An electronic device according to the present invention is an electronic device which is capable of performing eye proximity sensing to sense contact of an eye with an eyepiece and line of sight detection to detect a line of sight, including: an eye proximity sensing sensor configured to receive light for the eye proximity sensing; a line of sight detection sensor configured to receive light for the line of sight detection, the line of sight detection sensor being separate from the eye proximity sensing sensor; and one or more light sources including a light source used for both the eye proximity sensing and the line of sight detection.

A display apparatus according to the present invention, includes: a display panel; a display optical system for looking at the display panel; an image sensor for capturing an eye of an user looking at the display panel, the image sensor having a rectangular imaging plane; and an imaging optical system for forming an optical image of the eye on the imaging plane, wherein the imaging optical system has an optical axis that is nonparallel to an optical axis of the display optical system, and a projected line of the optical axis of the display optical system on the imaging plane is substantially parallel to a long side of the imaging plane.

A display apparatus according to the present invention, includes: a display panel; a display optical system for looking at the display panel; an image sensor for capturing an eye of an user looking at the display panel, the image sensor having a rectangular imaging plane; and an imaging optical system for forming an optical image of the eye on the imaging plane, wherein the imaging optical system has an optical axis that is nonparallel to an optical axis of the display optical system, and a projected line of the optical axis of the display optical system on the imaging plane is substantially parallel to a long side of the imaging plane.

An electronic viewfinder unit includes a finder unit and a base member. The finder unit includes a display unit, an eyepiece portion, and a lens holding member holding a lens that guides a light flux emitted from the display unit to the eyepiece portion. The base member includes a guide member configured to guide the electronic viewfinder unit to a housed state and a protruding state. The base member includes a holding portion and a turning member. The holding portion is provided with a first holding member and a second holding member that face each other with an optical axis of the lens in between. The turning member has one end held by the first holding member and another end held by the second holding member, and is turnable about an axis orthogonal to the optical axis of the lens.

An electronic viewfinder unit includes a finder unit and a base member. The finder unit includes a display unit, an eyepiece portion, and a lens holding member holding a lens that guides a light flux emitted from the display unit to the eyepiece portion. The base member includes a guide member configured to guide the electronic viewfinder unit to a housed state and a protruding state. The base member includes a holding portion and a turning member. The holding portion is provided with a first holding member and a second holding member that face each other with an optical axis of the lens in between. The turning member has one end held by the first holding member and another end held by the second holding member, and is turnable about an axis orthogonal to the optical axis of the lens.

An electronic view finder includes a display element that displays an image, and an eyepiece lens that is disposed on an eyepoint side of the display element and that is used for observing the image. The eyepiece lens consists of a first lens, a second lens having refractive power of a different sign from the first lens, and a third lens having positive refractive power in order from a display element side. Diopter is adjustable by moving at least one lens of the eyepiece lens. A television distortion of the image displayed by the display element varies depending on the diopter.

An electronic view finder includes a display element that displays an image, and an eyepiece lens that is disposed on an eyepoint side of the display element and that is used for observing the image. The eyepiece lens consists of a first lens, a second lens having refractive power of a different sign from the first lens, and a third lens having positive refractive power in order from a display element side. Diopter is adjustable by moving at least one lens of the eyepiece lens. A television distortion of the image displayed by the display element varies depending on the diopter.

An observation device according to the present invention includes an image display element displaying an image, and a finder optical system used for observing the image displayed on an image display surface of the image display element. The finder optical system includes a positive first lens, a negative second lens, and a biconvex positive third lens arranged in this order from the image display surface side to the observation side. A focal length of the second lens, a focal length of the finder optical system, a curvature radius of a lens surface of the second lens on the image display surface side, a curvature radius of a lens surface of the second lens on the observation side, a diagonal length of the image display surface, and a curvature radius of a lens surface of the third lens on the image display surface side are appropriately set.

An observation device according to the present invention includes an image display element displaying an image, and a finder optical system used for observing the image displayed on an image display surface of the image display element. The finder optical system includes a positive first lens, a negative second lens, and a biconvex positive third lens arranged in this order from the image display surface side to the observation side. A focal length of the second lens, a focal length of the finder optical system, a curvature radius of a lens surface of the second lens on the image display surface side, a curvature radius of a lens surface of the second lens on the observation side, a diagonal length of the image display surface, and a curvature radius of a lens surface of the third lens on the image display surface side are appropriately set.

An imaging device is configured to include a finder and an eyecup unit. An eyecup is provided so as to surround an eyepiece window formed on a cover member. A base member holds the eyecup and the cover member. The eyecup is configured to include a curved and hollow eyepiece region, a first holding region comprising a first hole group, and a second holding region comprising a second hole group. The base member is configured to include a first protrusion group corresponding to the first hole group and a second protrusion group corresponding to the second hole group. The first hole group fits with the first projection group, and the second hole group fits with the second projection group.