Patent ID: 7022444
Filing Date: 2006-04-04
Classification: B41M,G03G

Abstract:
1. A color image forming method using microcapsule toner which includes a plurality of larger microcapsules each of which contains a plurality of kinds of smaller microcapsules dispersed therein, the plurality of kinds of smaller microcapsules being different in at least one of outer diameter, shell thickness and material so as to be broken by ultrasonic waves of different resonant frequencies respectively, each smaller microcapsule containing an air bubble and having a protective wall breakable with an ultrasonic wave of a corresponding predetermined resonant frequency, each smaller microcapsule containing inside its protective wall one of two reacting substances that react with each other when mixed to thereby cause a coloring reaction and the other of the two reacting substances being disposed outside the protective wall, the method comprising the steps of: forming a toner image on an image carrier by applying the microcapsule toner to the image carrier in accordance with ORed items generated by OR operation means of image information about respective colors or forming a toner image pattern on the image carrier depending on the ORed items generated by OR operation means of the image information about the respective colors and then applying the microcapsule toner to the toner image pattern to thereby form a toner image; transferring the toner image, formed on the image carrier, directly or through an intermediate transfer medium to paper; irradiating the toner image applied to the image carrier with ultrasonic waves of different predetermined resonant frequencies corresponding to respective color component items of the image information, the ultrasonic waves being focused within a width of one pixel in a primary scan direction, between the time when the toner image was formed on the image carrier and the time when the toner image was transferred to the paper such that the protective wall of relevant ones of the plurality of kinds of smaller microcapsules of the toner image is broken by the ultrasonic waves of the predetermined resonant frequencies to thereby cause the two reacting substances to mix and react with each other to thereby color the toner image; and fixing the colored toner image to the paper whereby a color image based upon the toner image is formed on the paper.