An optical scanning device and an imaging apparatus are provided. The optical scanning device includes a light source for emitting a light beam, a first optical unit for collimating the light beam emitted by the light source in a main scanning direction and focus the light beam in an auxiliary scanning direction, an optical deflector for deflecting the light beam, and an imaging optical system for guiding the light beam to a scanned surface for imaging. When the optical deflector deflects the light beam at a maximum deflection angle, the light beam in the main scanning direction forms a maximum incident angle Φ.sub.max with a normal line of the scanned surface. A spot tilt rate e/a of a light spot on the scanned surface satisfies $\frac{e}{a}\le 10\%,$
where a is a size of the light spot in the main scanning direction and e is a spot tilt.

An image forming apparatus includes a light scanning device, a developing portion, a control portion and a storage portion. The storage portion stores an evaluation chart. The evaluation chart includes a first evaluation pattern and a second evaluation pattern. The first evaluation pattern includes a first patch row. The first patch row is formed by arranging a plurality of first evaluation patches. The first evaluation patch includes a first dot row and a second dot row. The second evaluation pattern includes a second patch row. The second patch row is formed by arranging a plurality of second evaluation patches.

An image forming apparatus includes a light scanning device, a developing portion, a control portion and a storage portion. The storage portion stores an evaluation chart. The evaluation chart includes a first evaluation pattern and a second evaluation pattern. The first evaluation pattern includes a first patch row. The first patch row is formed by arranging a plurality of first evaluation patches. The first evaluation patch includes a first dot row, a second dot row and an auxiliary dot row. The second evaluation pattern includes a second patch row. The second patch row is formed by arranging a plurality of second evaluation patches.

In an optical deflector, a polygon mirror and a drive motor are covered by a cover body including a first cover portion and a second cover portion. The first cover portion includes a top wall disposed above the polygon mirror, and a peripheral wall formed having a cylindrical shape extending downward from an outer peripheral end edge of the top wall and having a first opening opened by facing the deflection surface of the polygon mirror. The peripheral wall has an upper-end edge-defining portion and a lower-end edge-defining portion defining an opening end edge of the first opening, and the top wall has, on an inner surface side of a specific portion connected to the upper-end edge-defining portion, a first slope portion inclined downward toward the upper-end edge-defining portion.

An optical scanning device comprises an optical box that houses an optical component(s). The optical box includes a box main body and a cover member. A first engaging portion is formed on a side wall of the box main body, and a second engaging portion that engages with the first engaging portion is formed on a first fitting wall portion of the cover member. The box main body is provided with a vertical wall that is erected inside the first engaging portion. Moreover, there is formed on the cover member with a first barrier wall that is protruded downward from a top wall so as to enter a space between the first engaging portion and the vertical wall.

An image forming apparatus includes a photoconductive body, a light source, a deflector to deflect a light beam from the light source, a scanning optical system to image the deflected light beam onto the photoconductive body, a developing unit to supply developer to the photoconductive body, an optical sensor to detect the deflected light beam, a moving mechanism to move the developing unit to a first position and to a second position, and a controller configured to start driving the deflector, when the developing unit is in the second position, the light source to emit the light beam, thereby obtaining a detection signal of the light beam from the optical sensor, and after obtaining the detection signal of the light beam from the optical sensor, control the moving mechanism to move the developing unit to the first position.

A printing head and a method for applying a correction for mounting deviation of light-emitting chips are provided. The printing head includes a plurality of light-emitting chips. Each light-emitting chip includes a plurality of primary light-emitting elements that are continuously arranged. At least one of two adjacent light-emitting chips further includes at least one spare light-emitting element continuously and linearly arranged after the primary light-emitting elements. If the two adjacent light-emitting chips are both at a target mounting position, first N light-emitting units of one of the two light-emitting chips respectively face to first N light-emitting units of the other one of the two light-emitting chips, where N≥1. Each two of the light-emitting units facing to each other form a group. One of the two light-emitting units in each of the groups is set to a light emission disabled state.

An image forming apparatus includes a photoconductor, a bearing body, an abutting portion, a support frame, an exposure device, and an urging body. The photoconductor includes a shaft portion at an end portion. The bearing body is configured to receive the shaft portion. The abutting portion is coupled to the bearing body. The support frame is configured to support the abutting portion and the bearing body. The exposure device faces the photoconductor, abuts on the abutting portion, and includes a light source exposing the photoconductor to light. The urging body is configured to press the exposure device toward the support frame, urge the abutting portion toward the bearing body and the shaft portion, and urge the bearing body toward the support frame.

An image forming apparatus includes a photoconductor, an exposure device, and a shutter assembly. The exposure device includes a light source configured to expose the photoconductor. The light source is repositionable between a proximity position at a first distance from the photoconductor and a separation position at a second distance from the photoconductor. The first distance is less than the second distance. The shutter assembly is configured to move away from the light source in response to the light source moving toward the proximity position. The shutter assembly is configured to move to cover the optical path of the light source in response to the light source moving toward the separation position.

An image forming apparatus includes a plurality of image bearers, a plurality of optical writing devices, a plurality of image forming units, and circuitry. The plurality of optical writing devices scan and irradiate the plurality of image bearers with a plurality of light beams according to image data to form latent images on the plurality of image bearers. The plurality of image forming units develop the latent images formed on the plurality of image bearers. The circuitry changes scanning speeds of the plurality of light beams and sets, to each of the plurality of optical writing devices, a correction value of an image misregistration on corresponding one of the plurality of image bearers caused by a change of a scanning speed of corresponding one of the plurality of light beams.