Disclosed are various embodiments regarding a head-mounted device. According to an embodiment, a mount device comprises: a housing comprising a front surface, a rear surface that can be mounted on a head, and a side surface surrounding the front surface and the rear surface; a coupling portion can be disposed in housing, and can be configured to be coupled so as to slope an external electronic device at a designated angle with regard to the side surface; a prism comprising a first surface capable of facing, at the designated angle, at least a part of a display included in the external electronic device that can be coupled to the coupling portion, a second surface capable of changing (through total reflection) the direction of light that is incident from the display through the first surface, and a third surface capable of emitting the light, the direction of which has changed; a mirror arranged between at least a part of the side surface and the third surface; and a splitter arranged between the mirror and the third surface to be capable of transmitting at least a part of light emitted through the third surface and changing the direction of the light, which is transmitted and then reflected by the mirror, to a direction corresponding to the rear surface. Various other embodiments are possible.

An optical system, capable to admit a light beam, the optical system comprising: a plurality of reflectors configured to reflect the light beam, wherein each of the reflectors is configured to reflect an incident light beam such that the path of the incident light beam and the path of the reflected light beam are parallel to each other. Each of the reflectors has a reflection center axis positioned centrally between the path of the incident light beam and the path of the reflected light beam. At least two of the reflectors are arranged relative to each other such that their respective reflection center axes do not overlap, thereby enabling the path of the light beam to pass at least one of the at least two of the reflectors multiple times.

An interior rearview mirror assembly for a vehicle includes a reflective element disposed at a housing. The housing and the reflective element are tandemly and pivotally adjustable about a mounting structure mounted at an interior portion of the vehicle to provide a desired rearward field of view to a driver of the vehicle. A user input is actuatable by the driver of the vehicle. A motorized actuator is operable responsive to actuation of the user input to tilt the reflective element and the housing in tandem about a horizontal axis. Responsive to actuation of the motorized actuator responsive to the user input, the motorized actuator tandemly tilts the reflective element and the housing about the horizontal axis to orientate an outermost front surface of the reflective element more towards the driver or more away from the driver.

An interior rearview mirror assembly for a vehicle includes a reflective element disposed at a housing. The housing and the reflective element are tandemly and pivotally adjustable about a mounting structure mounted at an interior portion of the vehicle to provide a desired rearward field of view to a driver of the vehicle. A user input is actuatable by the driver of the vehicle. A motorized actuator is operable responsive to actuation of the user input to tilt the reflective element and the housing in tandem about a horizontal axis. Responsive to actuation of the motorized actuator responsive to the user input, the motorized actuator tandemly tilts the reflective element and the housing about the horizontal axis to orientate an outermost front surface of the reflective element more towards the driver or more away from the driver.

A light path adjustment mechanism includes a bracket, a light valve, a carrier, a first axis, a second axis and an optical plate member. A surface normal of a surface of the light valve crosses the bracket to define an intersection closest to the surface of the light valve, and the bracket has an end point furthest from the intersection measured in the direction of the surface normal. A distance between the intersection and the surface measured in the direction of the surface normal is smaller than a distance between the intersection and the end point measured in the direction of the surface normal.

A light path adjustment mechanism includes a bracket, a light valve, a carrier, a first axis, a second axis and an optical plate member. A surface normal of a surface of the light valve crosses the bracket to define an intersection closest to the surface of the light valve, and the bracket has an end point furthest from the intersection measured in the direction of the surface normal. A distance between the intersection and the surface measured in the direction of the surface normal is smaller than a distance between the intersection and the end point measured in the direction of the surface normal.

An optical imaging system for an ophthalmic laser beam delivery system, which includes a focusing objective including a plurality of lenses, a semi-transparent folding mirror disposed near an entrance of the focusing objective for reflecting a treatment laser beam into the focusing objective, a prism disposed adjacent a back surface of the folding mirror, the prism having a first, a second and a third surface, the second surface being disposed adjacent the back surface of the folding mirror, the prism being configured to reflect a light that has entered the second surface sequentially by the first surface and by the second surface toward the third surface to be output, a focusing lens module disposed adjacent the third surface of the prism to focus light output from the third surface of the prism, and an image sensor disposed to receive the light focused by the focusing lens module to form an image.

A deflection prism assembly for an endoscope having a lateral viewing direction, the deflection prism assembly including: a prism holder; and a deflection prism accommodated in the prism holder; wherein the deflection prism has a light outlet surface and an opposite light inlet surface arranged obliquely to the light outlet surface, the deflection prism further having a lateral surface extending between the light inlet surface and the light outlet surface; and the prism holder accommodates the deflection prism such that the prism holder surrounds less than all regions of the lateral surface of the deflection prism.

An optical system (OS) for focusing a beam of radiation (B) on a region of interest in a metrology apparatus is described. The beam of radiation (B) comprises radiation in a soft X-ray or Extreme Ultraviolet spectral range. The optical system (OS) comprises a first stage (S1) for focusing the beam of radiation at an intermediate focus region. The optical system (OS) comprises a second stage (S2) for focusing the beam of radiation from the intermediate focus region onto the region of interest. The first and second stages each comprise a Kirkpatrick-Baez reflector combination. At least one reflector comprises an aberration-correcting reflector.

An optical system (OS) for focusing a beam of radiation (B) on a region of interest in a metrology apparatus is described. The beam of radiation (B) comprises radiation in a soft X-ray or Extreme Ultraviolet spectral range. The optical system (OS) comprises a first stage (S1) for focusing the beam of radiation at an intermediate focus region. The optical system (OS) comprises a second stage (S2) for focusing the beam of radiation from the intermediate focus region onto the region of interest. The first and second stages each comprise a Kirkpatrick-Baez reflector combination. At least one reflector comprises an aberration-correcting reflector.