Disclosed is an optical deflector which includes: a polygonal mirror, a drive motor, a cover member, and a temperature detection unit. The cover member includes: a first cover portion defining a first space in which the polygonal mirror is installed, wherein the first cover portion is formed with a first opening opened in opposed relation to an outer peripheral surface of the polygonal mirror; a second cover portion defining a second space which is communicated with the first space and in which the drive motor is installed, wherein the second cover portion is formed with a second opening opened in opposed relation to a motor body of the drive motor; and a third cover portion defining a third space which is communicated with the second space. The temperature detection unit is mounted to the third cover portion so as to close the third space.

Disclosed is an optical deflector including a polygonal mirror and a drive motor each mounted on a substrate, a cover member covering the polygonal mirror and the drive motor, and an electronic component. The cover member includes: a first cover portion defining a first space in which the polygonal mirror is installed, wherein the first cover portion is formed with a first opening opened in opposed relation to an outer peripheral surface of the polygonal mirror; and a second cover portion defining a second space which is communicated with the first space and in which the drive motor is installed, wherein the second cover portion is formed with a second opening opened in opposed relation to a motor body of the drive motor. When viewed in the first direction, the electronic component is disposed such that it falls within an open region of the second opening.

An image forming apparatus includes an optical system unit and an attachment board. The optical system unit forms an electrostatic latent image by irradiating an image bearing member with light. The optical system unit is attached to the attachment board. The attachment board includes a mounting surface, a first recess portion, and a second recess portion. The optical system unit is mounted on the mounting surface. The first recess portion and the second recess portion are provided in the mounting surface to form air paths. The first recess portion is located below a lower surface of the optical system unit, extending in a first direction. The second recess portion is located below the lower surface of the optical system unit, extending in a direction different from the first direction and crossing the first recess portion.

An example is a lens mirror array in which a plurality of optical elements, which comprises a first lens surface formed at the top of convex portion protruding outwards for converging light, a protrusion which includes a first mirror surface that reflects the light emitted from the first lens surface at the top and a light-shielding surface that has side walls at two sides thereof with respect to a light advancing direction and prevents advance of the light through the side walls, a second mirror surface that reflects the light reflected by the first mirror surface of the protrusion and a second lens surface that images the light emitted from the second mirror surface on an image plane, is arranged in a horizontal scanning direction.

The present invention roughens at least a partial region of an outer planar surface of at least one of an optical case and a lid of a laser scanner; thus, electrification of the optical case to be caused by friction with another member or a person is reduced, and damage to an electronic component is prevented.

An exposure device includes an optical system member that forms an image of light from a light emitting element array having multiple light emitting elements arranged, an optical system support part that supports the optical system member, and a restraining member that restrains the optical system member to the optical system support part. The optical system support part has sliding parts, which are able to slide relative to the restraining member, formed on a light emitting element side face and an image forming side face in positions opposing the both end parts or the vicinity of both end parts in a longitudinal direction of the optical system support part, and in the both end parts or in the vicinity of the both end parts in the longitudinal direction, the restraining member is formed between the sliding parts and the optical system member, fixed to the optical system member, and slidable in the longitudinal direction relative to the optical system support part.

Provided is imaging optical system, including: a first lens array including a plurality of lens rows each having a plurality of lenses arrayed in main array direction, the plurality of lens rows arranged in sub-array direction; and a second lens array including a plurality of lens rows each having a plurality of lenses arrayed in main array direction, the plurality of lens rows being arranged in sub-array direction. The imaging optical system forms an erect image of object in main array cross section, and forms an inverted image of object in sub-array cross section. At least one of first and second lens arrays includes at least one of a scattering and light-shielding portions arranged between adjacent lens rows. D/Rs≦0.2 is satisfied, where D represents length of at least one of scattering and light-shielding portions in sub-array direction, and Rs represents an effective diameter of imaging optical system in sub-array direction.

An image forming apparatus includes a rotating polygon mirror, a motor, a bearing portion, a measurement processing portion, and a determination processing portion. The rotating polygon mirror causes a light beam emitted from the light source to be scanned. The motor rotates the rotating polygon mirror. The bearing portion rotatably supports a rotation shaft of the motor via a lubricant. The measurement processing portion measures a transition time that is a time required for the motor to transition from a stationary state to a driving state in which the motor rotates at a predetermined speed. The determination processing portion determines whether or not a maintenance is required, based on the transition time measured by the measurement processing portion.

A focus adjustment mechanism for adjusting a focus position of a printhead includes a rotatable pin that is rotatable around a pin axis. The rotatable pin includes a cam section located having a surface whose radial distance from the pin axis varies around its perimeter, and a gripping feature. An adjustment plate includes a gripping feature and is adapted to fit over and engage with the gripping feature of the rotatable pin such that the adjustment plate rotates together with the rotatable pin. A fastener fastens the adjustment plate to a support structure when the adjustment plate is positioned in a desired orientation. The printhead includes a frame feature which is pulled firmly against the cam section of the rotatable pin such that as the rotatable pin is rotated the frame feature rides on the surface of the cam section thereby adjusting the focus position of the printhead.

In order to provide a polygon mirror which can reduce a light amount difference among respective image heights on a scanned surface with suppressing an increase in size in a light scanning apparatus, the polygon mirror according to the present invention includes a plurality of rectangular reflecting surfaces in which the following condition is satisfied:

0.02<|1−B/A|<0.10

where A represents a reflectivity at a center of the reflecting surface with respect to a light flux which is incident at a predetermined incident angle, and B represents the reflectivity at a predetermined point between the center and an end in the longitudinal direction of the reflecting surface with respect to the light flux which is incident at the predetermined incident angle.