Abstract: The disclosure provides a visual system, sequentially including from a first side to a second side along an optical axis: a first lens with a positive refractive power, a reflective polarizing element, a quarter-wave plate, a second lens with a positive refractive power, a partially-reflective element and a third lens with a positive refractive power. A position of the first lens on the optical axis relative to an imaging surface of the second side is fixed, and a distance of the second lens on the optical axis relative to the first lens is adjustable. The visual system satisfies: 1.15?fg/f2?1.50 and 1.55<?L/?f<2.1.

Abstract: The disclosure provides a VR eyepiece system. The VR eyepiece system sequentially includes a first lens, a connecting assembly, a second lens, a diffractive optical element, a third lens, a semi-transparent and semi-reflective film and a display screen, where the diffractive optical element is closely fitted to an image-side surface of the second lens; the display screen is located on an imaging surface of the VR eyepiece system; F1, a combined focal length of the first lens, the connecting assembly, the second lens and the diffractive optical element, f3, an effective focal length of the third lens, and f, an effective focal length of the VR eyepiece system satisfy: 0.024?f/(F1?f3)?0.043; and the F1 and the f3 satisfy: ?2.066?f3/F1??0.036. The disclosure solves problems of low definition and a large chromatic aberration at an edge field of view of VR glasses in the related art.

Abstract: The disclosure provides a visual system, sequentially including, from a first side to a second side along an optical axis: a first lens with a positive refractive power, a second lens, a third lens, a partially-reflective element, a fourth lens with a negative refractive power, a second quarter-wave plate and a polarizing filter. The visual system further includes a reflective polarizing element and a first quarter-wave plate attached to each other; an included angle ?1.0 between the optical axis and a tangent of a second side surface of the third lens at a position of an intersection point of a chief ray in a 1.0 field of view after being reflected by the partially-reflective element and the second side surface of the third lens satisfies: 80.5°<?1.0<83.2°.

Abstract: A visual optical system is provided. The visual optical system includes a first optical system and a second optical system. The first optical system includes, sequentially from the first side to the second side along a first optical axis, a reflective polarizing element, a quarter wave plate, and a positive first lens piece. The second optical system includes, sequentially from the first side to the second side along a second optical axis, a positive first lens and a second lens. A radius of curvature R1m of the first-side surface of the first lens piece, a radius of curvature R2m of the second-side surface of the first lens piece, a combined focal length f12e of the first lens and the second lens, and a distance TDe on the second optical axis from a first-side surface of the first lens to a second-side surface of the second lens satisfy: 0.8<(R1m/R2m)/(f12e/TDe)<2.0.

Abstract: The disclosure provides an optical module and a VR eyepiece system. The optical module sequentially includes along an optical axis from an eye side to an image side: a cemented lens group, including a pair of plano-convex lenses, a first transflective film located between the pair of plano-convex lenses, a pair of first quarter-wave plates respectively arranged outside of the pair of plano-convex lenses, a pair of first polarizing reflective films respectively arranged outside of the pair of first quarter-wave plates; a refraction and reflection assembly, including a third lens, and a second quarter-wave plate and a second transflective film which are respectively arranged at an eye-side surface and an image-side surface of the third lens. In this way, light achieves multiple reflections within the cemented lens group, which is also able to increase an optical energy utilization of the cemented lens group while achieving folding of an optical path.

Abstract: Disclosed are a visual optical system and a virtual reality device with the visual optical system. The visual optical system includes a first lens, a composite film layer, a second lens, and a partially reflective film in sequence from a first side to a second side along an optical axis; where each of the first lens and the second lens has a positive refractive power; the composite film layer is arranged on the second side surface of the first lens, the composite film layer includes a polarizing reflective film and a quarter-wave plate, and the polarizing reflective film is located between the first lens and the quarter-wave plate; and the partially reflective film is arranged on the second side surface of the second lens, and the second side surface of the second lens is a convex surface and also a Fresnel surface.

Abstract: Disclosed is an optical system, sequentially including along the optical axis from a first side to a second side: a first lens having positive refractive power, its first side surface being convex and its second side surface being planar; a reflective polarizing element; a first quarter-wave plate; a second lens having positive refractive power, its first side surface being convex; a third lens having negative refractive power, its first side surface being concave and its second side surface being planar; a partially reflective element; a second quarter-wave plate; a polarizer; and a fourth lens having negative refractive power; wherein the number of lenses with refractive power in the optical system is four; the effective focal length f1 of the first lens and the effective focal length f3 of the third lens satisfy: ?1.5<f3/f1<?1.0; and it is satisfied: 2 ? ( CT ? 3 + CTQ ? 2 + CTL ) / ( CT ? 1 + CTR + CTQ ? 1 ) < 2.9 .

Abstract: The present disclosure discloses an optical system, including: a first lens having a positive refractive power, a reflective polarizing element, a first quarter wave plate, a second lens having a positive refractive power, a third lens having a negative refractive power, a partially reflective element, a fourth lens having a refractive power, a second quarter wave plate and a polarizer. An effective focal length f1 of the first lens and an effective focal length f2 of the second lens satisfy: 0.15<f2/f1<1.6; and center thicknesses CT1, CTR, CTQ1 and CT2 of the first lens, the reflective polarizing element, the first quarter wave plate and the second lens respectively on the optical axis satisfy: 0.35<(CT1+CTR)/(CTQ1+CT2)<1.05.

Abstract: An optical system is disclosed, which sequentially comprises along an optical axis from a first side to a second side: a first lens, a reflective polarizing element, a first quarter-wave plate, a second lens, a third lens, a partially reflective element, a fourth lens, a second quarter-wave plate, and a polarizer; wherein the first lens has positive refractive power, and its first side surface is a convex surface and its second side surface is a concave surface; the second lens has positive refractive power, and its first side surface is a plane and its second side surface is a convex surface; the third lens has negative refractive power, and its first side surface is a concave surface; the second side surface of the fourth lens is a plane; wherein the number of lenses with refractive power in the optical system is four, and it is satisfied: 0.4<fz1/|R1+R4|<1.2.

Abstract: A visual system includes a lens barrel, and a lens group and a spacing element group. The lens group includes, arranged in sequence: a first lens having a positive refractive power, a reflective polarizing element, a first quarter wave plate, a second lens having a negative refractive power, a third lens having a refractive power, a partially reflective element, a second quarter wave plate, a polarizer, and a fourth lens having a refractive power. A spacing EP01 from a first side surface of the lens barrel to a first side surface of the first spacing element along the optical axis and a center thickness CT1 of the first lens on the optical axis satisfy: 1.0<EP01/CT1<1.7; and an inner diameter dos of the first side surface of the lens barrel and a radius of curvature R1 of a first side surface of the first lens satisfy: 1.75<d0s/R1<2.3.

Abstract: The disclosure provides a visual optical lens assembly and a Virtual Reality (VR) eyepiece system. The visual optical lens assembly sequentially includes, along an optical axis from an object side to an image side: a first lens having a refractive power, a reflective polarizing element, a second lens having a negative refractive power, a quarter-wave plate, a third lens having a negative refractive power, and a partially-reflective element. An image-side surface of the first lens is a convex surface; object-side surfaces and image-side surfaces of the second and third lenses respectively are concave surfaces and convex surfaces; the first lens to the third lens are sequentially glued, and the visual optical lens assembly meets a relational expression: 1 < TTL / ( ImgH × tan ? ( Semi - FOV ) ) < 2.3 ; and 0.9 < ? CT / TD < 1 .

Abstract: The present invention relates to a massager with a plurality of massage modes and a massage method. The massager comprises an outer housing, a control board arranged in the outer housing, and a battery and a control button which are connected to the control board, wherein a handle is formed at one end of the outer housing, a charging port for charging the battery is arranged on the handle, at least one group of massagers are also arranged on the outer housing, one group of massagers comprises a first vibration motor and a transmission mechanism connected to the first vibration motor, at least one group of massage columns are arranged at an end portion of the transmission mechanism, and the massage columns are moved by the transmission mechanism when the first vibration motor is working.

Abstract: The disclosed embodiments relate to systems and methods for a surgical tool or a surgical robotic system.

Abstract: The present disclosure discloses a virtual reality apparatus, including a first optical system and a second optical system; the first optical system sequentially includes, along a first optical axis from a first side to a second side, a first lens having a positive refractive power, a reflective polarizing element, a quarter wave plate, a second lens and a third lens having a positive refractive power; the second optical system sequentially includes, along a second optical axis from an object side to an image side: a first lens element having a negative refractive power; a second lens element having a negative refractive power; a third lens element having a positive refractive power; a fourth lens element having a positive refractive power; a fifth lens element; a sixth lens element having a negative refractive power; a seventh lens element having a positive refractive power; and an eighth lens element.

Abstract: A visual optical system comprises a first optical system and a second optical system. The first optical system comprises a first lens having a positive refractive power, a reflective polarizing element, a quarter-wave plate, a second lens having a refractive power and a third lens having a positive refractive power. The second optical system comprises, sequentially along a second optical axis from the first side to the second side, first to sixth lens elements. An effective focal length f3? of the third lens, a distance TD? from a first-side surface of the first lens to a second-side surface of the third lens on the first optical axis, an effective focal length f1 of the first lens element and a distance TD from a first-side surface of the first lens element to a second-side surface of the sixth lens element on the second optical axis satisfy: 1.9<(f3?/TD?)/(|f1|/TD)<5.7.

Abstract: A visual optical system is provided, including a first optical system and a second optical system, the first optical system sequentially includes: a first element group, a second element group and a third element group, the first element group including a first lens element, a reflective polarizing element and a quarter wave plate; and the second optical system sequentially includes: a first lens, a second lens er, a third lens and a fourth; where, a distance TDm from a first side surface of the first element group to a second side surface of the third element group on the first optical axis and a distance TDe from a first surface of the first lens to a second surface of the fourth lens on the second optical axis satisfy: 5.0<TDm/TDe<15.0.

Abstract: A DC-DC converter, an on-board charger, and an electric vehicle are disclosed. The DC-DC converter includes: a first adjustment module, a resonance module, a second adjustment module, a current detection module, and a controller. The current detection module is configured to detect a current signal of the resonance module; and the controller is configured to control the first adjustment module and the second adjustment module to reduce an output power when the current signal is greater than a current threshold. By directly detecting the current signal of the resonance module, a high precision and a faster response are achieved.

Abstract: The present disclosure provides a cargo handling system. The cargo handling system comprises a first cargo handling robot and a second cargo handling robot, wherein the first cargo handling robot and the second cargo handling robot are configured to transport a cargo unit from a first position to a second position, the first cargo handling robot and the second cargo handling robot configured to move in two dimensions about a cargo deck.

Abstract: A massage device includes an outer housing, a control board arranged in the outer housing, a battery connected to the control board, and a control button connected to the control board and a charging port for charging the battery which are arranged on the outer housing. The outer housing is provided with an accommodation cavity, a contact massage portion is arranged in the accommodation cavity, the contact massage portion is connected to the outer housing by a main body, and the contact massage portion can completely enter a massage site for massage and can be pulled out from the massage site by the main body and placed in the accommodation cavity.