Exposure head and image forming apparatus

An exposure head configured to form an electrostatic latent image by exposing a charged surface of an image bearing member that is movable in a first direction, the exposure head comprising:

• a plurality of light emitting boards each including a plurality of light emitting elements disposed side by side in a second direction intersecting with the first direction, the plurality of light emitting boards being disposed along the second direction and alternately in the first direction, the plurality of light emitting boards including a first light emitting board group and a second light emitting board group, the first light emitting board group being disposed on a first side in the first direction, the second light emitting board group being disposed on a second side in the first direction;
• a first lens array configured to condense light emitted from the plurality of light emitting elements disposed on the first light emitting board group onto the surface of the image bearing member;
• and
• a second lens array configured to condense light emitted from the plurality of light emitting elements disposed on the second light emitting board group onto the surface of the image bearing member,
• wherein, in a case where a light emitting element disposed on the first light emitting board group is a first light emitting element and a light emitting element disposed on the second light emitting board group is a second light emitting element, the first light emitting element and the second light emitting element are disposed so as to expose a same position on the surface of the image bearing member, and the first light emitting element is disposed such that a distance in the second direction between the first light emitting element and the second light emitting element is equal to or less than 5 μm, and
• wherein the light emitting elements are organic electroluminescence elements.

An exposure head configured to form an electrostatic latent image by exposing a charged surface of an image bearing member that is movable in a first direction, the exposure head comprising:

• a plurality of light emitting boards each including a plurality of light emitting elements disposed side by side in a second direction intersecting with the first direction, the plurality of light emitting boards being disposed along the second direction and alternately in the first direction, the plurality of light emitting boards being divided into a first light emitting board group and a second light emitting board group, the first light emitting board group being disposed on a first side in the first direction, the second light emitting board group being disposed on a second side in the first direction;
• a first lens array configured to condense light emitted from the plurality of light emitting elements disposed on the first light emitting board group onto the surface of the image bearing member;
• and
• a second lens array configured to condense light emitted from the plurality of light emitting elements disposed on the second light emitting board group onto the surface of the image bearing member,
• wherein a distance in the first direction between the first light emitting board group and the second lens array is set such that a light amount entering the second lens array is equal to or less than 20% of a light amount emitted from the plurality of light emitting elements disposed on the first light emitting board group,
• wherein a distance in the first direction between the second light emitting board group and the first lens array is set such that a light amount entering the first lens array is equal to or less than 20% of a light amount emitted from the plurality of light emitting elements disposed on the second light emitting board group, and
• wherein the plurality of light emitting elements are disposed side by side in the first direction and the second direction.

An exposure head configured to form an electrostatic latent image by exposing a charged surface of an image bearing member that is movable in a first direction, the exposure head comprising:

• a plurality of light emitting boards each including a plurality of light emitting elements disposed side by side in a second direction intersecting with the first direction, the plurality of light emitting boards being disposed along the second direction and alternately in the first direction, the plurality of light emitting boards including a first light emitting board group and a second light emitting board group, the first light emitting board group being disposed on a first side in the first direction, the second light emitting board group being disposed on a second side in the first direction;
• a first lens array configured to condense light emitted from the plurality of light emitting elements disposed on the first light emitting board group onto the surface of the image bearing member;
• and
• a second lens array configured to condense light emitted from the plurality of light emitting elements disposed on the second light emitting board group onto the surface of the image bearing member,
• wherein, in a case where a light emitting element disposed on the first light emitting board group is a first light emitting element and a light emitting element disposed on the second light emitting board group is a second light emitting element, the first light emitting element and the second light emitting element are disposed so as to expose a same position on the surface of the image bearing member, and the first light emitting element is disposed such that a distance in the second direction between the first light emitting element and the second light emitting element is equal to or less than 5 μm, and
• wherein the plurality of light emitting elements are disposed side by side in the first direction and the second direction.