Abstract: Methods and apparatus include improving print quality of a bi-directionally scanning electrophotographic (EP) device, such as a laser printer or copy machine, according to ambient pressure in which operated. A moving galvanometer or oscillator reflects a laser beam to create scan lines of a latent image in opposite directions. A damping of the motion occurs per air density implicated by temperature and pressure, where the pressure changes occurring especially from altitude changes. During use, a drive signal, such as a pulse train, moves the galvanometer or oscillator at or near its resonant frequency. Based on a parameter of the drive signal, such as pulse width, the ambient pressure can be made known. In general, a high-pressure environment requires a relatively longer pulse width to resonate the galvanometer or oscillator in comparison to a shorter pulse width for a low-pressure environment. Corrections to print quality stem from the determined ambient pressure.

Abstract: Methods and apparatus include improving print quality of a bi-directionally scanning electrophotographic (EP) device, such as a laser printer or copy machine, according to ambient pressure in which operated. A moving galvanometer or oscillator reflects a laser beam to create scan lines of a latent image in opposite directions. A damping of the motion occurs per air density implicated by temperature and pressure, where the pressure changes occurring especially from altitude changes. During use, a drive signal, such as a pulse train, moves the galvanometer or oscillator at or near its resonant frequency. Based on a parameter of the drive signal, such as pulse width, the ambient pressure can be made known. In general, a high-pressure environment requires a relatively longer pulse width to resonate the galvanometer or oscillator in comparison to a shorter pulse width for a low-pressure environment. Corrections to print quality stem from the determined ambient pressure.

Abstract: Methods and apparatus include improving print quality of a bi-directionally scanning electrophotographic (EP) device, such as a laser printer or copy machine, according to ambient pressure in which operated. A moving galvanometer or oscillator reflects a laser beam to create scan lines of a latent image in opposite directions. A damping of the motion occurs per air density implicated by temperature and pressure, where the pressure changes occurring especially from altitude changes. During use, a drive signal, such as a pulse train, moves the galvanometer or oscillator at or near its resonant frequency. Based on a parameter of the drive signal, such as pulse width, the ambient pressure can be made known. In general, a high-pressure environment requires a relatively longer pulse width to resonate the galvanometer or oscillator in comparison to a shorter pulse width for a low-pressure environment. Corrections to print quality stem from the determined ambient pressure.

Abstract: Methods and apparatus include improving print quality of a bi-directionally scanning electrophotographic (EP) device, such as a laser printer or copy machine, according to ambient pressure in which operated. A moving galvanometer or oscillator reflects a laser beam to create scan lines of a latent image in opposite directions. A damping of the motion occurs per air density implicated by temperature and pressure, where the pressure changes occurring especially from altitude changes. During use, a drive signal, such as a pulse train, moves the galvanometer or oscillator at or near its resonant frequency. Based on a parameter of the drive signal, such as pulse width, the ambient pressure can be made known. In general, a high-pressure environment requires a relatively longer pulse width to resonate the galvanometer or oscillator in comparison to a shorter pulse width for a low-pressure environment. Corrections to print quality stem from the determined ambient pressure.

Abstract: A toner patch including a toner having a given excitation wavelength and a given emission wavelength may be deposited onto a control surface. Light may be provided onto the toner patch and at least a portion of emitted light may be detected from the toner patch at the given emission wavelength by a detector. Furthermore, an operating parameter may be adjusted based on the detected emitted light.

Abstract: Methods and apparatus include improving print quality of a bi-directionally scanning electrophotographic (EP) device, such as a laser printer or copy machine, according to ambient pressure in which operated. A moving galvanometer or oscillator reflects a laser beam to create scan lines of a latent image in opposite directions. A damping of the motion occurs per air density implicated by temperature and pressure, where the pressure changes occurring especially from altitude changes. During use, a drive signal, such as a pulse train, moves the galvanometer or oscillator at or near its resonant frequency. Based on a parameter of the drive signal, such as pulse width, the ambient pressure can be made known. In general, a high-pressure environment requires a relatively longer pulse width to resonate the galvanometer or oscillator in comparison to a shorter pulse width for a low-pressure environment. Corrections to print quality stem from the determined ambient pressure.

Abstract: A toner patch including a toner having a given excitation wavelength and a given emission wavelength may be deposited onto a control surface. Light may be provided onto the toner patch and at least a portion of emitted light may be detected from the toner patch at the given emission wavelength by a detector. Furthermore, an operating parameter may be adjusted based on the detected emitted light.

Abstract: An image scanning apparatus and a torsion oscillator are capable of operating across a dynamic range of possible operating frequencies. The image scanning apparatus uses a light source to produce a light beam, and the oscillator scans the light beam through a scanning pattern. The oscillator includes a plate member having a non-rectangular shape. At least one magnet is disposed on the plate. A surface of the plate member includes a reflective surface for reflecting a light beam. A frame is disposed in a spaced apart relation to a lower surface of the plate member. The frame includes at least one coil configured to induce an electromagnetic force on the at least one magnet to thereby oscillate the reflective surface to a rotational angle of oscillation at an oscillation frequency. The system also includes an imaging surface disposed in the path of the scanning pattern so that the light beam scans across the imaging surface, and a mechanical drive to move the imaging surface.

Abstract: An image scanning apparatus and a torsion oscillator are capable of operating across a dynamic range of possible operating frequencies. The image scanning apparatus uses a light source to produce a light beam, and the oscillator scans the light beam through a scanning pattern. The oscillator includes a plate member having a non-rectangular shape. At least one magnet is disposed on the plate. A surface of the plate member includes a reflective surface for reflecting a light beam. A frame is disposed in a spaced apart relation to a lower surface of the plate member. The frame includes at least one coil configured to induce an electromagnetic force on the at least one magnet to thereby oscillate the reflective surface to a rotational angle of oscillation at an oscillation frequency. The system also includes an imaging surface disposed in the path of the scanning pattern so that the light beam scans across the imaging surface, and a mechanical drive to move the imaging surface.

Abstract: An image scanning apparatus and a torsion oscillator are capable of operating across a dynamic range of possible operating frequencies. The image scanning apparatus uses a light source to produce a light bean, and the oscillator scans the light beam through a scanning pattern. The oscillator includes a plate member having a non-rectangular shape. At least one magnet is disposed on the plate. A surface of the plate member includes a reflective surface for reflecting a light beam. A frame is disposed in a spaced apart relation to a lower surface of the plate member. The fame includes at least one coil configured to induce an electromagnetic force on the at least one magnet to thereby oscillate the reflective surface to a rotational angle of oscillation at an oscillation frequency. The system also includes an imaging surface disposed in the path of the scanning pattern so that the light beam scans across the imaging surface, and a mechanical drive to move the imaging surface.

Abstract: An optical system having a single, monolithic scan element as shown in the drawing in which surface 6 is concave, surface 7 is convex, surface 8 is convex, surface 9 is convex and the circumference of surface 9 is convex, surface 10 is convex, surface 11 is convex, and surface 13 is flat. f-theta correction is made primarily at surfaces 6, 9, 10 and 13. The element is molded from optical grade plastic and provides improved performance, no assembly adjustment, performance enhancement from its complex surfaces, and low cost.

Abstract: A light source, which has a time varying chromatic output, back lights or front lights a plurality of liquid crystal displays disposed in a desired arrangement. Two different colors can be produced at two different times by using a fluorescent light as the light source. The fluorescent light is a sealed tube having a high vacuum with an insert gas therein for energization of the gas and a low pressure mercury vapor. The tube has a coating on the inner surface of the tube of at least one phosphor. Energization of the inert gas causes the low pressure mercury vapor to arc to produce light of a first color during a first time period with the light of the second color being produced solely from the phosphor coating upon the gas being deenergized during the second time period. Each of the liquid crystal displays can be activated during the first time period, the second time period, both time periods, or remain inactivated during both time periods.

Abstract: A scanner for mechanically distinguishing light from dark areas of an image, having a light source 4, a collecting lens 7 directing light from the source to surface 11 of a total internal reflective block 62 (block 9 in FIG. 1). The top, parallel surface 13 reflects the light through a focusing, hemispherical condenser lens 17. Light reflected from area 21 on document 23 is collected by the center of lens 17, passes through notch 64 (an area of non-surface 15 in block 9 in FIG. 1), and then through an objective lens 27, from which it is focused on phototransistor 29. The scanner functions well without precise positioning of document.

Abstract: An illumination system for a document scanner comprising a fluorescent lamp for illuminating a document to be scanned and an efficient light guide which "pipes" the light to the target document area. The fluorescent lamp has an aperture defined by an aperture angle wherein the lamp radiance is determined by the aperture angle. The light guide has a trapezoidal longitudinal cross section. An input window associated with the narrow base of the trapezoidal shape light guide is coupled to the aperture of the lamp. An output window associated with the wide base of the trapezoidal shape light guide is directed to the document area.

Abstract: A system for reproducing the image on a document comprises a scanning system including a galvanometer driven mirror which reflects a collimated image of an illuminated band via a focusing lens system onto a line array of photosensitive elements. Relative movement between the scanning system and the document causes the scan of successive bands across the document, generating signals at the photosensitive elements that represent line image variations. The photosensitive elements are arranged in 1:1 correspondence to individual ones of a line array of ink jet printers disposed adjacent a copy document. Both the signal generating and image reproducing systems scan their associated documents in synchronism so that the image may be reproduced in direct fashion or using interleaving for higher density with given inter-element spacing.

Abstract: A three piece aperture comprising a centerpiece positioned much as an "island" between two outer pieces so as to form two light transmissive slits. The two outer pieces may contain symmetrical light transmission edges. The aperture is of particular use in electrophotographic copier machines where substantially continuously variable reduction is practiced.