The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 17, 1988
Filed:
Oct. 24, 1986
Hidekazu Sekizawa, Yokohama, JP;
Naofumi Yamamoto, Tokyo, JP;
Tutomu Saito, Yokohama, JP;
Haruko Kawakami, Funabashi, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A color copier comprises a color line-image sensor, a matrix circuit, and a color conversion circuit. The color line-image sensor reads a color document, to output a plurality of fundamental color signals. The matrix circuit converts the fundamental color signals into a brightness signal and two color-difference signals. The color-conversion circuit converts the brightness and color difference signals into ink-amount control signals for controlling the amounts of color inks used in a color printer. In order to decrease the memory capacity of the color conversion circuit and faithfully reproduce dark colors, a nonlinear conversion circuit is provided at the preceding stage of the matrix circuit. The nonlinear conversion circuit is arranged to increase a change in level of an input signal in a low-level range, to an extent greater than that in a high-level range.