Abstract: An optical head comprises a substrate on which optical elements are arranged in a main scanning direction, a lens unit that transmits light emitted from the optical elements or light entering the optical elements, and a holder that holds the lens unit. The holder has a sidewall extending in the main scanning direction. The sidewall has a hole at a position facing the lens unit. A fixing member is provided in the hole. The fixing member fixes the lens unit to the sidewall.

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 optical head comprises a substrate on which optical elements are arranged in a main scanning direction, a lens unit that transmits light emitted from the optical elements or light entering the optical elements, and a holder that holds the lens unit. The holder has a sidewall extending in the main scanning direction. The sidewall has a hole at a position facing the lens unit. A fixing member is provided in the hole. The fixing member fixes the lens unit to the sidewall.

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 image forming apparatus includes a photosensitive drum that rotates in a predetermined direction, an LED head that exposes the photosensitive drum, a drum contact surface that contacts against the outer peripheral surface of the photosensitive drum, and a head contact surface that contacts the LED head. Further, the image forming apparatus includes a spacer for regulating a distance between the photosensitive drum and the LED head, and a coil spring for pressing the LED head toward the spacer. The LED head has an engagement hole to engage the spacer. The spacer has a protrusion that engages with the engagement hole and regulates movement of the LED head in a predetermined direction.

Abstract: An image forming apparatus includes a photosensitive drum that rotates in a predetermined direction, an LED head that exposes the photosensitive drum, a drum contact surface that contacts against the outer peripheral surface of the photosensitive drum, and a head contact surface that contacts the LED head. Further, the image forming apparatus includes a spacer for regulating a distance between the photosensitive drum and the LED head, and a coil spring for pressing the LED head toward the spacer. The LED head has an engagement hole to engage the spacer. The spacer has a protrusion that engages with the engagement hole and regulates movement of the LED head in a predetermined direction.

Abstract: An optical print head for illuminating an image carrier facing the optical print head includes: a substrate on which a light emitting element array is mounted; a lens array for focusing light emitted from the light emitting element array onto the image carrier; a holder holding the substrate and the lens array; and at least one spacer member, disposed on the holder, for maintaining a predetermined distance between the lens array and the image carrier, the at least one spacer member being made of curable resin that is cured under a predetermined condition or fixed to the holder with curable adhesive that is cured under a predetermined condition.

Abstract: An optical print head for illuminating an image carrier facing the optical print head includes: a substrate on which a light emitting element array is mounted; a lens array for focusing light emitted from the light emitting element array onto the image carrier; a holder holding the substrate and the lens array; and at least one spacer member, disposed on the holder, for maintaining a predetermined distance between the lens array and the image carrier, the at least one spacer member being made of curable resin that is cured under a predetermined condition or fixed to the holder with curable adhesive that is cured under a predetermined condition.

Abstract: An exposure device includes: a substrate having a first and second surface opposed to each other, wherein a light-emitting element array is mounted on the first surface; a protective sheet covering the second surface while exposing a part of the second surface in the vicinity of an edge of the substrate to define an exposed part of the second surface; a holder that supports a condenser lens array and that supports the substrate, with a gap formed between the holder and the exposed part of the substrate, to position the substrate such that light emitted from the light-emitting element array is condensed on a predetermined irradiation location through the condenser lens array; and a thermally-conductive sealant that covers the exposed part of the second surface of the substrate and seals the gap.

Abstract: An exposure device includes: a substrate having a first and second surface opposed to each other, wherein a light-emitting element array is mounted on the first surface; a protective sheet covering the second surface while exposing a part of the second surface in the vicinity of an edge of the substrate to define an exposed part of the second surface; a holder that supports a condenser lens array and that supports the substrate, with a gap formed between the holder and the exposed part of the substrate, to position the substrate such that light emitted from the light-emitting element array is condensed on a predetermined irradiation location through the condenser lens array; and a thermally-conductive sealant that covers the exposed part of the second surface of the substrate and seals the gap.

Abstract: An exposure device includes: a substrate on which a plurality of light emitting elements are mounted; an optical system that converges light irradiated from the light emitting elements onto a photosensitive surface; a holding member that holds and fixes the substrate; a support member that supports the optical system and the holding member; a first adhesive member that is provided between the substrate and the holding member; and a second adhesive member that is provided between the holding member and the support member, wherein the first adhesive member has higher elongation and lower hardness than the second adhesive member.

Abstract: An exposing device includes a plurality of light emitting elements, a substrate to which the plurality of light emitting elements are mounted, an optical system that focuses lights emitted by the plurality of light emitting elements, and a holder that holds the optical system. The holder has a substrate abutting surface that abuts against the substrate. The holder includes a base material portion made of metal, and a substrate abutting portion formed integrally with the base material portion. The substrate abutting portion is made of resin having electrical insulation property. The surface abutting surface is formed on the surface abutting portion.

Abstract: An exposure device includes a substrate on which a light emitting element array is provided, a focusing lens that focuses light emitted by the light emitting element array, a supporting member that supports the substrate and the focusing lens. The supporting member has a contact surface. A base is provided for forcing the substrate against the contact surface of the supporting member. The base has a first engaging portion that engages a second engaging portion formed on an inner wall of the supporting member. The base is mounted to the supporting member by the engagement of the first engaging portion and the second engaging portion.

Abstract: An exposure device includes: a substrate on which a plurality of light emitting elements are mounted; an optical system that converges light irradiated from the light emitting elements onto a photosensitive surface; a holding member that holds and fixes the substrate; a support member that supports the optical system and the holding member; a first adhesive member that is tprovided between the substrate and the holding member; and a second adhesive member that is provided between the holding member and the support member, wherein the first adhesive member has higher elongation and lower hardness than the second adhesive member.

Abstract: An exposing device includes a plurality of light emitting elements, a substrate to which the plurality of light emitting elements are mounted, an optical system that focuses lights emitted by the plurality of light emitting elements, and a holder that holds the optical system. The holder has a substrate abutting surface that abuts against the substrate. The holder includes a base material portion made of metal, and a substrate abutting portion formed integrally with the base material portion. The substrate abutting portion is made of resin having electrical insulation property. The surface abutting surface is formed on the surface abutting portion.

Abstract: An exposure device includes a substrate on which a light emitting element array is provided, a focusing lens that focuses light emitted by the light emitting element array, a supporting member that supports the substrate and the focusing lens. The supporting member has a contact surface. A base is provided for forcing the substrate against the contact surface of the supporting member. The base has a first engaging portion that engages a second engaging portion formed on an inner wall of the supporting member. The base is mounted to the supporting member by the engagement of the first engaging portion and the second engaging portion.

Abstract: An exposure device includes a substrate on which a light emitting element array is provided, a focusing lens that focuses light emitted by the light emitting element array, a supporting member that supports the substrate and the focusing lens. The supporting member has a contact surface. A base is provided for forcing the substrate against the contact surface of the supporting member. The base has a first engaging portion that engages a second engaging portion formed on an inner wall of the supporting member. The base is mounted to the supporting member by the engagement of the first engaging portion and the second engaging portion.

Abstract: An exposure device includes a substrate on which a light emitting element array is provided, a focusing lens that focuses light emitted by the light emitting element array, a supporting member that supports the substrate and the focusing lens. The supporting member has a contact surface. A base is provided for forcing the substrate against the contact surface of the supporting member. The base has a first engaging portion that engages a second engaging portion formed on an inner wall of the supporting member. The base is mounted to the supporting member by the engagement of the first engaging portion and the second engaging portion.

Abstract: An LED head is supplied which is able not only to reduce cost but also to improve disintegration efficiency and assembly efficiency. The LED head comprises a SLA holder with electroconductivity which has a insulating cover and supports a rod lens array with convergency; a substrate which is mounted in the SLA holder and is used for installing a LED array chip; a base with electroconductivity used for fixing the substrate at the SLA holder; and a clamp with electroconductivity which presses and contacts the base, wherein the clamp, while mounted onto the SLA holder, scrapes off contact part of the insulating cover.

Abstract: A positioning apparatus for an optical head includes a cylindrical photoconductive drum, an optical head, and at least one spacer. The cylindrical photoconductive drum extends in a direction of a longitudinal axis thereof. The optical head extends parallel to the longitudinal axis. The spacer is disposed to abut the photoconductive drum, limiting a distance between the optical head and the photoconductive drum. The photoconductive drum has a photoconductor and the spacer is in contact with the photoconductor through sliding friction. The spacer has a first surface in contact with the photoconductor. The photoconductor has a second surface in contact with the first surface. The first surface has a first curvature and the second surface has a second curvature. When the first surface is pressed against the second surface, the spacer may deform resiliently so that the first curvature becomes substantially equal to the second curvature.