Abstract: The lens unit includes a first lens array including a plurality of first lens elements each of which has a first optical axis and which are arranged in an arrangement direction perpendicular to the first optical axis. A second lens array includes a plurality of second lens elements each of which has a second optical axis and which are arranged in the arrangement direction while facing the first lens elements. The second lens array is in a positional relationship relative to the first lens array such that the second lens array is rotated about a virtual line perpendicular to both the first optical axis and the arrangement direction as the rotational axis by 180 degrees. The optical axes of the lens elements located at the substantially centers of the lens arrays in the arrangement direction are arranged to substantially coincide with each other.

Abstract: The lens unit includes a first lens array including a plurality of first lens elements each of which has a first optical axis and which are arranged in an arrangement direction perpendicular to the first optical axis. A second lens array includes a plurality of second lens elements each of which has a second optical axis and which are arranged in the arrangement direction while facing the first lens elements. The second lens array is in a positional relationship relative to the first lens array such that the second lens array is rotated about a virtual line perpendicular to both the first optical axis and the arrangement direction as the rotational axis by 180 degrees. The optical axes of the lens elements located at the substantially centers of the lens arrays in the arrangement direction are arranged to substantially coincide with each other.

Abstract: An exposure head according to one or more embodiments may include: a light emitting element board on which light emitting elements are arranged; a holder that holds the light emitting element board and is provided with an opening; a transparent cover arranged at a position to shield the opening, such that a first attachment surface of the holder is attached to a second attachment surface of the transparent cover by using an adhesive; and an optical system arranged between the light emitting element board and the transparent cover. The exposure head satisfies an expression defined as ?1<?2, where ?1 is a contact angle on the first attachment surface representing wettability of the first attachment surface, and ?2 is a contact angle on the second attachment surface representing wettability of the second attachment surface.

Abstract: An exposure head according to one or more embodiments may include: a light emitting element board on which light emitting elements are arranged; a holder that holds the light emitting element board and is provided with an opening; a transparent cover arranged at a position to shield the opening, such that a first attachment surface of the holder is attached to a second attachment surface of the transparent cover by using an adhesive; and an optical system arranged between the light emitting element board and the transparent cover. The exposure head satisfies an expression defined as ?1<?2, where ?1 is a contact angle on the first attachment surface representing wettability of the first attachment surface, and ?2 is a contact angle on the second attachment surface representing wettability of the second attachment surface.

Abstract: An exposing device according to an embodiment includes: a light emitter; a first light blocking member including first apertures; a first lens array including first lenses, wherein each of the first lenses converges the light passing through the corresponding first aperture; a second light blocking member including second apertures; and a second lens array including second lenses, wherein each of the second lenses converges the light passing through the corresponding second aperture. An optical axis of each of the first lenses and an optical axis of the corresponding one of the second lenses substantially coincide with each other. A first aperture center of each of the first apertures and a second aperture center of the corresponding second aperture are disposed at a predetermined distance from the optical axis of the corresponding first lens and the optical axis of the corresponding second lens in an array direction of the light emitter.

Abstract: An exposing device according to an embodiment includes: a light emitter; a first light blocking member including first apertures; a first lens array including first lenses, wherein each of the first lenses converges the light passing through the corresponding first aperture; a second light blocking member including second apertures; and a second lens array including second lenses, wherein each of the second lenses converges the light passing through the corresponding second aperture. An optical axis of each of the first lenses and an optical axis of the corresponding one of the second lenses substantially coincide with each other. A first aperture center of each of the first apertures and a second aperture center of the corresponding second aperture are disposed at a predetermined distance from the optical axis of the corresponding first lens and the optical axis of the corresponding second lens in an array direction of the light emitter.