Abstract: In monochromatic printing, a recording method for middle area processing is utilized in the middle portion of the recording execution area, and bottom processing, in which the sub-scanning feed amount is smaller than in the middle area processing, is applied in the vicinity of the rear end of the recording execution area. Meanwhile, in color printing, the same recording method is applied in both the middle portion and the vicinity of the rear end of the recording execution area.

Abstract: A shape of the drive signal within each one-pixel period of main scan is modified to have N different waveforms corresponding to N different values of the print signal, the N different values of the print signal representing formation of the N different dots. The N different waveforms of the drive signal are changed between the forward pass and the reverse pass. This will align the hitting positions of ink droplets in the main scanning direction during forward and reverse passes.

Abstract: The sub-scanning drive section includes a first sub-scanning drive mechanism of a relatively high precision, and a second sub-scanning drive mechanism of a relatively low precision. An actuator 40 of a print head 36 is provided with a black nozzle array 40K and a color nozzle array. The color nozzle array is arranged so that at an arbitrary point on a print medium yellow dots are formed after dots of other chromatic colors. During color printing, when the print medium is being fed at a low precision in the vicinity of the trailing edge of the print medium, only the yellow nozzles are used to form dots.

Abstract: The present invention generates voltage signals or driving waveforms to actuate driving elements of a print head according to the programmable generation method discussed below. The procedure first provides a first memory area and a second memory area, in which driving waveform data used to generate the driving waveforms are stored. Different sets of the driving waveform data are stored in the respective memory areas. The procedure selects a working memory area at a predetermined interval of selection and carries out arithmetic operations using the set of driving waveform data stored in the selected working memory area, so as to generate a driving waveform signal. The selective use of the working memory area enables the resulting driving waveform to be switched over at a high speed at the predetermined interval of selection. The two memory areas may be constructed by separate memory chips.

Abstract: A printing method drives each of the n(j) number of nozzles to enable the nozzle to form dots intermittently at a rate of one in m×q dot positions on the j-th main scan line during one main scan, where m is an integer of 1 or more, and q is an integer of 2 or more, to thereby complete dot formation on the j-th main scan line with the n(j) number of nozzles during n(j) number of main scans. The printing method attains high recording speed and high image quality, comparing to cases when all main scan lines are recorded using a fixed number of nozzles.

Abstract: An inkjet printer uses interlaced printing to form raster lines at intervals in the sub-scanning direction. The paper is transported by feed rollers on the upstream side relative to the sub-scanning, and ejection rollers on the downstream side. After the trailing edge of the paper clears the feed rollers, it is printed while being moved in the sub-scan direction by just the ejection rollers. The feed used for the interlaced printing is set at an amount that produces an area between a high-precision area of raster lines formed using the feed rollers to effect sub-scanning, and a low-precision area in which the raster lines are formed using just the ejection rollers to effect sub-scanning. The area thus includes raster lines from both of the other areas. Performing sub-scanning at that feed amount makes the difference in quality between the high-precision area and the low-precision area less noticeable, making it possible to increase the size of the printable area.

Abstract: The sub-scanning drive section includes a first sub-scanning drive mechanism of a relatively high precision, and a second sub-scanning drive mechanism of a relatively low precision. An actuator 40 of a print head 36 is provided with a black nozzle array 40K and a color nozzle array. The color nozzle array is arranged so that at an arbitrary point on a print medium yellow dots are formed after dots of other chromatic colors. During color printing, when the print medium is being fed at a low precision in the vicinity of the trailing edge of the print medium, only the yellow nozzles are used to form dots.

Abstract: A print head has a nozzle array to achieve printing of dots of identical color along a plurality of main scanning lines during a main scanning pass, and to achieve formation of multiple dots of the color at a substantially fixed pitch in a sub-scanning direction. Partial overlap printing is effected, using a specific part of the plurality of dot forming elements, by executing dot printing in one main scanning pass on at least one target main scanning line which is also a target of dot printing during another main scanning pass.

Abstract: In a multi-level printer that enables a plurality of dots to be created in each pixel, the technique of the present invention reduces the unevenness of density and the roughness due to localization of dots in each pixel. The principle of the present invention is applicable to, for example, an ink jet printer that enables ink to be ejected successively in each pixel in the course of the main scan. Multiple tones are expressible in each pixel corresponding to the number of dots created therein. A dot formation pattern is set in such a manner that the center of all dots to be created in each pixel is substantially coincident with the center of the pixel. This arrangement effectively interferes with the localization of dots in each pixel and thereby reduces the unevenness of density and the roughness.

Abstract: In an ink jet recording apparatus 1, a fixing signal output section 461 outputs a signal indicating that no ink drop is jetted as a mode fixing signal SP to a head driver circuit 50 for nozzle orifices 111 belonging to the group not used for recording, and a mode fixing circuit 18 of the head driver circuit 50 fixes the nozzle orifices belonging to the corresponding group to a condition of jetting no ink drops based on the mode fixing signal SP. Therefore, serial conversion and serial transfer of the data indicating that no ink is jetted (“0” data) as record data SI need not be executed for the group of jetting no ink drops, so that fruitless processing time can be eliminated.

Abstract: In a conventional printer that enables creation of different types of dots having different sizes, banding often appears in a certain area where only small-diametral dots are created. In a multi-value printer that enables creation of both a large dot and a small dot, the technique of the present invention stores in advance the relations between the recording ratios of the large dot and the small dot and the tone value into a ROM and carries out a multi-valuing process based on the relations. In a certain area where only small dots are created, a conspicuous banding often appears when the recording ratio of the small dot exceeds a certain upper limit value. Large dots are accordingly mixed with small dots in a specific area where the recording ratio of the small dot exceeds the upper limit value. The upper limit value depends upon a printing condition including the type of a printing medium, so that the recording ratios of the respective dots are set corresponding to each printing condition.

Abstract: The recording technique of the present invention is applied to a printer that has a print head, which causes a partial area of main scan to have a lower positional accuracy of dot creation, and carries out bi-directional printing, which causes the print head to create dots on a printing medium in both forward and backward passes of the main scan. The recording technique records dots in such a manner that forward pass dots created in the forward pass of the main scan and backward pass dots created in the backward pass of the main scan are present at substantially equal rates in at least specific areas close to both ends of the main scan. This arrangement of the present invention desirably improves the printing quality in the case of bi-directional printing.

Abstract: The print head has a first nozzle array and a second nozzle array. The first nozzle array includes a plurality of chromatic color nozzle groups, arranged in the sub-scanning direction, for forming dots of different inks. The second nozzle array includes a plurality of nozzles, arranged parallel to the first nozzle array, for forming black dots, where each of the plurality of chromatic color nozzle groups has an equal number of nozzles. The second nozzle array includes at least a plurality of nozzles disposed at the same sub-scanning positions as the nozzles included in the plurality of chromatic color nozzle groups. In color printing, dots are formed on the print medium using a mutually equal number N (where N is an integer of at least 2) of the nozzles of each chromatic color nozzle group, and of the plurality of nozzles included in the second nozzle array, j sets (where j is an integer of at least 1) of black nozzles, each comprised of N nozzles, are used to form black dots.

Abstract: In monochrome printing mode, a first correction value is set for correcting printing positional deviation between ink droplets printed during forward and reverse main scanning passes. In color printing mode, a second correction value is set for correcting printing positional deviation between ink droplets printed during forward and reverse main scanning passes. An adjustment value is determined for reducing printing positional deviation during forward and reverse main scanning passes. For this, in monochrome printing mode the first correction value is used as an adjustment value, and in color printing mode at least a second correction value is used to determine an adjustment value. Following this, the adjustment value is used to adjust printing positions during forward and reverse main scanning passes.

Abstract: A printing head includes a first type nozzle groups for ejecting respective inks of a first ink group, and a second type nozzle group for ejecting respective inks of a second ink group. The second type nozzle group includes twice the number of nozzles in the first type nozzle group. On the forward passes of the main scanning, ink droplets are ejected from both the first type nozzle group and the second type nozzle group. On the reverse passes of the main scanning, ink droplets are ejected from only from the first type nozzle group. With respect to the first type nozzle group, the ejection timing of the ink droplets is corrected on the reverse passes of the main scanning on the basis of a specific correction value for dot misalignment.

Abstract: A print head has a nozzle array to achieve printing of dots of identical color along a plurality of main scanning lines during a main scanning pass, and to achieve formation of multiple dots of the color at a substantially fixed pitch in a sub-scanning direction. Partial overlap printing is effected, using a specific part of the plurality of dot forming elements, by executing dot printing in one main scanning pass on at least one target main scanning line which is also a target of dot printing during another main scanning pass.

Abstract: In an inkjet printer controlled by a program in a recording medium, the interlace method is applied to record an image in a first area where the rollers in the feeding section ensure the accuracy of sheet feeding, in order to attain the high picture quality. A printable area where an image can be recorded is extended to a second area, where rollers in a delivering section are used to carry out the sheet feeding of relatively low accuracy after the lower end of the printing medium comes off the rollers in the feeding section. The second area does not directly adjoin to the first area, but there is a middle area that adjoins to both the first area and the second area and enables image recording with sufficient accuracy of sheet feeding.

Abstract: A print head has a nozzle array to achieve printing of dots of identical color along a plurality of main scanning lines during a main scanning pass, and to achieve formation of multiple dots of the color at a substantially fixed pitch in a sub-scanning direction. Partial overlap printing is effected, using a specific part of the plurality of dot forming elements, by executing dot printing in one main scanning pass on at least one target main scanning line which is also a target of dot printing during another main scanning pass.

Abstract: Image quality is improved by correcting printing position deviation arising between forward and reverse passes in the main scanning direction during bidirectional printing. An adjustment value is prepared with respect to at least one type of specific target dots other than those dots having the highest density out of the plural types of dots. Printing positions during forward and reverse main scanning passes are adjusted with the adjustment value to reduce printing positional deviation between forward and reverse main scanning passes.

Abstract: The technique of extending a printable area, in which an image can be recorded, by carrying out a sub-scan with rollers in a delivering section of a printer having a lower accuracy of sheet feeding often causes dropout of raster lines and thereby deteriorates the picture quality of a resulting printed image. In an ink jet printer of the present invention, the interlace method is applied to record an image in a first area where rollers in a feeding section ensure the accuracy of sheet feeding, in order to attain the high picture quality. The printable area Is extended to a second area, where the rollers in the delivering section are used to carry out the sheet feeding of the lower accuracy after the lower end of a printing medium comes off the rollers in the feeding section. In the present invention, recording of dots is carried out by the interlace method with a reduced number of working nozzles in the second area. This decreases each amount of sub-scan and thereby reduces an error in sheet feeding.