Paper transfer control method for image forming device

Abstract

A paper transfer control method for an image forming device having a plurality of paper feeding cassettes for storing paper sheets; a pickup roller for picking up a paper sheet from one of the plurality of paper feeding cassettes to load the picked up paper on a paper transfer path; a transfer roller for feeding the loaded paper sheet; an image forming unit having a photosensitive medium for forming an image on the paper sheet; a driving motor for driving the photosensitive medium, the transfer roller and the pickup roller; and a plurality of sensors for sensing whether the paper sheet is transferred. The method includes: selecting a paper feeding cassette which picks up a paper sheet according to a received printing command; transmitting a linear-velocity control command to the driving motor, the linear-velocity control command based on a paper transfer path of the selected paper feeding cassette; and picking up the paper sheet, and transferring the picked up paper along the paper transfer path.

1 . A paper transfer control method for an image forming device having a plurality of paper feeding cassettes for storing paper sheets; a pickup roller for picking up a paper sheet from one of the plurality of paper feeding cassettes to load the picked up paper on a paper transfer path; a transfer roller for feeding the loaded paper sheet; an image forming unit having a photosensitive medium for forming an image on the paper sheet; a driving motor for driving the photosensitive medium, the transfer roller and the pickup roller; and a plurality of sensors for sensing whether the paper sheet is transferred, comprising: 
 selecting a paper feeding cassette which picks up a paper sheet according to a received printing command;    transmitting a linear-velocity control command to the driving motor, the linear-velocity control command based on a paper transfer path of the selected paper feeding cassette; and    picking up the paper sheet, and transferring the picked up paper along the paper transfer path.    
   
   
       2 . The method of  claim 1 , wherein the picking up is based on the driving of the driving motor.  
   
   
       3 . The method of  claim 1 , wherein the linear-velocity control command is determined by a real measured value according to at least an angle and a friction coefficient of every paper transfer path.  
   
   
       4 . The method of  claim 3 , wherein the linear-velocity control command dictates that the transfer roller, the pickup roller and the photosensitive medium are driven at the same linear velocity.  
   
   
       4 . (Cancelled)  
   
   
       5 . The method of  claim 3 , further comprising upgrading the linear-velocity control command.  
   
   
       6 . The method of  claim 5 , wherein the upgrading is based on at least one of a part abrasion and future circumstances.  
   
   
       7 . An image forming device comprising: 
 a plurality of paper feeding cassettes which store paper sheets;    a pickup roller which picks up a paper sheet from one of the plurality of paper feeding cassettes to load the picked up paper on a paper transfer path;    a transfer roller which feeds the loaded paper sheet;    an image forming unit having a photosensitive medium which forms an image on the paper sheet;    a driving motor which drives the photosensitive medium, the transfer roller and the pickup roller;    a plurality of sensors which sense whether the paper sheet is transferred; and    a memory unit which stores a linear-velocity control command for rotating the photosensitive medium, the pickup roller and the transfer roller at the same linear velocity.    
   
   
       8 . The device of  claim 7 , wherein the memory unit includes a ROM for storing a control program for controlling components of the image forming device and a RAM for temporarily storing data generated when controlling the image forming device.  
   
   
       9 . The device of  claim 7 , wherein the memory unit stores compensation data to compensate for a difference between real linear velocities between paper transfer paths.  
   
   
       10 . The device of  claim 9 , wherein the difference is caused by a resistance factor.  
   
   
       11 . The device of  claim 10 , wherein the resistance factor is one of an angle regarding a paper transfer path and a friction coefficient.  
   
   
       12 . The device of  claim 9 , wherein the compensation data is stored in the RAM.  
   
   
       13 . The device of  claim 12 , wherein the compensation data is upgradable.  
   
   
       14 . The device of  claim 7 , wherein the linear-velocity control command instructs that the photosensitive medium, the pickup roller and the transfer roller rotate at the same linear velocity.  
   
   
       15 . The device of  claim 7 , wherein the real linear velocity for a paper transfer path is determined by the following equation:  
       Vreal=Vcommand−Vres,  
     where Vreal is the real linear velocity, Vcommand is a linear-velocity control command, and Vres is a reduced linear velocity.  
   
   
       16 . The device of  claim 15 , wherein Vres is based on one of an angle of the paper transfer path and a friction force.  
   
   
       17 . The device of  claim 15 , wherein the memory unit stores compensation data to compensate for a difference between real linear velocities (Vreal) between paper transfer paths, the compensation data is based on a compensation factor α determined by the following equation:  
       α=V 1 real−V 2 real,  
     where V 1  is a real linear velocity of a first paper transfer path and V 2  is a real linear velocity of a second paper transfer path.  
   
   
       18 . A paper transfer control method, comprising: 
 selecting a paper feeding cassette in response to an input print command;    determining whether there is a paper sheet in the selected paper feeding cassette;    transmitting, when it is determined that a paper sheet is not present in the selected paper feeding cassette, a linear-velocity control command to a driver, the linear-velocity control command based on a type of the selected paper feeding cassette, and driving the driver at a real linear velocity based on the linear-velocity control command; and picking up the paper sheet from the selected paper feeding cassette, transferring the picked up paper along the paper transfer path, and outputting the sheet of paper.    
   
   
       19 . The method of  claim 18 , further comprising displaying a paper state when it is determined that t there is a paper sheet in the paper feeding cassette.  
   
   
       20 . The method of  claim 18 , further comprising repeating the selecting and the determining to continuously print and output the image.  
   
   
       21 . A printing method, comprising: 
 selecting a cassette from a plurality of paper feeding cassettes;    using compensation data to generate a linear-velocity control command which to drive a motor and which compensates for a difference between paper feeding cassettes; and    driving the motor to pick up the paper sheet from the selected paper feeding cassette, transfer the picked up paper along the paper transfer path, and output the sheet of paper.    
   
   
       22 . The method of  claim 3 , further comprising storing the linear-velocity control command.