| 摘要 |
<p>PURPOSE:To prevent the development of a stepped part in a margin and to obtain an image of good image quality, in an optical device equipped with an optical member having a plurality of optical element rows each having a large number of linearly arranged light emitting elements, by using a method of appropriately arranging the light emitting elements. CONSTITUTION:In an optical device for exposure, a light emitting member 1 is constituted of first and third EL element rows 2, 3 and the element rows 2, 3 are constituted of rectangular long light emitting elements 4 (4a, 4c, 4e...), 6 (6a, 6c, 6e...) and rectangular short light emitting elements 5 (5b, 5d, 5f...), 7 (7b, 7d, 7f...). At this time, the respective light emitting elements 4-7 are linearly arranged along the longitudinal direction of the light emitting elements and the short light emitting elements 5, 7 between the long light emitting elements 4, 6 are arranged at an equal pitch. The ratio of the length of the long light emitting elements 4, 6 and that of the short light emitting elements 5, 7 in an arrangement direction are almost set to 3:1 and the element rows 2, 3 are parallelly arranged so as to be mutually shifted at a 1/2 pitch.</p> |
