Image processing apparatus generating print data including dot formation states for respective pixels by using image data

Patent metadata

Field	Value
Publication number	US-10137681-B2
Application number	US-201615350419-A
Country	US
Kind code	B2
Filing date	Nov 14, 2016
Priority date	Nov 30, 2015
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

In an image processing apparatus, a controller generates print data using target image data. The print data represents dot formation states classified for respective pixels. Each dot formation state is classified into a one of a plurality of dot types. The controller determines a dot type from a plurality of dot types including a first type dot and second type dot. The first type dot is formed by a first process for supplying a pressure applying section with a specific signal. The second type dot is formed by a second process that is not for supplying the pressure applying section with the specific signal. The first type dot is to be formed in an edge printing area. The first type dot is not to be formed but the second type dot is to be formed in an interior printing area.

First claim

What is claimed is:

1. An image processing apparatus comprising a controller configured to perform:
acquiring target image data;
generating print data using the target image data, the print data representing dot formation states for respective pixels in a printing area, the printing area including an edge printing area and an interior printing area inside the edge printing area, the edge printing area including an outer area outside a recording sheet; and
supplying the print data to a print execution machine, the print execution machine including a plurality of nozzles configured to eject ink droplets; a pressure applying section configured to apply pressure to ink to eject the ink droplets; and a drive section configured to supply a pulse signal to drive the pressure applying section,
wherein the generating print data comprises determining a dot type from a plurality of dot types including a first type dot and second type dot, each of the dot formation states being classified into one of the plurality of dot types,
wherein the first type dot is formed by a first process, the first process being for supplying the pressure applying section with a first drive pulse signal and an additional pulse signal subsequent to the first drive pulse signal, the first drive pulse signal being used to control one of the plurality of nozzles to eject an ink droplet, the additional pulse signal being used to apply pressure to the ink in the one of the plurality of nozzles in a direction opposite to an oscillating direction of a surface of the ink in the one of the plurality of nozzles,
wherein the second type dot is formed by a second process, the second process being for supplying the pressure applying section with a second drive pulse signal without supplying the additional pulse signal, the second drive pulse signal being used to control the one of the plurality of nozzles to eject an ink droplet,
wherein the determining determines that the first type dot is to be formed in the edge printing area, and
wherein the determining determines that the first type dot is not to be formed but the second type dot is to be formed in the interior printing area.

2. The image processing apparatus according to claim 1 , wherein the determining determines that the second type dot is not to be formed in at least a part of outer peripheral area of the edge printing area.

3. The image processing apparatus according to claim 1 , wherein the first type dot is formed by ejecting N number of ink droplets from the one of the plurality of nozzles, where N is a natural number,
wherein the second type dot is formed by ejecting M number of ink droplets from the one of the plurality of nozzles, where M is a natural number,
wherein the N number of ink droplets are capable of reaching a point separated from the one of the plurality of nozzles by a specific distance that is larger than a distance between the recording sheet and the one of the plurality of nozzles, and
wherein the M number of ink droplets are capable of reaching the recording sheet from the one of the plurality of nozzles and incapable of reaching the point.

4. The image processing apparatus according to claim 1 , wherein the additional pulse signal has rectangular-shaped waveform.

5. The image processing apparatus according to claim 1 , wherein each of the first drive pulse signal, the second drive pulse signal, and the additional pulse signal has rectangular-shaped waveform.

6. The image processing apparatus according to claim 1 , wherein the generating print data further includes:
calculating a calibrated gradation value for a target pixel by using a gradation value of the target pixel and an error value concerning at least one pixel other than the target pixel; and
determining dot formation state of the target pixel by comparing the calibrated gradation value with one of a plurality of threshold values, the plurality of threshold values being respectively correlated with the plurality of dot types,
wherein the second type dot includes a first size dot having a first size, and a second size dot having a second size larger than the first size,
wherein the plurality of threshold values including a first type threshold value and a second type threshold value, the first type threshold value being correlated with the first type dot, the second type threshold value includes a first size threshold value and a second size threshold value, the first size threshold value being correlated with the first size dot, the second size threshold value being correlated with the second size dot, the second size threshold value being larger than the first size threshold value,
wherein the determining dot formation state of the target pixel compares the calibrated gradation value with the second size threshold value, with the first type threshold value, and with the first size threshold value, in stated order,
wherein the first type threshold value is equal to the first size threshold value in at least a part of outer peripheral area of the edge printing area, and
wherein the first type threshold value is equal to the second size value in the interior printing area.

7. The image processing apparatus according to claim 5 , wherein the first drive pulse has a sign opposite to a sign of the additional pulse signal, and
wherein the additional pulse signal starts within an interval when the surface of the ink moves in a direction toward exterior of the one of the plurality of nozzles from interior of the one of the plurality of nozzles.

8. The image processing apparatus according to claim 5 , wherein the first drive pulse has a sign same as a sign of the additional pulse signal, and
wherein the additional pulse signal starts within an interval when the surface of the ink moves in a direction toward interior of the one of the plurality of nozzles from exterior of the one of the plurality of nozzles.

9. The image processing apparatus according to claim 8 , wherein the second type dot further includes a third size dot having a third size larger than the first size and smaller than the second size,
wherein the second type threshold value includes a third size threshold value larger than the first size threshold value and smaller than the second size threshold value, the third size threshold value being correlated with the third size dot,
wherein the determining dot formation state of the target pixel compares the calibrated gradation value with the second size threshold value, with the first type threshold value, with the third size threshold value, and with the first size threshold value, in stated order, and
wherein the third size threshold value is equal to the first type threshold value in the at least a part of outer peripheral area of the edge printing area.

10. A non-transitory computer readable storage medium storing a set of program instructions installed on and executed by a computer, the set of program instructions comprising:
acquiring target image data;
generating print data using the target image data, the print data representing dot formation states for respective pixels in a printing area, the printing area including an edge printing area and an interior printing area inside the edge printing area, the edge printing area including an outer area outside a recording sheet; and
supplying the print data to a print execution machine, the print execution machine including a plurality of nozzles configured to eject ink droplets; a pressure applying section configured to apply pressure to ink to eject the ink droplets; and a drive section configured to supply a pulse signal to drive the pressure applying section,
wherein the generating print data comprises determining a dot type from a plurali

Assignees

• Brother Ind Ltd

Inventors

• Yoshida Yasunari

Classifications

• B41J11/0065

  Means for printing without leaving a margin on at least one edge of the copy material, e.g. edge-to-edge printing · CPC title

• B41J2/04586

  controlling heads of a type not covered by groups B41J2/04575 - B41J2/04585, or of an undefined type · CPC title

• B41J2/04581 Primary

  controlling heads based on piezoelectric elements · CPC title

• B41J2/04596

  Non-ejecting pulses · CPC title

• B41J2/04595

  Dot-size modulation by changing the number of drops per dot · CPC title