JPH08258291A - Method and apparatus for positioning dot in printer of mixedresolution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance printing quality while performing the printing of an image appearing frequently at a high speed by emphasizing important characteristics frequently appearing on a page to be printed such as a text by using a pen having higher capacity. SOLUTION: An ink jet printer has an inlet tray 12 in which media 14 are housed and each medium 14 passes through a printing region to enter an outlet tray 16 through an outlet 18. A movable carriage 20 holds printing cartridges 22, 24, 26, 28 of yellow, magenta, cyan and black inks. The support bumper mounted on a guide is provided to the front surface of the carriage and a large number of bushes mounted on a slide rod 36 are provided to the rear surface of the carriage. Various ink nozzles on the printing cartridge selectively eject inks in proper timing during the scanning of the carriage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to printers, and more particularly to printing devices and techniques for black and white and color printers capable of achieving high quality resolution.

[0002]

High quality printers typically describe their resolution in terms of dots per inch (25.4 millimeters) (dpi). As for this resolution, one number usually indicates the resolution in the X-axis direction (herein, the X-axis means the carriage scanning axis of the swath printer), and the other number indicates the resolution in the Y-axis direction (herein, the Y-axis direction). The axis means the medium feed axis of the swath printer) and is represented by a two-dimensional coordinate system indicating the resolution. Therefore, a resolution of 300/300 dpi typically represents a carriage scan axis resolution of 300 dots / inch and a media feed axis resolution of 300 dots / inch. d
When only one pi number is shown, it means that the dpi in both axial directions is the same.

Printhead resolution is primarily determined by the actual printout dot size that appears in the printout.

Applicants have developed a 600 dpi inkjet pen that produces very high resolution printouts. For reference, one example of this pen is "INK DELIVE
Brian entitled "RY SYSTEM FOR AN INKJET PRINTHEAD"
It is described in US Pat. No. 5,278,584 owned by Hewlett-Packard by J. Keefe et al. This 600 dpi pen nozzle array has 300 nozzles and a width of about 0 along the X axis.
Print 5 inches. Some Hewlett-Packard color printers have a 600 dpi pen with black ink and one
Some have a scanning carriage that houses one or more color inkjet pens. Currently, such color inkjet pens have a resolution of 300 dpi and a width of about 1/3 inch.

By successfully selecting the alignment of the 600 dpi printhead and the 300 dpi printhead in the carriage, as well as the alignment of the printed high resolution dots and low resolution dots, certain characteristics can be achieved. Benefits are obtained.

[0006]

In a printer having a plurality of pens, it is important to improve the output quality of printed pages and output speed as economically and easily as possible. In the printer mechanism,
The output quality of the printed page is a function of the printhead resolution. The higher the resolution, the higher the print quality.
Also, in swath printers that use a scanning carriage, the output speed is a function of the swath width covered by the printhead.

In current multi-pen printers, each pen has the same resolution and usually the same swath width. This requires that all support structures, mechanics, and electronics be sophisticated so that all pen resolutions are supported. 1 such hardware
One pen has the desired high resolution and large print width, while the other pen has a higher resolution and print width, but is more expensive than hardware that supports a collection of multi-resolution, multi-print width pens. .

[0008]

The scanning carriage of a color inkjet printer, in its preferred form, has a high resolution printhead for black (or black and white) printing and one or more low resolution printheads for color printing. The print head of is stored.

By selecting the black printhead and color printhead nozzle configurations, the paper feed increments, and the ink ejection frequency, the large color ink dots and the small black ink dots are aligned in various ways to a minimum. The above ink is used to maximize the ink adhesion area or create a new shade. In one embodiment, the center of gravity of the dot group consisting of four smaller dots is aligned with the center of gravity of one larger dot in the scanning direction (ie, the X direction). In another embodiment, the midpoint between the two vertically aligned smaller dots is aligned in the scan direction with the centroid of the one larger dot. Each dot in a group of four smaller dots should make an angle of 90 ° to the X and Y axes or 45 ° to the X and Y axes around the center of gravity of this dot group. Can be placed at.

[0010]

DETAILED DESCRIPTION OF THE INVENTION In one embodiment of the present invention, a high resolution inkjet pen and one or more lower resolution inkjet pens are incorporated into the same scanning carriage of a printer. Print quality can be improved by using a higher performance pen to emphasize important features that often appear in printed pages, such as text. Also, this pen improves the throughput because it can print such frequently appearing images at high speed. The other low performance printer can be used for printing infrequent or less demanding images such as graphics and color printing.

In the example described herein, 600 dpi
Combines a black pen with a 1/2 inch print width and three color pens at 300 dpi, each printing width is about 1/3 inch. High performance black pens are commonly used to print text and other "black only" images, thus improving the output quality and throughput of such images. When printing a color graphic or a color image, the output quality of the color graphic or the color image is improved by combining the black pen with the three color pens having lower performance. The black component, which often occupies most of the color graphics, has a high resolution and therefore a high output quality level. The larger print width can be combined with the print algorithm to improve the throughput of color graphics.

Although the present invention can be used in any printing environment in which text and / or graphics are printed on media using black and white and / or color components, the presently preferred embodiment of the invention is shown in FIG. Used in various types of inkjet printers. Inkjet printer in detail
10 has an input tray 12 containing a medium (14)
(14) goes through the print area and through the outlet 18 to the output tray 1
Enter 6. As shown in FIGS. 1 and 2, movable carriage 20 includes print cartridges 22, 24, 26, and 28, each of which holds yellow (Y), magenta (M), cyan (C), and black (K) ink. Hold. A support bumper 30 mounted on a guide 32 is provided on the front surface of the carriage, and a large number of bushes (34
Etc.) are provided. The encoder strips 38 determine the position of the carriage bidirectionally across the media so that the various ink nozzles on each print cartridge are selectively fired at the appropriate times during the carriage scan. There is.

In another embodiment of the printer, instead of the color print cartridges 22, 24, and 26, FIGS.
And a single three color cartridge with a nozzle plate as shown in FIG. 16 is used.

As shown in FIGS. 3-6, a 300 dpi color ink jet cartridge 4 having a tab (TAB) circuit having an electrical connection 42 consisting of 32 pads in 4 rows.
0 is one carriage 50 (FIG. 4) and three storage sections 44, 4
It is removably arranged in 6, 48. A flexible circuit member 52 (FIG. 6) having three corresponding groups of conductive pads 54, 56, 58 is attached to the flexible frame pin 60 and engages with the cartridge when attached to the corresponding storage. . Total of 6 rows with different layouts on flexible circuit members
An enlarged conductive pad group 62 covering a larger area, which is an array of 52 conductive pads, is designed to engage the cartridge pads on a 600 dpi black inkjet cartridge 64 (see FIG. 9). .

600 dpi for color print head storage
Suitable structure and technique for preventing mis-mounting of the black printhead or conversely the mismounting of the 300 dpi color printhead into the black printhead compartment is described in the above-mentioned co-pending patent application. .

Because the electrical connections on the 600 dpi cartridge have different configurations, also the current x / y /
A unique connection method is used to avoid significant changes in the z reference plane structure. In this regard, the X-axis cartridge reference plane 65 is the X-axis carriage reference plane 66, the Y-axis cartridge reference plane 67 is the Y-axis carriage reference plane 68, the Z-axis cartridge reference plane 69 is the Z-axis carriage reference plane 70, and In the manner described in more detail in the above-mentioned co-pending patent applications.

As best seen in FIGS. 9-11, a spring assembly having a backing sheet 74, a plate 76 and a gimbal spring 78 is a flexible circuit frame.
The openings 80 of 82 are fitted to ensure the electrical connection of the three color cartridges.

A unique spring assembly for interconnecting 600 dpi cartridges has a sheet larger than opening 80.
It has a single elastic foam member 84 that enters 86. Mounting pegs
88 fits into matching hole 90 and bottom ledge 91 and bottom ledge 93 and top side ledge 92 and top ledge 94 lock the foam in place, ensuring electrical connections are engaged during operation To do.

FIGS. 7 and 8 show a 300 dpi nozzle array 96 for a color printhead and 600 for a black printhead.
1 illustrates one of the possible mounting relationships between a dpi nozzle array 98. Control circuit on board (including multiplexer) 99
52 black printhead 300 jet resistors by
Can be controlled via 32 connection pads, as well as all 104 firing resistors of each color printhead can be controlled via 32 connection pads.

FIG. 12 is a schematic diagram of a color pen (ie, pen cartridge) 30 produced by the preferred embodiment herein.
FIG. 7 is a schematic diagram showing the difference between a 0 dpi printout and a black pen 600 dpi printout. Ink bleed depends on the type of paper used and other well known factors. The actual printed dot diameter shown in FIG. 12 will change accordingly.

[0021] Different resolutions can be combined with each print head, and the difference in resolution can be arbitrarily set according to the existing print heads that can be used, or the difference in resolution (20% larger resolution, 30% larger resolution). like)
It can be expressed as a decimal number, or (300 dpi, but the maximum resolution is 4
It can also be expressed as an integer ratio (00 dpi, or 300 dpi, but with a maximum resolution of 450 dpi).
In this regard, the present invention can be practiced with any of the existing inkjet cartridges currently available, with best results using printheads in the 180 dpi range and above.

A preferred embodiment of the alignment between the high resolution nozzle array and the low resolution nozzle array and a preferred embodiment of the alignment of the high resolution print dots and the low resolution print dots is shown in FIGS. It is also possible to use other alignment conditions to obtain their respective advantages.

FIGS. 13A, 13B, and 13C show three different alignments of a 0.5 inch, 600 dpi black inkjet pen 110 and one or more color inkjet pens 112 in one carriage. Indicates the status. Only the front of the nozzle array is shown for simplicity.

When a three (CMY) color pen is used, only one inkjet pen 112 needs to be used with the black inkjet pen 110. In the embodiment shown in FIGS. 13A-13D, the other two color pens 112, which are used when the three color pens are not used, are shown in dashed outline.

FIGS. 14, 15 and 16 show the printhead nozzle array surfaces 113, 114, 115 of a three color ink jet pen having three separate ink chambers containing cyan, magenta and yellow inks, respectively. Three different embodiments are shown. 14 to 16 show three different groups of nozzles for cyan (C), magenta (M), and yellow (Y) inks in the nozzle array plane. The nozzles of each color can be vertically aligned as shown in FIG. 14, can be staggered as shown in FIG. 15, and can be horizontally aligned as shown in FIG. You can also Two rows of staggered nozzles 116 are provided for each color to provide high vertical dot density. A printer incorporating a three color cartridge is similar to the printer shown in FIG. 1 except that the cartridges 22, 24 and 26 are one three color cartridge juxtaposed with a black inkjet cartridge 28.

FIG. 17 shows a nozzle array of three separate color pens 118, 119, and 120 disposed within the carriage 50 of FIG. As shown in FIG. 2, the pen 118 can be a cyan pen, the pen 119 can be a magenta pen, and the pen 120 can be a yellow pen, but the order of the pens is not critical to the invention.

In FIG. 13A, the top of the printhead of color pen 112 is positioned near or at the top of the printhead of black pen 110 and is spaced from the paper exit or paper output roller. The paper feeding direction is indicated by an arrow 124. By performing such alignment, the color ink is applied to the paper at a position away from the output roller, and the time for drying the color ink before the paper is discharged by the output roller can be taken longer. A comparative example of positioning a printhead with respect to the output roller of a color printer was assigned to the applicant of this application by Brent W. Richtsmeier et al. “STAGGERED PENS I.
US patent entitled "N COLOR THERMAL INK-JET PRINTER"
No. 5,376,958. The principles described herein may be applied to the printer shown in this patent and other printers. The relative alignment shown in FIG. 13A allows the advantages described above to be obtained regardless of the actual distance from the nozzle array to the output roller.

FIG. 13B shows an embodiment in which the bottom of the printhead of the color inkjet pen 112 is positioned near or in line with the bottom of the printhead of the black inkjet pen 110 and is positioned closer to the paper output roller. Show. This reduces the amount of time ink from the black pen 110 remains in the print area before the paper is ejected. This is desirable because the printed area may be hot or otherwise subject to adverse conditions.

In FIG. 13C, the color inkjet pen 112 is shown.
The center of the printhead is a black inkjet pen 110
Positioned near or at the center of the printhead. Generally, this causes the properties of the paper to be symmetrical about the centers of pens 110 and 112.
As a result, there is an advantage in print quality in that the effects obtained by the above two alignment states are balanced. The alignment of the pen 110 and the pen 112 can be offset from the center by various degrees to obtain the best print result. For example, the dimension A in FIG. 13C can be double or triple the dimension B,
The reverse is also possible.

In FIG. 13D, a high resolution black pen 110.
The size of the printhead is a low resolution color pen 112
The size of the print head is the same. The ends of the print heads of pen 110 and pen 112 are aligned. The problem with the embodiment shown in FIG. 13D is that there may not be a color printhead that has the same width as the printhead of the black pen 110.

In one embodiment, the high resolution nozzle array is
With a print width of 5 inches and 300 nozzles (two staggered rows of 150 nozzles each), each nozzle has an ink drop of about 35 picoliters. About 42 milliliters of black ink is contained in the ink reservoir of this high resolution pen. Color ink can also be used. However, 1
The liter is 1000 cubic cm.

In one embodiment of a three color pen having a nozzle plate as shown in FIG. 14, FIG. 15 or FIG. 16, the amount of ink dropped at each nozzle is about 30 picoliters. Each of the three color reservoirs of this three-color pen contains about 19.1 milliliters of ink. Each color is connected to 64 nozzles of one print head.

In the embodiment of the individual color pen 118, 119 or 120 shown in FIG. 17, the ink drop volume at each nozzle is about 104 picoliters and the ink reservoir holds about 42 milliliters of ink. Each printhead has about 104 nozzles at 300 dpi.

In addition to the attention paid to the alignment between the color inkjet printhead and the black printhead, the alignment between the individual dots printed by the black pen 110 and the color pen 112 is selected. It is possible to obtain desired printing characteristics.

FIGS. 18-22 show various alignments between high resolution dots of about 1/600 inch diameter and low resolution dots of about 1/300 inch diameter. The ink of adjacent dots may be mixed due to the ink flow.
In FIGS. 18 to 22, the dots are shown in a separated state for easy understanding. It is assumed that the paper is fed toward the bottom of the drawing and the scanning direction of the pen is perpendicular to the paper feed direction.

In FIG. 18, the center of gravity 130 of the dot group 132 composed of four high resolution dots is one low resolution dot 136.
It is aligned with the center of gravity 134. This aims to minimize the amount of ink applied to the page while at the same time maximizing the ink application area. By aligning the dots as shown in FIG. 18, this effect can be obtained even if it is not completely achieved.
In one application, the centroid 134 of the low resolution dots 136 is superimposed on the centroid 130 of the group of four high resolution dots 132. Such an overlap is shown. This may be suitable when trying to obtain a particular color or printing characteristic. Also, one or more rows of high resolution dots 132 can be printed between rows of low resolution dots 136. Further, the low resolution dots 136 may be completely surrounded by the high resolution dots 132 so that one low resolution dot 136 is placed in the center of the array of high resolution dots 132 as shown in FIG.

FIG. 19 illustrates another dot alignment situation where the low resolution dots 136 are offset by half or above the diameter of the high resolution dots 132.

FIG. 20 shows another dot alignment state where the center of gravity of the low resolution dot 136 is aligned with the center of gravity of the high resolution dot 132, or between the two high resolution dots 132. The low resolution dots 136 may be printed directly above the high resolution dots 132, or may be printed so as to partially overlap the high resolution dots 132 as shown.

18 to 20, four high resolution dots 132 are arranged around the center of gravity 130 thereof at an angle of about 45 ° with respect to the X axis and the Y axis. It is also possible to arrange the four high resolution dots 132 along the 90 ° axis as shown in FIG. Such an array of high resolution dots 132 would produce the dot array shown in Figure 21 within a single print width by changing the array of nozzles in the inkjet pen nozzle array (or by tilting the pen). Alternatively, it can be configured by combining the change of the energization speed of the inkjet ejection resistor and the reduction of the sheet feeding step. Figure
The mixed resolution dot array shown in 21 is effective in drawing a figure. The pattern of the dot group consisting of the low resolution dots 136 may be diamond-shaped as shown in FIG. 21, or may be square as shown in FIGS. 18 to 20.

By generating a dot group consisting of 9 dots or 16 dots for one low resolution dot, another intermediate dot resolution of 3: 1 or 4: 1 can be realized.

22 to 24 show other alignment states of high resolution dots and low resolution dots.

In FIG. 22, adjacent rows of high resolution dots 132 are arranged in a staggered manner, and the center of gravity of a dot group consisting of four high resolution dots 132 is aligned with the center of gravity of low resolution dots 136.

The arrangement shown in FIG. 23 is similar to that of FIG. 22 except that the low resolution dots 136 are shifted down by an amount corresponding to half the diameter of the high resolution dots 132.

FIG. 24 shows a variation of the pattern of the high resolution dots 132 and the pattern of the low resolution dots 136, and for this reason, various combinations of arrangements which can be obtained by various variations are shown.

Any combination of high-resolution dots and low-resolution dots can be directly overlapped to produce various colors and shades or strong colors. The black high resolution dots 132 can be printed during the same scan as the low resolution dots 136 or during another scan to reduce ink flow and other print quality improvements.

The array shown in FIGS. 18 to 24 or a combination thereof can be used to maximize the ink application area on the page while minimizing the ink application amount. The dot arrangement can be changed during printing or when switching print jobs, as necessary. The choice of a particular array can be made according to the expected ink flow and ink characteristics as well as the particular image to be printed.

While particular embodiments of the present invention have been described, it will be apparent to those skilled in the art that changes and modifications can be made without departing from the invention. Accordingly, the claims are intended to include all such changes and modifications that fall within the spirit and scope of the invention.

Although the embodiments of the present invention have been described in detail above, examples of each embodiment of the present invention will be shown below. [Embodiment 1] A mixed resolution printer characterized by having the following devices a) to e): a) a frame for holding a medium (14) to be printed in a printing area, b) supported on the frame A scanning carriage (20) arranged in the vicinity of the printing area, and c) supported on the carriage, while the carriage scans the medium in the X direction and in the Y direction perpendicular to the X direction, A first print head (110) for printing dots of a first size (132) at a first printing resolution along the X direction and the Y direction; d) supported on the carriage, the carriage When scanning over the medium in the X direction, a dot having a second size larger than the first size with a second printing resolution lower than the first printing resolution in the X direction and the Y direction ( 136) to print Two print heads (112), e) such that the dots of the first size and the dots of the second size are aligned with each other on the medium in a predetermined manner in the X and Y directions. The first printhead and the second printhead for printing on a sheet.

[Embodiment 2] The dots (132) of the first size and the dots (136) of the second size.
Means that when printing on the medium (14), the center of gravity of the dots of the first size in one row of dots along the X direction is the same as that of the dots of the second size in the X direction. The printer according to the first embodiment, characterized in that the printer is aligned with the center of gravity (FIGS. 20, 21, and 23).

[Third Embodiment] Dots in a dot group consisting of four dots (132) of the first size form an angle of 45 ° with respect to the X and Y directions around the center of gravity of the dot group. The printer according to Embodiment 1 or 2 (FIGS. 19 and 20), which is characterized in that the printer is arranged.

[Embodiment 4] Dots (132) in a dot group consisting of four dots of the first size form an angle of 90 ° with respect to the X and Y directions around the center of gravity of the dot group. The printer according to the first embodiment or the second embodiment, which is characterized in that the printer is arranged (FIGS. 21-24).

[Embodiment 5] Embodiment 1 and Embodiment 1 characterized in that the first print head (110) prints black ink and the second print head (112) prints color ink. The printer according to Aspect 2, Aspect 3, or Aspect 4.

[Embodiment 6] A mixed resolution printer (1) characterized by comprising the steps f) to h) below.
Printing method using 0): f) The first print head scans the medium (14) in the X direction and the Y direction at right angles to the X direction while moving the first print head along the X direction and the Y direction. A step of printing a dot (132) of a first size with a print resolution of: g) When the first print head and the second print head scan the medium in the X direction, A printhead (112) of the second print resolution (136) having a second print resolution lower than the first print resolution and gently arranging a second size dot (136) larger than the first size in the X and Y directions. And h) the first printhead and the second printhead print the first size dot and the second size dot in the X and Y directions. Aligned with each other on the medium in a predetermined manner The step of printing to be.

[Embodiment 7] The dots (132) of the first size and the dots (136) of the second size.
Means that when printing on the medium (14), the center of gravity of the dots of the first size in one row of dots along the X direction is the same as that of the dots of the second size in the X direction. Method according to embodiment 6, characterized in that it is aligned to the center of gravity (Figure 20, Figure 21, Figure 23).

[Embodiment 8] The dots (132) in the dot group consisting of four dots of the first size form an angle of 45 ° with respect to the X and Y directions around the center of gravity of the dot group. The method according to Embodiment 6 or Embodiment 7, which is characterized by being arranged (FIGS. 19 and 20).

[Embodiment 9] The dots (132) in the dot group consisting of four dots of the first size form an angle of 90 ° with respect to the X and Y directions around the center of gravity of the dot group. The method according to embodiment 6 or embodiment 7, characterized in that it is arranged (FIGS. 21-24).

[Embodiment 10] Embodiments 6 and 7 characterized in that the second print head (112) prints an ink containing a color component selected from cyan, magenta and yellow. The method according to Embodiment 8 or Embodiment 9.

[0058]

As described above, according to the present invention, print quality can be improved by emphasizing an important characteristic frequently appearing on a printed page such as a text by using a pen having a higher performance. . In addition, this pen is capable of printing such frequently appearing images at high speed, thus improving the throughput.

[Brief description of drawings]

FIG. 1 is a perspective view showing a typical inkjet printer in which the apparatus and method of the present invention can be used.

FIG. 2 is a perspective view showing a carriage having a removable multicolor print cartridge in which the apparatus and method of the present invention can be used.

FIG. 3 is a perspective view showing a preferred example of a low resolution color inkjet print cartridge used in an embodiment of the present invention.

FIG. 4 is a perspective view of a carriage using an embodiment of the present invention in an inkjet printer.

5 is a plan view of the carriage of FIG.

FIG. 6 is a partial view showing a flexible circuit connecting portion on the carriage of FIGS. 4 and 5 by cutting out an inner carriage wall.

FIG. 7 is a schematic block diagram of a print cartridge according to an embodiment of the present invention.

FIG. 8 is a schematic bottom view looking up from the medium side, showing one of the alignment relationships of the nozzle array of FIG.

FIG. 9 is a schematic diagram showing the use of a foam member to connect a flexible circuit to a high resolution black inkjet cartridge.

10 is a flexible circuit frame portion of the carriage, a foam spring member of FIG. 9 for compression-connecting the flexible circuit to the high-resolution black inkjet cartridge, and a metal spring for compression-connecting the flexible circuit to the low-resolution color inkjet cartridge. It is an exploded view showing a member.

11 is a front view of the flexible circuit frame in FIG. 10.

FIG. 12 illustrates a black print head according to an embodiment of the present invention.
600 dpi printout and 300 of color printheads
FIG. 6 is a schematic diagram showing the relative resolution of a dpi printout.

FIG. 13A is a schematic view from the medium side showing an aspect of alignment of a high-resolution nozzle array and one or more low-resolution nozzle arrays.

FIG. 13B is a schematic view from the medium side showing another aspect of alignment of a high resolution nozzle array and one or more low resolution nozzle arrays.

FIG. 13C is a schematic view from the medium side illustrating another aspect of alignment of a high resolution nozzle array and one or more low resolution nozzle arrays.

FIG. 13D is a schematic view from the medium side illustrating another aspect of alignment of a high resolution nozzle array with one or more low resolution nozzle arrays.

FIG. 14 is a schematic diagram of an example of a single plate nozzle array for a 3-color inkjet pen.

FIG. 15 is a schematic diagram of another example of a single plate nozzle array of another 3-color inkjet pen.

FIG. 16 is a schematic diagram of another example of a single plate nozzle array of another 3-color inkjet pen.

FIG. 17 shows a nozzle array of three different color pens.
FIG. 3 is a schematic view showing a case where the carriage is arranged in the carriage.

FIG. 18 is a diagram illustrating an example of alignment of printed high-resolution dots and low-resolution dots.

FIG. 19 is a diagram showing another example of alignment of printed high-resolution dots and low-resolution dots.

FIG. 20 is a diagram illustrating another example of alignment of printed high-resolution dots and low-resolution dots.

FIG. 21 is a diagram showing another example of alignment of printed high-resolution dots and low-resolution dots.

FIG. 22 is a diagram showing another example of alignment of printed high-resolution dots and low-resolution dots.

FIG. 23 is a diagram illustrating another example of alignment of printed high-resolution dots and low-resolution dots.

FIG. 24 is a diagram showing another example of alignment of printed high-resolution dots and low-resolution dots.

[Explanation of symbols]

 10: inkjet printer 14: medium 20: movable carriage 110: first print head 112: second print head 113, 114, 115: print head nozzle array surface 132: first size dot 136: second print head Size dot

Front Page Continuation (72) Inventor John A. Christianson 31 Esty Avenue, Vancouver, Washington, United States 10502 (72) Inventor Douglas El Franz Vancouver, Washington, United States. N. W. 136 Street 1508 (72) Inventor Donald G. Harris, Little Creed Road, Escondade, California, United States 7627 (72) Inventor Majid As Moon, Cole Collina, Poway, California 13476

Claims (1)

[Claims] 1. A mixed resolution printer comprising the following a) to e) devices: a) a frame for holding a medium to be printed in a print area, b) supported on the frame, A scanning carriage arranged in the vicinity of a printing area, c) supported on the carriage, while the carriage scans the medium in the X direction and the Y direction perpendicular to the X direction while the X direction and the Y direction. A first printhead for printing dots of a first size at a first printing resolution along a direction, d) supported on the carriage, the carriage scanning the medium in the X direction. A second print head for printing dots of a second size larger than the first size with a second printing resolution lower than the first printing resolution in the X direction and the Y direction, e) the The first printhead and the first printhead for printing the dots of one size and the dots of the second size such that they are aligned with each other on the medium in a predetermined manner in the X and Y directions. 2 print heads.