An image forming apparatus includes: a halftone processing unit configured to perform halftone processing on image data by a dither matrix that includes a plurality of submatrices and decide an exposure region of an image. In at least one of a first dither matrix corresponding to a first section, and a second dither matrix corresponding to a second section adjacent to the first dither matrix in the main scanning direction and corresponding to a second section different from the first section in tone value, at least a size of an exposure region of an image formed by using a first submatrix corresponding to a predetermined tone value in the dither matrix and a size of an exposure region of an image formed by using a second submatrix corresponding to the predetermined tone value are different.

A method and system for generating a three-dimensional (3D) map of an environment is provided. An example method includes receiving, by a processor system, via a 3D scanner, located at a scan position, a 3D scan of the environment. The method further includes receiving via a two-dimensional (2D) scanner accessory, a portion of a 2d map of the environment. The method further includes receiving coordinates of the scan position in the 2d map in response to the 3D scanner initiating the acquisition of the 3D scan. The method further includes associating the coordinates of the scan position with the portion of the 2D map. The method further includes determining a displacement vector for the 2D map using a loop closure algorithm. The method further includes computing a revised scan position based on the scan position and the displacement vector, where the 3D scan is registered using the revised scan position.

An anamorphic optical element and an adjustment mechanism for selectively rotating the optical element either around an axis substantially in a vertical direction, an axis substantially in an optical axis direction, an axis substantially in a plane formed by the vertical direction and the optical axis direction, or combination of axes thereof is used to vary a vertical separation between two or more spots.

A light scanning device includes: a first semiconductor laser 44a that emits a light beam L1; a polygonal mirror 42 that deflects the light beam L1; a reflective mirror 64a that reflects the light beam L1 deflected by the polygonal mirror 42 and causes the light beam L1 to enter a photosensitive drum 13; and a BD sensor 72 that detects the light beam L1 deflected by the polygonal mirror 42. The light scanning device scans the photosensitive drum 13 with the light beam L1 and set scanning timing of the photosensitive drum 13 using the light beam L1 based on detection timing of the light beam L1 using the BD sensor 72. The BD sensor 72 is arranged in the position farther from the polygonal mirror 42 than the last reflective mirror 64a that reflects the light beam L1 immediately before entering the photosensitive drum 13 and arranged inside a scanning angle range of the light beam L1 corresponding to an effective scan area of the photosensitive drum 13.

An image-forming apparatus includes a light-irradiation unit configured to move a spot of laser light on a surface of a photosensitive member at a non-constant scanning velocity in a main scanning direction to form a latent image on the photosensitive member, an image data correcting unit configured to correct a length in the main scanning direction of image data by inserting one or more image data pieces into the image data, the number of the image data pieces increasing as the scanning velocity increases, and/or extracting one or more image data pieces from the image data, the number of the image data pieces increasing as the scanning velocity decreases, and a brightness correcting unit configured to correct a brightness of the laser light so that an emission brightness increases as the scanning velocity increases and/or the emission brightness decreases as the scanning velocity decreases.

An image-forming apparatus includes a light-irradiation unit configured to move a spot of laser light on a surface of a photosensitive member at a non-constant scanning velocity in a main scanning direction to form a latent image on the photosensitive member, an image data correcting unit configured to correct a length in the main scanning direction of image data by inserting one or more image data pieces into the image data, the number of the image data pieces increasing as the scanning velocity increases, and/or extracting one or more image data pieces from the image data, the number of the image data pieces increasing as the scanning velocity decreases, and a brightness correcting unit configured to correct a brightness of the laser light so that an emission brightness increases as the scanning velocity increases and/or the emission brightness decreases as the scanning velocity decreases.

A light scanning device includes: a first semiconductor laser 44a that emits a light beam L1; a polygonal mirror 42 that deflects the light beam L1; a reflective mirror 64a that reflects the light beam L1 deflected by the polygonal mirror 42 and causes the light beam L1 to enter a photosensitive drum 13; and a BD sensor 72 that detects the light beam L1 deflected by the polygonal mirror 42. The light scanning device scans the photosensitive drum 13 with the light beam L1 and set scanning timing of the photosensitive drum 13 using the light beam L1 based on detection timing of the light beam L1 using the BD sensor 72. The BD sensor 72 is arranged in the position farther from the polygonal mirror 42 than the last reflective mirror 64a that reflects the light beam L1 immediately before entering the photosensitive drum 13 and arranged inside a scanning angle range of the light beam L1 corresponding to an effective scan area of the photosensitive drum 13.

An image forming apparatus, including: an image signal generating portion configured to generate an image signal as bit data obtained by splitting image data by a predetermined integer value for each pixel; a first storage portion configured to store a profile indicating magnification correction data for each of a plurality of regions in a main scanning direction; and a second storage portion configured to store a partial magnification granularity being a size of a processing unit used for splitting a partial magnification correction start value, wherein the image signal generating portion calculates a split region boundary address indicating a main scanning position at which a scanning region on the surface of a photosensitive member to be scanned by a light beam is split in the main scanning direction for each partial magnification granularity based on the partial magnification correction start value extracted from the profile and the partial magnification granularity.

A reading module has a light source, an optical system imaging, as image light, reflected light of light radiated from the light source to a document, a sensor where a plurality of imaging regions for converting the image light imaged by the optical system into an electrical signal are arranged next to each other in the main scanning direction, and a housing the light source, the optical system, and the sensor. The optical system has a mirror array where a plurality of reflection mirrors whose reflection surfaces are aspherical concave surfaces are coupled together in an array in the main scanning direction, and an aperture stop portion adjusting the amount of the image light reflected from the reflection mirror. The amount of the image light striking the reflection mirror is increasingly small from opposite end parts of the reflection mirror toward its central part in the main scanning direction.

An image forming apparatus includes a control unit: starting up a rotary polygon mirror based on a first signal output by a driving unit thereof; causing a light source to emit a laser-beam while controlling a rotational speed of the rotary polygon mirror based on the first signal to acquire a second signal output from a detecting unit of the laser-beam; turning off the light source after acquiring a phase relation between the first and second signals; causing a charging unit to charge a photosensitive member; making the laser-beam to enter onto the detecting unit without exposing the photosensitive member based on the phase relation in response to the rotational speed reaching a target speed; controlling the rotational speed based on the second signal in response to the laser-beam being entered; and starting image formation in response to the rotational speed converging within a predetermined range including the target speed.