An optical print head that performs optical writing to a photoreceptor includes: a light transmissive substrate; a light emitting unit including light emitting element groups, each of which includes two or more light emitting elements disposed on a first main surface of the substrate; a lens array including lenses that correspond one-to-one to the light emitting element groups; light detection units disposed above the second main surface of the substrate in one-to-one correspondence to the light emitting element groups and that detects the light from each of the light emitting elements; and correction unit that corrects light amounts of the light emitting elements of the light emitting element group based on detection of the light detection units.

An optical print head that performs optical writing to a photoreceptor includes: a light transmissive substrate; a light emitting unit including light emitting element groups, each of which includes two or more light emitting elements disposed on a first main surface of the substrate; a lens array including lenses that correspond one-to-one to the light emitting element groups; light detection units disposed above the second main surface of the substrate in one-to-one correspondence to the light emitting element groups and that detects the light from each of the light emitting elements; and correction unit that corrects light amounts of the light emitting elements of the light emitting element group based on detection of the light detection units.

A casing of an optical scanning apparatus includes: a mounting portion to which a sound-insulating member is mountable; a first and a second support portions supporting a reflective mirror in the casing on which the sound-insulating member is mounted and brought into contact with a back surface of the reflective mirror; and a third and a fourth support portions supporting a reflective mirror in the casing on which the sound-insulating member is not mounted and brought into contact with a back surface of the reflective mirror, wherein the first and the second support portions are positioned between the third and the fourth support portions in a longitudinal direction of the reflective mirror, and contact portions of the third and the fourth support portions protrude toward a reflective surface side of the reflective mirror to be arranged with respect to contact portions of the first and the second support portions.

A casing of an optical scanning apparatus includes: a mounting portion to which a sound-insulating member is mountable; a first and a second support portions supporting a reflective mirror in the casing on which the sound-insulating member is mounted and brought into contact with a back surface of the reflective mirror; and a third and a fourth support portions supporting a reflective mirror in the casing on which the sound-insulating member is not mounted and brought into contact with a back surface of the reflective mirror, wherein the first and the second support portions are positioned between the third and the fourth support portions in a longitudinal direction of the reflective mirror, and contact portions of the third and the fourth support portions protrude toward a reflective surface side of the reflective mirror to be arranged with respect to contact portions of the first and the second support portions.

A holding member includes a first opposing portion (first inner wall surface) and a second opposing portion (second inner wall surface) which oppose side wall surfaces of a lens array. Side wall surfaces of the lens array on opposite end sides with respect to a longitudinal direction of the lens array are exposed from opposite ends of the first opposing portion and opposite ends of the second opposing portion.

A light-emitting element includes, on a substrate, a shift thyristor and a light-emitting thyristor. The shift thyristor and the light-emitting thyristor each include a semiconductor multilayer structure consisting of first to fourth semiconductor layers stacked with alternating conductivity types. The shift thyristor includes a current diffusion layer in contact with the semiconductor multilayer structure, and a first metal electrode in this order, or the first metal electrode which is in contact with the semiconductor multilayer structure on the semiconductor multilayer structure; and wherein in the shift thyristor, a region in which a region in which the current diffusion layer or the first metal electrode and the semiconductor multilayer structure come into contact with each other is projected in a stacked direction of the semiconductor multilayer structure is included in a region in which the first metal electrode is projected in the stacked direction.

A light-emitting element includes, on a substrate, a shift thyristor and a light-emitting thyristor. The shift thyristor and the light-emitting thyristor each include a semiconductor multilayer structure consisting of first to fourth semiconductor layers stacked with alternating conductivity types. The shift thyristor includes a current diffusion layer in contact with the semiconductor multilayer structure, and a first metal electrode in this order, or the first metal electrode which is in contact with the semiconductor multilayer structure on the semiconductor multilayer structure; and wherein in the shift thyristor, a region in which a region in which the current diffusion layer or the first metal electrode and the semiconductor multilayer structure come into contact with each other is projected in a stacked direction of the semiconductor multilayer structure is included in a region in which the first metal electrode is projected in the stacked direction.

A casing of an optical scanning apparatus housing a rotary polygon mirror and an optical member: a mounting portion on which a sound insulation member separating the optical member from the rotary polygon mirror is mountable; a first support portion supporting a transparent member which covers an opening of the casing on which the sound insulation member is mounted; a second support portion supporting a transparent member which covers the opening of the casing on which the sound insulation member is not mounted and is thicker than the transparent member to be supported by the first support portion; and a bearing surface of the second support portion located on an inner side of the casing than a bearing surface of the first support portion so that light beam emission surfaces of the transparent members to be supported by the first and second support portions are on a substantially same plane.

A casing of an optical scanning apparatus housing a rotary polygon mirror and an optical member: a mounting portion on which a sound insulation member separating the optical member from the rotary polygon mirror is mountable; a first support portion supporting a transparent member which covers an opening of the casing on which the sound insulation member is mounted; a second support portion supporting a transparent member which covers the opening of the casing on which the sound insulation member is not mounted and is thicker than the transparent member to be supported by the first support portion; and a bearing surface of the second support portion located on an inner side of the casing than a bearing surface of the first support portion so that light beam emission surfaces of the transparent members to be supported by the first and second support portions are on a substantially same plane.

An optical print head that performs optical writing to a photoreceptor includes: a light transmissive substrate; a light emitting unit including light emitting element groups, each of which includes two or more light emitting elements disposed on a first main surface of the substrate; a lens array including lenses that correspond one-to-one to the light emitting element groups; light detection units disposed above the second main surface of the substrate in one-to-one correspondence to the light emitting element groups and that detects the light from each of the light emitting elements; and correction unit that corrects light amounts of the light emitting elements of the light emitting element group based on detection of the light detection units.