Gerber Scientific Products, Inc.

Metromedia, Inc.

The Gerber Scientific Instrument Company

Gulf & Western Corporation

Gerber Garment Technology, Inc.

Gerber Optical, Inc.

Metromedia Company

Leonard G Rich

David J Logan

Mark E Guckin

H Joseph Gerber

Ronald B Webster

Verner Anderson

Dale G Blake

Heinz J Gerber

Jeffrey J Murray

Russell F Croft

Geoff McCue

Henry F Berdat

Charles M Hevenor, Jr

Robert I Sinclair

Raymond Phillips

Jay T Niland

Brian Phelan

Disclosed is control circuitry for providing controlling a motor responsive to feedback signals. The control circuit includes a velocity sensor for coupling with the motor for providing a velocity feedback signal responsive to the velocity of the motor, and circuitry for providing a feedback signal responsive to a voltage associated with the motor, such as the back emf of a coil associated with the motor. The control circuitry can be used enhance the Z-axis control of a tool of a work apparatus for performing work operations on a work material, such as a cutting apparatus for cutting a sheet of vinyl having a releasable backing for generating graphic products.

Method and apparatus for the improved control of motors and of motor-actuated work apparatus

A friction drive apparatus for feeding strip material in a longitudinal direction includes a first friction wheel and a second friction wheel rotated by a first motor drive and a second motor drive, respectively. The friction drive apparatus also includes a sensor disposed behind the friction wheels with respect to the motion of the strip material to detect a lateral or skewing error and a motion processor that drives the first and the second motor drives independently at different speeds to correct the lateral or skewing error of the strip material. The friction drive apparatus also detects a longitudinal error of the strip material by tracking an actual position of the strip material and comparing it to the commanded position to correct the error. If there is a discrepancy between the actual position and the commanded position of the strip material, the rotational speed of each friction wheel is either decreased or increased to correct any longitudinal creep or slippage, respectively, of the strip material.

Friction drive apparatus for strip material

The friction drive system for printing, plotting or cutting graphic images on strip material includes a feedback for a drive motor driving a plurality of friction wheels for advancing strip material in a longitudinal direction. The feedback signal includes a short-term response component and a long-term response component to accurately pinpoint the exact longitudinal location of the strip material. The short-term response component is generated by comparing a motor encoder signal from a motor encoder secured to the drive motor with a commanded longitudinal position of the strip material and passing the resultant differential error signal through an all pass filter. The long-term response component is generated by comparing a detecting encoder signal from a detecting encoder secured to a device detecting the actual longitudinal position of the strip material with the commanded longitudinal position of the strip material and passing the differential error signal through a low pass filter.

Material advance tracking system

A laminated web has a carrier sheet and a sign material sheet superimposed on it and a first layer of permanently tacky adhesive attaching the sign material sheet to the carrier. A second permanently tacky adhesive layer is provided on the side of the sign material sheet facing away from the base layer and is coated or is provided with a film which deadens the exposed tacky surface such that the web may be cut in an automated sign generated machine and the web weeded thereby leaving free standing characters on which the second permanently tacky adhesive can then be exposed for application onto a substrate surface.

Sign making web with tack killing overcoat removable by washing and

A method for making a printing screen wherein a screen having an unexposed emulsion layer applied thereto is placed in a printing device, such as an ink jet printer, and a graphic is printed directly on the emulsion layer. The graphic is precisely and automatically positioned relative to the screen by orienting the screen with respect to the X, Y and Z printing axes of the printing device, alinging a selected location on the screen with a selected coordinate position on the X and Y printing axes and providing the printing device with data defining the graphic to be printed on the emulsion layer, data defining the dimensions of the screen, and data defining selected coordinates within the dimensions of the screen with which corresponding reference coordinates of the graphic are to register when the graphic is printed on the emulsion layer.

Method and apparatus for making a painting screen using an ink jet

In a method and apparatus for making a lens for a pair of prescription eyeglasses a lens blank is shaped and finished on one of its major surfaces through the use of a machine controlled by the prescription information and with a new expendable lap being made each time a new lens is wanted. A machine for cutting a lens blank and/or a lap blank is controlled in three axes by a set of point data related to and obtained in response to the input into the control system for the machine of prescription information. Lap blanks and lens blanks usable by the machine are distinguishable from one another by each lap blank, or each lens blank, having an anomaly, such as a piece of magnetic material detectable by a sensor or the blank is rotated by the machine.

Blanks for making prescription eyeglass lenses

In a method and apparatus for making a lens for a pair of prescription eyeglasses a lens blank is shaped and finished on one of its major surfaces through the use of a machine controlled by the prescription information and with a new expendable lap being made each time a new lens is wanted. A machine for cutting a lens blank and/or a lap blank is controlled in three axes by a set of point data related to and obtained in response to the input into the control system for the machine or prescription information.

Method and apparatus for making prescription eyeglass lenses

A hydraulic servomechanism for controlling the pressure of ink supplied to an ink jet printer head includes a bellows located between an ink source and the head and arranged for expansion and contraction to decrease and increase the pressure of ink in the bellows. Pressure is sensed at the bellows output connected to the ink head and the sensed pressure is compared to a desired ink pressure to produce a driving signal which excites an electromagnetic driver coupled to the bellows. The driver applies a force to the bellows to adjust the pressure to the desired pressure. A position sensing switch is responsive to the volume of the bellows and controls a valve located between an ink source and the bellows input to maintain the volume of ink in the bellows within a predetermined volumetric range.

Hydraulic servomechanism for controlling the pressure of writing fluid

A hydraulic circuit and related method are provided for dynamically varying the pressure of ink supplied to an ink jet printer head to obtain consistent volume ejected ink drops despite differences in the time elapsing between successive drops. A dot rate command signal related to an actuation frequency and corresponding to the pressure of ink at the head necessary for producing an ejected drop having a desired volume is compared with the ink pressure at the head to produce a pressure control signal for varying the pressure of the ink in a variable volume fluid chamber to deliver ink to the head at the desired pressure. The pressure control signal is one chosen by experiment as that required to produce the desired ink drop volume for the specific ink supply and ink jet printer head employed.

Dynamically varying the pressure of fluid to an ink jet printer head

An ink jet head for ejecting drops of ink in an ink jet printing system is designed for easy disassembly for cleaning and can readily be made in different sizes including one capable of ejecting relatively large volume drops of heavily pigmented and relatively viscous ink as may be used for printing outdoor billboards or other large scale graphics. The head also includes a means for reducing the size of or entirely eliminating any blob of ink which may form over the ejection port at low actuating frequencies, thereby making the velocity and other characteristics of the ejected drops more uniform over the full range of operating frequencies.

Ink drop ejecting head

A circuit and related method are provided for maintaining a desired spacing between an ink-jet printing means and a receiving surface along a line scanned by the printing means. An ultrasonic transducer transmits signals at timed intervals to the receiving surface from the printing means. A reflected signal from the receiving surface is sensed by the transducer during a receiving time window after the signal is transmitted. A reference position signal representative of the head to surface spacing at a printing location is compared to the desired head to surface spacing to produce a position error signal. A servomotor responds to the position error signal to move the printing means toward and away from the receiving surface to maintain the desired spacing.

Apparatus and method for positioning an ink-jet printing head

Ink jet printing apparatus is provided for vertically randomizing the flight paths of ink drops ejected from an ink jet printing head to print dots at positions randomly deviated vertically with respect to a line scanned by the printing head. Ejected ink drops are passed through an electric field having a randomly varying intensity and direction to randomly deflect the ink drop flight path with respect to a line scanned by the printing head.

Ink jet printing randomizing droplet placement apparatus

A circuit and related method are provided for driving an ink jet printer to achieve a consistent velocity of ejected ink drop despite differences in the time elapsing between successive drops. Timing pulses timing the ejection of drops each trigger the production of a fundamental waveform. This waveform is then multiplied by a multiplying factor selected from a look-up table in response to the time elapsing between the timing pulse causing the generation of the waveform and the preceding timing pulse, and the modified waveform so produced is used to drive the printing head through a power amplifier. The multiplying factor is one chosen by experiment as that required to produce the desired ink jet velocity. In a preferred embodiment both the fundamental waveform and the multiplying factor may each be obtained through the use of an associated PROM so that the waveform shape and multiplying factor versus dot frequency characteristic may be readily changed to suit the particular printer head in question.

Apparatus and method for driving ink jet printer

A method for cutting limp sheet material with a rigid, cantilevered blade that is reciprocated as it advances along a cutting path through sheet material employs a load sensor to measure lateral loads applied to the blade by the sheet material during cutting. A load signal from the sensor is applied to the blade controls through a variable gain feedback circuit and causes the blade to be oriented slightly toward the side of the cutting path from which an unbalanced load is applied. The adjustment of the gain in the feedback network is made by means of speed sensors which measure the rate at which the cutting blade advances through the sheet material and adjust the feedback gain in inverse relationship.

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West Hartford, CT, United States of America

Leonard G Rich