Color printer with power saving recording head

Abstract

The present invention relates to a color printer and particularly to a color printer reducing power consumption and complying with international criteria ensuring sustained earth environment. In a color printer having multiple optical writing heads for individual recording colors, the activated periods of individual color recording heads are set to different periods and one writing period of individual recording heads is divided into multiple periods, video data for recording one dot line are divided into multiple blocks in the main scan direction, and the divided video data are used for emission at different times in the sub-scan direction, whereby a smaller number of optical writing elements are simultaneously driven for emission and the peak power consumption of the entire apparatus is reduced.

What is claimed is: 
     
         1 . A printer creating video data corresponding to recording colors based on print information entered from a host machine, supplying the video data to corresponding recording color optical writing recording heads comprising an array of light emitting elements arranged in a main scan direction, and forming images by exposing image lights consequently emitted on corresponding photoconductive bodies for recording color, the photoconductive bodies being provided to face the optical writing recording heads and moving in a sub-scan direction perpendicular to the main scan direction, and the printer comprising:
 a recording head selection/activated unit activating individual color optical writing recording heads in sequence to enable optical writing in each of periods equal to one n-th of one writing period of the optical writing recording heads, where n represents a number of divisions into which one dot line image to be recorded is divided in the sub-scan direction;   a video data supply unit supplying video data corresponding to the one dot line image to be recorded to the optical writing recording heads during an activated period by the recording head selection/activated unit; and   a divided emission control unit selectively activating a plurality of blocks comprising a given number of light emitting elements of the optical writing recording heads so as to allow the light emitting elements in the plurality of blocks to selectively emit light based on video data applied to the optical writing recording heads during the activated period by the recording head selection/activated unit.   
     
     
         2 . The printer according to  claim 1 , wherein the recording color optical writing recording heads are provided such that each of the blocks are shifted in the sub-scan direction by a quantity to cancel an emission time-lag between the light emitting elements in different blocks activated with a time-lag by the divided emission control unit. 
     
     
         3 . A printer creating video data corresponding to recording colors based on print information entered from a host machine, supplying the video data to corresponding recording color optical writing recording heads comprising an array of light emitting elements arranged in a main scan direction, and forming images by exposing image lights consequently emitted on corresponding photoconductive bodies for recording color, the photoconductive bodies being provided to face the optical writing recording heads and moving in a sub-scan direction perpendicular to the main scan direction, and the printer comprising:
 a recording head selection/activated unit activating individual color optical writing recording heads in sequence to enable optical writing in each of periods equal to one n-th of one writing period of the optical writing recording heads, where n represents a number of divisions into which one dot line image to be recorded is divided in the sub-scan direction;   a video data dividing/supply unit dividing an activated period by the recording head selection/activated unit into m periods where m represents an integer equal to or greater than two, and applying, to the optical writing recording heads, only video data corresponding to each piece of one dot line image data divided into the number m in the main scan direction during each of the m periods; and   a divided emission control unit selectively activating a specific block of light emitting elements of the optical writing recording heads so as to allow the light emitting elements in the block to selectively emit light based on video data applied to the optical writing recording heads in each of the activated periods by the selection/activated unit in the m periods.   
     
     
         4 . The printer according to  claim 3 , wherein the individual color optical writing recording heads are provided such that each of the blocks are shifted in the sub-scan direction by a quantity to cancel an emission time-lag between the light emitting elements in different blocks activated with a time-lag by the divided emission control unit. 
     
     
         5 . A non-transitory computer-readable recording medium having a program stored thereon for controlling a printer that (i) creates video data corresponding to recording colors based on print information entered from a host machine, (ii) supplies the video data to corresponding recording color optical writing recording heads comprising an array of light emitting elements arranged in a main scan direction, and (iii) forms images by exposing image lights consequently emitted on corresponding photoconductive bodies for recording color, wherein the photoconductive bodies are provided to face the optical writing recording heads and move in a sub-scan direction perpendicular to the main scan direction, and wherein the program is executable to control the printer to function as units comprising:
 a recording head selection/activated unit activating individual color optical writing recording heads in sequence to enable optical writing in each of periods equal to one n-th of one writing period of the optical writing recording heads, where n represents a number of divisions into which one dot line image to be recorded is divided in the sub-scan direction;   a video data supply unit supplying video data corresponding to the one dot line image to be recorded to the optical writing recording heads during an activated period by the recording head selection/activated unit; and   a divided emission control unit selectively activating a plurality of blocks comprising a given number of light emitting elements of the optical writing recording heads so as to allow the light emitting elements in the plurality of blocks to selectively emit light based on video data applied to the optical writing recording heads during the activated period by the recording head selection/activated unit.   
     
     
         6 . A non-transitory computer-readable recording medium having a program stored thereon for controlling a printer that (i) creates video data corresponding to recording colors based on print information entered from a host machine, (ii) supplies the video data to corresponding recording color optical writing recording heads comprising an array of light emitting elements arranged in a main scan direction, and (iii) forms images by exposing image lights consequently emitted on corresponding photoconductive bodies for recording color, wherein the photoconductive bodies are provided to face the optical writing recording heads and move in a sub-scan direction perpendicular to the main scan direction, and wherein the program is executable to control the printer to function as units comprising:
 a recording head selection/activated unit activating individual color optical writing recording heads in sequence to enable optical writing in each of periods equal to one n-th of one writing period of the optical writing recording heads, where n represents a number of divisions into which one dot line image to be recorded is divided in the sub-scan direction;   a video data dividing/supply unit dividing an activated period by the recording head selection/activated unit into m periods where m represents an integer equal to or greater than two, and applying, to the optical writing recording heads, only video data corresponding to each piece of one dot line image data divided into the number m in the main scan direction during each of the m periods; and   a divided emission control unit selectively activating a specific block of light emitting elements of the optical writing recording heads so as to allow the light emitting elements in the block to selectively emit light based on video data applied to the optical writing recording heads in each of the activated periods by the selection/activated unit in the m periods.