Abstract: A method for creating an image to be printed is provided. A first halftone pattern and a second halftone pattern for respective first and second periodic clustered dot halftone regions of the image are selected. The regions have respective frequencies and one of the frequencies is higher than the other frequency. A transition region is determined. The transition region includes a boundary between the two regions and includes additional portions of the two regions beyond the boundary. The two halftone patterns are blended with each other in the transition region based on a blending ratio of the two halftones where the blending ratio changes as a function of distance between the edges of the transition region.

Abstract: A method for creating an image to be printed is provided. A first halftone pattern and a second halftone pattern for respective first and second periodic clustered dot halftone regions of the image are selected. The regions have respective frequencies and one of the frequencies is higher than the other frequency. A transition region is determined. The transition region includes a boundary between the two regions and includes additional portions of the two regions beyond the boundary. The two halftone patterns are blended with each other in the transition region based on a blending ratio of the two halftones where the blending ratio changes as a function of distance between the edges of the transition region.

Abstract: A color table calibration system produces multiple color samples for each target color point in a color table. Each sample is offset from the target color within the color space by a random amount that is equal to a fixed offset plus a random interval. In the preferred implementation, the fixed offset is equal to a distance approximately equal to the color excursion caused by noise and the random interval is constrained to not exceed the fixed offset. The color table calibration system prints a set of multiple samples for each color point. The color samples are measured using conventional measuring devices and then averaged. The color table calibration system uses the sample average to derive a calibrated color table. The pseudo random supersampling and averaging for each color point reduces errors introduced by mechanical and environmental variations.

Abstract: A single pass EP color printer includes a photoreceptor web having multiple layers and including a charge transport layer and a charge generation layer. Four exposure devices (e.g. either laser-based or thin film electroluminescent edge emitting (TFEL) devices) are serially arrayed along the photoreceptor web and act to expose the photoreceptor web in accordance with cyan, magenta, yellow and black color image pixel data. A liquid toner developer module is associated with each exposure device and includes a liquid toner reservoir, a developer roll for carrying the liquid toner to a transfer point and a squeegee roll. Each developer module is fixed so as to position its developer roll at a constant prescribed distance from the photoreceptor web at the toner transfer point and to create a fluid interfacial layer between its developer roll and the photoreceptor web. In addition, each squeegee roll is maintained in constant contact with the photoreceptor web.

Abstract: Disclosed are apparatus and methods for transducing mechanical movement into electrical signals indicative of the movement. The apparatus is an improved optical encoder of the type having a source of light, a code wheel for modulating the light according to movement of the object whose position is being measured and a photo detector for receiving the modulated light. The code wheel modulates the light from the light source into spiral-shaped beams of light separated by columns of spiral-shaped dark areas. Photo detectors are oriented to receive the modulated light.

Abstract: An optical shaft angle encoder has a code wheel with alternating reflective and non-reflective areas in a circumferential path on one face of the wheel. A light emitting diode is spaced apart from the reflective areas on the wheel. Four photodetectors are also spaced apart from the same face of the wheel so that, as the wheel rotates, the photodetectors are alternately illuminated or not illuminated by light from the light emitting diode that is reflected from the reflective areas. Preferably the light emitting diode is relatively nearer the shaft axis than the photodetectors and is in a radial direction from the shaft axis which bisects the array of photodetectors.