Abstract: A method for calibrating a printer including a light-emitting diode (LED) printhead for non-uniformity on an image plane. The LED recording elements are arranged in a plurality of arrays. A plurality of characteristics (102, 104, 106, 108, 110) associated with each recording element are measured and from the measured characteristics a plurality of parameters (112, 114, 116, 118, 120) associated with each recording element is determined. Adjustment factors for a plurality of parameters are combined mathematically to determine an adjusted power density (122) for each recording element on the image plane. Correction factors (130) are then assigned to each recording element to correct for the adjusted power density (122). The correction factors (130) are stored in a memory (132) associated with the LED printhead.

Abstract: The invention adjusts the calibration of each light emitting element, such as a light emitting diode (LED) by storing data representative of the difference between a linear or non-linear characteristic of the LED. In a printer or copier, a print engine uses LEDs to form a latent image on a photosensitive member. A linear regression identifies the differences between the slope of the individual LED and the average LED. A further, non-linear regression identifies the curvature of the individual LEDs. The differences in linear slope and/or curvature are stored and used to correct the calibration of each LED when the LED is recalibrated during operation and in response to a global calibration signal, GREF.

Abstract: A reproduction apparatus utilizing clear marking particles in the development of an image, the clear marking particles being laid down so as to prevent offset upon fusing of an image to a receiver member. The reproduction apparatus is disclosed as including a dielectric member adapted to have latent images formed thereon. A development station, is provided including a plurality of developer units respectively containing marking particles of different colors, at least one developer unit containing black marking particles and another developer unit containing clear marking particles. The development station selectively develops latent images with marking particles from the developer units respectively. A transfer station serves to transfer developed marking particle images to a receiver member, and a fuser assembly fuses a marking particle image on a receiver member.

Abstract: A clear protective overcoat is provided to an image formed in a silver halide photographic element. The overcoat is formed by electrostatically applying a uniform distribution of clear toner to an imaged photographic element and then fusing the toner to form an overcoat. The toner can be applied only in a limited area of the element.

Abstract: A bleachable composition, including an acid photogenerator and a near-infrared radiation-absorbing dye or pigment, is utilized in a method of migration imaging to prevent unwanted absorptions. This composition can be incorporated either in the thermoplastic imaging surface layer of the imaging element, in the marking particles applied to the element, or both. Alternatively, the components of the bleachable composition can be separated with one in the thermoplastic imaging surface layer and the other in the marking particles. After the imaging element is marked and exposed with near-infrared radiation, the bleachable composition caused exposed portions of the imaging element to be bleached. If further bleaching is needed, the element can subsequently be exposed with near-ultraviolet radiation. A migration imaging method, which does not employ the bleachable composition of the present invention, wherein marking particles are magnetically attracted to the imaging element, is also provided.

Abstract: A bleachable composition, including an acid photogenerator and a near-infrared radiation-absorbing dye or pigment, is utilized in a method of migration imaging to prevent unwanted absorptions. This composition can be incorporated either in the thermoplastic imaging surface layer of the imaging element, in the marking particles applied to the element, or both. Alternatively, the components of the bleachable composition can be separated with one in the thermoplastic imaging surface layer and the other in the marking particles. After the imaging element is marked and exposed with near-infrared radiation, the bleachable composition causes exposed portions of the imaging element to be bleached. If further bleaching is needed, the element can subsequently be exposed with near-ultraviolet radiation.

Abstract: A toner image is transferred from an image member to a receiving sheet through first and second intermediate members. The first intermediate member is optimized for transfer from the photoconductor and has greater affinity for the toner than does the second intermediate member, which is optimized for transfer to the receiving sheet. This three transfer system provides transfer improvement over two transfer systems.

Abstract: First and second toner images are created on a primary image member. The first toner image is transferred to an intermediate image member and then transferred back to the primary image member to combine the two images. Preferably, the intermediate image member is a light roller that is inarticulatable and maintained in contact with the primary image member which is preferably an endless belt with sufficient wrap to drive the intermediate image member with low pressure in the contact nip. Cleaning is effected by transferring residual toner back to an empty portion of the primary image member from where it may be cleaned off by a primary image member cleaning station. Intrack registration of the images is maintained by adjusting the time between flashes in creating the two images.

Abstract: A migration imaging system using a laser-addressable thermoplastic imaging member 10. The imaging member 10 comprises a supporting section 15 and a thermoplastic imaging surface layer 14. A charged, uniform layer of marking particles 24 is deposited on the imaging surface layer 14. An imagewise-modulated laser beam 24 transforms selected volumes of the imaging surface layer 14 in an imagewise pattern to a permeable state. Charged marking particles 42 that overlay a transformed volume then migrate into the imaging surface layer 14, due to an electrostatic attraction to the imaging member 10, so as to be retained. Unaddressed marking particles 56 are cleaned away by particle removing device 20B comprised of a magnetic brush utilizing hard magnetic carrier particles. The imaging member 10, or solely the imaging surface layer 14, may be transferred and bonded to a receiver member such as a drum for use as an exposure mask in a xeroprinting process, or to a receiver sheet 64 to provide a hard copy reproduction.

Abstract: Method and apparatus for producing a hardcopy reproduction of image information. A uniform layer of toner particles is applied to a surface. A receiver sheet with a thermoplastic outer layer is placed over the layer of toner particles, the thermoplastic layer contacting the layer of toner particles. An electrostatic attraction is established between the layer of toner particles and the receiver sheet. The thermoplastic layer is imagewise exposed to heat to selectively soften the thermoplastic layer, allowing the toner particles opposite the softened thermoplastic to migrate into the layer. The receiver sheet is then removed from the surface, taking with it the migrated particles in an imagewise pattern.

Abstract: Image forming apparatus includes a cleaning device for cleaning toner from a surface. Magnetic particulate cleaning material is moved through a cleaning zone by a rotating magnetic core. The particulate cleaning material moves on a surface which is extended generally in an upstream direction with respect to movement of the surface being cleaned. The extension increases the effectiveness of the cleaning without increasing pickup of the cleaning material by the surface.An alternative cleaning device includes a magnetic shunt between a rotating core and a shell in which magnetic particulate cleaning material is driven by rotation of the core. The shunt interrupts the magnetic field of the core to increase the effectiveness of the cleaning without adversely affecting its softness.

Abstract: A uniform layer of charged toner particles is deposited onto a photoconductive layer of an imaging member. The toner particles are imagewise heated to imagewise tack selected ones of the particles to the photoconductive layer. The photoconductive layer is uniformly exposed to actinic radiation to discharge the toner particles while the layer is subjected to a gentle cleaning process which removes the nontacked toner particles.

Abstract: An image forming apparatus includes both a toner applying station and a toner cleaning station. The toner applying and toner cleaning stations adjoin each other. Each of the stations includes an elongated element which is to be closely spaced to an image surface. A toner removing roller is positioned between the toner cleaning station and the toner applying station and removes toner from particulate cleaning material in the toner cleaning station and supplies it to the toner applying station to conveniently recycle toner. The toner cleaning station includes a rotating magnetic core which moves hard magnetized carrier around a shell providing a soft cleaning brush.

Abstract: The present invention is used in an image-recording apparatus wherein a substantially uniform layer of triboelectrically charged thermoplastic toner particles is deposited onto an imaging member. The toner particles are imagewise heated such that the heated toner particles are thermally tacked to the imaging member. The imaging member is then contacted with a mass of magnetic carrier particles to attract nonheated toner particles to the carrier particles, thereby removing nonheated toner particles from the imaging member and ladening the carrier particles with the removed toner particles. In accordance with the invention, upon using the carrier particles to attract and remove toner from the imaging member, the toner-laden carrier particles are mixed with a supply of carrier particles in which the average number of toner particles per carrier particle is lower than that of said toner-laden carrier particles.

Abstract: A xeroprinting master includes a fixed insulative toner image on an electrophotographic element of the type exhibiting charge injection at an interface between a charge injection electrode and a charge transport layer. In xeroprinting use the master is charged to a polarity opposite that which is injectable. The charge is neutralized by charges injected from the electrode which migrate to the charged surface. Charge retained on the fixed toner image can be toned. The master can be made by positively charging it to a polarity the same as that which is injectable, imagewise exposing it and toning and fixing.

Abstract: The present invention relates to a photoelectrographic element having a conductive layer in electrical contact with an acid photogenerating layer which is free of photopolymerizable materials and contains an electrically insulating binder and acid photogenerator. A dye which absorbs near-infrared radiation is included in the photoelectrographic element so that the element, when used in electrostatic copying, can be exposed with near-infrared radiation. A method for forming images with this element is also disclosed.

Abstract: A photoelectrographic element for electrostatic imaging, containing a conductive layer and a photosensitive layer, is produced using photosensitive layer materials which form a barrier to charge injection where exposed to near-infrared radiation. As a result, exposed areas can be charged, while unexposed portions cannot. The photosensitive layer contains an organic photoconductor, a near-infrared radiation sensitizer, and, optionally, an organic binder. A method of forming images with this phctoelectrographic element is also disclosed.

Abstract: A method and apparatus for producing an image on an imaging member. The apparatus includes a magnetic brush for depositing a substantially uniform layer of thermoplastic toner particles onto the imaging member. A laser scanner device is utilized to imagewise heat selected toner particles such that the selected toner particles are lightly tacked to the imaging member. The imaging member is contacted by a second magnetic brush, which includes a supply of magnetic carrier particles preferably having a coercivity of greater than about 100 oersteds, at least two times to remove nonselected toner particles from the imaging member. Alternatively, the imaging member may be contacted by two separate magnetic brushes at least one time to remove nonselected toner particles from the imaging member.

Abstract: In accordance with the invention, there is provided a magnetic brush laydown/pickup apparatus having a shell surrounding a plurality of alternating pole magnets, said shell and magnets being relatively movable to transport developer mix through a development zone. Developer mix, comprised of toner particles and carrier particles, is selectively supplied to the surface of the shell at a location upstream of a development zone. The developer mix is selectively removed from the surface of the shell at a location downstream of the development zone. Toner particles are selectively stripped from the developer mix on the shell.

Abstract: A migration imaging system using a laser-addressable thermoplastic imaging member. The imaging member comprises a supporting section and a thermoplastic imaging surface layer. A charged, uniform layer of marking particles is deposited on the imaging surface layer. An imagewise-modulated laser beam transforms selected volumes of the imaging surface layer in an imagewise pattern to a permeable state. Charged marking particles that superpose a transformed volume then migrate into the imaging surface layer so as to be retained. Unaddressed marking particles are cleaned away. The imaging member, or solely the imaging surface layer, may be transferred and bonded to a receiver such as a drum for use as an exposure mask, or to a receiver sheet to provide a hard copy reproduction. The processed imaging member is usable as a master in a xeroprinting system.