Line head controlling method and image forming method

A method for controlling a line head including,

• a focusing optical system,
• first light emitters, light from which being focused by the focusing optical system,
• second light emitters disposed next to the first light emitters in a first direction, light from the second light emitters being focused by the focusing optical system, and
• third light emitters disposed next to the second light emitters in the first direction, light from the third light emitters being focused by the focusing optical system, the method comprising:
• turning on the first light emitters at time t0;
• turning on the second light emitters after a period t1 has passed since the time t0;
• and
• turning on the third light emitters after a period t2 has passed since the time t0, wherein
• the periods t1 and t2 are controlled under a following condition:
• t2≠n×t1 (n is an integer two or greater),
• first latent images formed by the first light emitters at the time t0 on a scanned surface that moves in the first direction, second latent images formed by the second light emitters after the period t1 has passed on the scanned surface that moves in the first direction, and third latent images formed by the third light emitters after the period t2 has passed on the scanned surface that moves in the first direction are formed in a second direction perpendicular to or substantially perpendicular to the first direction, and
• a distance between the second latent images and the third latent images is a non-integral multiple of a width of any of the first latent images in the second direction.

A method for forming an image comprising:

• providing a latent image carrier that moves in a first direction;
• providing an exposure head including a focusing optical system that is an erect optical system, first light emitters, light from which being focused by the focusing optical system, second light emitters disposed next to the first light emitters in the first direction, light from the second light emitters being focused by the focusing optical system, and third light emitters disposed next to the second light emitters in the first direction, light from the third light emitters being focused by the focusing optical system;
• turning on the first light emitters at time t0;
• turning on the second light emitters after a period t1 has passed since the time t0;
• and
• turning on the third light emitters after a period t2 has passed since the time t0, wherein
• the periods t1 and t2 are controlled under the following condition:
• t2≠n×t1 (n is an integer two or greater),
• first latent images formed by the first light emitters at the time t0 on the latent image carrier, second latent images formed by the second light emitters after the period t1 has passed on the latent image carrier, and third latent images formed by the third light emitters after the period t2 has passed on the latent image carrier are formed in a second direction perpendicular to or substantially perpendicular to the first direction, and
• a distance between the first latent images and the second latent images in the first direction is a non-integral multiple of a width of any of the first latent images formed by the first light emitters on the latent image carrier in the second direction.

A method for forming an image comprising:

• providing a latent image carrier that moves in a first direction;
• providing an exposure head including a focusing optical system that is an erect optical system, first light emitters, light from which being focused by the focusing optical system, second light emitters disposed next to the first light emitters in the first direction, light from the second light emitters being focused by the focusing optical system, and third light emitters disposed next to the second light emitters in the first direction, light from the third light emitters being focused by the focusing optical system;
• turning on the first light emitters at time t0;
• turning on the second light emitters after a period t1 has passed since the time t0;
• and
• turning on the third light emitters after a period t2 has passed since the time t0, wherein
• the periods t1 and t2 are controlled under the following condition:
• t2≠n×t1 (n is an integer two or greater),
• first latent images formed by the first light emitters at the time t0 on the latent image carrier, second latent images formed by the second light emitters after the period t1 has passed on the latent image carrier, and third latent images formed by the third light emitters after the period t2 has passed on the latent image carrier are formed in a second direction perpendicular to or substantially perpendicular to the first direction, and
• a distance between the second latent images and the third latent images in the first direction is a non-integral multiple of a width of any of the first latent images formed by the first light emitters on the latent image carrier in the second direction.