of generating dot-on-dot graphics area fill on a print medium using an ink-jet device including at least one printhead having a set of primitives, each primitive comprising a plurality of nozzle~ one dot apart fluidically connected to a reservoir of a given colour, 0 the method comprising:
printing a first row of a first colour;
printing a second row of a second colour; and printing further rows of alternating first and second colours, each further row of each colour being 5 contiguous with the previous row of that colour;
characterised in that each row of the second colour is offset from its respective row of the first colour by a predetermined displacement toward the previous row of the first colour.
The offset printing may be done by moving either the print medium or the printhead relative to the other.
Also, primitives on the printhead may be staggered to achieve the desired effect.
B
2~P
By overlapping, or interleaving, swaths of the individual colors, the bands present in the conventional print mode are eliminated. This results in improved print quality and homogeneity of graphics output.
Other aspects of this invention are as follows:
An improved method or generating dot-on-dot graphics area fill on a print medium using an ink-jet device, said device including at least one printhead having a set of primitives, each primitive comprising a plurality of adjacent nozzles one dot apart fluidically connected to a reservoir of a given color, said method comprising:
(a) printing a first swath of a first color by ejecting ink through said plurality of nozzles;
(b) partially overprinting said first swath with a narrower swath of a second color such that part of said first swath is exposed as a partial swath of said first color, said overprinting being accomplished by ejecting inX through a ~econd plurality of nozzles;
¢c) printing a second swath of said first color abutting said partial swath;
(d) printing another swath of said second color over said partial and an adjacent portion of said second swath of said first color;
(e) repeating steps (c) and (d) until said graphic area is completely colored; and (f) finally overprinting any remaining narrow swath of said first color with a partial swath of said second color.
An improved method of generating dot-on-dot graphics area fill on a print medium using an ink-jet device including at least on¢ printhead having a set of primitives, each primitive comprising a plurality of nozzles one dot apart fluidically connected to a 3S reservoir of a given color, said method comprising:
~L304980 2b (a) printing a first swath of a first color by ejecting ink through said plurality of nozzles associated with said first color;
(b) overprinting approximately the top 50% of said first swath with a swath of a second color by ejecting ink through a second plurality of nozzles;
(c) printing a second swath of said first color abutting said first swath;
(d) printing another swath of said second color over approximately the lower 50% of said first swath and the top 50~ of said second swath of said first color;
(e) repeating steps (c) and (d) until said graphic area is completely colored; and (f) overprinting the remaining 50% of the last swath of said first color with a 50% swath of said second color.
~RIEF DESC~TION OF THE DRAW~GS
PIGS. la-d are top plan views of printing two colors to achieve a third color, employing a conventional print .~
~304980 1 mode used ln t~le pr~or art: a~ld FIGS. 2a-e are top plan vlews of prlrltillg two colors to acllleve a thlrd color ln accorda~lce wlth the ~nventlon.
BEST MODES FOR CARRYI~G OUT THE Ir~VENTION
Referrll~g now to the drawlngs wherei~ llke numerals of reference designate li~e elements throughout, FIGS. la-d deplct the sequence of events ln fllling in an area of a third color achleved by printing multlple rowY of two colors. In the descriptlon wh~ch follows, the color green ls acl~leved by pr1tltlng alternatlng rows of cyan and yel-low. However, it wlll be understood that other comblna-tions suffer from the same effect to be described, and that such other combinations wlll also benefit from em-ploying the method of the lnventlon.
FIG. la illustrates the prlntlng of a first row 10 of a first color, here, cyan, on a print medlum 12. Employ-lng ink-~et techllology, tlle row lO, and sub6eque~lt rows, are generated by flrlng all nozzles of a prlmltlve on the prlnthead. As an example, a prlmltive may contaln ten nozzles, although fewer or greater numbers of nozzles may be employed.
In FIG. lb, a row 14 of a second color, here, yellow, i~ overlald directly over the flrst row 10, elther in the same pass across the medium 12 or ln a subsequent pass.
However, the print medlum 12 is saturated with the flrst color, so the second color tends to run off the flrst color, creating tlle thlrd color ln the central portion 16 and a border 18 of the second color.
In FIG. lc, a second row 20 of tllé flrst color 19 printed, and lts top edge is allgned substantlally ad~a-cent tlle bottom edge of the first row 10 of the first color. Whlle tllat portlon 22 of the border 18 overlald by ~5 the second row 20 suffers from the saturatlon effect~
1 discussed 11l conneeti~n wlt}) FIG. la, lt llevertheless i~
converted to t~le t~llrd color. I~owever, w~lereas the cen-tral portlon 16 compr~ses the second color on top of the first color, t~le border portlo~l 22 comprlses t~,e flrst color Oll top of t~le secor~d color. T~lls dlstlnction wlll be dlscussed s~lortly.
Irl FIG. ld, another row 24 of the second color ls overlaid dlrectly over the second row 20. Again, due to saturatlon of the prlnt medlum, the thlrd color i9 gener-ated in the central portion 16', and a border 18' of thesecond color i9 formed, as ln FIG. lb.
It wlll be appreclated that prlntiny of subsequent rows of the flrst color overlald wlth rows of the ~econd color generates two reglons of a th~rd color, namely a central portlon 16 (and 16', etc.) and a border portlon 22 ~and 22', etc,). Whlle both are of the same color, the ~ormer reglon ls a thlrd color of the ca~t of the first color (due to the prlor absorptlon of the flrst color therein1, while the latter reglon 15 a thlrd color of the cast of the second color ~due to the prior absorption of the second color thereln).
Thus, in the case of rows 10, 20 of cyan overlaid with rows 14, 24 of yellow, the central portions 16, 16' are green wlth a blulsh cast, whlle the border portionY
22, 22' are green with a yellowish cast. The resultlng area-flll comprlses large swaths of one shade of green separated by narrow bands of another shade of green. The dlstinct banding is consldered ob~ectionable.
In accordance wlth the invention, the percelved qual-ity of the area fill is improved by overlapping, or lnter-leavlng, swat~ls of the indlvldual colors. The preferred sequence of the overlapplng is depicted in FIGS. Za-e.
FIG. 2a shows a flrst row 3~ of a first color, agaln, cyar~, for example, prlr~ted on a medlum 12. ~ complete 1 flrst row ts ~ritlted. Rey~on "A" comprlses the flrst color.
In FIG. 2b, only a portlon of a second row 32 of a second color, agaln, yellow, for example, ls prlnted, off~et from the,flrst row by a speclflc, predetermined amount. The portlon (reglon "A"') not prlnted by the second color relates to the amount of over~ap, or offset, and here 15 one-half of a row. Thus, one-half row is lnitially printed, and tl~e offset ls one-~lalf row, so that lo the second row 32 covers the top one-half of the prlnted portlon of the flrst row 30. The row 32 creates the thlrd color, again, green, for example, whlle the bottom half of the row 30 remalns the ftrst color. Region l'B" is now the third color, whlle that portlon of region "A" not prlnted on i5 denoted IIA"'.
In FIG. 2c, a thlrd row 3~ of the flrst color ls prlnted adJacent the row 30, agaln, offset from the ~econd row 32 by the predetermlned amoullt, here, one-half row.
Thus, the top of row 34 butts agalnst the bottom of row 30. Region "B", beirlg unaffected in thl~ step, remalns the third color, reglon "A"', also unaffected, remalns the flr~t color, and region "A" is the newly-printed flrst color.
In FIG. 2d, a fourth row 36 of the second color ls printed, offset from the thlrd row 34 by the predetermlrled amount, agaln, one-half row. Region "B", being unaffected ln this step, remains the third color, reglon "A"' and the upper portion of region "A" are now the third color, as denoted by "B", and the lower portion of region "A" not printed on t5 denoted "A "', the first color.
The method may be continued as many times a~ deslred, printing of rows of alternating flrst and second colors, untll the area ls filled. In order to termlnate the la~t row of the area to provide only one color, only a portion of the last row is printed, and is the amount of offset, here, one-half of a row 38, as shown in FIG. 2e.
It will be appreciated that in the preferred embodiment, one color (the first color, here, cyan) is always overlaid by another color (the second color, here, yellow), so that the resulting third color is always of the same cast. Thus, the objectionable banding achieved with the prior art method is avoided.
The offsetting of one color relative to another color can be done using several methods, so that the nozzles in each primitive are located one dot apart.
First, individual primitives on a single printhead containing separate colors can be physically offset relative to each other. Second, if the primary colors are contained in separate pens, the pens themselves can be offset relative to one another. Third, w].th a print-head having primitives not offset, or with a pen fixturing con~iguration not having the pens offset, les~ than the full number of nozzle~ in each primitive, or pen, can be used in order to allow for offsetting of the remaining nozzles.
The third method allows for offsetting without having to make a physical change to an existing pen or to the pen fixturing (in the case when each color is in a separate pen).
By physically offsetting the nozzles of one color relative to the nozzles of the other color using any of the methods stated previously, the two colors can be deposited during the sam~ pass of the printhead across the medium. In FIG. 2, this would be accomplished by depositing the rows 30 and 32 represented in FIGS. 2a and 2b in the same pass, as well as the rows 34 and 36 represented in FIGS. 2c and 2d during the same pass.
Two additional methods can be used to create the offset of the two colors. In the fourth method, the print medium 12 can be moved relative to the printhead. In the fifth method, the printhead can be moved relative to the ~304980 1 prlnt medlum 12. T~lese mettlods requlre that the medium or prlntllead deperldl~lg ~n w~1c~l is being mcved move back-ward (opposlte the dlrectlon of the progression of print-ing down tlle page) to allow for the offsettlng of t~le second color relative to the f lrst color. The prlnthead or medlum must then be moved ~orward to depo61t the first color oJI a~l ut~printed section of medlum again tllen move backward to prlnt the second color and continue in thls fashion untll the area-fill block is complete. Thus lo these methods require that one pass of the prlnthead across the medium be made for each primary color depos-ited.
The advantage of printing the first and second colors during the same pass of the printhead or prlntheads across the medlum is that the tlme required to print a section of area-fill ls approximately halved. However, with the off~et conflguration, tl)e prlnt quality 18 better w~len tlle sectlon 19 prlnted ln two pass modeR rather than ln a slllgle pass mode. Ttle reason for t~lis 18 t}~at one sectlon of the thlrd color ls created by combinlng the flrst and second colors in the same pass, and another section 18 created by depositlng the second color on top of the first color which was deposited in the prevlous pas~ of the printhead across the medium. The d~fference creates a variation in hue between the two sections whlch ls no-tlceable.
In the two-pass mode, the second color ls depos'ted on two sectlons of the flrst color. ~ne sectlon was de-posited in tlle previous pass arld t~e ot~ler was put down three passes pr~or to the pass of the cecond color. The two sectlons oP the flrst color are very simllar, s~nce both have ~lad sufficient time to dry and result ln a uniform area of the third color.
The extent of offset may be var'ed. In the one-pa~
mode maximum print quality is achieved at an offset of 100%, while slight improvement is made with slight amounts of offset of at least about 10%, such as an offset of at least one nozzle or one dot row. In the two-pass mode, maximum print quality is achieved at an offset of 100% also, but major improvements are obtained with slight amounts of offset of at least about 10%, such as an offset of at least one nozzle or one dot row.
INDUSTRIAL APPLICABILITY
The use of offset partial row printing in accordance with the invention is expected to find use in color ink-jet printers.
Thus, there has been disclosed a method of improving dot-on-dot graphics area fill using an ink-jet device. It will be clear to one of ordinary skill in the art that various changes and modifications of an obvious nature may be made, and all such changes and modi~ications are considered to fall within the scope of the invention as defined by the appended claims.
B
By overlapping, or interleaving, swaths of the individual colors, the bands present in the conventional print mode are eliminated. This results in improved print quality and homogeneity of graphics output.
Other aspects of this invention are as follows:
An improved method or generating dot-on-dot graphics area fill on a print medium using an ink-jet device, said device including at least one printhead having a set of primitives, each primitive comprising a plurality of adjacent nozzles one dot apart fluidically connected to a reservoir of a given color, said method comprising:
(a) printing a first swath of a first color by ejecting ink through said plurality of nozzles;
(b) partially overprinting said first swath with a narrower swath of a second color such that part of said first swath is exposed as a partial swath of said first color, said overprinting being accomplished by ejecting inX through a ~econd plurality of nozzles;
¢c) printing a second swath of said first color abutting said partial swath;
(d) printing another swath of said second color over said partial and an adjacent portion of said second swath of said first color;
(e) repeating steps (c) and (d) until said graphic area is completely colored; and (f) finally overprinting any remaining narrow swath of said first color with a partial swath of said second color.
An improved method of generating dot-on-dot graphics area fill on a print medium using an ink-jet device including at least on¢ printhead having a set of primitives, each primitive comprising a plurality of nozzles one dot apart fluidically connected to a 3S reservoir of a given color, said method comprising:
~L304980 2b (a) printing a first swath of a first color by ejecting ink through said plurality of nozzles associated with said first color;
(b) overprinting approximately the top 50% of said first swath with a swath of a second color by ejecting ink through a second plurality of nozzles;
(c) printing a second swath of said first color abutting said first swath;
(d) printing another swath of said second color over approximately the lower 50% of said first swath and the top 50~ of said second swath of said first color;
(e) repeating steps (c) and (d) until said graphic area is completely colored; and (f) overprinting the remaining 50% of the last swath of said first color with a 50% swath of said second color.
~RIEF DESC~TION OF THE DRAW~GS
PIGS. la-d are top plan views of printing two colors to achieve a third color, employing a conventional print .~
~304980 1 mode used ln t~le pr~or art: a~ld FIGS. 2a-e are top plan vlews of prlrltillg two colors to acllleve a thlrd color ln accorda~lce wlth the ~nventlon.
BEST MODES FOR CARRYI~G OUT THE Ir~VENTION
Referrll~g now to the drawlngs wherei~ llke numerals of reference designate li~e elements throughout, FIGS. la-d deplct the sequence of events ln fllling in an area of a third color achleved by printing multlple rowY of two colors. In the descriptlon wh~ch follows, the color green ls acl~leved by pr1tltlng alternatlng rows of cyan and yel-low. However, it wlll be understood that other comblna-tions suffer from the same effect to be described, and that such other combinations wlll also benefit from em-ploying the method of the lnventlon.
FIG. la illustrates the prlntlng of a first row 10 of a first color, here, cyan, on a print medlum 12. Employ-lng ink-~et techllology, tlle row lO, and sub6eque~lt rows, are generated by flrlng all nozzles of a prlmltlve on the prlnthead. As an example, a prlmltive may contaln ten nozzles, although fewer or greater numbers of nozzles may be employed.
In FIG. lb, a row 14 of a second color, here, yellow, i~ overlald directly over the flrst row 10, elther in the same pass across the medium 12 or ln a subsequent pass.
However, the print medlum 12 is saturated with the flrst color, so the second color tends to run off the flrst color, creating tlle thlrd color ln the central portion 16 and a border 18 of the second color.
In FIG. lc, a second row 20 of tllé flrst color 19 printed, and lts top edge is allgned substantlally ad~a-cent tlle bottom edge of the first row 10 of the first color. Whlle tllat portlon 22 of the border 18 overlald by ~5 the second row 20 suffers from the saturatlon effect~
1 discussed 11l conneeti~n wlt}) FIG. la, lt llevertheless i~
converted to t~le t~llrd color. I~owever, w~lereas the cen-tral portlon 16 compr~ses the second color on top of the first color, t~le border portlo~l 22 comprlses t~,e flrst color Oll top of t~le secor~d color. T~lls dlstlnction wlll be dlscussed s~lortly.
Irl FIG. ld, another row 24 of the second color ls overlaid dlrectly over the second row 20. Again, due to saturatlon of the prlnt medlum, the thlrd color i9 gener-ated in the central portion 16', and a border 18' of thesecond color i9 formed, as ln FIG. lb.
It wlll be appreclated that prlntiny of subsequent rows of the flrst color overlald wlth rows of the ~econd color generates two reglons of a th~rd color, namely a central portlon 16 (and 16', etc.) and a border portlon 22 ~and 22', etc,). Whlle both are of the same color, the ~ormer reglon ls a thlrd color of the ca~t of the first color (due to the prlor absorptlon of the flrst color therein1, while the latter reglon 15 a thlrd color of the cast of the second color ~due to the prior absorption of the second color thereln).
Thus, in the case of rows 10, 20 of cyan overlaid with rows 14, 24 of yellow, the central portions 16, 16' are green wlth a blulsh cast, whlle the border portionY
22, 22' are green with a yellowish cast. The resultlng area-flll comprlses large swaths of one shade of green separated by narrow bands of another shade of green. The dlstinct banding is consldered ob~ectionable.
In accordance wlth the invention, the percelved qual-ity of the area fill is improved by overlapping, or lnter-leavlng, swat~ls of the indlvldual colors. The preferred sequence of the overlapplng is depicted in FIGS. Za-e.
FIG. 2a shows a flrst row 3~ of a first color, agaln, cyar~, for example, prlr~ted on a medlum 12. ~ complete 1 flrst row ts ~ritlted. Rey~on "A" comprlses the flrst color.
In FIG. 2b, only a portlon of a second row 32 of a second color, agaln, yellow, for example, ls prlnted, off~et from the,flrst row by a speclflc, predetermined amount. The portlon (reglon "A"') not prlnted by the second color relates to the amount of over~ap, or offset, and here 15 one-half of a row. Thus, one-half row is lnitially printed, and tl~e offset ls one-~lalf row, so that lo the second row 32 covers the top one-half of the prlnted portlon of the flrst row 30. The row 32 creates the thlrd color, again, green, for example, whlle the bottom half of the row 30 remalns the ftrst color. Region l'B" is now the third color, whlle that portlon of region "A" not prlnted on i5 denoted IIA"'.
In FIG. 2c, a thlrd row 3~ of the flrst color ls prlnted adJacent the row 30, agaln, offset from the ~econd row 32 by the predetermlned amoullt, here, one-half row.
Thus, the top of row 34 butts agalnst the bottom of row 30. Region "B", beirlg unaffected in thl~ step, remalns the third color, reglon "A"', also unaffected, remalns the flr~t color, and region "A" is the newly-printed flrst color.
In FIG. 2d, a fourth row 36 of the second color ls printed, offset from the thlrd row 34 by the predetermlrled amount, agaln, one-half row. Region "B", being unaffected ln this step, remains the third color, reglon "A"' and the upper portion of region "A" are now the third color, as denoted by "B", and the lower portion of region "A" not printed on t5 denoted "A "', the first color.
The method may be continued as many times a~ deslred, printing of rows of alternating flrst and second colors, untll the area ls filled. In order to termlnate the la~t row of the area to provide only one color, only a portion of the last row is printed, and is the amount of offset, here, one-half of a row 38, as shown in FIG. 2e.
It will be appreciated that in the preferred embodiment, one color (the first color, here, cyan) is always overlaid by another color (the second color, here, yellow), so that the resulting third color is always of the same cast. Thus, the objectionable banding achieved with the prior art method is avoided.
The offsetting of one color relative to another color can be done using several methods, so that the nozzles in each primitive are located one dot apart.
First, individual primitives on a single printhead containing separate colors can be physically offset relative to each other. Second, if the primary colors are contained in separate pens, the pens themselves can be offset relative to one another. Third, w].th a print-head having primitives not offset, or with a pen fixturing con~iguration not having the pens offset, les~ than the full number of nozzle~ in each primitive, or pen, can be used in order to allow for offsetting of the remaining nozzles.
The third method allows for offsetting without having to make a physical change to an existing pen or to the pen fixturing (in the case when each color is in a separate pen).
By physically offsetting the nozzles of one color relative to the nozzles of the other color using any of the methods stated previously, the two colors can be deposited during the sam~ pass of the printhead across the medium. In FIG. 2, this would be accomplished by depositing the rows 30 and 32 represented in FIGS. 2a and 2b in the same pass, as well as the rows 34 and 36 represented in FIGS. 2c and 2d during the same pass.
Two additional methods can be used to create the offset of the two colors. In the fourth method, the print medium 12 can be moved relative to the printhead. In the fifth method, the printhead can be moved relative to the ~304980 1 prlnt medlum 12. T~lese mettlods requlre that the medium or prlntllead deperldl~lg ~n w~1c~l is being mcved move back-ward (opposlte the dlrectlon of the progression of print-ing down tlle page) to allow for the offsettlng of t~le second color relative to the f lrst color. The prlnthead or medlum must then be moved ~orward to depo61t the first color oJI a~l ut~printed section of medlum again tllen move backward to prlnt the second color and continue in thls fashion untll the area-fill block is complete. Thus lo these methods require that one pass of the prlnthead across the medium be made for each primary color depos-ited.
The advantage of printing the first and second colors during the same pass of the printhead or prlntheads across the medlum is that the tlme required to print a section of area-fill ls approximately halved. However, with the off~et conflguration, tl)e prlnt quality 18 better w~len tlle sectlon 19 prlnted ln two pass modeR rather than ln a slllgle pass mode. Ttle reason for t~lis 18 t}~at one sectlon of the thlrd color ls created by combinlng the flrst and second colors in the same pass, and another section 18 created by depositlng the second color on top of the first color which was deposited in the prevlous pas~ of the printhead across the medium. The d~fference creates a variation in hue between the two sections whlch ls no-tlceable.
In the two-pass mode, the second color ls depos'ted on two sectlons of the flrst color. ~ne sectlon was de-posited in tlle previous pass arld t~e ot~ler was put down three passes pr~or to the pass of the cecond color. The two sectlons oP the flrst color are very simllar, s~nce both have ~lad sufficient time to dry and result ln a uniform area of the third color.
The extent of offset may be var'ed. In the one-pa~
mode maximum print quality is achieved at an offset of 100%, while slight improvement is made with slight amounts of offset of at least about 10%, such as an offset of at least one nozzle or one dot row. In the two-pass mode, maximum print quality is achieved at an offset of 100% also, but major improvements are obtained with slight amounts of offset of at least about 10%, such as an offset of at least one nozzle or one dot row.
INDUSTRIAL APPLICABILITY
The use of offset partial row printing in accordance with the invention is expected to find use in color ink-jet printers.
Thus, there has been disclosed a method of improving dot-on-dot graphics area fill using an ink-jet device. It will be clear to one of ordinary skill in the art that various changes and modifications of an obvious nature may be made, and all such changes and modi~ications are considered to fall within the scope of the invention as defined by the appended claims.
B
Claims (16)
1. An improved method or generating dot-on-dot graphics area fill on a print medium using an ink-jet device, said device including at least one printhead having a set of primitives, each primitive comprising a plurality of adjacent nozzles one dot apart fluidically connected to a reservoir of a given color, said method comprising:
(a) printing a first swath of a first color by ejecting ink through said plurality of nozzles;
(b) partially overprinting said first swath with a narrower swath of a second color such that part of said first swath is exposed as a partial swath of said first color, said overprinting being accomplished by ejecting ink through a second plurality of nozzles;
(c) printing a second swath of said first color abutting said partial swath;
(d) printing another swath of said second color over said partial and an adjacent portion of said second swath of said first color;
(e) repeating steps (c) and (d) until said graphic area is completely colored; and (f) finally overprinting any remaining narrow swath of said first color with a partial swath of said second color.
(a) printing a first swath of a first color by ejecting ink through said plurality of nozzles;
(b) partially overprinting said first swath with a narrower swath of a second color such that part of said first swath is exposed as a partial swath of said first color, said overprinting being accomplished by ejecting ink through a second plurality of nozzles;
(c) printing a second swath of said first color abutting said partial swath;
(d) printing another swath of said second color over said partial and an adjacent portion of said second swath of said first color;
(e) repeating steps (c) and (d) until said graphic area is completely colored; and (f) finally overprinting any remaining narrow swath of said first color with a partial swath of said second color.
2. The method of Claim 1 wherein said partial swath of said first color is at least one nozzle wide.
3. The method of Claim 2 wherein said predetermined amount comprises up to 100% offset.
4. The method of Claim 2 wherein said partial swath of said first color comprises about one-half swath.
5. The method of Claim 1 wherein said partial swaths are attained by moving said medium with respect to said printhead.
6. The method of Claim 1 wherein said partial swaths are attained by moving said printhead with respect to said medium.
7. The method of Claim 1 wherein said partial swaths are attained by staggering said primitives with respect to each other.
8. The method of Claim 1 wherein said printing commences with printing said first swath, followed by printing said narrower swath of said second color, and terminates with printing said partial swath of said second color, such that the width of said narrower swath of said second color plus the width of said partial swath of said second color equal the width of one swath.
9. The method of Claim 8 wherein said printing commences with printing the bottom one-half of said first swath and terminates with printing the upper one-half of said last swath.
10. The method of Claim 1 wherein said swaths of alternating first and second colors are printed in one pass of said at least one printhead across said print medium.
11. The method of Claim 1 wherein said swaths of alternating first and second colors are printed in two passes of said at least one printhead.
12. An improved method of generating dot-on-dot graphics area fill on a print medium using an ink-jet device including at least one printhead having a set of primitives, each primitive comprising a plurality of nozzles one dot apart fluidically connected to a reservoir of a given color, said method comprising:
(a) printing a first swath of a first color by ejecting ink through said plurality of nozzles associated with said first color;
(b) overprinting approximately the top 50% of said first swath with a swath of a second color by ejecting ink through a second plurality of nozzles;
(c) printing a second swath of said first color abutting said first swath;
(d) printing another swath of said second color over approximately the lower 50% of said first swath and the top 50% of said second swath of said first color;
(e) repeating steps (c) and (d) until said graphic area is completely colored; and (f) overprinting the remaining 50% of the last swath of said first color with a 50% swath of said second color.
(a) printing a first swath of a first color by ejecting ink through said plurality of nozzles associated with said first color;
(b) overprinting approximately the top 50% of said first swath with a swath of a second color by ejecting ink through a second plurality of nozzles;
(c) printing a second swath of said first color abutting said first swath;
(d) printing another swath of said second color over approximately the lower 50% of said first swath and the top 50% of said second swath of said first color;
(e) repeating steps (c) and (d) until said graphic area is completely colored; and (f) overprinting the remaining 50% of the last swath of said first color with a 50% swath of said second color.
13. The method of Claim 12 wherein said swaths are located on said print medium by moving said medium with respect to said printhead.
14. The method of Claim 12 wherein said swaths are located on said print medium by moving said printhead with respect to said medium.
15. The method of Claim 12 wherein said swaths of alternating first and second colors are printed in one pass of said at least one printhead across said print medium.
16. The method of Claim 12 wherein said swaths of alternating first and second colors are printed in two passes of said at least one printhead.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US5713087A | 1987-06-01 | 1987-06-01 | |
| US057,130 | 1987-06-01 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1304980C true CA1304980C (en) | 1992-07-14 |
Family
ID=22008689
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000558642A Expired - Lifetime CA1304980C (en) | 1987-06-01 | 1988-02-10 | Method of improving dot-on-dot graphics area-fill using an ink-jet device |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0300595B2 (en) |
| JP (1) | JP2730907B2 (en) |
| CA (1) | CA1304980C (en) |
| DE (1) | DE3868749D1 (en) |
| HK (1) | HK63192A (en) |
| SG (1) | SG64092G (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SG44724A1 (en) * | 1989-01-28 | 1997-12-19 | Canon Kk | Ink jet recording method and color ink jet recording device for practising the same |
| US6406114B1 (en) | 1991-06-05 | 2002-06-18 | Canon Kabushiki Kaisha | Tonal product recorded by ink and having a plurality of pixels with plural tonal levels |
| US5430469A (en) * | 1991-06-05 | 1995-07-04 | Canon Kabushiki Kaisha | Tone recording method using ink recording head |
| EP0517521B1 (en) * | 1991-06-05 | 2000-05-10 | Canon Kabushiki Kaisha | Tone recording method using ink jet recording head |
| JP2891799B2 (en) * | 1991-06-07 | 1999-05-17 | キヤノン株式会社 | Inkjet recording method |
| US5247315A (en) * | 1992-02-06 | 1993-09-21 | Gerber Scientific Products, Inc. | Method of printing a graphic having uniform ink density on an emulsion coated printing screen |
| JP5733883B2 (en) * | 2009-04-07 | 2015-06-10 | キヤノン株式会社 | Inkjet recording apparatus and inkjet recording method |
| JP6432247B2 (en) * | 2014-09-26 | 2018-12-05 | ブラザー工業株式会社 | Inkjet printer |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2925812C2 (en) * | 1979-06-26 | 1982-10-21 | Siemens AG, 1000 Berlin und 8000 München | Ink printing device for multi-colored printing on a recording medium |
| JPS57129749A (en) * | 1981-02-06 | 1982-08-11 | Fuji Photo Film Co Ltd | Method and device for bringing out medium tone in ink-jet printer |
| US4515487A (en) * | 1982-03-29 | 1985-05-07 | Pentel Kabushiki Kaisha | Multicolor printer |
| JPS58179655A (en) * | 1982-04-16 | 1983-10-20 | Canon Inc | Recording system |
| JPS58194540A (en) * | 1982-05-11 | 1983-11-12 | Canon Inc | Recording apparatus |
| JPS58194544A (en) * | 1982-05-11 | 1983-11-12 | Canon Inc | Recording apparatus |
| JP2539783B2 (en) * | 1984-08-02 | 1996-10-02 | メトロメディア・カンパニ− | Inkjet printing head controller |
-
1988
- 1988-02-10 CA CA000558642A patent/CA1304980C/en not_active Expired - Lifetime
- 1988-05-05 DE DE8888304047T patent/DE3868749D1/en not_active Expired - Lifetime
- 1988-05-05 EP EP19880304047 patent/EP0300595B2/en not_active Expired - Lifetime
- 1988-06-01 JP JP63135388A patent/JP2730907B2/en not_active Expired - Fee Related
-
1992
- 1992-06-22 SG SG64092A patent/SG64092G/en unknown
- 1992-08-20 HK HK63192A patent/HK63192A/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| EP0300595B2 (en) | 1995-08-02 |
| EP0300595B1 (en) | 1992-03-04 |
| JP2730907B2 (en) | 1998-03-25 |
| SG64092G (en) | 1992-09-04 |
| JPS63315249A (en) | 1988-12-22 |
| HK63192A (en) | 1992-08-28 |
| EP0300595A1 (en) | 1989-01-25 |
| DE3868749D1 (en) | 1992-04-09 |
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