an elongated print head (22,23,24,25) with a longitudinal axis, comprising at least a first array (16) of marking elements and a second array (17) of marking elements for printing different colours, each array of marking elements comprising a set of equally spaced active marking elements (12,13,14,15); a mechanism to transporting the receiver relative to the printhead in between the printing steps;
ideal printing efficiency is obtained when a first active marking element of the first array (16) of marking elements (12) of the printhead is spaced apart in the direction of the longitudinal axis from a first active marking element of the second array (17) of marking elements of the printhead (22) over a distance d of at least n/P of a length of an array of marking elements, n being an integer larger than 1, P being a number of mutually interstitial printing steps used when printing an image.
摘要:
A laser beam scanning unit (53) adapted for scanning laser beams on a surface of a charged image bearing member (5) is provided. The laser beam scanning apparatus (53) comprises a semiconductor laser array (21) having a plurality of light emitting portions (21a) and a rotating polygon mirror (3) adapted for deflecting laser beams emitted from the light emitting portions to the image bearing member (5). The light emitting portions (21a) are disposed two-dimensionally on a surface of the semiconductor laser array. The lighting and the amount of light of the light emitting portions (21a) are discretely controlled by a control unit (60).
摘要:
A two-pass printing method and related printing system are disclosed. In the first pass a checkerboard pattern of 3 X 3 dot clusters are printed. After the first pass, the print medium (38) is advanced and a different group of nozzles is used to print a second pass over the same swath also using 3 X 3 dot clusters in a checkerboard pattern, which dot clusters fill in the interstitial positions left during the first pass. In this manner, all print positions are addressed by the print mode. Image data (46) received from the driver is typically segmented into square halftone cells having eight pixels per side or a multiple of eight pixels per side. The 3 X 3 dot cluster print mode provides a print mask pattern dot width that is not an integer divisor of the typical dither cell dot widths. The disclosed printing method ensures that different nozzles will be used for any pixel location in the repeating dither cells. Thus if any single nozzle is defective, the other functioning nozzle will in part hide the defect.
摘要:
A three-pass printing method and related printing system are disclosed. In the first pass a pattern of 2 X 2 dot clusters are printed. The dot clusters are contiguous in the diagonal position and arranged in diagonal rows. After the first pass, the print medium (38) is advanced and a different group of nozzles are used to print a second pass over the same swath also using 2 X 2 dot clusters in a diagonal row in positions not printed during the first or second pass. A third pattern of 2 X 2 dot clusters is then printed in a third pass in the interstitial positions not printed during either the first or second passes. In this manner, all print positions are addressed by the print mode. The three-pass 2 X 2 dot clusters print mode avoids excessive amounts of data loss resulting from alignment errors between two successive print passes. The print mode also provides a print mask frequency that is not an integer divisor of the typical dither cell sizes. This provides the beneficial result that the print mode mask frequency does not beat with the dither cell frequency. The disclosed printing method ensures that different nozzles will be used for any pixel location in the dither cell. Thus if any single nozzle is defective, the other functioning nozzle will in part hide the defect.
摘要:
A laser beam scanning unit (53) adapted for scanning laser beams on a surface of a charged image bearing member (5) is provided. The laser beam scanning apparatus (53) comprises a semiconductor laser array (21) having a plurality of light emitting portions (21a) and a rotating polygon mirror (3) adapted for deflecting laser beams emitted from the light emitting portions to the image bearing member (5). The light emitting portions (21a) are disposed two-dimensionally on a surface of the semiconductor laser array. The lighting and the amount of light of the light emitting portions (21a) are discretely controlled by a control unit (60).
摘要:
The invention relates to a illuminating device for digitally scanning images comprising two or more independent light sources that are placed so as to achieve from each separate light source different light beams falling on the active scanning area, so that by modulating the light intensity of each light source through manual or automatic dimming, different configurations of the light falling on the object to be digitized and of its reflections in the sensor and, therefore, corresponding changes in digital images are achieved.
摘要:
P (fifteen) recording heads are arranged in two columns in a zigzag pattern in a recording unit. The P recording heads are divided into N (two) groups in the sub-scanning direction (up-down direction in the figure). The N (two) controllers respectively control the recording heads pertaining to corresponding groups. Therefore, the number of the boundary (M/S boundary line) of the recording regions (master recording region and slave recording region) of the recording heads controlled by the different controllers becomes at least N-1 (one). The N controllers control recording based on fixed data and on variable data such that a variable image based on the variable data does not straddle the boundary of recording regions in the second direction between the recorders controlled by different controllers.