The Gerber Scientific Instrument Company

Henry F Berdat

Robert J Pavone

Bruce L Davidson

Leonard G Rich

Kerry D Baines

An indexing system for selectively orienting one of a series of arcuately oriented different sized and/or shaped apertures formed around an aperture disc used in a photohead for exposing upon a photosensitive surface detailed graphic information using a light beam. The aperture disc has formed thereon, equidistantly spaced indicators in the form of slots allowing radiant energy generated by a light emitter to impede upon and energize a split cell photosensitive detector. A control system rotates an aperture wheel to a next selected position at a first velocity until a selected aperture is within the vicinity of the next selected position and subsequently rotates the aperture disc at a second slower velocity to precisely position the next selected position in registry with the light beam. A method for creating the aperture disc includes inscribing with a light beam upon a film, the pattern of the aperture and the indicators, developing the film as a master and contact printing copies of the images formed on the master.

Aperture disc and method of making the same

A system for projecting a spot of radiant energy includes a lamp for projecting a light spot onto a surface and includes means for providing a selection of differently sized spots. Drive means moves the light spot relative to the surface and is capable of moving the light spot at a maximum given velocity which is the same for all of the differently sized spots. Velocity output means produces a velocity signal representing the velocity of the spot and a normalized velocity signal is produced by dividing the volocity signal by the maximum given velocity. Each differently sized spot is assigned a different lamp command voltage signal and a selected one of the lamp command voltage signals is multiplied by the normalized velocity signal to produce a resultant lamp command voltage signal which energizes the lamp.

Lamp driver scheme

An indexing system for selectively orienting one of a series of arcuately oriented different sized and/or shaped apertures formed around an aperture disc used in a photohead for exposing upon a photosensitive surface detailed graphic information using a light beam. The aperture disc has formed thereon, equidistantly spaced indicators in the form of slots allowing radiant energy generated by a light emitter to impede upon and energize a split cell photosensitive detector. A control system rotates an aperture wheel to a next selected position at a first volocity until a selected aperture is within the vicinity of the next selected position and subsequently rotates the aperture disc at a second slower velocity to precisely position the next selected position in registry with the light beam. A method for creating the aperture disc includes inscribing with a light beam upon a film, the pattern of the apertures and the indicators, developing the film as a master and contact printing copies of the images formed on the master.

Photohead system for positioning an aperture wheel and method of making

A flashing lamp unit comprising a fluorescent lamp, an ionization electrode in close proximity to the lamp, and an electrical means for exciting the lamp and ionization electrode to cause the lamp to flash. In one embodiment, the lamp is torroidal in shape, the ionization electrode is arc-shaped and abuts the lamp, and an optical scanning device peers through the center space of the lamp so that the lamp provides a substantially uniform illuminated field for viewing by the scanning device.

Flashing lamp unit

A photoplotter includes an autofocus control for maintaining a precise focal distance between a photohead in the plotter and the film surface which is exposed by the head. The autofocus control employs a dual frequency ultrasonic ranging apparatus which permits coarse focus control at one frequency and fine focus control at a second, higher frequency.

Multiple frequency ranging apparatus for focus control

A plotting apparatus for plotting on a light sensitive material uses an optical head with an adjustable aperture plate to project a light beam through changeable apertures onto the light sensitive material. Encoding means are associated with the various apertures of the plate and comprise detectable indicia corresponding to the optical characteristics of the apertures. A detector on the optical head senses the indicia of the individual apertures as the plate is adjusted and sends signals corresponding to the identity of such characteristics to a control device responsible for adjustment of the plate or other component in the plotting apparatus.

Plotting apparatus and method utilizing encoded optical means

A circuit is disclosed for flashing a flash lamp in a photoexposure device which exposes lines on a photosensitive surface by projecting onto the surface a repetitive series of light spots the locus of which is moved relative to the surface so that the individual light spots partially overlap one another as a chain to synthesize the desired line. During each flash cycle, started by a cycle initiate pulse from an associated control circuit, conduction through the lamp is initiated by a high voltage pulse produced by the discharge of a triggering capacitor, through a high voltage pulse generating circuit, and conduction is thereafter continued by the discharge of a firing capacitor which supplies power at a lower voltage to the lamp. To optimize the maximum rate at which the lamp may be flashed the circuit operates, during each flash cycle, to trigger discharge of the capacitors immediately, or almost immediately, upon their reaching their desired charge. The flashing circuit also automatically compensates for changes in the voltage level at which the flash lamp extinguishes in each flash cycle, thereby maintaining the amount of light produced per flash relatively constant despite such changes.

Growing community of inventors

Manchester, CT, United States of America

Henry F Berdat