Abstract: An ink-jet printing device according to the present invention includes: first and second nozzles each configured to discharge ink droplets onto a recording medium being conveyed; a calculation unit to calculate a landing position difference on the recording medium being conveyed at a conveyance speed based on first and second conveyance speeds and first and second landing position differences; and a timing control unit to control each of timings of ink droplet discharge from the first and second nozzles based on the landing position difference calculated by the calculation unit. This configuration allows appropriate correction of variance in the landing positions of ink droplets discharged from the nozzles.

Abstract: A liquid ejecting device includes: a piezoelectric element that is deformed by applying at least one drive waveform among a plurality of drive waveforms to the piezoelectric element, the plurality of drive waveforms including a first drive waveform and a second drive waveform; a cavity that is filled with a liquid and is increased or decreased in internal pressure due to deformation of the piezoelectric element; a nozzle that communicates with the cavity, and ejects the liquid as a liquid droplet; and a selection section that selects at least one drive waveform from the plurality of drive waveforms, the liquid droplet including a first liquid droplet ejected when the first drive waveform has been selected, and a second liquid droplet ejected when the second drive waveform has been selected, an ejection volume of the first liquid droplet being almost equal to an ejection volume of the second liquid droplet.

Abstract: An ink-jet printing device according to the present invention includes: first and second nozzles each configured to discharge ink droplets onto a recording medium being conveyed; a calculation unit to calculate a landing position difference on the recording medium being conveyed at a conveyance speed based on first and second conveyance speeds and first and second landing position differences; and a timing control unit to control each of timings of ink droplet discharge from the first and second nozzles based on the landing position difference calculated by the calculation unit. This configuration allows appropriate correction of variance in the landing positions of ink droplets discharged from the nozzles.

Abstract: A liquid ejecting device includes: a piezoelectric element that is deformed by applying at least one drive waveform among a plurality of drive waveforms to the piezoelectric element, the plurality of drive waveforms including a first drive waveform and a second drive waveform; a cavity that is filled with a liquid and is increased or decreased in internal pressure due to deformation of the piezoelectric element; a nozzle that communicates with the cavity, and ejects the liquid as a liquid droplet; and a selection section that selects at least one drive waveform from the plurality of drive waveforms, the liquid droplet including a first liquid droplet ejected when the first drive waveform has been selected, and a second liquid droplet ejected when the second drive waveform has been selected, an ejection volume of the first liquid droplet being almost equal to an ejection volume of the second liquid droplet.

Abstract: A liquid ejecting device includes: a piezoelectric element that is deformed by applying at least one drive waveform among a plurality of drive waveforms to the piezoelectric element, the plurality of drive waveforms including a first drive waveform and a second drive waveform; a cavity that is filled with a liquid and is increased or decreased in internal pressure due to deformation of the piezoelectric element; a nozzle that communicates with the cavity, and ejects the liquid as a liquid droplet; and a selection section that selects at least one drive waveform from the plurality of drive waveforms, the liquid droplet including a first liquid droplet ejected when the first drive waveform has been selected, and a second liquid droplet ejected when the second drive waveform has been selected, an ejection volume of the first liquid droplet being almost equal to an ejection volume of the second liquid droplet.

Abstract: In a head part of inkjet printer, a leading droplet and a following droplet are ejected from an outlet by inputting one driving signal, and the leading droplet and the following droplet land onto a recording paper. At this time, a waveform of the driving signal is set such that an average of distance from the center of a main dot element formed by the leading droplet to the farthest point in a group of dot elements formed by the leading droplet and the following droplet is equal to or more than 1.1 times an average of radius of the main dot element and equal to or less than 3.0 times the average. Therefore, the dot shape can be made noncircular, and as the result, it is possible to suppress jaggies on edges of an image on the recording paper and lowering of density in a solid area.

Abstract: A liquid ejecting device includes: a piezoelectric element that is deformed by applying at least one drive waveform among a plurality of drive waveforms to the piezoelectric element, the plurality of drive waveforms including a first drive waveform and a second drive waveform; a cavity that is filled with a liquid and is increased or decreased in internal pressure due to deformation of the piezoelectric element; a nozzle that communicates with the cavity, and ejects the liquid as a liquid droplet; and a selection section that selects at least one drive waveform from the plurality of drive waveforms, the liquid droplet including a first liquid droplet ejected when the first drive waveform has been selected, and a second liquid droplet ejected when the second drive waveform has been selected, an ejection volume of the first liquid droplet being almost equal to an ejection volume of the second liquid droplet.

Abstract: In an inkjet printer, an ejecting part for K color is previously selected as an ejecting part for outputting three values used for formation of a large dot, formation of a medium dot, and non-ejection (step S12). In the course of image recording (steps S13, S14, and S15), three values are output regarding K color, and four values used for formation of a large dot, formation of a medium dot, formation of a small dot, and non-ejection are output regarding C, M, and Y colors. Thus, even if the quality of a dot in K color is reduced at the time of outputting four values, a high-quality dot can be formed regarding K color, so that the quality of a recorded image can be improved in a case where line drawing or a character or the like is recorded.

Abstract: In an inkjet printer, for forming a large dot on a recording paper in the course of image recording, a second ejection pulse (721) and a first ejection pulse (713) are selected from a basic waveform (70), as a driving signal. For forming a medium dot, a first minute pulse (711) and the first ejection pulse (713) are selected. For forming a small dot, a third ejection pulse (722) is selected. At the time of non-ejection, a second minute pulse (712) is selected. As a result, by adjusting the waveform of the first minute pulse (711), it is possible to form high-quality dots of respective sizes while shortening a driving cycle with the use of the first ejection pulse (713) for forming a large dot and a medium dot.

Abstract: In an inkjet printer, an ejecting part for K color is previously selected as an ejecting part for outputting three values used for formation of a large dot, formation of a medium dot, and non-ejection (step S12). In the course of image recording (steps S13, S14, and S15), three values are output regarding K color, and four values used for formation of a large dot, formation of a medium dot, formation of a small dot, and non-ejection are output regarding C, M, and Y colors. Thus, even if the quality of a dot in K color is reduced at the time of outputting four values, a high-quality dot can be formed regarding K color, so that the quality of a recorded image can be improved in a case where line drawing or a character or the like is recorded.

Abstract: In an inkjet printer, for forming a large dot on a recording paper in the course of image recording, a second ejection pulse (721) and a first ejection pulse (713) are selected from a basic waveform (70), as a driving signal. For forming a medium dot, a first minute pulse (711) and the first ejection pulse (713) are selected. For forming a small dot, a third ejection pulse (722) is selected. At the time of non-ejection, a second minute pulse (712) is selected. As a result, by adjusting the waveform of the first minute pulse (711), it is possible to form high-quality dots of respective sizes while shortening a driving cycle with the use of the first ejection pulse (713) for forming a large dot and a medium dot.

Abstract: In recording an image by an inkjet printer, when not forming a dot on a recording paper, non-ejection operation of droplet is performed in a head part by a non-ejection pulse (P21) which indicates the non-ejection operation and which is included in each driving signal, and when forming a medium dot, a droplet(s) is ejected from an outlet by the non-ejection pulse (P21) and an ejection pulse (P12) included in the driving signal. It is therefore possible to appropriately form dots having a desired size without adding any ejection pulse to the driving signal in high-speed image recording.

Abstract: In a head part of inkjet printer, a leading droplet and a following droplet are ejected from an outlet by inputting one driving signal, and the leading droplet and the following droplet land onto a recording paper. At this time, a waveform of the driving signal is set such that an average of distance from the center of a main dot element formed by the leading droplet to the farthest point in a group of dot elements formed by the leading droplet and the following droplet is equal to or more than 1.1 times an average of radius of the main dot element and equal to or less than 3.0 times the average. Therefore, the dot shape can be made noncircular, and as the result, it is possible to suppress jaggies on edges of an image on the recording paper and lowering of density in a solid area.

Abstract: A timing signal generator generates an ejection timing signal each time a printing paper travels a predetermined distance relative to a head, and a driving signal generator inputs a driving signal based on writing data to the head each time an ejection timing signal is generated. In the course of printing, when an interval between two continuous ejection timing signals is equal to or longer than twice a basic time period of input of driving signal which is fixed for a head, a non-ejection driving signal which is a driving signal indicating a non-ejecting operation is input to the head between two driving signals respectively associated the two continuous ejection timing signals. Accordingly, it is possible to reliably and properly perform ejection of ink based on writing data with a time period equal to or longer than the basic time period.

Abstract: A timing signal generator generates an ejection timing signal each time a printing paper travels a predetermined distance relative to a head, and a driving signal generator inputs a driving signal based on writing data to the head each time an ejection timing signal is generated. In the course of printing, when an interval between two continuous ejection timing signals is equal to or longer than twice a basic time period of input of driving signal which is fixed for a head, a non-ejection driving signal which is a driving signal indicating a non-ejecting operation is input to the head between two driving signals respectively associated the two continuous ejection timing signals. Accordingly, it is possible to reliably and properly perform ejection of ink based on writing data with a time period equal to or longer than the basic time period.

Abstract: A CPU calculates an optimum inclination angle, an optimum movingspeed (V.sub.X) and an optimum displacement time of delay timing on the basis of input signals commanding resolution, a rotation cycle (T) and the number of beams, supplied from an operating part, and outputs a control signal (V.sub.CONT4) providing the inclination angle to a motor (9). As the result, an LED holder (30) rotates with respect to a central axis (37) at the inclination angle and stops. A zoom lens (24) is adjusted by a control signal (V.sub.CONT3) providing a magnification which is responsive to the resolution. A motor (7) is driven by a control signal (V.sub.CONT2), to drive an exposure head (20) at the moving speed (V.sub.X). A cylinder (36) rotates by a control signal (V.sub.CONT1) in a subscanning direction (Y) at the rotation cycle (T). As the result, an image forming region (34) is inclined with respect to the central axis (37) at the inclination angle.

Abstract: The present invention relates to an image reader 3 which reads the reflected light obtained by lightening from underneath a transparency board 6 on which an image original is placed, especially a cover 30 for the image reader 3 for adjusting the bend of the image original. The cover 30 comprise a vacuum pump (not shown) for reducing the air pressure in the space formed by the transparency board 6 and a bend member 48 and an airtight member 50. Therefore the image reader 3 utilizing the cover 30 can correctly read image on both a transparency original and a reflection original, and yet be easy to manipulate when reading the reflection original.

Abstract: An amount of a read position error in the subscanning direction between line image sensors (for example, CCD1, CCD2, CCD3) is obtained by initially scanning and reading a correction read pattern (6a, 6b). In scanning of an original, output image signals from the line image sensors (CCD1, CCD2, CCD3) are relatively delayed by a line number corresponding to the amount of the read position error between the line image sensors (CCD1, CCD2, CCD3), to correct time difference, caused by the read position error, in information reading in the boundary portion of the line image sensors. An arrangement of line memories is also provided for correcting angular deviations of the line image sensors.