34results about How to "Small aberration" patented technology

A holographic projection system with a display screen and an optical wave tracking means for controlling the direction of propagation of a modulated wave uses a position controller and an eye finder. An extremely wide tracking range is realised in the projection system for simultaneous viewing of the reconstruction by multiple observers, which are situated beside one another. The reconstruction of the scene is reconstructed for each eye position of an observer such that the entire scene is visible in the visibility region in a large tracking range with minimal errors. The projection system reconstructs the scene with the help of modulated partial waves. Projection means direct these partial waves with separately holographically reconstructed segments of the scene at the desired eye position through a structure of screen segments which are at least horizontally staggered on the display screen.

The present invention provides a compact electron lens causing little aberration, and a charged particle beam apparatus such as a scanning electron microscope that is super compact and offers a high resolution. An upper magnetic pole and a sample-side magnetic pole are magnetically coupled to the respective poles of a permanent magnet that is made of a highly strong magnetic material such as a rare-earth cobalt system or a neodymium-iron-boron system, that is axially symmetrical, and that has a hole in the center thereof. An inner gap is created on the side of a center axis. Thus, a magnetic lens is formed axially. Moreover, a semi-stationary magnetic path that shields an outside magnetic field and has the magnetic reluctance thereof regulated is disposed outside. The sample-side magnetic pole and magnetic path defines a region where magnetic reluctance is the highest outside the permanent magnet. A space defined by the permanent magnet, upper magnetic pole, sample-die magnetic pole, and semi-stationary magnetic path is filled with a filling made of a non-magnetic material. Thus, an objective lens is constructed.

A wide-angle lens system having a long back focal length, disposed in front of a ⅓″ CCD camera and the focal length (f) for all lens groups is 3.0 mm, the F-number is 3.0 and the half-field angle is 46°. The following conditions are met by the first lens group: 1≦d/d3<1.2; R3/R2=0.99; and d2/f=0.03. Here, (d) indicates the thickness of the second lens along the normal line at a given distance from the optical axis within the maximum effective diameter of the object side convex surface of the lens. d3 is the thickness of the second lens along the optical axis.

A lens manufacturing method including a holding step of holding a lens in a lens holding fixture, and a machining step of machining a surface to be machined in the held lens. A reverse surface of the surface to be machined is machined into a non-planar shape with a first surface shape error. A lens holding surface of the lens holding fixture is machined into the same shape as the non-planar shape with a second surface shape error smaller than the first surface shape error. In the holding step, the reverse surface is brought into surface contact with the holding surface in imitation of the holding surface to correct the shape of the lens such that the reverse surface runs along the holding surface. In the machining step, the surface to be machined is machined in a state where the correction has been made by the holding step.

The invention provides a quasi-periodic optical metasurface imaging element. The quasi-periodic optical metasurface imaging element comprises a substrate and a plurality of cuboid nanorods generated on the substrate, the nanorods are divided into a first size and a second size which respectively correspond to a first wavelength lambda 1 and a second wavelength lambda 2; the first size of nanorodsand the second size of nanorods are alternately arranged in a gold spiral shape at intervals; the length and the width of the nanorod are coupled with the wavelength of an incident light beam; and therotation angle of the nanorod is coupled with the wavelength, focal length, additional phase modulation value and position of the incident light beam, so that the focal length of the element to the parallel incident light with two wavelengths is the same. By adjusting the length, the width and the rotation angle of the nanorod, adaptation to incident beams with various wavelengths can be achieved, the incident beams are focused at the same point and have the quasi-periodic characteristic, and the universality of the design scheme is greatly higher than that of an existing scheme.

A catadioptric objective system used for storage and/or reproduction of information by use of an optical near field. The catadioptric objective system is composed of a catadioptric objective lens and a light transmitting plate. The lens has a first surface and a second surface. The first surface has a positive optical power and transmits incident rays. The second surface has a positive optical power and reflects incident rays, and a plane portion is formed in the center of the second surface. The light transmitting plate has a third surface and a fourth surface which are substantially parallel to each other, and the third surface is bonded to the second surface. Incident rays pass through the first surface and are reflected by the second surface. Thereafter, the rays enter into the first surface again and are reflected by the first surface. Then, the rays pass through the plane portion of the second surface, and the rays are converged in vicinity of the fourth surface.

A zoom lens includes, in order from the object side: a positive first lens group; a negative second lens group; a positive third lens group; a negative fourth lens group; and a positive fifth lens group. The distance between the first and second lens groups constantly increases, the distance between the second and third lens groups constantly decreases, the distance between the third and fourth lens groups constantly changes, and the distance between the fourth and fifth lens groups constantly increases when changing magnification from the wide angle to the telephoto end. The first lens group includes, in order from the object side, a negative lens, a positive lens, and a positive lens. The fourth lens group includes, in order from the object side, a negative lens, a negative lens, and a positive lens, and moves toward the image side when focusing from a far distance to a close distance.