The present disclosure provides a printing apparatus. The printing apparatus includes a light-emitting device, a reflector, and a light-sensing device. The light-emitting device emits printing light. The reflector is at least partially located in an irradiation region of the printing light, and has a surface reflecting the printing light at different positions to generate reflected light having different exit directions. The light-sensing device includes a light-sensing surface. The light-sensing surface is at least partially located in an irradiation region of the reflected light and senses the reflected light to generate a plurality of continuously-distributed light spots on the light-sensing surface with any adjacent light spots equally spaced apart.

The shifted laser surface texturing method is a method of writing of large arrays of small objects (5) on surface or inside of a material. The whole array of objects (5) is produced by repeated linear raster (1) laser processing with sequential shifting of linear raster between each repetition of the scanning process. The linear raster is a set of paths (1) for laser beam scanning. Distance between spots (2) in the laser beam path (1) of the linear raster is defined by speed of laser beam scanning and by period between laser pulses. Sequence of linear raster shifts (4) defines the form of the small objects (5) in the array. Computational data for an array of the same objects (5) is very low. It is comparable to the number of lines N in one linear raster plus number of spots in one object. The presented method eliminates heat accumulation effect and strongly decreases plasma shielding effect, while at the same time enables effective use of high average power pulsed lasers.

An optical scanning apparatus includes a deflector configured to deflect a light beam from a light source and scan a surface to be scanned in a main-scanning direction and a single imaging optical element configured to guide the light beam deflected by the deflector to the surface to be scanned. Scanning speeds of the light beam on the surface to be scanned at an on-axis image height and at an off-axis image height are different from each other, and conditions

0.0<(R1.sub.h/2+R2.sub.h/2)/(R1.sub.h/2R2.sub.h/2)<1.7 and

0.8<h/TC<2.0

are satisfied.

An image forming apparatus including: a light source configured to emit a light beam; a rotary polygon mirror including a plurality of reflection surfaces each configured to deflect the light beam emitted by the light source so that the light beam scans a surface of a photosensitive member; a light receiving portion configured to output a light receiving signal by receiving the light beam reflected by each of the plurality of reflection surfaces; a conversion unit configured to convert the light receiving signal to a pulse signal; a measurement unit configured to measure pulse widths of a plurality of pulse signals corresponding to the plurality of reflection surfaces, respectively; and an identification unit configured to identify a rotation phase of the rotary polygon mirror based on a measurement result of the measurement unit and reference values to be compared with the measurement result.

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.

A brushless motor device configured to: determine a first upper limit of a current value which flows through a coil when a rotation speed of a rotor is accelerated from a first speed to a second speed, wherein, in a case where the current value of the first upper limit flows through the coil when the rotor is rotated at the second speed, a first time period, which is from a start of a non-energization time period of the coil until an induced voltage reaches a threshold value, is longer than a second time period, which is from the start of the non-energization time period until a counter-electromotive voltage becomes zero; and change switching of each switching element of an inverter circuit by using a second upper limit greater than the first upper limit and the first upper limit.

An optical scanning apparatus includes a semiconductor laser, a coupling lens, a polygon mirror, a motor, an optical scanning system including a first scanning lens with an optical surface, a housing, a cover, and a partition with an opening closed with the first scanning lens. Shifting amounts of a focus position of a beam with respect to a reference imaging plane in a main scanning direction are in relations ?A<0 and ?A<?B<?C, where ?A mm and ?B mm are shifting amounts when the semiconductor laser, the coupling lens, and the optical scanning system are at a normal ambient temperature and at an upper-limit ambient temperature, respectively, and ?C mm is a shifting amount when the semiconductor laser and the coupling lens are at the normal ambient temperature and the first scanning lens is at a first temperature.

An image forming apparatus includes: a unit configured to form an electrostatic latent image using a plurality of scan lines on a photosensitive body by, on a basis of an image signal, performing scanning of the photosensitive body in a main scan direction using one or more scanning beams repeatedly in a sub-scan direction orthogonal to the main scan direction; and a unit configured to store start position information indicating start positions in the main scan direction of the plurality of scan lines. In a case where scan positions in the sub-scan direction of the plurality of scan lines are linearly shifted relative to a target position with a period of N number of scan lines, the start position information indicates to linearly shift the start positions of N scan lines in the main scan direction along the sub-scan direction.

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.

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.