A CPU is provided which controls a first light emission state in which a light source is controlled to emit a light beam to scan a full-scanning region and a second light emission state in which the light source is controlled to emit a light beam to scan a non-image region in a period from start of activation of a scanning motor to when the number of rotations of the scanning motor reaches a target number of rotations. The CPU acquires BD cycle values of BD signals generated by a main-scanning synchronization sensor, determines a second timing for changing from the first light emission state to the second light emission state on the basis of the two serial BD cycle values, and changes the semiconductor laser from the first light emission state to the second light emission state according to the second timing.

An optical member that refracts a light beam to diverge or focus the light beam, includes: at least three pairs of opposing surfaces. Each of the three pairs of opposing surfaces include a lens. Curvatures of the lenses at one side surfaces of the respective three pairs of surfaces are all the same, or curvatures of the lenses at one side surfaces of respective pairs of at least two pairs of the three pairs of surfaces are different from each other, and respective shortest distances between optical axes of the lenses at the one side surfaces of respective pairs of the at least two pairs of surfaces, and reference sides which are each any one of respective sides surrounding surfaces including the lenses are different from each other.

The present invention introduces a scanning arrangement and a method suitable for coating processes applying laser ablation. The arrangement is suited to prolonged, industrial processes. The arrangement comprises a target, which has an annular form. The laser beam direction is controlled by a rotating mirror locating along the center axis of the annular target. The scanning line will rotate circularly along the inner target surface when the mirror rotates. The focal point of the laser beams may be arranged to locate on the inner target surface to ensure a constant spot size. A ring-formed, a cylinder-shaped or a cut conical-shaped target may be used. The inner surface of the target may thus be tapered in order to control the release direction of the ablated material towards a substrate to be coated.

In an image-forming apparatus, an optical scanning device that is adjustable in a turn available manner around a turn axis line parallel to an axis line orthogonal to a main scanning direction of a light beam is attached to an image-forming apparatus body. The image-forming apparatus body has a shaft support that supports the optical scanning device in a turn available manner around a turn axis line and a holder facing a housing at a position different from that of the shaft support. The optical scanning device is held by the image-forming apparatus body in a state in which an elastic member is sandwiched between the housing and the holder in a pressed manner.

The present disclosure describes a system and method for coaxial LiDAR scanning. The system includes a first light source configured to provide first light pulses. The system also includes one or more beam steering apparatuses optically coupled to the first light source. Each beam steering apparatus comprises a rotatable concave reflector and a light beam steering device disposed at least partially within the rotatable concave reflector. The combination of the light beam steering device and the rotatable concave reflector, when moving with respect to each other, steers the one or more first light pulses both vertically and horizontally to illuminate an object within a field-of-view; obtain one or more first returning light pulses, the one or more first returning light pulses being generated based on the steered first light pulses illuminating an object within the field-of-view, and redirects the one or more first returning light pulses.

An object detector and a sensing apparatus are provided. The object detector includes a light source, a light deflector configured to deflect light emitted from the light source, and a photodetector configured to detect the light that is deflected by the light deflector and then is reflected at an object, where the light deflector includes a plurality of reflection planes that rotate on a rotation axis, the reflection planes are oblique to the rotation axis and are rotationally symmetrical about the rotation axis, and the light that is emitted from the light source enters the light deflector in a direction parallel to the rotation axis. The sensing apparatus includes the object detector, and a monitoring controller configured to determine whether an object is present, and obtain movement information of the object including at least one of moving direction and moving speed of the object.

An optical scanning device includes a deflector for deflecting a light beam to optically scan a scanned region on a scanned surface in a main scanning direction, and an imaging optical system for guiding the light beam deflected by the deflector, to the scanned surface. The imaging optical system includes an imaging optical element in which, in the main scanning direction, a distance to an optical axis from one effective end portion through which a light beam that enters one end portion of the scanned region passes is longer than a distance to the optical axis from another effective end portion through which a light beam that enters another end portion of the scanned region passes. In the imaging optical element, a thickness in an optical axis direction of the one effective end portion is thinner than a thickness in the optical axis direction of the other effective end portion.

A laser scanning device includes a polygon mirror, one or more lenses, and a plurality of light shielding plates. The polygon mirror reflects a light beam during rotation of the polygon mirror. The lenses allow the light beam reflected off the polygon mirror to pass through the lenses. The plurality of light shielding plates are arranged at a distance from each other and block an undesirable beam, which is part of the light beam, reflected off at least one of the lenses and heading for an optical device. The plurality of light shielding plates form an air channel that allows an air current generated by the rotation of the polygon mirror to flow through the air channel.

A scanning optical device includes a semiconductor laser, a coupling lens, a condenser lens, a deflector, a scanning optical system, a frame, and a first cover. The coupling lens converts light emitted by the first semiconductor laser to a light beam. The light beam received from the coupling lens is concentrated through the condenser lens. The deflector includes a polygon mirror configured to deflect the light beam received from the condenser lens. The scanning optical system directs the light beam deflected by the deflector toward an image plane. The deflector and the scanning optical system are fixed to the frame. The first cover covers at least a portion of the frame on which the deflector is located. The frame includes a wall having an opening through which a light beam traveling toward the polygon mirror passes. The condenser lens closes the opening.

An optical scanning apparatus of the present invention includes: a splitting element which splits a light flux emitted from a light source into first and second light fluxes; a deflecting unit which deflects the first and second light fluxes to scan first and second scanned surfaces in a main scanning direction; and an imaging optical system which includes a first imaging lens on which both the first and second light fluxes deflected by the deflecting unit are incident and guides the first and second light fluxes to the first and second scanned surfaces. The condition expressed by

−1.1≦α1/α2≦−0.9

is satisfied where α1 and α2 are angles within a main scanning cross section between a first axis parallel to the main scanning cross section and directions of incidence of the first and second light fluxes on the deflecting unit, respectively.