Title:
ASYMMETRIC SPATIAL FILTER MEANS FOR PULSE TYPE IMAGE FORMING PULSE WIDTH MODULATION RASTER OUTPUT SCANNER FOR THREE-LEVEL EXPOSURE
Document Type and Number:
Japanese Patent JP3691087
Kind Code:
B2
Abstract:
PURPOSE: To attain exact strength level maintenance by controlling overshoot by correcting the overshoot in the power strength of a raster output scanner(ROS) through respective asymmetric filters at an optical system before a polygon.
CONSTITUTION: An asymmetric spatial frequency band pass filter 198 decreases the overshoot at a three-level zero graphy system. This spatial frequency band pass filter 198 is made asymmetric to a Fourier transforming modulation strength profile 202. However, this asymmetric spatial frequency band pass filter 198 blocks two side part lobes 206 and 208 of the strength profile 202 but a central lobe 204 can pass through this filter 198. Then, the central lobe 204 of the Fourier transforming modulation strength profile 202 generates intermediate exposure, namely, white exposure 210 in the three-level zero graphy system.
Inventors:
Anthony Ang
Chies Tan
Chies Tan
Application Number:
JP20387794A
Publication Date:
August 31, 2005
Filing Date:
August 29, 1994
Export Citation:
Assignee:
XEROX CORPORATION
International Classes:
G02B27/46; G06K15/12; H04N1/113; H04N1/40; (IPC1-7): G02B27/46; H04N1/113
Domestic Patent References:
| JP5219312A | ||||
| JP5219313A | ||||
| JP557796A |
Attorney, Agent or Firm:
Minoru Nakamura
Fumiaki Otsuka
Shishido Kaichi
Hideto Takeuchi
Toshio Imajo
Nobuo Ogawa
Village shrine Atsuo
Fumiaki Otsuka
Shishido Kaichi
Hideto Takeuchi
Toshio Imajo
Nobuo Ogawa
Village shrine Atsuo
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