Abstract: A light emitting device includes a light emitting unit that generates heat as light is emitted, a support portion that supports the light emitting unit, a heating unit that is disposed close to a surface opposite to the light emitting unit with respect to the support portion and that heats the support portion, an air blowing unit that blows air to the light emitting unit from a heating unit side, and a cover portion that is provided between the heating unit and the air blowing unit and that covers the heating unit against wind caused by the air blowing unit.

Abstract: A light emitting device includes: a member having a first surface facing in one direction and a second surface facing an opposite side to the first surface; a light emitter that is disposed at the first surface, generates heat due to light emission, and has a lower stiffness than the member; and a heater that is disposed at the second surface of the member, and heats the member from the second surface.

Abstract: A display system includes an optical element through which light diverges and an imaging optical system configured to form an image by projecting diverging light diverging through the optical element. In the display system, the image formed by the imaging optical system is visually recognized by a viewer, and a condition in an equation tan 0?(T×B)/(S×O) is satisfied, where ? denotes a divergence angle of the optical element, T denotes distance between the image forming optical system and the formed image, B denotes a range of an eye box that is an area through which the formed image can visually be recognized, S denotes distance between the formed image and a viewpoint of the viewer of the formed image, and O denotes distance between the optical element and the image forming optical system. In the above equation, each distance indicates length of an optical path that passes through a center of an image formed by the light when an object is observed from a reference eyepoint.

Abstract: A light emitting device includes: a member having a first surface facing in one direction and a second surface facing an opposite side to the first surface; a light emitter that is disposed at the first surface, generates heat due to light emission, and has a lower stiffness than the member; and a heater that is disposed at the second surface of the member, and heats the member from the second surface.

Abstract: An imaging device includes an imaging element, and an image capturing optical system configured to generate an image of an object on the imaging element. The image capturing optical system has a gradient decreasing region in which a change of a gradient of an image magnification rate with respect to an angle of view of the image generated on the imaging element decreases as a concerned position deviates farther away from an optical axis of the image capturing optical system, and a gradient increasing region in which the change of the gradient of the image magnification rate with respect to the angle of view of the image generated on the imaging element increases as the concerned position deviates farther away from the optical axis of the image capturing optical system.

Abstract: An imaging device includes an imaging element, and an image capturing optical system configured to generate an image of an object on the imaging element. The image capturing optical system has a gradient decreasing region in which a change of a gradient of an image magnification rate with respect to an angle of view of the image generated on the imaging element decreases as a concerned position deviates farther away from an optical axis of the image capturing optical system, and a gradient increasing region in which the change of the gradient of the image magnification rate with respect to the angle of view of the image generated on the imaging element increases as the concerned position deviates farther away from the optical axis of the image capturing optical system.