| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To make the lens diameter of each lens system as small as possible in an optical writing line head in which a plurality of light emitting elements are arrayed in rows corresponding to each lens system of a plurality of arrayed positive lens systems. <P>SOLUTION: A light emitter array 1 includes a plurality of light emitter groups spaced apart in at least the main scanning direction, each light emitter group including one or more rows of light emitting elements where a plurality of light emitting elements are arrayed in a row or rows in the main scanning direction; a lens array is placed in the light-exiting side of the emitter array 1 in such a manner that each positive lens system 5 is aligned to the light emitter group; and a writing plane 41 is disposed in an imaging side of the lens array. Each positive lens system 5 constituting the lens array comprises two lens groups L1 and L2 having positive refractive power, configuring the image side to be approximately telecentric; and the focal length of the image-side lens L2 and the width of the light emitting element image group along the main scanning direction on the writing plane 41 satisfy conditional expressions (21) and (24). <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
