An exposure control device includes an exposure light amount calculator that obtains, for each of correction points that are associated with a respective one of primary correction values and are separated from each other, a correction factor for correcting the primary correction value of the correction point, based on a pixel value of the correction point, calculates, for each correction point, a secondary correction value based on the primary correction value and the correction factor of the correction point, and calculates a distribution of the secondary correction values on an image based on the secondary correction values of the correction points, and an exposure controller that causes an exposure unit to form a latent image by exposure to light having a corrected light amount obtained by correcting a light amount corresponding to a pixel value of each point based on the secondary correction value of the point.

An optical scanning device includes a light source, a beam detector that takes a main scanning start time of a light beam emitted from the light source and deflection-scanned in a predetermined main scanning direction by a deflection-scanning component, and a housing with a support portion that supports reflecting mirrors in different arrangement positions so arrangement angles are different from each other. The support portion includes a first support portion that supports a first side surface of the reflecting mirror in a plurality of arrangement positions. A second support portion supports the first side surface of the mirror with the first support portion, causing a first arrangement angle in the first arrangement position of the reflecting mirror. A third support portion supports the first side surface of the reflecting mirror with the first support portion, causing a second arrangement angle in a second arrangement position of the reflecting mirror.

According to an embodiment, a signal generation circuit includes a generation unit configured to generate a second clock signal from division of a first clock signal and generate a timing signal with a cycle length that is a sum of a predetermined number of half-cycle periods of the second clock signal. A period changing unit of the signal generation circuit is configured to adjust the cycle length of the timing signal by changing a length of at least one half-cycle period of the second clock signal. An output unit of the signal generation circuit is configured to output the second clock signal and the timing signal.

An image forming apparatus includes a first light source, a second light source, an optical sensor, a storage, and a hardware processor, wherein the storage stores a first threshold for determining a type of the recording material based on the basis weight, and the hardware processor calculates a first transmittance from the mount of the first emission light and the amount of the first transmission light, calculates a second transmittance from the amount of the second emission light and the amount of the second transmission light, derives a first basis weight corresponding to the first transmittance and a second basis weight corresponding to the second transmittance, by using predetermined determination criteria, determines the type of the recording material based on the first basis weight and the second basis weight, and derives the basis weight according to the determination criteria based on the determined type of the recording material.

An optical scanning device includes a light transmitting member, a guide rail, a holding member, and a cleaning member. The light transmitting member extends in a main scanning direction and transmits a light beam. The guide rail extends in the main scanning direction and is arranged parallel to the light transmitting member. The holding member extends in a cross direction intersecting the main scanning direction and moves in the main scanning direction along the guide rail. The cleaning member is held by the holding member and cleans a light emitting surface of the light transmitting member by means of movement of the holding member in the main scanning direction.

According to one embodiment, the exposure device includes an exposure head, a holder, a biasing member, a lifting mechanism, a support member, a harness, and a protrusion. The holder supports the exposure head movably in a first direction of approaching the photosensitive drum and a second direction of being spaced from the photosensitive drum. The harness has one end portion connected to the exposure head. The harness is positioned with respect to the support member in a positioning location having a length direction position different from that of the one end portion. The harness has a folding portion formed between the one end portion and the positioning location. The protrusion enters inside of the folding portion to regulate movement of the folding portion of the harness in the first direction or the second direction. The protrusion protrudes from the holder in a third direction intersecting the first direction.

In an optical scanning device, an outer wall closest to a circumscribed circle of a rotating polygon mirror has a space in a position facing to a position of a reflection surface of the rotating polygon mirror in an axial direction of a rotating shaft. A part of a cover is provided in a position farther from the circumscribed circle than the outer wall so as to close the space, when the optical scanning device is viewed in a direction perpendicular to the axial direction of the rotating shaft.

An image forming apparatus includes a third link portion which is rotatably connected to said first link portion at a position between said first connecting portion and said first moving portion so that said first moving portion and said second moving portion are moved toward said drum unit by rotation of said first link portion about said first connecting portion as a rotation shaft and by rotation of said second link portion about said second connecting portion as a rotation shaft in interrelation with slide of said slidable portion, and which is rotatable relative to the apparatus main assembly. The third link portion is out of contact with the optical print head at a portion corresponding to an end portion on the optical print head side.

An optical scanning device includes a housing, a transmissive member, a wire-shaped member, a driving portion, a cleaning holder, a cleaning member, a stopper, and a control portion. The control portion is capable of executing a cleaning mode including at least one of a forward travel operation of controlling the wire-shaped member to travel in a first direction so that the cleaning holder moves along the transmissive member and a backward travel operation of, after executing the forward travel operation, controlling the wire-shaped member to travel in a second direction so that the cleaning holder moves in an opposite direction to a direction of the forward travel operation. The control portion executes a load releasing operation of controlling the cleaning holder to move by a prescribed amount in an opposite direction to the direction of the forward travel operation or the direction of the backward travel operation.

An image forming apparatus includes a photoconductor drum, a charging device, an exposure device, a development device, and an exposure position changing unit. The charging device is configured to charge the photoconductor drum. The exposure device is configured to irradiate the photoconductor drum and thereby form an electrostatic latent image on the photoconductor drum. The development device is configured to cause toner to adhere to the electrostatic latent image on the photoconductor drum in a two-component-development manner. The exposure position changing unit is configured to change, on the photoconductor drum, an exposure position of the exposure device to a position getting close to the development device from an exposure position for print image development when electric power cutoff is detected.