A light deflector includes: a polygon mirror made of plastic and having a plurality of reflecting surfaces; a motor including a rotor and configured to rotate the polygon mirror; and a pressing member configured to press the polygon mirror toward the rotor in an axial direction of the motor. The polygon mirror has a first surface having a polygonal shape, and a second surface opposite to the first surface in the axial direction and having a polygonal shape. The second surface faces the rotor. The polygon mirror includes a plurality of first contact portions configured to be in contact with and pressed by the pressing member, and the first contact portions are provided on the first surface at positions equally distant from an axis of the motor between each of vertices of the first surface and the axis of the motor.

A spectrometer is provided. In one implementation, for example, a spectrometer comprises an excitation source, a focusing lens, a movable mirror, and an actuator assembly. The focusing lens is adapted to focus an incident beam from the excitation source. The actuator assembly is adapted to control the movable mirror to move a focused incident beam across a surface of the sample.

A light scanning apparatus, including: a light source; a deflector having a rotary polygon mirror configured to deflect the light beam emitted from the light source, and a motor configured to rotate the polygon mirror; a plurality of reflecting mirrors configured to reflect the light beam to the photosensitive member; and an optical box on which the light source is mounted, wherein the optical box has an installation wall on which the deflector is installed and a support wall positioned on a side of the photosensitive member with respect to the polygon mirror, the support wall being provided with a support portion configured to support at least one reflecting mirror, a stepped portion having a plurality of steps is formed between the installation wall and the support wall, and a back surface of the stepped portion has a shape following an inside surface of the stepped portion.

A rotary polygon mirror has no recess in a thickness region of one of the reflecting surfaces of the rotary polygon mirror in the direction of the rotation axis of the rotary polygon mirror and has a protruding portion protruding from the thickness region in a direction away from the thickness region.

In order to provide a polygon mirror which can reduce a light amount difference among respective image heights on a scanned surface with suppressing an increase in size in a light scanning apparatus, the polygon mirror according to the present invention includes a plurality of rectangular reflecting surfaces in which the following condition is satisfied:

0.02<|1−B/A|<0.10

where A represents a reflectivity at a center of the reflecting surface with respect to a light flux which is incident at a predetermined incident angle, and B represents the reflectivity at a predetermined point between the center and an end in the longitudinal direction of the reflecting surface with respect to the light flux which is incident at the predetermined incident angle.

A laser scanning unit (LSU) identification method and an image forming device are provided. The image forming device includes a processor and a target LSU, where the target LSU includes a laser diode, a laser diode drive unit, a polygon mirror, and a motor. The method includes providing a signal related to a quantity of reflective surfaces of the polygon mirror to the processor by the target LSU; identifying the quantity of the reflective surfaces of the polygon mirror of the target LSU according to the signal related to the quantity of the reflective surfaces of the polygon mirror provided by the target LSU, and determining a control parameter of the target LSU according to an identified quantity of the reflective surfaces by the processor, thereby controlling the target LSU according to the control parameter; and operating according to the control parameter by the target LSU.

An image display system can include a plurality of light sources configured to emit uncollimated light, and an eyepiece waveguide having an input port configured to receive beams of light at differing angles. The image display system also includes a scanning mirror having a surface with positive optical power configured to receive light emitted by the plurality of light sources. The surface with positive optical power is configured to collimate light emitted by the plurality of light sources to form a plurality of collimated light beams and direct the plurality of collimated light beams to the input port.

Disclosed herein are various forms of prime polygon reflectors. In its various forms it is a device of predetermined geometric shape with aspects and scalable dimensions derived from a prime number and its mathematical square root. Geometric shapes based on the prime polygon have reflective surfaces that cause multiple internal reflections of incident waveform energy. In some forms the reflectors are truncated comprising arrayed truncated prime polygon reflectors. When used in conjunction with or absent absorptive media, coatings, or linings, they reject passage of electromagnetic energy within a band that varies with reflector size and can be used with or without a ground. Applications include but are not limited to acoustic, solar, and radar energy absorption, as well as passive barriers for reduction of electromagnetic radiation exposure, and bandwidth-tunable panels for architectural electromagnetic shielding.

In one example, a method of fabricating a polygon assembly of a Light Detection and Ranging (LiDAR) module is provided. The method comprises: forming, on a backside surface of a first silicon-on-insulator (SOI) substrate, a multi-facet polygon of the polygon assembly; forming, on a frontside surface of the first SOI substrate, an axial portion of a support structure of the polygon assembly, the axial portion forming a stack with the polygon along a rotation axis; forming, on a frontside surface of a second SOI substrate, a plurality of radial portions of the support structure; forming, on a backside surface of the second SOI substrate, a cavity that encircles the plurality of radial portions; and bonding, based on a wafer bonding operation, the axial portion to the plurality of radial portions to form the polygon assembly.

In one example, a Light Detection and Ranging (LiDAR) module is provided. The LiDAR module comprises a semiconductor integrated circuit comprising a micro-electromechanical system (MEMS) formed on a surface of a silicon substrate, and a controller, the MEMS comprising a polygon assembly, the polygon assembly comprising: a polygon; a support structure connected to the polygon and forming a stack with the polygon along a rotation axis; a plurality of anchors formed on the surface of the substrate; and a plurality of actuators, each actuator of the plurality of actuators being connected between the support structure and an anchor of the plurality of actuators. The controller is configured apply a voltage across each actuator of the plurality of actuators, wherein the voltage causes each actuator to exert a torque on the support structure to rotate the polygon around the rotation axis by a target rotation angle.