31results about How to "Wide field angle" patented technology

A zoom lens system includes a first lens group which has a negative refractive power, a second lens group which has a positive refractive power, and a third lens group which has a positive refractive power in this order from the object side and changes the distances among these lens groups to vary the power from the wide-angle end to the telephoto end. The second lens group has a three-element cemented lens including a positive lens c1, a negative lens c2, and a positive lens c3.

To realize a zoom lens system, including, in order from an object side to an image side: a first lens unit having a negative optical power; a second lens unit having a positive optical power; a third lens unit having a negative optical power; and a fourth lens unit having a positive optical power, in which: during zooming, an interval between the first lens unit and the second lens unit at a telephoto end is smaller than that at a wide angle end, an interval between the second lens unit and the third lens unit at the telephoto end is larger than that at the wide angle end, and an interval between the third lens unit and the fourth lens unit at the telephoto end is smaller than that at the wide angle end; and specific conditions are satified.

A zoom lens includes a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, and a rear unit including one or more lens units, which are arranged in order from the object side to the image side. The zoom lens performs zooming by changing distances between the first, second, and rear lens units. A first focusing unit and a second focusing unit which move independently of each other during focusing are provided. The first and second focusing units are adequately set.

An objective lens system consisting of a first lens unit having a negative refractive power and a second lens unit having a positive refractive power wherein the first lens unit or the second lens unit comprises at least one radial type gradient index lens element which has a refractive index distribution in a radial direction from an optical axis. This objective lens system favorably corrects chromatic aberration and other aberrations by adequately selecting a value expressing an Abbe's number and a refractive power of medium for the radial type gradient index lens element.

A zoom lens including a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power and a fifth lens group having a negative refractive power, in an order from an object; wherein a variable power from a wide angle end to a telephoto end is performed by changing distances among the respective lens groups, and the fourth lens group comprises a three cemented lens comprising a positive c1 lens, a negative c2 lens, and a positive c3 lens from an order from the object.

An image scanning lens includes, arranged in order from the object side, a first lens element having negative refractive power and a meniscus shape with its convex surface on the object side, a biconvex second lens element and a biconcave third lens element that are cemented together, a stop, a biconcave fourth lens element and a biconvex fifth lens element that are cemented together, and a sixth lens element having negative refractive power and a meniscus shape with its convex surface on the image side. The image scanning lens may include only these six lens elements. The image scanning lens satisfies certain conditions related to the focal lengths of the first lens element, the second and third lens elements together, the entire image scanning lens, radii of curvature of various surfaces, and anomalous dispersion of various lens elements. An image reader with an image pickup device, such as a CCD, uses the image scanning lens.

A zoom lens includes a negative first lens group, a positive second lens group, and a positive third lens group; wherein, when changing power from a wide-angle end state to a tele end state, the first lens group moves such that air space between the first lens group and the second lens group decreases, and air space between the second lens group and the third lens group increases, and the second lens group moves toward the object side; and wherein the first lens group includes a negative lens with both faces formed aspherically and the concave face facing the image side, and a positive meniscus lens with at least one face formed aspherically and the convex face facing the object side, satisfying2.8<|f1 / fw|<3.3where f1 represents the focal length of the first lens group, and fw represents the entire focal length in the wide-angle end state.

A zoom lens comprises a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, and a rear group including at least one lens unit, in order from an object side to an image side. Each of the lens units is configured to move so that a total lens length at a wide-angle end is longer than that at a telephoto end to perform a zoom operation. A movement amount M1 of the first lens unit at the wide-angle end and the telephoto end with respect to an imaging surface, a focal length f1 of the first lens unit, and focal lengths fw and ft of a whole system at the wide-angle end and the telephoto end are appropriately set.

Disclosed are a short-range optical amplification module, spectacles, a helmet and a VR system. The amplification module includes a reflective polarizing plate, a first phase delay plate, a second lens and a second phase delay plate that are arranged in turn, and a first lens is further set on either side of any one of the reflective polarizing plate, the first phase delay plate, the second lens and the second phase delay plate; in the second lens, the optical surface adjacent to the second phase delay plate is a transflective optical surface; the first focal length f2 of the second lens meets the condition: 1.2F≤f2≤2F, wherein F is the system focal length of the optical amplification module. By performing parameter refining on the first focal length f2 that influences the optical amplification effect, the module can keep a small overall thickness while obtaining a large optical amplification effect, and the VR device can realize a good field angle, a large eyebox and a high-quality imaging effect, and hence a better user experience.

A projection system includes a first lens group to an n-th lens group with n being 6 or 7 sequentially arranged from a enlargement side. The first lens group includes a first-first lens group and a first-second lens group sequentially arranged from the enlargement side. The two lens groups are separated from each other by a variable distance for image plane correction. The first lens group and the n-th lens group are fixed and the second lens group to the (n−1)-th group are moved when the magnification is changed. The following conditional expression is satisfied: 2<BF / fw<2.8, where fw represents the focal length of the projection system operating at the wide angle end, and BF represents the air conversion length of the back focal distance of the projection system.

The present invention discloses a short-range optical amplification module, which includes, sequentially from the image side to the object side, a reflective polarizing plate, a first phase delay plate, a third lens and a second phase delay plate, wherein the short-range optical amplification module further includes a first lens and / or a second lens that are / is located on either side of any one of the reflective polarizing plate, the first phase delay plate, the third lens and the second phase delay plate. In the third lens, the optical surface adjacent to the second phase delay plate is a transflective optical surface; the reflection surface-containing focal length f3 of the third lens meets the following condition: 1F≤f3≤2F, wherein F is the focal length of the short-range optical amplification module. By performing parameter refining on the f3 that influences the optical amplification effect, the module can keep a small overall thickness while obtaining a large optical amplification effect and it can be applied in a small-size VR device, so that the VR device can realize a wide field angle, a large eyebox and high-quality imaging effect, and hence a better user experience.

At least one exemplary embodiment is directed to a zoom lens which includes, in order from the object side to the image side, a first lens unit having a negative refractive power, a second lens unit having a negative refractive power, a stop, a third lens unit having a positive refractive power, and a fourth lens unit having a positive refractive power. The distance between the first lens unit and the second lens unit changes during zooming. At least one of the second, third, and fourth lens units moves so that the distance between the second lens unit and the third lens unit at the telephoto end is smaller than that at the wide-angle end and so that the distance between the third lens unit and the fourth lens unit at the telephoto end is larger than that at the wide-angle end. The distance between the stop and the third lens unit changes during zooming.