231results about How to "Diffraction reduction" patented technology

In order to minimize light diffraction along the direction of switching and more particularly light diffraction into the acceptance cone of the collection optics, in the present invention, micromirrors are provided which are not rectangular. Also, in order to minimize the cost of the illumination optics and the size of the display unit of the present invention, the light source is placed orthogonal to the rows (or columns) of the array, and / or the light source is placed orthogonal to a side of the frame defining the active area of the array. The incident light beam, though orthogonal to the sides of the active area, is not however, orthogonal to any substantial portion of sides of the individual micromirrors in the array. Orthogonal sides cause incident light to diffract along the direction of micromirror switching, and result in light ‘leakage’ into the ‘on’ state even if the micromirror is in the ‘off’ state. This light diffraction decreases the contrast ratio of the micromirror. The micromirrors of the present invention result in an improved contrast ratio, and the arrangement of the light source to micromirror array in the present invention results in a more compact system. Another feature of the invention is the ability of the micromirrors to pivot in opposite direction to on and off positions (the on position directing light to collection optics), where the movement to the on position is greater than movement to the off position. A further feature of the invention is a package for the micromirror array, the package having a window that is not parallel to the substrate upon which the micromirrors are formed. One example of the invention includes all the above features.

A multifocal diffractive lens comprises a multifocal diffractive structure coupled to a refractive component. The refractive component comprises at least one curved surface. The multifocal diffractive structure comprises a first plurality of substantially monofocal echellettes having a first optical power for near vision correction and a second plurality of substantially monofocal echellettes for far vision correction. The first plurality of substantially monofocal echellettes combined with the second plurality of substantially monofocal echellettes can provide a multifocal diffractive profile having decreased light scatter, chromatic aberration, and diffraction to non-viewing orders such that dysphotopsia is substantially inhibited. A third plurality of substantially monofocal echellettes having an intermediate optical power can be combined with the first plurality of substantially monofocal echellettes and the second plurality of substantially monofocal echellettes.

A multifocal diffractive lens comprises a multifocal diffractive structure coupled to a refractive component. The refractive component comprises at least one curved surface. The multifocal diffractive structure comprises a first plurality of substantially monofocal echellettes having a first optical power for near vision correction and a second plurality of substantially monofocal echellettes for far vision correction. The first plurality of substantially monofocal echellettes combined with the second plurality of substantially monofocal echellettes can provide a multifocal diffractive profile having decreased light scatter, chromatic aberration, and diffraction to non-viewing orders such that dysphotopsia is substantially inhibited. A third plurality of substantially monofocal echellettes having an intermediate optical power can be combined with the first plurality of substantially monofocal echellettes and the second plurality of substantially monofocal echellettes.

A compact and versatile multi-spot inspection imaging system employs an objective for focusing an array of radiation beams to a surface and a second reflective or refractive objective having a large numerical aperture for collecting scattered radiation from the array of illuminated spots. The scattered radiation from each illuminated spot is focused to a corresponding optical fiber channel so that information about a scattering may be conveyed to a corresponding detector in a remote detector array for processing. For patterned surface inspection, a cross-shaped filter is rotated along with the surface to reduce the effects of diffraction by Manhattan geometry. A spatial filter in the shape of an annular aperture may also be employed to reduce scattering from patterns such as arrays on the surface. In another embodiment, different portions of the same objective may be used for focusing the illumination beams onto the surface and for collecting the scattered radiation from the illuminated spots simultaneously. In another embodiment, a one-dimensional array of illumination beams are directed at an oblique angle to the surface to illuminate a line of illuminated spots at an angle to the plane of incidence. Radiation scattered from the spots are collected along directions perpendicular to the line of spots or in a double dark field configuration.