Abstract: A video display device is provided that naturally displays a video without blocking an observer's field of view, and includes the following: a display optical system that displays a video; an ocular optical system that guides video light emitted from the display optical system to the optical pupil of an observer; and a support that supports the ocular optical system upon the light path of video light emitted from the display optical system. The support includes a first support plate and a second support plate that face each other, and the ocular optical system is located between the first support plate and the second support plate. An opening through which the observer's line of sight passes is formed at least partially between the first support plate and the second support plate.

Abstract: A video display device is provided that naturally displays a video without blocking an observer's field of view, and includes the following: a display optical system that displays a video; an ocular optical system that guides video light emitted from the display optical system to the optical pupil of an observer; and a support that supports the ocular optical system upon the light path of video light emitted from the display optical system. The support includes a first support plate and a second support plate that face each other, and the ocular optical system is located between the first support plate and the second support plate. An opening through which the observer's line of sight passes is formed at least partially between the first support plate and the second support plate.

Abstract: A head-mounted display is provided, including: a display optical system that displays a video; an eyepiece optical system that projects the video displayed by the display optical system as a virtual image; a ranging unit that measures the visual range to an object facing the observer's eye or to the observer's point of regard; a projection distance adjusting unit that adjusts the projection distance of the virtual image projected by the eyepiece optical system on the basis of the visual range measured by the ranging unit; a view fluctuation detecting unit that detects fluctuations in the observer's direction of view; and a control unit. If fluctuations in the observer's direction of view are detected by the view fluctuation detecting unit, the control unit transmits a control signal to the ranging unit so as to initiate measurement of the visual range.