A head-mounted display optical module includes an optical lens group located at a light-emitting display side of the display panel and a protective layer located on an optical path between the display panel and the optical lens group. The protective layer includes at least one first protective layer. A refractive index of the first protective layer continuously changes therein at least along a radial direction that is located in a plane of the first protective layer and points from a center of the first protective layer to an edge of the first protective layer.

An optical system includes an image surface, an aperture stop, a first and a second quarter-wave plate, a partial reflector, a reflective polarizer, a first and a second optical lens element. The image surface and the aperture stop are respectively at a front side and a rear side of the optical system. The first quarter-wave plate is between the image surface and the aperture stop. The partial reflector between the first quarter-wave plate and the aperture stop has an average light reflectivity of 35%. The second quarter-wave plate is between the partial reflector and the aperture stop. The reflective polarizer is between the second quarter-wave plate and the aperture stop. The first optical lens element between the image surface and the aperture stop has a convex front-side surface. The second optical lens element between the first optical lens element and the aperture stop has a concave rear-side surface.

An optical system for displaying an image to a viewer includes a partial reflector, a reflective polarizer, and a first retarder layer. A light ray propagates along the optical axis and passes through the plurality of optical lenses, the partial reflector, the reflective polarizer, and the first retarder layer without being substantially refracted. For a cone of light incident on the optical system from an object comprising a spatial frequency of about 70, 60, 50, 40, or 30 line pairs per millimeter and filling the exit pupil with a chief ray of the cone of light passing through a center of the opening of the exit pupil of the optical system and making an angle of about 20 degrees with the optical axis, a modulation transfer function of the optical system is greater than about 0.2.

An eyepiece device for a surgical instrument, the eyepiece device including: an eyepiece frame; and at least one optical unit accommodated in the eyepiece frame, wherein the at least one optical unit comprises at least one first optical element and a second optical element connected with the at least one first optical element, wherein the second optical element is formed from a second material with abnormal dispersion and the first and the second optical elements together correct chromatic aberration; wherein the eyepiece frame comprises an expansion chamber for at least the second optical element, the expansion chamber forming an installation space for at least the second optical element in a radial direction.

An eyepiece includes a substrate and an in-coupling grating patterned on a single side of the substrate. A first grating coupler is patterned on the single side of the substrate and has a first grating pattern. The first grating coupler is optically coupled to the in-coupling grating. A second grating coupler is patterned on the single side of the substrate adjacent to the first grating coupler. The second grating coupler has a second grating pattern different from the first grating pattern. The second grating coupler is optically coupled to the in-coupling grating.

An object of the present invention is to provide a compact head-up display device. The head-up display device of the present invention includes an image forming unit that emits image light containing image information, and an eyepiece optical system that displays a virtual image by reflecting the image light, in which the eyepiece optical system includes a concave lens, a free curved surface lens, and a free curved surface concave mirror disposed in order from the image forming unit side along the emission direction of the image light.

Techniques and mechanisms for fabricating an eyepiece from a lens blank including blank bodies that are bonded to each other. In an embodiment, the blank bodies are formed by injection molding and adhered to one another. Fabrication of the eyepiece includes variously machining the blank bodies to shape respective lens bodies of the eyepiece. One or more blocking structures are coupled to reinforce the lens blank during at least part of such machining. In another embodiment, any blocking structures that are to resist forces of a particular machining process are coupled only indirectly to one of the blank bodies.

Disclosed herein are a slim immersive display device and a slim visualization device. The slim immersive display device includes a slim visualization module for forming an image on a retina of an eyeball of a user based on an externally input image signal, a state information acquisition unit for acquiring a state of an external device as a state image, and a content control unit for analyzing the state image, generating an image corresponding to virtual-reality environment information, and inputting the image to the slim visualization module.

An endoscope including: a shaft; a main body arranged at a proximal end of the shaft; an eyepiece arranged at a proximal end of the main body; an eyepiece system tube, in which the eyepiece is arranged; an eyepiece cone arranged at a proximal end of the eyepiece, wherein the eyepiece cone comprises at least two parts; and an electronic component arranged between the at least two parts of the eyepiece cone; wherein the electronic component is connected to an electronic circuit arranged inside the endoscope and outside the eyepiece system tube.

An observation optical system includes a display element and an eyepiece lens disposed on an eyepoint side of the display element. The eyepiece lens includes a first lens having positive optical power, a second lens having negative optical power, and a third lens consecutively in order from closest to a display element side to the eyepoint side. In a case where a half value of a longest diameter of a display region in the display element is denoted by H, and a focal length of the eyepiece lens in a state where diopter is −1 diopter is denoted by f, the observation optical system satisfies a conditional expression represented by 0.35<H/f<0.6.