An image forming apparatus includes a photosensitive member, a light source, a deflecting unit, a storing unit, a correcting unit, and a light source driving portion. Magnification correction data is determined using a quadratic function of a variable representing a scanning position with respect to a scanning direction. Coefficients of two quadratic functions corresponding to adjacent two regions included in a plurality of scanning regions are set so that a differential value calculated at the variable corresponding to a boundary of the two regions by a differential of the quadratic function for one region and a differential value calculated at the variable corresponding to the boundary of the two regions by a differential of the quadratic function for the other region are equal to each other.

An image forming apparatus includes a photosensitive member, a light source, a deflecting unit, a storing unit, a correcting unit, and a light source driving portion. Magnification correction data is determined using a quadratic function of a variable representing a scanning position with respect to a scanning direction. Coefficients of two quadratic functions corresponding to adjacent two regions included in a plurality of scanning regions are set so that a differential value calculated at the variable corresponding to a boundary of the two regions by a differential of the quadratic function for one region and a differential value calculated at the variable corresponding to the boundary of the two regions by a differential of the quadratic function for the other region are equal to each other.

An image forming apparatus includes a first medium scanned with a first signal, a second medium scanned with a second signal, a rotary polygon mirror that deflects the first and second signals, a synchronization signal generation circuit that generates a synchronization signal representing a time to start scanning the first medium, and at least one pseudo synchronization signal generation circuit that generates a pseudo synchronization signal with the synchronization signal. The pseudo synchronization signal represents a time to start scanning the second medium. Based on a previously calculated period of the synchronization signal and a period of the synchronization signal counted on a particular surface of the polygon mirror, the pseudo synchronization signal generation circuit generates a particular value for generating the pseudo synchronization signal. Based on the particular value, the pseudo synchronization signal generation circuit starts generating the pseudo synchronization signal when the synchronization signal is enabled.

An encoder includes a light emitting portion emitting light, an optical element portion splitting the light into a first beam and a second beam, an optical scale receiving the first beam and the second beam from the optical element portion, and a light receiving portion receiving the first beam and the second beam from the optical scale and outputting a signal in accordance with intensity of the received light, in which the optical element portion includes a prism on which the light is incident, a beam splitter disposed on the prism and splitting the light incident on the prism into the first beam heading for the optical scale and the second beam heading for an inside of the prism, and a first mirror portion disposed on the prism and reflecting the second beam from the beam splitter toward the optical scale.

An encoder includes a light emitting portion emitting light, an optical element portion splitting the light into a first beam and a second beam, an optical scale receiving the first beam and the second beam from the optical element portion, and a light receiving portion receiving the first beam and the second beam from the optical scale and outputting a signal in accordance with intensity of the received light, in which the optical element portion includes a prism on which the light is incident, a beam splitter disposed on the prism and splitting the light incident on the prism into the first beam heading for the optical scale and the second beam heading for an inside of the prism, and a first mirror portion disposed on the prism and reflecting the second beam from the beam splitter toward the optical scale.

A laser marking system includes a laser, an image capture device, a marking head including electromagnetic energy deflectors and a lens, beam paths of the laser of the image capture device both passing through the lens, and a computer system. The computer system is programmed to perform a method including generating an image calibration model at each of multiple areas across a marking field of the laser marking system, adjusting the electromagnetic energy deflectors to direct the beam path of the image capture device to multiple different locations within the marking field of the laser marking system, and capturing image tiles at each of the multiple different locations with the image capture device, wherein at each of the multiple different locations, if a location corresponds to an area at which an image calibration model was generated, correcting the image tile according to the image calibration model generated at the location.

A laser marking system includes a laser, an image capture device, a marking head including electromagnetic energy deflectors and a lens, beam paths of the laser of the image capture device both passing through the lens, and a computer system. The computer system is programmed to perform a method including generating an image calibration model at each of multiple areas across a marking field of the laser marking system, adjusting the electromagnetic energy deflectors to direct the beam path of the image capture device to multiple different locations within the marking field of the laser marking system, and capturing image tiles at each of the multiple different locations with the image capture device, wherein at each of the multiple different locations, if a location corresponds to an area at which an image calibration model was generated, correcting the image tile according to the image calibration model generated at the location.

Disclosed is a method of adjusting a plurality of optical elements associated with a printing system Laser Imaging Module (LIM). According to one exemplary embodiment, sensitivity analysis is performed on a computer model of the LIM system and an optical element alignment sequence is generated to minimize the number of optical element adjustments needed to achieve a predefined LIM performance.

Disclosed is a method of adjusting a plurality of optical elements associated with a printing system Laser Imaging Module (LIM). According to one exemplary embodiment, sensitivity analysis is performed on a computer model of the LIM system and an optical element alignment sequence is generated to minimize the number of optical element adjustments needed to achieve a predefined LIM performance.

An image forming apparatus includes a photosensitive member and a scanning unit including a light source, a rotatable polygonal mirror, and a sensor. The image forming apparatus includes setting of an operation in a first mode and setting of an operation in a second mode. The image forming apparatus further comprises, a surface identifying portion and a correction data storing portion configured to prestore correction data including first correction data for a first rotational speed and second correction data for a second rotational speed. Positional deviation in a main scan direction of laser light is corrected on the basis of the first correction data or the second correction data.