234results about How to "Maintain image quality" patented technology

The image forming apparatus includes: a head which ejects ink droplets; an intermediate transfer body having a transfer surface on which a transfer image is formed by means of the ink droplets ejected from the head; a transfer device which performs transfer of the transfer image formed on the transfer surface of the intermediate transfer body to a prescribed transfer-receiving medium; a transfer surface reading device which obtains read image data by reading in the transfer surface of the intermediate transfer body after the transfer; a judgment device which performs judgment of a transfer state of the transfer surface of the intermediate transfer body in accordance with the read image data obtained by the transfer surface reading device; and a transfer condition changing device which changes a transfer condition of the transfer device in accordance with the judgment of the judgment device.

A method is provided of estimating an in-focus position of a target in an image scanning apparatus. A first part of the target is scanned at a nominal focus level so as to obtain corresponding image information. One or more further parts of the target are scanned at one or more respective further focus levels so as to obtain corresponding image information. A focus parameter is then calculated for each of the nominal and the one or more further focus levels using the respective image information. An in-focus position common to each of the first and further parts of the target is then estimated using the calculated focus parameters. Corresponding apparatus for performing the method is also provided.

Rise times and fall times provided by a high voltage generator are controlled to maintain image quality during such scans. The rise and fall times are controlled by first measuring rise and fall times at each transition. Then, a closed-loop controller is used to adjust control parameters of the high voltage generator, based on an error determined from the measurement, to achieve substantially constant rise and fall times. This invention may be based on the implementation of two closed-loop controllers on rise and fall time of fast-kV exposures. As a result, image quality may be improved and system calibration time may be reduced.