Abstract: A printing apparatus which avoids the occurrence of banding due to errors of sheet feeding. The apparatus includes a print head with a nozzle array including a plurality of nozzles, a main scan driving unit, a print head driving unit that drives nozzles selected from the array, a sub-scan driving unit that drives the print medium in the sub-scanning direction and a control unit. The control unit controls the main scan driving unit, the sub-scan driving unit and the print head driving unit and also carries out printing on the print medium with the print head. The control procedure of the control unit causes each of the nozzles which are not used in the process of constant pitch sub-scan printing or overlap printing, to create a dot adjoining two dots, where banding is often observed.

Abstract: A printing system of the present invention reduces a total amount of discharge of at least three different color inks that are mixable to express hues in a predetermined range without deteriorating the degree of granularity. The printing system of the invention reads recording ratios of the respective color inks corresponding to input tone data regarding the respective color inks from tables TC, TM, and TY and forms dots according to the recording ratios. Yellow ink Y has a higher dye density than a balancing density that ensures a color balance. This makes the recording ratio of the yellow ink Y lower than the recording ratios of cyan ink C and magenta ink M. The yellow ink Y has high lightness, so that sparely formed dots do not increase the degree of granularity even in an area of low tone data. The enhanced density of the yellow ink Y reduces the total amount of inks discharged from a head to satisfy a required printing density.

Abstract: A specific image is first recorded according to a plurality of dot recording schemes which have an identical resolution and which are different at least in sub-scan feed operations. Then a desired dot recording scheme is selected corresponding to a desired recorded image which has been selected out of a plurality of recorded images recorded according to the plurality of dot recording schemes, and scheme selection information for specifying the desired dot recording scheme is stored into a rewritable non-volatile memory. In actual image recording, the scheme selection information stored in the non-volatile memory is read out, and a desired image is recorded on a recording medium according to the desired dot recording scheme specified by the scheme selection information.

Abstract: An ink jet recording apparatus including a supply roller for supplying a sheet in a sheet feed direction. A carriage is slidably mounted within the ink jet printer for displacement in a scanning direction. A head is mounted on the carriage, and a first ink cartridge containing high color-density inks of a plurality of colors and a second ink cartridge containing low color-density inks of a plurality of colors are mounted on the carriage for supplying ink to the head. First and second ink cartridges are removably attached to the head and may be positioned adjacent to each other in a sheet feed direction, in a scanning direction or in a direction orthogonal to the sheet feed direction and the scanning direction.

Abstract: A specific image is first recorded according to a plurality of dot recording schemes which have an identical resolution and which are different at least in sub-scan feed operations. Then a desired dot recording scheme is selected corresponding to a desired recorded image which has been selected out of a plurality of recorded images recorded according to the plurality of dot recording schemes, and scheme selection information for specifying the desired dot recording scheme is stored into a rewritable non-volatile memory. In actual image recording, the scheme selection information stored in the non-volatile memory is read out, and a desired image is recorded on a recording medium according to the desired dot recording scheme specified by the scheme selection information.

Abstract: A printing system of the present invention reduces a total amount of discharge of at least three different color inks that are mixable to express hues in a predetermined range without deteriorating the degree of granularity. The printing system of the invention reads recording ratios of the respective color inks corresponding to input tone data regarding the respective color inks from tables TC, TM, and TY and forms dots according to the recording ratios. Yellow ink Y has a higher dye density than a balancing density that ensures a color balance. This makes the recording ratio of the yellow ink Y lower than the recording ratios of cyan ink C and magenta ink M. The yellow ink Y has high lightness, so that sparely formed dots do not increase the degree of granularity even in an area of low tone data. The enhanced density of the yellow ink Y reduces the total amount of inks discharged from a head to satisfy a required printing density.

Abstract: The technique of the present invention utilizes two different inks that are mixed with each other to express an achromatic color, in order to reduce the degree of granularity while decreasing the total quantity of inks. The black ink used in the present invention to create dots of black color is mixing black ink (Bk) that contains magenta and yellow dyes as well as a black dye, such as Food black, and thereby has a less quantity of the black dye. In order to express black color, dots of the mixing black ink (Bk) are mixed with dots of cyan ink (C), which compensates for a certain hue that is insufficient in a black color expressed by the mixing black ink (Bk). The mixing black ink (Bk) has higher lightness than a conventional real black ink and thereby reduces the degree of granularity in a resulting printed image.

Abstract: The present invention prevents deterioration of the quality in interlace printing. The printing system of the present invention uses a head that regulates the amount of ink spouting from nozzles and forms dots of different diameters. While the diameter of dots formed in one primary scan is restricted to a fixed value, the system of the present invention enables dots of different diameters to coexist at an appropriate ratio, thereby improving the printing quality. The printing system of the present invention shifts a nozzle array, in which nozzles are arranged at intervals of a predetermined dot pitch, by a predetermined amount in the secondary scanning direction and varies the dot diameter on every primary scan, while controlling the nozzles in an overlapping state. This enables the dots of different diameters to coexist in a specified area.

Abstract: In a printer that allows dual-way printing, a test pattern is formed to adjust the print timing with a high accuracy, or more concretely to eliminate a deviation of dots created in the course of a main scan in a backward direction from dots created in the course of the main scan in a forward direction. The test pattern is based on a normal dither matrix. The test pattern includes a plurality of dots that are regularly arranged both in a main scanning direction and in a sub-scanning direction. When the test pattern is printed at an appropriate timing, it is observed as a substantially homogeneous state without unevenness of the density. In case that the dot print timing is deviated, on the other hand, a deviation in dot interval causes unevenness of the density. The deviation of the dot print timing is accurately detected, based on the presence or the non-presence of such unevenness of the density.

Abstract: In accordance with the invention, in order to increase the volume of an ink cartridge containing color inks, to prevent the ink cartridge from being improperly mounted on a print head, to ensure that required rigidity of an ink cartridge, and to ensure the viscosities of different inks remain uniform, in an ink cartridge body, a plurality of ink chambers are arranged in at least two linear arrays, and ink supplying ports associated with the ink chambers are also arranged in two linear arrays, whereby the size of the ink cartridge can be reduced, and easy loading of the ink cartridge can be insured. Additionally, the ink supply ports may be arranged in a zig-zag, offset manner to allow for a further reduction in the size of the ink chambers and ink cartridge. The open outer ends of the ink supply ports are formed substantially flush with the bottom walls of the ink chambers. Therefore, the volumes of each of the ink chambers is increased.

Abstract: Integers that are no less than 2 and relatively prime are selected for the nozzle pitch k and the number of effective nozzles Neff which represents the net number of raster lines in a main scanning direction recorded by one main scan,. A plurality of different values are used in combination for the sub-scan feed amount L. It is preferable to select the plurality of different values for the sub-scan feed amount L in such a manner that the offset G, which is a remainder obtained by dividing each value by the nozzle pitch k, is fixed to a constant value. The offset G preferably takes a value in the range of 2 to (k−2).

Abstract: The printing apparatus of the present invention adopts the technique of effectively utilizing two or more different types of dots having different ink densities and different ink weights. The printing apparatus has a head that provides inks of different densities with respect to at least one color and creates dots of different diameters. The density per unit area is varied by changing the combination of the ink density and the dot diameter. In the half tone area, the lightness of smaller dark dots is made substantially coincident with the lightness of larger light dots. Both the smaller dark dots and the larger light dots are created in the half tone, so as to prevent the banding from occurring in a resulting printed image. The smaller dark dots and the larger light dots may be arranged according to a predetermined pattern or at random. The pattern should be set by taking into account the ink duty of the recording paper.

Abstract: The pitch k of dot-forming elements is set at a product m·n of two integers m and n (where m an n are integers of no less than 2). The sub-scan feed is executed by plural sub-scan feed sets, each consisting of m sub-scan feeds. When feed amounts of the m sub-scan feeds in each sub-scan feed set are expressed as Li dots (where i is an integer of 1 to m), the following (1) and (2) hold: (1) the feed amounts Li (i=1 to (m−1)) at first through (m−1)-th sub-scan feeds are established so that a remainder obtained by dividing each feed amount Li by the pitch k is equal to the integer n; (2) a feed amount Lm in the m-th sub-scan is established so that a remainder obtained by dividing the feed amount Lm by the pitch k is an integer that is different from a value n·j that is j times the integer n (where j denotes an arbitrary integer).

Abstract: The structure of the present invention effectively prevents banding and enables high-quality printing in a printer which carries out secondary scans in the interlacing manner and thereby prints an image. The printer of the present invention has a print head with a plurality of nozzle arrays formed thereon. Each nozzle array includes a plurality of nozzles arranged at predetermined pitches in the secondary scanning direction. The printer records an image by the interlacing method using part of the nozzles in each nozzle array. The nozzle block in the nozzle array used for formation of dots is changed in every primary scan, and the amount of feed in secondary scan is varied with the change of the nozzle block. Both the nozzle block and the amount of secondary scan are periodically changed in preset sequences. The variation in amount of secondary scan reduces the banding due to the accumulated errors in secondary scans.

Abstract: One of ink chambers 102 of an ink cartridge 70 has a larger volume. The color ink having the largest lightness value is stored in this ink chamber. For the amounts vc1, vc2, vm1 and vm2 of light and deep cyan and magenta inks contained in the ink chambers thereof, the amount vy of the ink having the largest lightness value contained in the cartridge thereof, or the yellow, is defined as:vy<vc1+vc2, and vy<vm1+vm2;Vc1<vy<Vc1+vc2, and Vm1<vy<vm1+vm2.When a natural picture or a graph painted with different monocolors are actually printed, those color inks are substantially uniformly used. There is no case where one ink is used up earlier than the remaining ones, and the color ink cartridge 70b must be replaced with a new one in a state that large amounts of the remaining inks are still left.

Abstract: A dot forming element array is driven during each main scan to enable successive formation in the main scanning direction of sets of N dots formed substantially along a straight line in a sub-scanning direction at intermittent timing which enables the dot forming element array conducting a scan in the main scanning direction to form a prescribed number of sets of N dots and thereafter disables it from forming dots for (s-1) dot positions (s being an integer greater than 1). An adjustment for shifting the recording positions of the sets of N of dots in the main scanning direction by an integral multiple of the dot pitch w from a prescribed basic position is effected in at least some main scans to enable servicing of multiple dot positions in a desired recording region on the recording medium.

Abstract: A color ink jet printer having high throughput and a high-quality printing capability is disclosed. Nozzle arrays for spouting black ink, cyan ink, magenta ink, and yellow ink are placed on a print head. Each of the nozzle arrays has N nozzles arranged in a vertical scanning direction at intervals of k times the dot pitch of a print image. The nozzles are driven at intermittent timing during the horizontal scanning of the print head for forming dots at intervals of s times the dot pitch. At the termination of the horizontal scanning, vertical scanning is executed by a given distance. The vertical scanning distance L is set so as to satisfy the following expression:L=N/(s.multidot.D.multidot.k)wherein s is an arbitrary integer greater than one and less than N, and a submultiple of N, k is an arbitrary integer greater than one and less than N having prime relation with N/s, and D is the number of nozzles existing per unit distance in the vertical scanning direction.

Abstract: The present invention utilizes a high-density ink and a low-density ink with respect to a specific color ink, so as to improve the printing quality. The procedure of the present invention reads a recording ratio of deep dots by the high-density ink corresponding to input tone data from a table and determines whether or not deep dots by the high-density ink are to be formed in a target pixel. In case that deep dots are to be formed, a piezoelectric element PE on a head of the high-density ink is driven to form deep dots. In case that deep dots are not to be formed, on the other hand, the procedure determines whether or not light dots by the low-density ink are to be formed in the target pixel by referring to the table, and specifies the on/off state of the light dots in order to cause a mean recording ratio of the light dots to be equal to a predetermined value.