A diffractive optical element includes: a substrate; a protrusion and recess portion that is formed on one surface of the substrate and imposes predetermined diffraction on incident light; and an antireflection layer provided between the substrate and the protrusion and recess portion. An effective refractive index difference Δn in a wavelength range of the incident light between a first medium constituting a protrusion of the protrusion and recess portion and a second medium constituting a recess of the protrusion and recess portion is 0.70 or more. An exit angle range θ.sub.out of diffraction light exiting from the protrusion and recess portion when the incident light enters the substrate from a normal direction of the substrate is 60° or more. Total efficiency of diffraction light exiting from the protrusion and recess portion in the exit angle range is 65% or more.

A light source apparatus includes a plurality of light emitting apparatuses. Each of the light emitting apparatuses includes a plurality of light emitting devices each of which has a light emitting area and a non-light emitting area on an emission surface thereof that emits light. At least two light emitting apparatuses of the light emitting apparatuses constitute a light emitting apparatus group disposed such that the emission surfaces of the respective light emitting apparatuses are parallel to each other with a predetermined distance, and that a distance between light emitting areas of the respective light emitting apparatuses when viewed along a direction perpendicular to the emission surfaces of the at least two of the light emitting apparatuses is shorter than a distance between the light emitting areas of the respective light emitting apparatuses when the emission surfaces of the respective light emitting apparatuses are on the same plane.

A projector includes a light projector and a position adjuster. The light projector includes a holder holding a plurality of lenses and a movable frame element provided to be pivotable around the optical axis of the plurality of lenses and that pivots to move a target lens out of the plurality of lenses along the optical axis. The position adjuster includes an arm member connected to the movable frame element that pivots along with the movable frame element, an operation member provided to be pivotable around a pivotal axis substantially parallel to the optical axis and pivots when an end portion of the operation member opposite the arm member is moved, and a linkage mechanism that links the arm member to the operation member and causes the arm member to pivot in response to the pivotal motion of the operation member.

An illumination system is adapted to provide an illumination light beam. The illumination system includes a light-source module and a light-shape adjustment module. The light-source module is adapted to emit a first light beam. The light-shape adjustment module is disposed on the transmission path of the first light beam and is adapted to adjust the light shape of the first light beam. The light-shape adjustment module includes a first light-diffusing element, a second light-diffusing element, and a first lens element. The first light beam sequentially passes through the first light-diffusing element, the first lens element, and the second light-diffusing element to form the illumination light beam. A projection device having the illumination system is also provided.

Devices and methods for improving the flow of traffic at an intersection are disclosed, such as a traffic light assistance system comprising a light emitter, a light-directing device, a vehicle sensor, a traffic signal detector, and a control unit. The traffic light assistance system can be configured to detect a vehicle and direct projected light toward said vehicle to indicate a change of status of a traffic light. Such devices and methods can alert an operator of a vehicle to a change of status of a traffic light, such as a traffic signal turning green, and indicating that the operator should accelerate the vehicle. By providing means to alert otherwise distracted or inattentive drivers, time spent in traffic can be reduced.

The disclosed subject matter relates to a method of projecting an image by means of a light source emitting light pulses and an oscillating micro-electro-mechanical system (MEMS) mirror deflecting the emitted light pulses, comprising: providing a matrix of durations for each pixel, and incrementing or decrementing a pixel index whenever a respective duration indexed by the respective pixel indices in the playout matrix has lapsed; for each light pulse: retrieving the respective intensity and durations indexed by the current pixel indices, calculating an interval from at least one of said durations, emitting said light pulse with said retrieved intensity, and waiting said calculated interval before emitting the next light pulse. The disclosed subject matter further relates to a projector carrying out said method.

An optical system (300) includes an optical modulation element (103) to reflect an incident light (250) in a different direction, and an illumination optical system (301) through which light emitted from a light source (101) is emitted toward the optical modulation element (103). The illumination optical system (301) includes a lens array (14A, 14B), a lens (15) disposed in an order listed from an upstream side of an optical path, and a shielding part (50) disposed upstream from the lens (15) on the optical path. The shielding part (50) shields light incident on an effective diameter of the lens (15). In a direction perpendicular to an optical axis of the light emitted from the light source (101), the optical axis (101A) is shifted from a center position (15M) of the effective diameter of the lens (15) in an opposite direction with reference to the shielding part (50).

An optical system (300) includes an optical modulation element (103) to reflect an incident light (250) in a different direction, and an illumination optical system (301) through which light emitted from a light source (101) is emitted toward the optical modulation element (103). The illumination optical system (301) includes a lens array (14A, 14B), a lens (15) disposed in an order listed from an upstream side of an optical path, and a shielding part (50) disposed upstream from the lens (15) on the optical path. The shielding part (50) shields light incident on an effective diameter of the lens (15). In a direction perpendicular to an optical axis of the light emitted from the light source (101), the optical axis (101A) is shifted from a center position (15M) of the effective diameter of the lens (15) in an opposite direction with reference to the shielding part (50).

An information processing apparatus includes a recognizer, based on captured image information generated by capturing a region on which a first image including an individual image is projected from a projector, to recognize an obstacle between the region and the projector, an identifier, when the obstacle is recognized, to identify, based on first image information indicating the first image and a recognition result by the recognizer, the individual image of which projection is blocked by the obstacle as a specific image, a decider to decide changing a first position in the region on which the specific image is projected to a second position in the region toward which projection of the specific image is not blocked by the obstacle, and a generator to generate second image information indicating a second image including an auxiliary image teaching association between the specific image located at the second position and the object.

An imaging system includes an imaging apparatus including a first optical system that transmits first wavelength range light, and a first image sensor that receives the first wavelength range light guided by the first optical system, and a projector including a first light source that emits the first wavelength range light, and a second optical system that emits the first wavelength range light emitted from the first light source to a subject side, in which an optical specification of the first optical system and an optical specification of the second optical system correspond to each other, the first optical system includes a first optical element that is displaced by receiving power generated by a first drive source, and the second optical system includes a second optical element that is displaced by receiving power generated by a second drive source.