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公开(公告)号：CA2012401C
公开(公告)日：1994-05-10
申请号：CA2012401
申请日：1990-03-16
Applicant: IBM
Inventor： DEWEY ANTHONY G , LENTH WILFRIED , RUGAR DANIEL
Abstract: An apparatus and method is described for detecting focus errors in an optical head by positioning a prism in the optical path of a return light beam reflected from an optical recording medium. The prism reduces the beam in one dimension by a factor of M and concurrently increases the divergence/convergence angle associated with a focus-error of the beam by a factor of M in said dimension, thereby desirably enhancing the focus error signal by a factor of M2. A focus error is detected by a segmented photodetector having inner and outer photosensitive regions. The photodetector generates an electrical signal indicative of the focus error from the difference in light intensities at the inner and outer regions. The photodetector preferably is segmented in such manner as to also provide a track error signal.
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公开(公告)号：CA1113619A
公开(公告)日：1981-12-01
申请号：CA307632
申请日：1978-07-18
Applicant: IBM
Inventor： DEWEY ANTHONY G , SINCERBOX GLENN T
Abstract: INTERACTIVE PROJECTION DISPLAY SYSTEM An interactive projection display system having a light pen device for use thereon is described. The projection display system has an image of a light valve on a projection screen which is formed by visible light of specified wavelengths. The projection screen also has a translatable crosswire image thereon which is formed by radiation which includes the visible light used to form the light valve image and an additional spectral component. The light pen device is sensitive to this additional spectral component. In a preferred embodiment, the image of the light valve and the crosswires are formed with white light (0.3 to 0.7 microns). The additional spectral component used for the crosswire image and the light pen sensing is a band of near-IR radiation (0.7 to 1 micron).
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公开(公告)号：CA1246911A
公开(公告)日：1988-12-20
申请号：CA461011
申请日：1984-08-14
Applicant: IBM
Inventor： DEWEY ANTHONY G , MARINELLI CHARLES P
Abstract: A fiber optic writing head delivers light from the ends of a close-packed array of optical fibers through a small inexpensive lens which images the light onto the writing surface. The ends of the individual fibers in the array are fixed at various angular positions to form a surface that is the image of the writing surface through the lens. The ends of the fibers are spaced along the surface so that the image that is produced on the writing surface has uniform spacing. The angular positions of the fibers are chosen such that the axis of the refracted beam emitted by each fiber is directed at the center of the entrance pupil of the lens.
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公开(公告)号：FR2410326A1
公开(公告)日：1979-06-22
申请号：FR7828297
申请日：1978-09-26
Applicant: IBM
Inventor： DEWEY ANTHONY G , SINCERBOX GLENN T
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