1. Field of the Invention
The present invention relates to a technique for recording dots on the surface of a recording medium with the aid of a dot-recording head, and more particularly to a technique for printing images up to the edges of printing paper without soiling the platen.
2. Description of the Related Art
Printers in which ink is ejected from the nozzles of a print head have recently become popular as computer output devices.
When an attempt is made to print images without blank spaces up to the edges of printing paper with the aid of such a printer, it is necessary to arrange the printing paper such that the edges of the printing paper are disposed underneath the print head (that is, on the platen) and to cause ink droplets to be ejected from the print head when print data are specified for the areas that extend up to the edges of the printing paper and printing is carried out. With such printing, however, blank spaces form in the edge portions of the printing paper due to errors developing during the feeding of the printing paper, a shift in the impact location of the ink droplets, or the like. In addition, the ink droplets sometimes miss the edges of the printing paper (for which the droplets have been originally intended) and end up depositing on the platen due to errors developing during the feeding of the printing paper, a shift in the impact location of the ink droplets, or the like. In such cases, the ink deposited on the platen soils the printing paper transported over the platen in the next step.
It is an object of the present invention, which was perfected in order to overcome the above-described shortcomings of the prior art, to provide a technique that allows images to be printed up to the edges of printing paper while preventing ink droplets from depositing on the platen.
Perfected in order to at least partially overcome the above-described shortcomings, the present invention envisages performing specific procedures for a dot-recording device designed to record dots on the surface of a print medium with the aid of a dot-recording head provided with a plurality of dot-forming elements for ejecting ink droplets. In a method of using a dot-recording head to eject ink droplets to a print medium without blank space up to the edges of the print medium according to print data, the method entails supporting the print medium opposite the dot-recording head, and ejecting ink droplets to a first area lying outside of an upper edge of the print medium and to a second area lying outside of a lower edge of the print medium. A length of a second area in a sub-scanning direction is greater than a length of the first area in the sub-scanning direction.
The platen may have a slot configured to extend in a main scanning direction, a width of the slot in the sub-scanning direction corresponding to a specific sub-scanning range on a surface of the dot recording head including at least part of the plurality of dot-forming elements.
The ejecting of ink droplets comprises positioning the print medium in the sub-scanning direction to eject ink droplets onto the upper edge of the print medium, such that the upper edge of the print medium is at a point above the slot extending in the main scanning direction, the point being located in the sub-scanning direction upstream of a dot-forming element at a downstream end in the sub-scanning direction, and positioning the print medium in the sub-scanning direction to eject ink droplets onto the lower edge of the print medium, such that the lower edge of the print medium is at a point above the slot, the point being located in the sub-scanning direction downstream of a dot-forming element at an upstream end in the sub-scanning direction.
With this arrangement, ink droplets can be prevented from being deposited on the platen, and images can be printed without blank spaces up to the edges of the print medium. Selecting the correct size for the expanded area in accordance with the type of print medium makes it possible to prevent situations in which time is wasted when images are printed by ejecting ink droplets over an area that is unnecessarily wide for a given size of print medium.
The type of print medium preferably depends on dimensions of the print medium. When a print medium tilts away from its intended orientation, the extent to which the edge portions of the print medium are shifted increases with the dimensions of the print medium. Consequently, selecting an expanded area in accordance with a category related to the dimensions of the print medium makes it possible to establish the expanded area in an appropriate manner such that ink droplets are prevented from depositing on the platen, and images are printed without blank spaces up to the edges of the printing paper.
The type of print medium should preferably be set in accordance with the material of the print medium. The feed error occurring during the sub-scanning of a print medium sometimes varies with the type of print medium. Consequently, selecting an expanded area in accordance with a category related to the material of the print medium makes it possible to establish the expanded area in an appropriate manner such that ink droplets are prevented from depositing on the platen, and images are printed without blank spaces up to the edges of the printing paper.
The following procedure should preferably be adopted when ink droplets are ejected onto an expanded area. When ink droplets are ejected onto the front edge of the print medium, the position of the print medium in the sub-scanning direction is set such that the print medium is supported on the platen, the front edge of the print medium is brought to a point above the slot, and the front edge of the print medium reaches a point located in the sub-scanning direction upstream of a dot-forming element at a downstream end in the sub-scanning direction. When ink droplets are ejected onto the rear edge of the print medium, the position of the print medium in the sub-scanning direction is set such that the print medium is supported on the platen, the rear edge of the print medium is brought to a point above the slot, and the rear edge of the print medium reaches a point located in the sub-scanning direction downstream of a dot-forming element at an upstream end in the sub-scanning direction. With this arrangement, ink droplets can be prevented from depositing on the platen, and images can be printed without blank spaces up to the front and rear edge of the print medium.
The following procedure should preferably be adopted during the preparation of print data when the platen has a pair of lateral slots that are separated apart at a distance substantially equal to the width of the print medium, and the lateral slots extend in a sub-scanning range in which ink droplets are ejected from the plurality of dot-forming elements. The print data for recording images in an expanded area is prepared. The expanded area extends widthwise beyond left and right edges of the print medium but remaining between farthermost side walls of the pair of lateral slots. With this arrangement, it is possible to prepare print data whereby ink droplets can be prevented from depositing on the platen, and images can be printed without blank spaces up to the left and right edges of the print medium.
The following procedure should preferably be adopted when ink droplets are ejected onto the expanded area. The position of the print medium in the main scanning direction is set such that the print medium is supported on the platen, and the left and right edges of the print medium are brought to a point above the lateral slots. Dots are formed on the basis of image data representing an image extending outside the print medium beyond the left and right edges. With this arrangement, ink droplets can be prevented from depositing on the platen, and images can be printed without blank spaces up to the left and right edges of the print medium.
Print data should preferably be prepared such it contains information about recording condition of dots at pixels inside the expanded area. Such an embodiment makes it easier to set up portions of the expanded area beyond the edges of a print medium.
In another aspect, the invention is embodied in a dot-recording device for ejecting ink droplets onto a print medium without blank space up to the edges of the print medium. Such a dot-recording device comprises a dot-recording head for ejecting ink-droplets, a support configured to support the print medium opposite the dot-recording head, and a controller configured to control the ejection of the ink droplets such that the dot-recording head ejects ink droplets to a first area lying outside of an upper edge of the print medium and to a second area lying outside of a lower edge of the print medium. The controller is further configured to control the ejection of ink droplets such that a length of the second area in a sub-scanning direction is greater than a length of the first area in the sub-scanning direction.
This arrangement allows print data to be generated such that ink droplets can be prevented from depositing on the platen, and images can be printed without blank spaces up to the edges of the printing paper. When an expanded area is employed, selecting correct size for it in accordance with the type of print medium makes it possible to generate print data such that situations are prevented in which time is wasted when images are printed by ejecting ink droplets over an area that is unnecessarily wide for a given size of print medium.
The following procedure should preferably be adopted when the expanded area is divided, in order from the top, into an external front edge portion disposed in an area beyond the front edge of the print medium and configured such that formation of dots in this portion is assigned to the dot-forming elements disposed opposite the slot; an internal front edge portion on the front-edge portion of the print medium and configured such that formation of dots in this portion is assigned to the dot-forming elements disposed opposite the slot; an intermediate portion of the print medium; an internal rear edge portion on the rear-edge portion of the print medium and configured such that formation of dots in this portion is assigned to the dot-forming elements disposed opposite the slot; and an external rear edge portion disposed in an area beyond the rear edge of the print medium and configured such that formation of dots in this portion is assigned to the dot-forming elements disposed opposite the slot. Specifically, the area size memory substantially contains the dimensions of the external front edge portion in the sub-scanning direction, the dimensions of the internal front edge portion in the sub-scanning direction, the dimensions of the internal rear edge portion in the sub-scanning direction, and the dimensions of the external rear edge portion in the sub-scanning direction.
With this arrangement, the position of the expanded area in relation to the print medium can be defined in an appropriate manner. Ejecting ink droplets onto the external front edge portion, internal front edge portion, internal rear edge portion, and external rear edge portion of the expanded area makes it possible to print images on the edge portions of the print medium without forming blank spaces along the edges of the printing paper or depositing the ink droplets on the platen.
In the printing, following procedures are preferable. A specific print mode is selected from among a plurality of print modes. The print data for recording images in an expanded area is prepared. The expanded area extends lengthwise beyond the front and rear edges of the print medium in accordance with he selected print mode. Then ink droplets are ejected from at least some of the dot-forming elements disposed opposite the slot when images are printed in the front- and rear-edge portions of the print medium on the basis of the print data.
Such an embodiment allows expanded areas suited to individual print modes to be prepared and dots to be formed such that images are printed in an appropriate manner without blank spaces in the edge portions of the print medium.
When there are a plurality of print modes which include print modes with mutually different recording densities for the raster lines in the sub-scanning direction, a number of raster lines constituting the expanded area should preferably be established in accordance with the selected print mode when print data are prepared. With this arrangement, the size of the expanded area in the sub-scanning direction can be defined in accordance with the print mode by adopting the concept of “raster line” for the printing device during actual printing.
Images should preferably be printed using solely the dot-forming elements disposed opposite the slot during printing in the front- and rear-edge portions of the print medium. Adopting this embodiment prevents the platen from being soiled when the front or rear edge shifts away from the slot during printing in the front- or rear-edge portion of the print medium.
The expanded area may be divided, in order from the top, into an external front edge portion, an intermediate portion, an internal front edge portion, an internal rear edge portion, an external rear edge portion. The external front edge portion is disposed in an area beyond the front edge of the print medium and configured such that formation of dots in this portion is assigned to the dot-forming elements disposed opposite the slot. The internal front edge portion corresponds to the front-edge portion of the print medium and is configured such that formation of dots in this portion is assigned to the dot-forming elements disposed opposite the slot. The intermediate portion corresponds to an intermediate portion of the print medium. The internal rear edge portion corresponds to the rear-edge portion of the print medium and is configured such that formation of dots in this portion is assigned to the dot-forming elements disposed opposite the slot. The external rear edge portion is disposed in an area beyond the rear edge of the print medium and is configured such that formation of dots in this portion is assigned to the dot-forming elements disposed opposite the slot.
It is preferable to set a number of raster lines for the external front edge portion according to the selected print mode such that dimensions of the external front edge portion remain the same in the sub-scanning direction with respect to different print modes having mutually different sub-scan resolutions, when the same type of print medium is used. It is also preferable to set a number of raster lines for the external rear edge portion such that the dimensions of the external rear edge portion remain the same in the sub-scanning direction with respect to different print modes having mutually different sub-scan resolutions, when the same type of print medium is used.
With this arrangement, the dimensions of the external front edge portion and external rear edge portion remain substantially the same in any print mode. For this reason, the expanded area can be established such that the likelihood of blank spaces forming in the edge portions of the print medium is reduced in a way that does not change with the print mode.
It is preferable to set a number of raster lines for the internal front edge portion such that the dimensions of the internal front edge portion remain the same in the sub-scanning direction with respect to different print modes having mutually different sub-scan resolutions, when the same type of print medium is used. It is also preferable to set a number of raster lines for the internal rear edge portion such that the dimensions of the internal rear edge portion remain the same in the sub-scanning direction with respect to different print modes having mutually different sub-scan resolutions, when the same type of print medium is used.
With this arrangement, the dimensions of the internal front edge portion and internal rear edge portion remain substantially the same in any print mode. For this reason, the expanded area can be established such that the likelihood of the platen being soiled is reduced in a way that does not change with the print mode.
When ink droplets are ejected onto the front edge of the print medium, the position of the print medium in the sub-scanning direction is preferably selected such that the print medium is supported on the platen, the front edge of the print medium is brought to a point above the slot, and the front edge of the print medium reaches a point located in the sub-scanning direction upstream of the dot-forming element at a downstream end in the sub-scanning direction. When ink droplets are ejected onto the rear edge of the print medium, the position of the print medium in the sub-scanning direction is preferably selected such that the print medium is supported on the platen, the rear edge of the print medium is brought to a point above the slot, and the rear edge of the print medium reaches a point located in the sub-scanning direction downstream of a dot-forming element at an upstream end in the sub-scanning direction. With this arrangement, ink droplets can be prevented from depositing on the platen, and images can be printed without blank spaces up to the front and rear edge of the print medium.
In the case that a plurality of print modes includes print modes having mutually different recording densities for the pixels in the main scanning direction, following embodiment is preferable. The dimensions of the expanded area is set such that the expanded area extends widthwise beyond left and right edges of the print medium but remains between farthermost side walls of the pair of lateral slots, and setting the number of pixels in the main scanning direction for the raster lines constituting the expanded area is specified substantially in accordance with the print mode thus selected. With this arrangement, it is possible to prepare print data whereby ink droplets can be prevented from depositing on the platen, and images can be printed without blank spaces up to the left and right edges of the print medium.
The position of the print medium in the sub-scanning direction is preferably set such that the print medium is supported on the platen, and the left and right edges of the print medium are brought to a point above the lateral slots. It is also preferable that dots are formed on the basis of image data representing an image extending outside the print medium beyond the left and right edges. With this arrangement, ink droplets can be prevented from depositing on the platen, and images can be printed without blank spaces up to the left and right edges of the print medium.
The present invention can be employed in connection with a dot-recording control device for forming print data to be sent to a dot-recording unit for recording dots on the surface of a print medium with the aid of a dot-recording head provided with a plurality of dot-forming elements for ejecting ink droplets.
In such arrangement, the print control device may comprise a user interface unit, an expanded area memory, and a print data generator. The user interface unit displays a selection screen that allows the user to select one of a plurality of preinstalled print modes on a display, and that allows the selection be entered; wherein the area size memory comprises. The expanded area memory contains, for each print mode, a number of raster lines constituting the expanded area extending lengthwise beyond the front and rear edges of the print medium. The print data generator generates the print data for recording dots with which images can be formed in the expanded area on the basis of the selected print mode, the number of raster lines stored in the expanded area memory, and the image data for the images to be recorded on the print medium. Such an embodiment allows an expanded area suited to individual print modes to be prepared and images to be printed in an appropriate manner without blank spaces in the edge portions of the print medium.
The following printing procedure may preferably be adopted when a dot-recording device is used that is designed to record dots on the surface of a print medium with the aid of a dot-recording head provided with a plurality of dot-forming elements for ejecting ink droplets. The print medium contains a usable area which is defined by a closed perforated line in the entire area of the print medium. In the printing procedure, an expanded area for image recording is set in accordance with a type of print medium. The expanded area extends beyond the ends of the usable area along the entire perimeter thereof, and print data for recording images in the expanded area are prepared. Then dots are recorded by ejecting ink droplets from at least some of the dot-forming elements to the expanded area. With this arrangement, dots are printed without any margin being left up to the edges of the usable area, which is to be split off by perforated lines.
In the printing procedure, it is preferable that the print data is prepared in accordance with the selected printing mode selected from a plurality of printing modes. With this arrangement, an appropriate extended area for each printing mode can be prepared so that printing can be carried out appropriately without leaving any margins at the periphery of the usable area.
The present invention can be implemented as the following embodiments.
(1) A dot-recording method, dot-recording control method, print control method, or printing method.
(2) A dot-recording device, dot-recording control device, print control device, or printing device.
(3) A non-transitory computer program product for operating the device or implementing the method.
These and other objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with the accompanying drawings.
Embodiments of the present invention will now be described through embodiments in the following sequence.
B1. Device Structure
B2. Image-recording Area
B3. Print Routine Sequence
B4. Dot Formation
C1. Modification 1
C2. Modification 2
C3. Modification 3
C4. Modification 4
C5. Modification 5
C6. Modification 6
C7. Modification 7
C8. Modification 8
C9. Modification 9
The portion of the recording area lying outside the upper edge Pf of the printing paper P is referred to as an external upper edge portion Rfp. The pixels of the external upper edge portion Rfp are recorded solely by those nozzles of the print head that are disposed facing the downstream slot of the platen. A specific portion of the recording area R lying downstream of the external upper edge portion Rfp in the sub-scanning direction is referred to as an internal upper edge portion Rfq. The internal upper edge portion Rfq is also recorded solely by the nozzles disposed at a position opposite the downstream slot. When the printing paper P shifts from the intended position during the recording of dots on the printing paper P, it is still possible to prevent blank spaces from forming in the edge portions of printing paper, and ink droplets from depositing on the platen as long as the upper edge of the printing paper P is inside the external upper edge portion Rfp or internal upper edge portion Rfq.
Provided the dimensions and the material of the printing paper for forming images remain the same, the external upper edge portion Rfp and internal upper edge portion Rfq can be selected to have substantially the same dimensions in the sub-scanning direction even when different image-recording densities or recording systems are used. Specifically, substantially the same values are selected for the dimensions of the external upper edge portion Rfp1 in the sub-scanning direction and the dimensions of the external upper edge portion Rfp2 in the sub-scanning direction, as well as for the dimensions of the internal upper edge portion Rfr1 in the sub-scanning direction and the dimensions of the internal upper edge portion Rfr2 in the sub-scanning direction. An expanded area can thereby be established such that the same effect is achieved in reducing the likelihood that blank spaces will be formed in the edge portions of a print medium when different print modes are employed. In other words, the range within which the printing paper P can shift without causing blank space to form in the edge portions of the printing paper or ink droplets to deposit on the platen can remain constant irrespective of the image recording density or recording system.
Images are recorded in the front-edge portion Rf and rear-edge portion Rr of the recording area R solely by the nozzles disposed opposite the slot in the platen. For this reason, the ink droplets designed to record images on the edge portions are prevented from soiling the platen when the printing paper P fails to reach its intended position due to an error affecting the feeding of the printing paper P in the sub-scanning direction, a tilt of the printing paper P away from the intended orientation, or the like. In the drawings, the front-edge portion Rf of the recording area R is labeled as Rf1-Rf6, and the rear-edge portion Rr as Rr1-Rr6.
In the present invention, the recording area R of image data is specified in accordance with the type of printing paper P. The printing paper P4 shown in
The printing paper P1, P2, and P3 have the same size but are made of different materials, and the ease with which they the paper slides during sub-scanning increases in the sequence P1, P2, P3. The length (in the sub-scanning direction) of the area R for recording images on each type of printing paper increases in the sequence R1, R2, R3. More specifically, the length of the portion of the expanded area R in the sub-scanning direction between the front-edge portion Rf and rear-edge portion Rr in which images can be recorded above the slot increases in the sequence R1, R2, R3. It is therefore unlikely that blank spaces will form along the edges of the printing paper or that ink droplets will deposit on the platen when slippery printing paper slips over a comparatively long distance during sub-scanning. Similarly, the printing paper P4, P5, and P6 have the same size but increase their slipperiness in the sub-scanning direction in the sequence P4, P5, P6, so the length of the portion of the recording area R between the front-edge portion Rf and rear-edge portion Rr increases in the sequence R4, R5, R6. In the present specification, the terms “upper edge (portion)” and “lower edge (portion)” may be used to designate the edges of the printing paper P corresponding to the top and bottom of the image data recorded on the printing paper P, and the terms “front edge (portion)” and “rear edge (portion)” may be used to designate the edges of the printing paper P corresponding to the direction in which the printing paper P is advanced during sub-scanning in the printer 22. In the present specification, the term “upper edge (portion)” corresponds to the front edge (portion) of the printing paper P, and the term “lower edge (portion)” corresponds to the rear edge (portion).
When the application program 95 generates a printing command, the printer driver 96 of the computer 90 receives image data from the application program 95, and the resulting data are converted to a signal that can be processed by the printer 22 (in this case, into a signal containing multiple values related to the colors cyan, magenta, light cyan, light magenta, yellow, and black). In the example shown in
The role of the resolution conversion module 97 is to convert the resolution of the color image data handled by the application program 95 (that is, the number of pixels per unit length) into a resolution that can be handled by the printer driver 96. The resolution conversion module 97 references the expanded area table EAT when the resolution of the image data is converted. The image data are converted to a type of data that allows an image-recording area determined based on data concerning paper types and on an expanded area table EAT (which are provided in advance) to be recorded at a specified resolution. The image-recording area and the expanded area table EAT will be described in detail below.
Because the image data converted in terms of resolution in this manner are still in the form of video information composed of three colors (RGB), the color correction module 98 converts these data into the data for each of the colors (cyan (C), magenta (M), light cyan (LC), light magenta (LM), yellow (Y), and black (K)) used by the printer 22 for individual pixels while the color correction table LUT is consulted.
The color-corrected data have a gray scale with 256 steps, for example. The halftone module 99 executes a halftone routine for expressing this gray scale in the printer 22 by forming dispersed dots. The halftone module 99 executes the halftone routine upon specifying the dot formation patterns of the corresponding ink dots in accordance with the gray scale of the image data by consulting the dot-forming pattern table DT. The image data thus processed are sorted according to the data sequence to be transferred to the printer 22 by the rasterizer 100, and are outputted as final print data PD. The print data PD contain information about the amount of feed in the sub-scanning direction and information about the condition of dot recording during each main scan. The raster data (which contain print data PD) and the data specifying the feed increments in the sub-scanning direction correspond to the image data D, which substantially indicate the images to be printed. In other words, these types of data contain, as image data, information about the recording condition of the dots in the pixels inside the expanded area. In the present embodiment, the sole role of the printer 22 is to form ink dots in accordance with the print data PD without processing the images, although it is apparent that such processing can also be carried out by the printer 22.
The overall structure of the printer 22 will now be described with reference to
The mechanism for reciprocating the carriage 31 in the axial direction of the platen 26 comprises a sliding shaft 34 mounted perpendicular to the direction of transport of the printing paper P and designed to slidably support the carriage 31, a pulley 38 for extending an endless drive belt 36 from the carriage motor 24, a position sensor 39 for sensing the original position of the carriage 31, and the like.
The carriage 31 can support a cartridge 71 for black ink (K) and a color-ink cartridge 72 containing inks of the following six colors: cyan (C), light cyan (LC), magenta (M), light magenta (LM), and yellow (Y). A total of six ink-ejecting heads 61 to 66 are formed in the print head 28 in the bottom portion of the carriage 31, and introduction tubes 67 for guiding the ink from the ink tank to each color head are provided to the bottom portion of the carriage 31. Mounting the cartridge 71 for the black (K) ink and the cartridge 72 for the color inks on the carriage 31 causes the introduction tubes 67 to enter the connection holes provided to each cartridge, and allows the ink to be fed from the ink cartridges to the ejection heads 61 to 66.
The print head 28 moves back and forth in the main scanning direction over the platen 26 sandwiched between the upstream paper feed rollers 25a and 25b and the downstream paper feed rollers 25c and 25d. The printing paper P is held by the upstream paper feed rollers 25a and 25b and the downstream paper feed rollers 25c and 25d, and an intermediate portion thereof is supported by the upper surface of the platen 26 while disposed opposite the rows of nozzles in the print head 28. The paper is fed in the sub-scanning direction by the upstream paper feed rollers 25a and 25b and the downstream paper feed rollers 25c and 25d, and images are sequentially recorded by the ink ejected from the nozzles of the print head 28.
The platen 26 is provided with an upstream slot 26f and a downstream slot 26r, which are located on the upstream and downstream sides, respectively, in the sub-scanning direction. The width of the upstream slot 26f or downstream slot 26r in the main scanning direction is greater than the maximum width of the printing paper P that can be accommodated by the printer 22. In addition, absorbent members 27f and 27r for accepting and absorbing ink droplets Ip are disposed in the bottom portions of the upstream slot 26f and downstream slot 26r, respectively. The downstream slot 26r is disposed opposite those nozzles Nz of the print head 28 that form a downstream group of nozzles Nr (the hatched group of nozzles in
The upstream slot 26f and downstream slot 26r correspond to the first slot.
The platen 26 further comprises a left slot 26a and a right slot 26b, which extend in the sub-scanning direction to connect the two corresponding ends of the upstream slot 26f and downstream slot 26r. The left slot 26a and right slot 26b are provided within a range (in the sub-scanning direction) greater than the range within which ink droplets can be deposited by the nozzles of the print head. The distance between the center lines (in the main scanning direction) of the left slot 26a and right slot 26b is selected such that the width (in the main scanning direction) of the portion of the printing paper on which images can be recorded by the printer 22 is equal to the maximum width of the printing paper P. The left slot 26a and right slot 26b should be configured such that one of the side-edge portions (side-edge portion Pa) of the printing paper P in the main scanning direction is disposed above the left slot 26a, and the other side-edge portion (side-edge portion Pb) is disposed above the right slot 26b when the widest possible printing paper P on which images can be printed by the printer 22 is brought to a specified main-scan position by the guides 29a and 29b. An arrangement in which the side-edge portions of the printing paper P are disposed at a point located inward or outward from the center lines of the left slot 26a and right slot 26b can therefore be adopted in addition to an embodiment in which the side-edge portions of the printing paper P are disposed along the center lines of the left slot 26a and right slot 26b when the printing paper is brought into a specified position in this manner. The upstream slot 26f, downstream slot 26r, left slot 26a, and right slot 26b are connected to each other, forming a quadrilateral slot.
The platen 26 also comprises right slots 26b2 and 26b3. These slots extend in the sub-scanning direction and connect together the intermediate portions of the upstream slot 26f and downstream slot 26r. The distance between the center lines of the right slot 26b2 and the left slot 26a is selected such that the resulting width is less than the maximum width (in the sub-scanning direction) of printing paper P recordable with the printer 22, and is equal to the width of a specific printing paper P. The same applies to the right slot 26b3. If the printer 22 can print images up to size A3 in a lengthwise arrangement, the distance between the center lines of the left slot 26a and right slot 26b corresponds to the length of the short side of size A3 paper. It may, for example, be possible in this case to arrange the left slot 26a and right slot 26b2 such that the distance between the center lines thereof is equal to the length of the short side for size B4, and to arrange the left slot 26a and right slot 26b3 such that the distance between the center lines thereof is equal to the length of the short side of size A4 paper. It is also possible to provide a right slot that corresponds to size A5, a right slot that corresponds to the postcard size, and the like. The group composed of the left slot 26a and right slot 26b, the group composed of the left slot 26a and right slot 26b2, or the group composed of the left slot 26a and right slot 26b3 correspond to the pair of lateral slots.
Absorbent members 27 for absorbing ink droplets Ip are disposed at the bottom of each slot. The absorbent members 27 for each of the slots are sometimes designated 27f, 27r, 27a, 27b, 27b2, and 27b3 in accordance with the labeling of the slots.
The printing paper P passes above the openings of the upstream slot 26f and downstream slot 26r when fed in the sub-scanning direction by the upstream paper feed rollers 25a and 25b and the downstream paper feed rollers 25c and 25d. The printing paper P is positioned on the platen 26 by the guides 29a and 29b in the main scanning direction such that the left edge Pa is disposed above the left slot 26a, and the right edge Pb is disposed above the right slot 26b, 26b2, or 26b3, depending on the width of the printing paper.
The inner structure of the control circuit 40 (see
In the printer 22 thus configured, the carriage 31 is reciprocated by the carriage motor 24 while paper P is transported by the paper feed motor 23, the piezoelement of each of the nozzle units belonging to the print head 28 is actuated at the same time, ink droplets Ip of each color are ejected, and ink dots are formed to produce multicolored images on the paper P.
In the printer of the present embodiment, the areas near the top and lower edges of printing paper are printed differently from the intermediate area of the printing paper because the upper edge Pf of the printing paper P is printed over the downstream slot 26r, and the lower edge Pr is printed over the upstream slot 26f. In the present specification, the routine whereby images are printed in the intermediate area of printing paper will be referred to as an “intermediate routine,” the routine whereby images are printed in the area near the upper edge of printing paper will be referred to as a “upper-edge routine,” and the routine whereby images are printed in the area near the lower edge of printing paper will be referred to as a “lower-edge routine.”
The dimensions of the expanded area R in the main scanning direction (horizontal direction in
The width Wr of the expanded area can therefore be expressed by the equation Wr=Wp+Wa+Wb, where Wp is the width of the printing paper in the main scanning direction (this width varies with the type of paper), Wa is the width of the portion of the expanded area R specified for the region beyond the left edge Pa, and Wb is the width of the portion of the expanded area R specified for the region beyond the right edge Pb. The width Wr of the expanded area R is greater than the width of the printing paper P (in the direction from left to right) but does not exceed the distance between the side walls of the exterior portions of the left slot 26a and right slot 26b. The right slot defines the width of the expanded area R. This slot is the right slot 26b in the case of a widest possible printing paper for which the printer 22 can be used, and the right slot 26b2 or right slot 26b3 in the case of narrower printing paper.
By contrast, the dimensions of the expanded area R in the sub-scanning direction (vertical direction in
Images are recorded in the external upper edge portion Rfp solely by the nozzles Nr disposed opposite the downstream slot 26r. These nozzles are some of the nozzles provided to the print head 28. As used herein, the term “only a specific group of nozzles is used” refers to the fact that the only nozzles used are those belonging to a specific group of nozzles. At least part of a specific group of nozzles should be used. Similar to the external upper edge portion Rfp, the portion of the expanded area R disposed inward from the upper edge Pf of the printing paper P adjacent to the external upper edge portion Rfp is recorded solely with the nozzles Nr. This portion is referred to as “an internal upper edge portion Rfq.” The external upper edge portion Rfp and internal upper edge portion Rfq are collectively referred to as “the front-edge portion Rf of the expanded area R.” Images are recorded in the external lower edge portion Rrp solely by the nozzles Nf disposed opposite the upstream slot 26f. These nozzles are some of the nozzles provided to the print head 28. Similar to the external lower edge portion Rrp, the portion disposed inward from the lower edge Pr of the printing paper P adjacent to the external lower edge portion Rrp is recorded solely with the nozzles Nf. This portion is referred to as “an internal lower edge portion Rrq.” The external lower edge portion Rrp and internal lower edge portion Rrq are collectively referred to as “the rear-edge portion Rr of the expanded area R.”
The printing paper P4 in
Although the dimensions of either the external upper edge portion Rfp or the internal upper edge portion Rfq or the front-edge portion Rf may be varied herein in accordance with the type of printing paper, it is more preferable to vary the dimensions of both these edges in accordance with the type of printing paper. Similarly, the dimensions of either the external lower edge portion Rrp or the internal lower edge portion Rrq of the rear-edge portion Rr may be varied in accordance with the type of printing paper, but it is more preferable to vary the dimensions of both these edges in accordance with the type of printing paper.
For example, the length Lfp of the external upper edge portion Rfp of printing paper (size: A4; material: P1) in the sub-scanning direction is 3.0 mm, as shown in
Similarly, the length Wa of the external left edge portion Rap of printing paper (size: postcard; material: P1) in the main scanning direction is 1.5 mm, as shown in
In other words, the expanded area table EAT (see
The resolution conversion module 97 establishes the expanded area by referencing an expanded area table EAT containing information of the type such as the one shown in
In the first embodiment, the size of the external upper edge portion Rfp, internal upper edge portion Rfq, external lower edge portion Rrp, and internal lower edge portion Rrq is determined by the size of the print medium, as shown in
Although the above description was made with reference to the lower edge Pr of a printing paper P, the same relation between the expanded area R and the tilting of the printing paper P applies to an area disposed along the upper edge Pf. For the area disposed along the upper edge Pf, the description related to upstream shifting is replaced with a description related to downstream shifting. Specifically, blank spaces are unlikely to form along the edges of the printing paper P when the printing paper P shifts upstream. It is also unlikely that the platen will be soiled by ink droplets when the printing paper P shifts downstream.
In the first embodiment, the size of the external upper edge portion Rfp, internal upper edge portion Rfq, external lower edge portion Rrp, and internal lower edge portion Rrq is determined in accordance with the material and dimensions of the print medium, as shown in
In
Thus, the first embodiment is such that blank spaces are unlikely to form along the edges of the printing paper P when excessive slippage occurs in the direction of sub-scanning, and the printing paper P is shifted downstream. The platen is unlikely to be soiled by ink droplets when the printing paper P shifts downstream. It is also possible to prevent situations in which time is wasted during printing as a result of the fact that ink droplets are ejected over an unnecessarily large area when the print medium is fed with high accuracy in the direction of sub-scanning. Although the above description was made with reference to the lower edge Pr of a printing paper P, the same relation between the expanded area R and the shifting of the printing paper P in the direction of sub-scanning applies to the area disposed along the upper edge Pf.
The expanded area table EAT (see
In step S1 in
For example, the window in
The user can select “high quality” or “high speed” after selecting “recommended settings” option instead of the “high resolution” option from the mode settings, as shown in
The user then clicks the “OK” icon in the lower portion of the window in
In
The operation then proceeds to the intermediate routine and the 5-, 2-, 3-, and 6-dot feed increments are repeated in the order indicated. The system in which sub-scanning is performed by combining different feed increments in this manner is referred to as “non-constant feeding.” Such feeding in the sub-scanning direction allows each raster line (with the exception of some raster lines) to be recorded by two nozzles. In other words, the present embodiment allows each raster line to be printed by two nozzles. In the example shown in
In
In
In the present embodiment, images can be recorded without blank spaces up to the upper edge of the printing paper. As described above, the present embodiment is such that images can be recorded by selecting the fifth and greater raster lines (printable area), as counted from the upstream edge in the sub-scanning direction, from among the raster lines on which dots can be recorded by the nozzles of the print head 28. Consequently, images could theoretically be recorded very close to the upper edge of printing paper by starting dot recording after the printing paper is positioned relative to the print head 28 such that the fifth raster line (as counted from the upper edge) is disposed exactly at the position occupied by the upper edge of the printing paper. There are, however, cases in which the feed increment errors occur during feeding in the sub-scanning direction. There are also cases in which the direction in which ink droplets are ejected shifts away as a result of a manufacturing error or another factor related to the print head. The formation of blank spaces along the upper edge of the printing paper should preferably be prevented in cases in which the position at which the ink droplets are ejected on the printing paper is shifted for these reasons. It is thus assumed with reference to the present embodiment that the image data D used for printing are provided starting from the fifth raster line, which is counted from the upstream edge in the sub-scanning direction and is selected from the raster lines on which dots can be recorded by the nozzles of the print head 28, and that printing is started from a state in which the upper edge of the printing paper P assumes the position occupied by the seventh raster line, as counted from the upstream edge in the sub-scanning direction. Consequently, the prescribed position occupied by the upper edge of the printing paper in relation to each raster line during the start of printing coincides with the position occupied by the seventh raster line, as counted from the upstream edge in the sub-scanning direction (
Specifically, the present embodiment is such that two raster lines are selected for the width Lfp of the external upper edge portion Rfp (see
In
As described above, the upper edge Pf of the printing paper P reaches the position of the seventh raster line (as counted from the upstream edge in the sub-scanning direction), which is one of the raster lines on which dots are recorded by the nozzles of the print head 28. Specifically, it follows from
There are also cases in which the upper edge of the printing paper P reaches the position occupied by the second raster line from the top of the printable area or by the raster line disposed in the uppermost tier of the printable area if the feed increment of the printing paper P exceeds the designed increment for any reason. The same applies to cases in which the printing paper is tilted and the left or right edge assumes a position downstream (in the sub-scanning direction) of the intended position. In such cases, the present embodiment still allows images to be recorded without blank spaces in the edge portions of the printing paper P because nozzle Nos. 1 and 2 eject ink droplets Ip in these raster lines (in the external upper edge portion Rfp specified for a position beyond the upper edge Pf of the printing paper P). Specifically, blank spaces can be prevented from forming along the upper edge of the printing paper P when the feed increment of the printing paper P exceeds the designed increment but the excessive feed increment is still no more than two raster lines, as shown by the dashed line in
Another possibility is that the feed increment of the printing paper P falls short of the designed increment for any reason. In such cases the printing paper fails to arrive at the designated position, and the ink droplets Ip end up depositing on the underlying structure. The same applies to cases in which tilting prevents the printing paper P to arrive at the position initially allocated therefor. In the present embodiment, the two raster lines along the intended upper-edge position of the paper sheet are recorded by nozzle Nos. 1 and 2, as shown in
As described above, it is the CPU 41 that specifies the position of the printing paper P in the sub-scanning direction such that the upper edge Pf of the printing paper P assumes a position above the opening of the downstream slot 26r during sub-scanning, and the upper edge Pf assumes a position upstream of the nozzles at the downstream edge in the sub-scanning direction. Specifically, the CPU 41 functions as “a front-edge positioning unit” shown in
In
In
In the present embodiment, images can be recorded without blank spaces up to the lower edge in the same manner for the upper edge. As described above, the present embodiment is such that images can be recorded by selecting the fifth and greater raster lines (printable area), as counted from the downstream edge in the sub-scanning direction, from among the raster lines that can be used to record dots by the nozzles of the print head 28. It is assumed, however, that images are recorded on the printing paper starting from the seventh raster line (as counted from the downstream edge in the sub-scanning direction) because of considerations related, among other things, to the feed increment errors that occur during feeding in the sub-scanning direction. Specifically, the lower edge of the expanded area R is aligned with the fifth raster line from the downstream edge in the sub-scanning direction, but the lower edge Pr of the printing paper P is aligned with the seventh raster line from the upstream edge in the sub-scanning direction. The two-raster line expanded area R specified for the region beyond the lower edge Pr of the printing paper P is the external lower edge portion Rrp. In the first embodiment, the expanded area R and the printable area coincide because the dots are arranged such that images are formed in all the pixels of the printable area.
If the distance over which the printing paper P is fed falls short of the intended distance for any reason (the dashed line in
The four raster lines (seventh to tenth raster lines from bottom in
As described above, it is the CPU 41 that specifies the position of the printing paper P in the sub-scanning direction such that the lower edge Pr of the printing paper P assumes a position above the opening of the upstream slot 26f during sub-scanning, and the lower edge Pr assumes a position downstream of the nozzles at the upstream edge in the sub-scanning direction. Specifically, the CPU 41 functions as “a rear-edge positioning unit” shown in
(iii) Printing in Left and Right Edge Portions
Performing printing in this manner allows images to be formed without blank spaces along the left and right edges of the printing paper P even when the printing paper P shifts somewhat in the main scanning direction. Because the nozzles positioned above the left slot 26a or right slot 26b are designed for printing images in the two edge portions of the printing paper, ink droplets are allowed to deposit in the left slot 26a or right slot 26b without depositing in the central portion 26c of the platen 26 when the ink droplets miss the printing paper P. It is therefore possible to prevent the printing paper P from being soiled by the ink droplets deposited in the central portion 26c of the platen 26.
The above description was given with reference to a case in which the printing paper that could be used with the printer 22 was a printing paper having maximum width in the sub-scanning direction, but the same reasoning can be applied to narrower printing paper. Specifically, the guides 29a and 29b (see
The present invention is not limited by the above-described embodiments or embodiments and can be implemented in a variety of ways as long as the essence thereof is not compromised. For example, the following modifications are possible.
It was assumed in the first embodiment that the width Wr of the expanded area R could be calculated by adding constant widths Wa and Wb to the width Wp of the print medium irrespective of the type of print medium. It is also possible, however, to adopt an approach in which the width of the portion of the expanded area extending beyond the right and left edges of the print medium is selected in accordance with the type of printing paper. As in the case shown in
Plain paper, photoprint paper, special glossy film, special OHP sheets, and the like were mentioned as the print media in the first embodiment, but the print media is not limited to these materials alone. It is possible, for example, to use fabric or a medium having certain rigidity, such as CD-R. The shape of the print medium is not limited to the rectangular shape alone and may include a circular shape such as that of a CD-R.
In this case, the slots on the platen should match the shape of each type of print medium, and the number of pixels in the raster lines constituting the expanded area should preferably match the shape of the print medium. Any print medium can be used as long as it allows images to be recorded using dot-forming elements.
In the first embodiment, a single left slot was provided, and a plurality of right slots were provided in accordance with the width of the print medium (see
In the first embodiment, the upstream slot 26f was disposed opposite some of the upstream nozzles Nf (see
The first embodiment involved performing constant feeding in 1-dot increments, in accordance with upper- and lower-edge routines. However, the feeding method of the upper- and lower-edge routines is not limited thereby and may include constant feeding in 2-, 4-, or 5-dot increments, depending on the nozzle pitch or the number of nozzles in a nozzle row. In other words, any feeding method may be adopted as long as the maximum feed increment in the sub-scanning direction is less than the maximum feed increment in the sub-scanning direction for the intermediate routine. In should be noted that adopting smaller feed increments in the sub-scanning direction for the upper-edge routine allows the upper edge of printing paper to be recorded with the nozzles disposed further downstream in the sub-scanning direction. The downstream slot can therefore be narrowed, and the upper platen surface for supporting the printing paper can be broadened. Similarly, adopting smaller feed increments in the sub-scanning direction for the lower-edge routine allows the upper edge of printing paper to be recorded with the nozzles disposed further upstream in the sub-scanning direction. The upstream slot can therefore be narrowed, and the upper platen surface for supporting the printing paper can be broadened.
Neither is the feeding method of the intermediate routine limited to an non-constant feeding arrangement in which the system is repeatedly fed in 5-, 2-, 3-, and 6-dot increments in the order indicated. For example, feeding the system in 5-, 3-, 2-, and 6-dot increments may be adopted for the structure described in the first embodiment. Depending on the number of nozzles, the nozzle pitch, or the like, combinations of other feed increments may be adopted, or constant feeding methods involving other feed increments carried out. In other words, any type of secondary scan feeding may be adopted as long as the maximum feed increment in the sub-scanning direction is less than the maximum feed increment in the sub-scanning direction for the upper or lower-edge routine.
Although the above embodiments were described with reference to cases in which both the upper- and lower-edge routine were carried out, it is also possible to perform only one of these routines as needed. In addition, the printing devices of the present embodiments were configured such that the platen 26 was provided with an upstream slot 26f and a downstream slot 26r on the upstream side and downstream sides, respectively, in the sub-scanning direction, although providing only one of them is also acceptable.
Although the above embodiments were described with reference to cases in which images were printed without blank spaces along the left and right edges of a printing paper P, it is also possible to adopt an arrangement in which images are printed only on one side as needed.
The present invention can be adapted to monochromatic printing in addition to color printing. The use of the present invention is not limited to ink-jet printers alone and commonly includes all dot-recording devices in which images are recorded on the surface of a print medium by a print head having a plurality of dot-forming element arrays. As used herein, the term “dot-forming element” refers to a dot-forming constituent element such as an ink nozzle of an ink-jet printer.
The extended area R has a size and shape such that it lies within the printing paper P, that is, the extended area R does not extend beyond the edges of the printing paper P. In modification 8, the shape of the extended area R is rectangular, and its dimensions are defined as follows. The width Wr of the extended area is greater than the horizontal width of the usable area Pu but less than the horizontal width of the printing paper P. Furthermore, the length Lr of the extended area R in the direction of printing paper feeding is greater than the vertical length of the usable area Pu but less than the length of the printing paper P in the direction of printer paper feeding. With this arrangement, printing can be accomplished without staining the platen 26 and without leaving any margin up to the edge of the usable area.
As in the case of the first embodiment shown in
The dimensions of the portion of extended area R in the direction of printing paper feeding, that extend beyond the top and bottom edges Pcf, Pcr of the printing paper P (i.e., extended upper and lower edge portions Rfp and Rrp) depend on the dimension of the usable area Pu in the direction of printing paper feeding and on the material comprising the printing paper P. With this arrangement, the dimensions, in the direction of printing paper feeding, of the extended upper and lower edge portions Rfp and Rrp can be defined according to the slipperiness and cumulative error of the printing paper during paper feeding.
As in the case of the first embodiment, when the sizes of the extended upper and lower edge portions Rfp and Rrp are defined by the number of main scan lines, and when the printing device used has two or more printing modes of differing dot printing resolution in the direction of printing paper feeding, it is preferable thet the number of main scan lines that define the extended upper and lower edge portions Rfp and Rrp is specified according to the printing mode. In such cases, it is preferable that the number of main scanning lines for a given type of printing medium are specified so that the extended upper and lower edge portions Rfp and Rrp in each printing mode have equal size.
In the above embodiments, software can be used to perform some of the functions carried out by hardware, or, conversely, hardware can be used to perform some of the functions carried out by software. For example, a host computer 90 can be used to perform some of the functions carried out by the CPU 41 (
The computer programs for performing such functions may be supplied as programs stored on floppy disks, CD-ROMs, and other types of computer-readable recording media. The host computer 90 may read the computer programs from these recording media and transfer the data to internal or external storage devices. Alternatively, the computer programs can be installed on the host computer 90 from a program-supplying device via a communications line. Computer programs stored by an internal storage device are executed by the host computer 90 when the functions of the computer programs are to be performed. Alternatively, computer programs stored on a storage medium may be executed directly by the host computer 90.
As used herein, the term “host computer 90” refers both to a hardware device and to an operating system, and designates a hardware device capable of operating under the control of an operating system. Computer programs allow such a host computer 90 to perform the functions of the above-described units. Some of the aforementioned functions can be performed by an operating system rather than an application program.
As used herein, the term “computer-readable recording medium” is not limited to a portable recording medium such as a floppy disk or a CD-ROM and includes various RAMs, ROMs, and other internal computer storage devices as well as hard disks and other external storage devices fixed to the computer.
Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.
Number | Date | Country | Kind |
---|---|---|---|
2000-294250 | Sep 2000 | JP | national |
2000-294293 | Sep 2000 | JP | national |
This application is a continuation of, and claims priority under 35 U.S.C. §120, on U.S. application Ser. No. 13/857,049, filed Apr. 4, 2013, which is a continuation of U.S. application Ser. No. 12/198,616, filed Aug. 26, 2008, which is a continuation of U.S. application Ser. No. 11/648,023, filed Dec. 29, 2006 (now U.S. Pat. No. 7,431,423), which is a continuation of U.S. application Ser. No. 11/600,366, filed Nov. 15, 2006 (now U.S. Pat. No. 7,562,955), which is a continuation of U.S. application Ser. No. 10/658,361, filed Sep. 8, 2003 (now U.S. Pat. No. 7,165,827), which is a continuation of U.S. application Ser. No. 09/965,678, filed Sep. 26, 2001 (now U.S. Pat. No. 6,746,101), which claims priority under 35 U.S.C. §119 on Japanese application nos. 2000-294293 and 2000-294250, each filed Sep. 27, 2000. Each of these related applications is incorporated by reference in its entirety.
Number | Date | Country | |
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Parent | 13857049 | Apr 2013 | US |
Child | 14476141 | US | |
Parent | 12198616 | Aug 2008 | US |
Child | 13857049 | US | |
Parent | 11648023 | Dec 2006 | US |
Child | 12198616 | US | |
Parent | 11600366 | Nov 2006 | US |
Child | 11648023 | US | |
Parent | 10658361 | Sep 2003 | US |
Child | 11600366 | US | |
Parent | 09965678 | Sep 2001 | US |
Child | 10658361 | US |