Abstract: A computer controlled photoplotter includes a row of LED's mounted to a light head positioned parallel to the film width. The light head is part of a light head assembly which is moved parallel to the film length. At the end of each pass the light head is indexed widthwise a short distance. During each lengthwise pass the LED's are illuminated at appropriate positions to expose the film at those positions according to the image being plotted. To equalize the illumination intensity of the LED's, the output of each LED is measured and the value is combined with a standard value. The result determining how long the LED is turned off during an intermediate segment of the actuation signal.

Abstract: In a pen pressure device including a carriage, a pen axially movably supported to the carriage in such a manner that a front end of the pen is opposed to a paper, a pen pressure spring for biasing the pen toward the paper, a return spring for biasing the pen in a direction apart from the paper; the improvement comprises a hammer mounted on the carriage and adapted to be biased by the pen pressure spring having a spring force greater than that of the return spring to thereby urge the pen, and a cam member for moving the hammer to a retracted position where the pen is not urged by the hammer.

Abstract: A device for installation in a motor vehicle for recording distances traveled on business or non-business journeys comprises an input from the vehicle indicative of the distance traveled by the vehicle and manually operable keys for inputting into the device the purpose of the journey. The distance traveled and the purpose can be recorded for later printing on a paper supply contained within the device. A clock also records the time and date of the journey. Gas purchases can be recorded. A decimal keyboard can be used to require the introduction of an identification code before the device can be operated.

Abstract: In a multi-position graphics plotter pen carousel system employing a pen capping mechanism therein at each pen position for capping and uncapping pens held by the carousel, an improvement for allowing the sensing of pen presence at the pen positions and the indexing of the carousel with a single sensor. Each pen capping mechanism is adapted to assume a first position with a pen in the pen position and assume a second position with no pen in the pen position. A plurality of first sensible attributes are associated with respective ones of the pen capping mechanisms for exhibiting a first characteristic when a pen is contained at the associated pen position and for exhibiting a second characteristic when no pen is contained at the pen position. A plurality of second sensible attributes are associated with respective ones of the pen positions for constantly exhibiting the first characteristic.

Abstract: A light beam scanning recording apparatus for recording information on a recording material by modulating a laser beam emitted by a semiconductor laser and scanning the recording material with the modulated laser beam is constituted to modulate the laser beam by combining pulse number modulation or pulse width modulation with intensity modulation. Intensity modulation of the laser beam is conducted by controlling the drive current of the semiconductor laser. A plurality of semiconductor lasers may be provided for scanning with a coalesced laser beam obtained by coalescing laser beams emitted by the semiconductor lasers, and intensity modulation may be conducted by changing the number of the laser beams which are coalesced.

Abstract: Two consecutive voltage pulses of equal duration (T.sub.1, T.sub.2) and opposite polarities are applied to the control circuit. The two pulses which are combined together and amplified give rise to a signal of a particular wave form, which is applied to the piezoelectric transducer (104) for the expulsion of a drop of ink, free from disturbances caused by vibration of the meniscus at the time of separation of the drop, and to provide for cancellation of the reflected waves in the conduit.The transducer (104) forms in the ink conduit (102) a pressure wave of complex form, a first portion thereof contributing to the expulsion of a drop of ink and a second portion which is suitably out-of-phase with respect to the first portion neutralizing the reflection phenomena caused by the first portion.

Abstract: A constant power laser driver for a laser diode in a laser printer reduces laser shadow by maintaining the junction temperature of the laser diode at a constant level. The constant temperature is maintained by a reverse or zener current through the laser diode when the laser is in an off state. The zener current is determined so that the product of the reverse laser current and reverse breakdown voltage is equal to the product of the forward bias voltage drop and forward current when the laser is on. Since these products are substantially equal to the current dissipated in the diode, equal amounts of power are dissipated as heat in the laser diode junction both when the laser is in a writing state and in a non-writing state. As a result, the junction temperature remains relatively constant and the light output remains constant when the laser is turned on, regardless of the length of time it was previously in the opposite state.

Abstract: A circuit for correcting the write power of a laser raster output scanner as it scans across the write drum. During calibration, a piece of glass reflects part of the beam into a photo multiplier tube, the output of which is converted into a digital signal. This is compared to a reference signal. The difference for each segment of the scan is stored in RAM and also is converted back to an analog signal to modulate an acousto-optic modulator in the laser optics to correct the write power. After the system has settled to a point where the write power at the drum does not vary across the scan, the glass may be removed and the system operates using the corrections stored in RAM.

Abstract: A computer controlled photoplotter includes a row of LED's mounted to a light head positioned parallel to the film width. The light head is part of a light head assembly which is moved parallel to the film length. At the end of each pass the light head is indexed widthwise a short distance. During each lengthwise pass the LED's are illuminated at appropriate positions to expose the film at those positions according to the image being plotted. The light head uses cylindrical lenses in which the index of refraction varies radially. The lenses are secured within the bores in the light head by resilient, cushioned material biased against the sides of the lenses through the slot opening into the sides of the bores.

Abstract: In the particular embodiment described in the specification, a hot melt ink jet system includes a temperature-controlled platen provided with a heater and a thermoelectric cooler electrically connected to a heat pump and a temperature control unit for controlling the operation of the heater and the heat pump to maintain the platen temperature at a desired level. The apparatus also includes a second thermoelectric cooler to solidify hot melt ink in a selected zone more rapidly to avoid offset by a pinch roll coming in contact with the surface of the substrate to which hot melt ink has been applied. An airtight enclosure surrounding the platen is connected to a vacuum pump and has slits adjacent to the platen to hold the substrate in thermal contact with the platen.

Abstract: A method and apparatus for exposing a pair of radiation sensitive surfaces to a beam of optical radiation is described. The apparatus comprises a support (20) for supporting the radiation sensitive surfaces which may be provided on opposite sides of an identification card. A laser (1) provides a laser beam which impinges on a pair of resonant scanners (10,11) which cause radiation impinging on their respective mirrors to be reflected onto opposite surfaces of the identification card. A control system (103) causes the mirrors of the scanners (10,11) to oscillate in quadrature. The laser beam passes through an A/O modulator (4) responsive to signals from the control system (103) to cause radiation to impinge alternately on one or the other of the scanners (10,11).

Abstract: A pen recorder includes a pen position detecting portion for periodically or nonperiodically detecting the position of a pen, and a position correcting circuit for calculating a driving amount and a driving direction of a motor used for correcting a pen position, in accordance with a pen position detected by the pen position detecting portion and a recording position of the pen corresponding to an input signal. The pen position detecting portion detects an actual position of the pen when the pen is moved to perform a recording operation in response to the input signal. In accordance with the actual pen position and the recording position of the pen corresponding to the input signal, a driving amount and a driving direction of the motor for moving the pen are calculated by the position correcting circuit, to thereby correct the pen position.

Abstract: A circuit for generating a set of center pulse-width modulated waveforms comprises a counter having a time changing count, and comparators which compare the count with respective preset counts. The preset counts to the comparators being set so that the set of waveforms created is center pulse-width modulated.

Abstract: An identification card with high-embossed data, in which the high-embossed data are superimposed by a security pattern which is inscribed in the identification card by means of a laser beam recorder. The security pattern may be present, for example, only on the high-embossed data themselves or else cover a larger area of the card. Attempted back-embossing of the high-embossed data is immediately recognizable due to distortion of the security pattern.

Abstract: In a device for recording information on strip chart paper, a paper tray, paper guide and door having a trench area are positioned relative to one another to inhibit lateral movement of the paper during recordal of the information. The trench area which is located between the paper storage tray and paper guide receives and traps the paper between its walls to ensure that the paper travels along a predetermined path. The paper storage tray is slightly tilted to further ensure that the paper follows the desired path of travel.

Abstract: A computer controlled photoplotter includes a row of LED's mounted to a light head positioned parallel to the film width. The light head is part of a light head assembly which is moved parallel to the film length. At the end of each pass the light head is indexed widthwise a short distance. During each lengthwise pass the LED's are illuminated at appropriate positions to expose the film at those positions according to the image being plotted. The light head uses cylindrical lenses in which the index of refraction varies radially. The outer lens surfaces are coplanar with the outer surface of the light head facing the film so the light sources have focal points at a common distance from such surface. This permits proper focusing of the photoplotter with different thickness film. The light head is moved until it touches the printing medium and then moved away from the film to obtain the focus desired.

Abstract: In an ink jet printing element in which the drop is expelled by generating a current pulse through the ink in the nozzle, in order to reduce the control voltage, a first pulse (Tr) for heating the ink is generated, followed by a vaporization pulse (Tv) with a delay such as to make the printing position independent of the direction of movement of the element with respect to the paper. The heating pulse (Tr) is generated by a circuit (31) controlled by a temperature sensor (34) so that the duration of the heating pulse has a negative temperature coefficient. The vaporization pulse (Tv) is generated by a circuit (32) manually controlled (potentiometer 39) to determine the pulse duration on the basis of the desired strength of the printing. The delay between the two pulses is controlled by a delay circuit (38), e.g. a monostable circuit. The two pulses are applied to a transformer (35) which generates the voltage between the electrodes.

Abstract: A color image copying system (10) employs a cathode-ray tube (16) that employs a diffraction grating face plate (38) which for each image disperses to predetermined focal regions (132, 143, and 136) light rays of corresponding wavelengths. The light rays sequentially expose a region 80 of a scrolled light-sensitive medium (42) to form a composite color copy of the image. Bands of phosphorescent materials (32, 34, and 36) are applied on angularly inclined subregions (146, 148, and 150) of the inner surface (144) of the face plate and intercept a raster-scanned electron beam (22) to develop light of the different wavelengths. The inner surface of the face plate has angularly inclined subregions (146, 148, and 150) that provide for incident light rays of each wavelength an angular offset of equal magnitude but opposite rotational sense to compensate for changes in diffraction angles (.beta..sub.1, .beta..sub.2, and .beta..sub.

Abstract: A method of ejecting droplets of phase change or hot melt ink jet ink upon a target such as paper includes a step of applying pressure to the droplets after they have cooled upon the paper in order to increase their coverage and, thus, minimize the volume of ink required to produce a high quality print with a high degree of resolution. Including a means for applying pressure to the cooled droplets, a suitable apparatus increases the area of the target covered by a particular droplet after spreading by at least five percent and preferably by twenty percent.

Abstract: A device for writing optical information including a roof mirror array, a lens array, an optical-path separator, a mirror member, a housing, and a self-scanned recording element. The roof mirror array, the lens array, the optical-path separator, and the mirror member are retained by the housing in a prescribed mutual positional relationship. The housing has a pair of slits, one of which is covered with the light-signal producing surface of the self-scanned recording element. The housing is shaped such that the light-signal producing surface of the self-scanned recording element is held in registration with an object surface on which an unmagnified object image would be formed by the lens array and the roof mirror array.