An optical scanning device includes a laser diode that emits a light beam, a holder to which the laser diode is fixed, and a holding unit that holds and arranges a plurality of holders side by side. The holder includes a first end portion and a second end portion that face each other across a center of the holder, and a first side portion and a second side portion that linearly extend from the first end portion toward the second end portion. The first side portion and the second side portion extend such that a distance therebetween gradually increases from the first end portion toward the second end portion. The adjacent ones of the holders in a state of being held by the holding unit are disposed such that the second end portion of the other holder is adjacent to the first end portion of one holder.

A mirror fastener fastens a first end portion of a mirror to a first mirror support portion of a housing. A second mirror support portion includes a pair of partitioning surfaces and a concave surface. The pair of partitioning surfaces oppose an end surface of a second end portion of the mirror while an interval is provided between the pair of partitioning surfaces and the end surface. The concave surface is formed between the pair of partitioning surfaces and opposes the end surface of the second end portion while an interval larger than the interval between the pair of partitioning surfaces and the end surface is provided between the concave surface and the end surface. An adhesive bonds the end surface of the second end portion and the pair of partitioning surfaces.

A first stepped structure configured to apply a reflectance difference and a second stepped structure configured to change a far field light intensity distribution are provided. A region in which a level difference of the first stepped structure is formed has a predetermined relationship with a region in which a level difference of the second stepped structure is formed.

An optical scanning apparatus includes a light source, an optical deflector having a rotary polygon mirror to deflect a light beam from the light source, a scanning optical system configured to focus the light beam deflected by the optical deflector on a target surface, a sync detecting sensor configured to determine a write start timing on the target surface, and a processing unit configured to correct detection data of the sync detecting sensor based on a measured value of a time needed for one revolution of the rotary polygon mirror.

An optical scanning device includes a holding member. The holding member has a boss part and an arm part that extends from the boss part in a direction perpendicular to the movement direction of the holding member and holds the cleaning member. The boss part is mounted with a posture correction member relatively movable in the movement direction of the holding member. The posture correction member is movably inserted into a groove between two second rail parts, and when the holding member moves, the posture correction member moves later than movement of the holding member, so that an inclined posture of the holding member is corrected by the delay operation in a direction perpendicular to the second rail part.

To restrict an angle change of a reflection surface of a reflection member that reflects a scanning light beam, an optical scanning device includes a first support portion that supports a reflection mirror at one point at an end in a longitudinal direction of the reflection mirror, a second support portion that supports the reflection mirror at a plurality of points at the other end, a reinforcement portion that reinforces a structure of the second support portion side of a housing in the longitudinal direction of the reflection mirror, compared to a structure of the first support portion side of the housing, one first fixing portion that is used to fix the housing to an image forming apparatus on the first support portion side, and a plurality of second fixing portions that are used to fix the housing to the image forming apparatus on the second support portion side.

In an optical scanning device including a vibration mirror part, elastically deformable resin portions are respectively provided at both end portions in a main scanning direction on a surface of the vibration mirror part, which is an opposite surface of a reflective surface, a collision member, which has a collision surface and can collide with each of the resin portion, is provided at a side opposite to a side of the reflective surface of the vibration mirror part, and a control unit allows the vibration mirror part to swing such that each of the resin portion collides with the collision surface at least once before light beam for image data writing is deflected and scanned by the vibration mirror part, and then allows the vibration mirror part to swing in a range in which each of the resin portion does not collide with the collision surface.

An image forming apparatus includes a light scanning device, a light detection unit, and a positional-deviation-amount calculation unit. The light detection unit includes a slit-shaped first light detection region and a slit-shaped second light detection region arranged to have mutually different angles with respect to a scanning direction of the light beam, and outputs a detection signal when the light beam passes through each of the light detection regions. The positional-deviation-amount calculation unit calculates a time period until when the light beam passes through the second light detection region from when the light beam has passed through the first light detection region for each scan of the light beam based on the detection signal output from the light detection unit, and calculates a variation characteristic of a positional deviation amount in a sub-scanning direction of the light beam associated with rotation of the polygon mirror.

Disclosed are methods and systems for compensating for process direction banding associated with a document processing system including a ROS. According to one exemplary embodiment, a ROS driver uses a plurality of beam delay/advance values to compensate for banding caused by an interaction of a halftone pattern and process direction density variations associated with the ROS.

A driving device of a rotating polygonal mirror which stops supply of a driving current or reduces output of the driving current in a state where the driving current is supplied to a driving motor, and detects a period of an FG signal based on a detected waveform output from a detection element in the state where the driving current is stopped.