An image forming apparatus includes an image processor, a converter, a light source driver, an identifying unit, and a pattern generator. The image processor generates image data of first resolution and generates tag information indicating whether to perform image processing and associated with pixels of the image data of first resolution. The converter converts the image data of first resolution to image data of a higher second resolution. The light source driver drives a light source using a modulation signal corresponding to the image data of second resolution. The identifying unit identifies a target pixel to be subjected to image processing in the image data of first resolution based on the tag information. The pattern generator generates an image-processed pixel pattern of the second resolution according to the target pixel. The converter converts the target pixel in the image data of first resolution to the generated image-processed pixel pattern.

An image forming apparatus includes an image processor, a converter, a light source driver, an identifying unit, and a pattern generator. The image processor generates image data of first resolution and generates tag information indicating whether to perform image processing and associated with pixels of the image data of first resolution. The converter converts the image data of first resolution to image data of a higher second resolution. The light source driver drives a light source using a modulation signal corresponding to the image data of second resolution. The identifying unit identifies a target pixel to be subjected to image processing in the image data of first resolution based on the tag information. The pattern generator generates an image-processed pixel pattern of the second resolution according to the target pixel. The converter converts the target pixel in the image data of first resolution to the generated image-processed pixel pattern.

A redundantly printed security-enhanced document, printing method and system are provided for ensuring the meaning of the information imparted by variable indicia printed on documents with removable scratch-off coatings by the redundant printing. By printing the variable indicia with multiple colors, redundancy and integrity of the intended indicia is achieved. Additionally, inverted color indicia countermeasures to pinprick attacks are also disclosed. The redundantly printed document, methods and systems enhance the overall appearance of the redundantly printed document, and reduce the consequences possibly resulting from misprinted variable indicia.

A printer performs a multi-pass printing including: (a) pass process executed with Ka number of nozzles; (c1) pass process executed with Kc1 number of nozzles; (c2) pass process executed with Kc2 number of nozzles; and (b) pass process executed with Kb number of nozzles. Kc1 and Kc2 are greater than or equal to Kb and smaller than Ka. An upstream gradient of dot recording rates of (c1) pass process is greater than a gradient of (a) pass process. A downstream gradient of (c1) pass process is the same as the gradient of (a) pass process. An upstream gradient of (c2)-pass process is the same as a gradient of (b) pass process. A downstream gradient of (c2)-pass process is greater than the gradient of the (a) pass process. Kc1 is greater than Kc2.

A method in a page-wide array printing apparatus comprising at least first and second printing dies that overlap in a page width direction comprises the steps of calibrating the printing apparatus in a media advance direction to a higher resolution than the page width direction, the media advance direction being perpendicular to the page width direction, and using printing masks to control the operation of a plurality of nozzles in an overlap area between the first and second printing dies to reduce any visible defects caused by dot placement errors in the page width direction.

A method in a page-wide array printing apparatus comprising at least first and second printing dies that overlap in a page width direction comprises the steps of calibrating the printing apparatus in a media advance direction to a higher resolution than the page width direction, the media advance direction being perpendicular to the page width direction, and using printing masks to control the operation of a plurality of nozzles in an overlap area between the first and second printing dies to reduce any visible defects caused by dot placement errors in the page width direction.

In an image forming apparatus (an ink jet printer 100), in a sub scanning direction, when an area in arrange of a nozzle at an end portion of a head (41) to a nozzle at a predetermined distance is set as a predetermined area, and a medium is transported in a certain amount by using the head (41), a scan portion, and a transport portion so as to form an image on medium sheet (10), the number of times of scanning for forming a dot array which is formed by using the nozzles included in the predetermined area is more than the number of times of the scanning for forming a dot array which does not use the nozzle in the predetermined area, and the number of times of the scanning for forming the dot array by using the nozzles included in the predetermined area is at least three times.

A method and apparatus for subdividing and printing regions of a substrate with multiple print heads or multiple print head assemblies which substantially decreases printing time is described. The method includes a feathering method which reduces overlap artifacts which is useful in any printing situation where adjacent regions are printed that could be misaligned, offset, or have slightly different colors.

In an image forming apparatus (an ink jet printer 100), in a sub scanning direction, when an area in arrange of a nozzle at an end portion of a head (41) to a nozzle at a predetermined distance is set as a predetermined area, and a medium is transported in a certain amount by using the head (41), a scan portion, and a transport portion so as to form an image on medium sheet (10), the number of times of scanning for forming a dot array which is formed by using the nozzles included in the predetermined area is more than the number of times of the scanning for forming a dot array which does not use the nozzle in the predetermined area, and the number of times of the scanning for forming the dot array by using the nozzles included in the predetermined area is at least three times.

When a corrected pixel value of a target pixel is within a first range and the target pixel is not a prohibited pixel, a first value indicating formation of a dot of a first type having a minimum size is determined as a pixel value of a print pixel corresponding to the target pixel. When the corrected pixel value is within a second range different from the first range and the target pixel is not the prohibited pixel, a second value indicating formation of a dot of a second type having a size greater than the dot of the first type is determined as the pixel value of the print pixel. When the corrected pixel value is within the first range and the target pixel is the prohibited pixel, a non-formation value indicating formation of no dots is determined as the pixel value of the print pixel