Morgan Construction Company

Coulter Information Systems, Inc.

Hss, Inc.

Willem Brouwer

Richard J Reardon

Harold S Stewart

Marion P Shuler, Jr

A lens testing method and apparatus is disclosed to test the transfer function of a lens at a multiple number of points in the lens and to locate the best focal plane and format position of the lens within the specified focal range of the lens. The lens is mounted in the lens tester between the object plane and the image plane. The object plane has a multiple number of beam forming apertures which are illuminated to project individual light images through the lens to respective targets or target segments in the image plane. The targets are a multiple number of apertures geometrically similar to the object aperture, having a fixed orientation to the object plane apertures. The target and object planes are moved relative to one another such that the individual light images are moved across the apertures of their corresponding targets. The light images passing through the target apertures are sensed to determine the transfer function of the lens at the respective points in the image plane. The lens may be rotated 90.degree. to test the meridional and the sagittal transfer function of the lens at each point. In operating the lens tester, the lens is first moved to a suitable focal plane and the value of the transfer function at the desired points in the image are compared with a predetermined minimum acceptable values of the transfer function. If the value of the transfer function at any tested point in the lens falls below the minimum acceptable value, the lens is moved to another suitable focal plane and again tested. Once all the points in the lens test above the minimum value of the transfer function for each respective point, the total of the transfer functions for each format position is determined by rotating the lens and testing again. The one best format position and focal plane is then found by comparing the total value of the transfer function for each point in each suitable focal plane within the lens focal range with the total value of the previous best focal plane. The lens may be rotated any number of steps in each focal plane to test as many format positions around the lens as desired to determine the best format position in the best focal plane.

Lens testing method and apparatus

An apparatus for observing the relative alignment of two pairs of guide rollers on a rolling mill roller guide. The roller guide is positioned with its guide roller pairs spaced along an axis extending between two light sources. A dichroic mirror is arranged between each pair of guide rollers and its adjacent light source. One dichroic mirror reflects blue light while transmitting red light, and the other dichroic mirror reflects red light while transmitting blue light. The light reflected from both dichroic mirrors is recombined by a third dichroic mirror and is then projected onto a screen as red and blue images which may be compared visually with a reference outline on the screen, the said outline being representative of proper guide roller alignment. When the roller pairs are properly aligned, the red and blue images coincide on the screen to produce a white image aligned with the reference outline.

Alignment apparatus for rolling mill roller guides

An instrument for responding to backscattered or backreflected radiation from a path through a medium in which a beam of electromagnetic radiation is transmitted along the path, and a receiver system is arranged to receive backscattered radiation returning along the path substantially coaxially with the beam, the receiver system including detection means for the backscattered radiation and equalizing means for producing a substantially equal response regardless of the point of backscatter along the path. The equalizing means comprises a passive radiation transmission structure interposed in the path of return prior to the detection means, the passive structure having a substantially constant acceptance solid-angle for the returning radiation from points over the range of the path whereby radiation reaching the detection means from various points along the path does not vary in intensity due to the different distances of the points from the detection means. The passive structure is shown in the form of a full circular hole and a doughnut-shaped hole in an opaque plate, with the return beam focused to fill the hole out to a range of interest. Other passive structures are illustrated by a Fabry-Perot filter combined with a telescope and a bundle of opaque walled tubes. Transmissivity of a medium out to a point r is determined by the ratio of the integral of power from r to an outer limit range L in which the passive structure is still functional, as numerator, over the integral from the instrument to limit L as denominator. The coaxial array is shown achieved by use of a beam splitter, the beam from the source proceeding via the beam-splitter outwardly, the beamsplitter sized so that all return signal reaching the detector is treated equally by the beam-splitter. A multiple beam-splitter is shown by which multiple beams from a single source are produced, with the respective returns concentrated on a single detector.

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Lexington, MA, United States of America

Willem Brouwer