International Business Machines Corporation

Other

Duane W Baxter

Leon Edward Gregg

Donald John Wanek

Michael M Siverling

Neil R Davie

William Jaaskelainen

Glenn Darrell Batalden

John H Wirz

Frederick E Axmear

Arthur Hamburgen

Richard Edward Shipway

Roy A Roble

William C Hoveland

Joseph L Evjen, Jr

Donald R Smith

John H Saxman

Photographic films, such as X-rays, are duplicated by exposing an unexposed copy film in the presence of an intimately overlying developed film to be copied. The device exposure station has a pair of rollers at the entrance to drive the film pair and to remove from the interface between the films trapped air that would compromise the accuracy of resolution and contrast of the copy. Another pair of rollers at the outlet from the exposure station cooperates with the roller pair at the exposure station inlet to maintain the film pair within the exposure station in a planar orientation to avoid curvature which is another principal source of compromised resolution in film copies. The source of illumination for copy film exposure is, preferably, a fluorescent tube that generates emissions that are approximately matched to the wave length response of the unexposed copy film and has a length such that each end is disposed beyond the portion of the exposure station confronting a film pair so that only the tube portion intermediate the heating elements at the tube ends, where emission is most uniform, confronts the film being exposed. The film pair is driven through the apparatus by a stepper motor controlled by a microprocessor which enables the average film pair speed (and thus the exposure time) to be selected from a range of incremented values contained in an addressable controller memory location. The sequence of incremented step rate values can be changed by addressing another addressable block of values in the controller memory.

Apparatus for duplicating X-ray type photographic films

An optical storage arrangement is provided where a unified optical disk, or other optical media, has separate Read/Write (R/W) and Write Once Read Many (WORM) areas. A Read/Write head or transducer selectively records data only once in the WORM area but records and re-records data in the R/W area. Both areas can be selectively read repetitively. The WORM area is used to store data records and the R/W area contains directories for the data records recorded in the WORM area.

Optical disk having R/W and worm area

An optical file system in which a command to store data results in a write operation in the next available storage position. A single optical path is used for both reading and writing. By dividing the detector in two equal parts along the direction of relative movement, it is possible to determine whether data has been written at a position which is in advance of the center of the area viewed by the detector. The write operation is conditioned on the output of the first part of the detector. Since the first part of the detector gives advance warning on the status of the oncoming data position, it is possible to switch from reading to writing without the requirement for a wasted revolution or wasted space. By dividing the signal resulting from a change of reflectance sensed during a write operation by a measure of the intensity of the write laser a read signal free of the write modulation is obtained.

System for preventing the overwriting of previously optically recorded

Sector servo seek control

A rotating magnetic memory, such as a disk drive using sector servo information, is initialized with servo information by first using the dedicated product head assembly, including transducers and the mounting and accessing mechanisms associated therewith, to write on the innermost and outermost data tracks, following which the tracks written by each transducer are read using a precision servowriter mechanism which is then positioned to duplicate the access path of the product head assembly and determine the position of such innermost and outermost tracks. By then offsetting the precision servowriter by a half track pitch and writing the servo information to form equally spaced tracks, the disk is initialized with full track pitch servo information which is positioned and aligned with the position and alignment of the dedicated product head assembly.

Disk initialization method

Successive areas of a high-resolution object image are compared with corresponding areas of a low-resolution master pattern to produce signals representing the quality of the object. Comparison is effected by detecting which of a set of features occurs in each area of the object image, detecting which feature of the same set occurs in a larger area of the master pattern, and determining whether these two features are the same.

Defect inspection of objects such as electronic circuits

Growing community of inventors

Rochester, MN, United States of America

Duane W Baxter