PURPOSE: To improve the contrast of an image forming light profile, by selectively coating only the end parts of the light emitting parts of the light emitting elements in a light emitting element array with a light pervious substance to increase the light at said end parts.
CONSTITUTION: SiN coating is selectively applied only to both terminal parts of each of LED elements A to form an SiN coating film 4 and, by raising the light emitting efficiency of said parts, the brightness of the end parts is enhanced. Therefore, the light emitting profile of the LED elements A shows such a state that the brightness is enhanced at both end parts of a light emitting part 2 and the image forming light profile passed through a concentrated rod lens array becomes a square wave form and the MAX thereof is suppressed and the bottom part of the groove part of said profile caused by the junction between LED chips 5 is raised to reduce the contrast of the whole. By this method, an image having high image quality can be obtained.
HIRAO HIDENORI
SANYO ELECTRIC CO
TOKYO SANYO ELECTRIC CO