| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a technique of enabling realization of good spot formation by suppressing distortion of a spot shape in a line head which uses a plurality of light emitting elements. <P>SOLUTION: The line head is equipped with a plurality of the light emitting elements arranged two-dimensionally, and an imaging lens which forms spots by imaging light beams from each of a plurality of the light emitting elements to a face to be scanned. When an intersection between a luminous flux center of the light beam emitted from a surface of the light emitting element and the surface is defined as a luminous flux center point of the light emitting element, the light emitting element whose luminous flux center point is farthest from an optical axis of the imaging lens among a plurality of the light emitting elements is defined as the outermost element, an intersection between a perpendicular line drawn from the luminous flux center point of the outermost element to the optical axis and the optical axis is defined as an element side intersection, and an intersection between a plane of incidence of the imaging lens and the optical axis is defined as an incidence plane side intersection, a distance L from the luminous flux center point of the outermost element to the optical axis and a distance Mr from the element side intersection to the incidence plane side intersection satisfy the following inequality L/Mr<0.08. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
