Title:
RASTER SCAN DEVICE
Document Type and Number:
Japanese Patent JP3237329
Kind Code:
B2
Abstract:
PURPOSE: To keep repeatability of an intermediate tone image very excellently by providing a non-high density modulation means for generating a light modulation signal corresponding to a non-high density level signal based on a time modulation.
CONSTITUTION: A light modulation means 1 separates an input image signal into a high density level signal and a non-high density level signal by a signal separation means 5, and light intensity modulation is performed by a high density modulation means 6 for the high density level signal. On the other hand, for the non-high density level signal, time modulation is performed by a non-high density modulation means 7 and a light modulation signal corresponding to the input image signal is outputted. Irradiation of light beam is performed by a light irradiation means 2 based on the light modulation signal and it is led to a scanning line of a photosensitive body 4 through a light conducting means 3. A separation threshold value changing means 8 changes a separation threshold value of the signal separation means 5 by a picture element pitch. By previously setting the separation threshold value at every picture element pitch, an optimum separation threshold value can be selected.
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Inventors:
Yoshinori Machida
Kiyoshi Shigehiro
Kiyoshi Shigehiro
Application Number:
JP20182493A
Publication Date:
December 10, 2001
Filing Date:
July 22, 1993
Export Citation:
Assignee:
Fuji Xerox Co., Ltd
International Classes:
B41J2/52; G02B26/10; G03G15/22; (IPC1-7): B41J2/52; G02B26/10; G03G15/22
Domestic Patent References:
| JP3159758A |
Attorney, Agent or Firm:
Masahiro Koizumi (2 outside)