Image processing apparatus which selects from one of plural generated clock counts
AssigneeCanon Kabushiki Kaisha
InventorsTakashi Kawana, Kaoru Seto, Hiroshi Mano, Hiromichi Yamada, Atsushi Kashihara, Tetsuo Saito
Life of this patent
Estimating the term…
Abstract
An image processing apparatus having an input device for receiving a multivalue image signal, a generating unit for generating a plurality of count clocks, a counting unit for counting the count clocks supplied from the generating unit, a pulse width modulation unit for performing a pulse width modulation by using an output from the counting unit and the multivalue image signal and a selection unit for selecting one count clock from a plurality of the count clocks in accordance with a value of the multivalue image signal.
Claims13
An image processing apparatus comprising:
- input means for receiving a multivalue image signal;
- generating means for generating a plurality of clock counts;
- selection means for selecting one clock count from said plurality of clock counts in accordance with a value of the multivalue image signal;
- count means for counting the selected count clock;
- and
- pulse width modulation means for performing a pulse width modulation by using an output from said count means and the multivalue image signal received by said input means.
An image processing apparatus comprising:
- input means for receiving a multivalue image signal;
- generating means for generating a plurality of count clocks;
- selection means for selecting one count clock from said plurality of count clocks;
- count means for counting the selected count clock;
- and
- pulse width modulation means for performing a pulse width modulation by using an output from said count means and the multivalue image signal received by said input means;
- wherein said selection means selects from among said plurality of count clocks in accordance with a count value of said count means.
An image processing method for use in an image forming apparatus for applying light to a photosensitive material in accordance with multivalue image data to form a halftone density image, said image processing method comprising the steps of:
- controlling an irradiation light quantity to strong and weak levels;
- irradiating a portion, which is added when the multivalue image data is changed from n gradations to n+2 gradations and which is irradiated with light of the strong light quantity, with light of the weak light quantity at n+1 gradations;
- and
- inhibiting weak light quantity irradiation in a case where the portion, which is added when the multivalue image data is changed from n gradations to n+2 gradations and which is irradiated with the light of the strong light quantity, has an area which is two times or larger a minimum unit area which can be controlled.
Dependencies are inferred from the claim text.