The disclosure provides a laser scanning unit, an image forming device and a scanning control method, where the laser scanning unit includes a deflection device, an optical system, a first light source, a second light source, a line synchronization detection unit and a controller. The controller is configured to adjust a first time interval and/or a second time interval according to a change value of a third time interval. The first time interval is a time interval between a start time of a first detection signal and a first scanning start time, the second time interval is a time interval between a start time of a second detection signal and a second scanning start time, and the third time interval is a time interval between the start time of the first detection signal and the end time of the second detection signal.

A drawing system according to an embodiment of the present disclosure includes a light source section and a scanning section. The light source section generates a plurality of laser light beams having wavelengths that are different from each other and each correspond to an absorption wavelength of a photothermal conversion agent included in a recording medium. The scanning section scans a surface of the recording medium with the plurality of laser light beams in a state in which irradiation spots of the plurality of laser light beams are arranged side by side at predetermined intervals in a direction orthogonal to or obliquely intersecting with a scanning direction of the plurality of laser light beams.

An image forming apparatus includes four photosensitive members, a first optical scanning unit, a second optical scanning unit, a first detection unit, a second detection unit and a control unit. The first optical scanning unit draws a first reference image and a first opposite image. The second optical scanning unit draws a second reference image and draws a second opposite image. The first detection unit detects the internal temperature of at least one of the first optical scanning unit and the second optical scanning unit. The second detection unit detects an apparatus internal temperature within an apparatus main body. The control unit corrects positions of the drawing of the first opposite image, the drawing of the second reference image and the drawing of the second opposite image based on the amount of change in the internal temperature and the amount of change in the apparatus internal temperature.

An optical scanning device includes: a scanner that includes multiple light-emitting element sets, the multiple light-emitting element sets being arranged in a main scanning direction so as to face a subject to be scanned and being each constituted by multiple light-emitting elements arranged in the main scanning direction, and that scans the subject by causing each of the multiple light-emitting element sets to emit light based on image information; a driver that drives each of the multiple light-emitting element sets for each scanning period; and a discard-current generator that generates a discard current which is to flow from the driver during a non-scanning period which is set between the scanning periods, the discard current being different from a current to flow to each of the multiple light-emitting element sets, and that also controls the generated discard current.

A method for marking of a receptacle while it is moved along a conveying path, including: moving the receptacle in a marking station along the conveying path; and simultaneously marking a first surface region and a second surface region of the receptacle while it is moved in the marking station along the conveying path, using a first laser beam and a second laser beam emitted in opposite directions on both sides of the receptacle, transversally to a conveying direction of the receptacle, wherein the first and second surface regions are arranged substantially at 180 from each other with respect to a main axis of the receptacle.

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.