Self-scanning light-emitting element array and driving method and circuit of the same

Abstract

A method for driving a self-scanning light-emitting element array is provided in which two light-emitting elements may be illuminated simultaneously in one chip. In a self-scanning light-emitting element array including a transfer element array and light-emitting element array, a magnitude of the write signal for illuminating adjacent two light-emitting elements simultaneously is two times that of the write signal for illuminating one light-emitting element. The self-scanning light-emitting element array is composed of a plurality of self-scanning light-emitting element array chips arranged in a linear manner, and the two-phase clock pulses are applied commonly to the plurality of self-scanning light-emitting element array chips.

1 . An optical writing head comprising: 
 a rod-lens array composed of a plurality of rod-lenses stacked and arranged so as to be geometrically axisymmetric in a thickness direction thereof;    and a light-emitting element array composed of a plurality of light-emitting element array chips arranged in a zigzag manner opposing to the rod-lens array, each light-emitting element array chip including a plurality of light-emitting elements arranged in a linear manner;    wherein the light-emitting element array chips are arranged in a zigzag manner opposing to two lines which are axisymmetric in the rod-lens array.    
   
   
       2 . An optical writing head comprising: 
 a rod-lens array composed of a plurality of rod-lenses stacked and arranged so as to be geometrically axisymmetric in a thickness direction thereof; and    a light-emitting element array composed of a plurality of light-emitting elements arranged in a zigzag manner opposing to the rod-lens array to form two rows of light-emitting elements,    wherein the light-emitting elements are arranged in a zigzag manner opposing to two lines which are axisymmetric in the rod-lens array.    
   
   
       3 . The optical writing head of  claim 1  or  2 , wherein the rod-lens array is composed of odd-numbered rows of rod-lenses stacked triangularly.  
   
   
       4 . The optical writing head of  claim 1  or  2 , wherein the rod-lens array is composed of a plurality of rod-lenses stacked tetragonally.  
   
   
       5 . An optical writing head comprising: 
 a rod-lens array composed of first and second sets of rod-lens sub-arrays stacked closely, each set of rod-lens sub-array consisting of a plurality rod-lenses stacked; and    a light-emitting element array composed of a plurality of light-emitting element array chip arranged in a zigzag manner opposing to the rod-lens array, each light-emitting element array including a plurality of light-emitting elements arranged in a linear manner;    wherein the light-emitting element array chips are arranged in a zigzag manner opposing to two lines which are obtained by moving a longitudinal first center line of the first set of rod-lens sub-array and a longitudinal second center line of the second set of rod-lens sub-array while maintaining a distance therebetween in a thickness direction of the rod-lens array.    
   
   
       6 . An optical writing head comprising: 
 a rod-lens array composed of first and second sets of rod-lens sub-arrays stacked closely, each set of rod-lens sub-array consisting of a plurality rod-lenses stacked; and    a light-emitting element array composed of a plurality of light-emitting elements arranged in a zigzag manner opposing to the rod-lens array to form two rows of light-emitting elements,    wherein the plurality of light-emitting elements are arranged in a zigzag manner opposing to two lines which are obtained by moving a longitudinal first center line of the first set of rod-lens sub-array and a longitudinal second center line of the second set of rod-lens sub-array while maintaining a distance therebetween in a thickness direction of the rod-lens array.    
   
   
       7 . The optical writing head of  claim 5  or  6 , wherein the rod-lens array is composed of even-numbered rows of rod-lenses stacked triangularly, the even-numbered rows of rod-lenses being four or more of rod-lenses.  
   
   
       8 . A method for arranging a rod-lens array and a light-emitting element array, comprising the steps of: 
 providing a rod-lens array composed of a plurality of rod-lenses stacked and arranged so as to be geometrically axisymmetric in a thickness direction thereof; and    arranging light-emitting element array chips in a zigzag manner opposing to two lines which are axisymmetric in the rod-lens array, each light-emitting element array chip including a plurality of light-emitting elements arranged in a linear manner.    
   
   
       9 . A method for arranging a rod-lens array and a light-emitting element array, comprising the steps of: 
 providing a rod-lens array composed of a plurality of rod-lenses stacked and arranged so as to be geometrically axisymmetric in a thickness direction thereof; and    arranging light-emitting elements in a zigzag manner opposing to two lines which are axisymmetric in the rod-lens array.    
   
   
       10 . A method for arranging a rod-lens array and a light-emitting element array, comprising the steps of: 
 providing a rod-lens array composed of first and second sets of rod-lens sub-arrays stacked closely, each set of rod-lens sub-array consisting of a plurality rod-lenses stacked; and    arranging light-emitting element array chips in a zigzag manner opposing to two lines which are obtained by moving a longitudinal first center line of the first set of rod-lens sub-array and a longitudinal second center line of the second set of rod-lens sub-array while maintaining a distance therebetween in a thickness direction of the rod-lens array.    
   
   
       11 . A method for arranging a rod-lens array and a light-emitting element array, comprising the steps of: 
 providing a rod-lens array composed of first and second sets of rod-lens sub-arrays stacked closely, each set of rod-lens sub-arrays consisting of a plurality rod-lenses stacked; and    arranging a plurality of light-emitting elements in a zigzag manner opposing to two lines which are obtained by moving a longitudinal first center line of the first set of rod-lens sub-array and a longitudinal second center line of the second set of rod-lens sub-array while maintaining a distance therebetween in a thickness direction of the rod-lens array.