Abstract: A printer or copier has an optical character generator for reproducing raster image data in grey-scale displays. Integrated light sources in the form of LEDs arranged in arrays are aligned to form a print line. A control IC is provided for each LED array. Groups of the control ICs are formed in which information is shifted for the switch on time of all LEDs of a group starting with the first control IC to the next IC. The ICs are connected together by bonding. A ramp circuit is provided to prevent current surges when the LEDs are switched on. A flat unit that extends along the character generator is used to transmit information and power to the control ICs. Busbars ensure that power is provided to the LEDs.

Abstract: An integrating xerographic light emitter array includes circuitry for operating an active matrix array of organic light emitting diodes (OLEDs). The light emitter array stages rows of emitters in the slow scan direction and moves the object image and synchronization with the photoreceptor. Grey scale resolution, increased emitter lifetime and the ability to operate at lower light levels are achieved in proportion to the number of stages. The entire printbar can be rewritten during each line time of the photoreceptor, which allows the exposure on any pixel on the photoreceptor to be varied in a number of grey levels from zero to the number of stages. Bringing a grey level signal to the photoreceptor allows improved continuous tone image quality and line placement. Additional grey resolution is obtained by analog driving of individual pixels. This technique is applicable to a variety of emitters or light valves, but is particularly suited to inexpensive OLEDs.

Abstract: In an array of light-emitting diodes formed by diffusion of an impurity into a semiconductor substrate, the width of the diodes in the array direction is between four-tenths and five-tenths of the array pitch. The width of the windows above the diodes is between three-tenths and four-tenths of the array pitch. Between one-fourth and one-half of the surface area of each diode is covered by an electrode making contact with the diode through the window. The distance from the centers of the light-emitting diodes at the ends of the array to the edges of the substrate is between twenty-five and sixty-five hundredths of the array pitch.

Abstract: An exposure head wherein a light-shielding panel having enclosing openings capable of receiving individual LED chips, and a front surface panel having small openings are disposed at a front surface of an LED panel in which the LED chips are arranged, is provided. In the exposure head, the LED chips and bonding wires can be housed in the enclosing openings, and can be protected from a medium to be exposed, by the front surface panel. Therefore, each dot can be irradiated with exposure light from the LED chips, which are disposed close to the photosensitive medium, so that each dot can be exposed without using a lens system. The inside surfaces of the enclosing openings are made reflective to prevent exposure light from leaking from the cells in which the individual LED chips are housed, into other LED chip cells, so that each dot can be exposed to high-intensity exposure light.

Abstract: An image recording apparatus which performs time division and driving of 128 recording devices arrayed within an LED chip includes shift registers for sequentially serially outputting 128 bits of continuous pixel data to 56 signal lines, corresponding to each LED, from one line of serially input pixel data row, selectors which perform time division of the 56 pieces of pixel data into 8 times of 7 pieces apiece and then outputs the data, and registers which hold the pixel data output from the selectors for each corresponding LED chip. The image recording apparatus may be used as a recording head for a printer using solid recording devices is simplified, and costs are reduced.

Abstract: A light emitting element module is provided including a board and plural chips arranged in the form of an array on the board. Each chip includes at least one light emitting element having a light emitting function and/or a photosensing function. The chips are arranged on the board so that the upper surfaces of adjacent chips which are located opposite to the board are positionally displaced in the height direction of the chips by at least the distance corresponding to the thickness of the chips. This uneven chip arrangement in the height direction may be established by alternately arranging thicker chips and thinner chips on the board.

Abstract: A recording head includes a light emitting element array comprised of a plurality of light emitting elements and a plurality of switch elements for scanning the plurality of light emitting elements, and a drive device for driving the light emitting element array. The drive device has a variable resistor in a route for supplying a driving current to the plurality of switch elements. The control voltage of the variable resistor is varied to thereby adjust the driving current for the plurality of switch elements.

Abstract: An electrostatographic reproduction method and apparatus includes an electrostatic recording member moving in a process direction. A plurality of recording elements on a writer imagewise expose the recording member to form electrostatic latent images on the recording member. The writer includes driver circuitry for actuating selected recording elements. The exposed recording member is then moved through a development station to develop the latent images. The developed images are transferred to a record member. An operator selectable adjustment controller is manually adjusted for generating adjustments in operation of the recording elements to compensate for a misalignment of a process station in the apparatus.

Abstract: There is disclosed a light-emitting device assembly use in a large-sized printhead. The assembly includes a number of insulating substrates including first and second substrates. A conducting layer is formed on each substrate. A conductive adhesive layer is formed on the conducting layer. The conducting layer on the first substrate extends close to the abutting end of this substrate. The conducting layer on the second substrate is set back a first distance from the abutting end of the second substrate. Light-emitting devices are disposed in the vicinity of the abutting end of the conducting layer on the second substrate. Light-emitting devices on the first substrate are made to protrude a second distance greater than the first distance from the abutting end of the first substrate. The light-emitting array protruding from the first substrate is made to bear against the light-emitting device array set back from the abutting end of the second substrate.

Abstract: The present invention provides a face emission printing system including an array of face emission electroluminescent devices coupled to an optical structure. The face emission EL printhead is comprised of a substrate; and a plurality of layer stack supported on the substrate, each of the layer stack including a thin film active layer which generates light in response to conduction of electrical current, a first thin film electrode layer and a second thin film electrode layer, where at least one of said electrode layers being spaced apart from said active layer by a thin film dielectric layer. The first thin film electrode layer is transparent and light is emitted through the surface of the first thin film electrode layer. The layer stacks are preferably staggered and the optical structure is preferably a micro lens are optical concentrator formed integral to the emitting surface of the plurality of layer stacks.

Abstract: Bit data of a received video signal is partially converted into a first signal representing a data sequence corresponding to the resolution of an LED head. The remaining bit data of the received video signal, which are not converted into the first signal are converted into a second signal representing another data sequence corresponding to the resolution of an LED head. The LED head includes a resolution conversion circuit which converts the video data into the first signal and the second signal. The signals are stored in a shift register having a plurality of line buffers. The first signal is printed on a basic raster line and the second signal is printed on an additional raster line. An LED head drive energy with which basic raster lines are printed and another LED head drive energy with which additional raster lines are printed are set independently of each other.

Abstract: Image source, for converting image data in the form of serial charges into a high-resolution imagewise light pattern, combines semiconductor charge-coupled devices for receiving the charges, associated small-scale field emission arrays for converting the charges to imagewise pattern of electron emissions, an electron multiplier for intensifying the electron emissions, and a luminescent phosphor layer susceptible to light output according to the impact of the intensified electron emission. The light output may be directed onto a photosensitive image recording medium to provide means for image recording. Second and third embodiments of the contemplated image source provide light output that forms an image to be viewed directly.

Abstract: An LED print head is for use in an LED printer. The LED print head has an LED circuit board on which a plurality of LED chips are mounted in line, and a lens assembly having rod lenses for focusing light emitted from the LED chips on a surface of a photosensitive drum in the LED printer. A first member or slider engages either the LED circuit board or the lens assembly and is adapted to displace stepwise to cause either the LED circuit board or the lens assembly to flex stepwise relative to the surface of the photosensitive drum. A second member or slider engages said first member to movably hold said first member. The LED circuit board or lens assembly is flexed so that a point on the photosensitive drum and the surface of the corresponding LED form a pair of conjugate points with respect to the corresponding rod lens.

Abstract: An image forming apparatus includes an LED array head to which a vibration applying unit driven by a driver is attached. The LED array head is shifted by a predetermined amount in a direction at an angle .theta. relative to the axis of a photosensitive drum. LEDs are driven to emit the light in accordance with video data before and after the shift, and an electrostatic latent image according to the video data is formed on the photosensitive drum. Since the LED array head is shifted in a diagonal direction relative to the axis of the photosensitive drum, it is possible to form high-resolution dot lines in the axial direction even if the photosensitive drum is rotated at a constant speed.

Abstract: An electrophotographic process and arrangement for generates a macro-charge zone inkable by toner applicators and delimited by an inking limit (EG) having an adjustable contour on a photoconductor of a printing or copying machine, using at least one exposure-variable and position-variable controllable light source (LED), such as an LED comb or laser. By controlling the exposure of the light source and its radiation position on the photoconductor and by controlling a bias voltage (UB) which can be applied between photoconductor and toner applicator, an electrostatic potential relief (UR) made up of individual adjacent micro-charge zones (UM) of exposure-dependent size is generated on the photoconductor and the inking limit (EG) is defined, the contour of the inking limit being determined by the bias voltage level (UB) on the potential relief (UR).

Abstract: An electrophotographic printer includes a plurality of recording heads connected in series in a closed cooling circuit. Each of the recording heads includes a linear array of light-emitting diodes (LEDs) on a common thermally conductive LED carrier bar. The carrier bar carries a series of modules, each module containing N LEDs with their associated drivers. The carrier bar is provided with a U-shaped duct inside a thermally conductive body which is in thermally conductive contact with the carrier bar. The duct extends between a fluid inlet and a fluid outlet and has a cooling fluid such as water flowing therethrough.

Abstract: Bit data of a received video signal is partially converted into a first signal representing a data sequence corresponding to the resolution of an LED head. The first signal is transmitted to the LED head in the form of a real printing data signal that is to be printed on a basic raster line in synchronism with a line timing signal. The remaining bit data of the received video signal, which are not converted into the first signal, are converted into a second signal representing another data sequence, and then stored in a line buffer. The second signal stored in the line buffer is transmitted to the LED head in the form of a real printing data signal that is to be printed on an additional raster line in synchronism with an additional line timing signal. The LED head drive energy with which the basic raster lines are printed and another LED head drive energy with which the additional raster lines are printed are set independently of each other. The LED head may be provided with such a resolution function.

Abstract: A thin film electroluminescent device, comprising a first electrode layer, first and second dielectric layers with an active phosphor layer disposed therebetween, and a second electrode layer, wherein there is provided within the phosphor layer at least one barrier layer comprising a thin layer of dielectric material.An array of such devices placed side to side is provided with a print head suitable for A4 electrographic printing.

Abstract: An image forming apparatus is provided with a photoreceptor, and an exposure device for exposing the photoreceptor based on image data so as to form an electrostatic latent image on the photoreceptor. The exposure device has a plurality of light emitting devices aligned along a main scanning direction of the photoreceptor, the respective light emitting devices having a plurality of luminescence portions, and a light emitting device driver for applying a voltage to the respective luminescence portions so that the luminescence area of the light emitting device increases step by step whenever the applied voltage increases by a predetermined voltage based on the image data. With the arrangement, tone expression is realized in the electrostatic latent image, according to the size of the luminescence area of the respective light emitting devices, which can be controlled by the voltage applied to the respective light emitting devices based on the image data.

Abstract: A method for manufacturing a display apparatus including a display device, a circuit device which supplies a driving current to the display device and a selecting circuit for regulating the drive current of the circuit device into a plurality of steps of current values. The display apparatus is manufactured in the following steps: a step of allocating the display device to one of a plurality of ranks according to its light quantity; a step of allocating the circuit device to one of a plurality of ranks according to its output current, and a step of selecting based on the rank of the display device and the rank of the circuit device a selection value of the selecting circuit previously prepared according to a combination of ranks of the display device and the circuit device.

Abstract: Uniformity light output of an LED printbar is achieved by a technique which senses the operational on time of each LED. When the on time difference between the LED with the longest on time and the LED with the shortest on time exceeds a predetermined value, the outputs of at least some LEDs comprising the printbar are compensated for to normalize their light output. This normalization is achieved via a drive circuit which drives each LED based upon correction data, and by determining an update of the correction data based upon the difference between the on time of individual LEDs. The correction data is determined when the difference between the on time of the LED with the longest on time and the on time of the LED with the shortest on time exceeds a predetermined maximum difference.

Abstract: Bit data of a received video signal is partially converted into a first signal representing a data sequence corresponding to the resolution of an LED head. The first signal is transmitted to the LED head in the form of a real printing data signal that is to be printed on a basic raster line in synchronism with a line timing signal. The remaining bit data of the received video signal, which are not converted into the first signal, are converted into a second signal representing another data sequence, and then stored in a line buffer. The second signal stored in the line buffer is transmitted to the LED head in the form of a real printing data signal that is to be printed on an additional raster line in synchronism with an additional line timing signal. The LED head drive energy with which the basic raster lines are printed and another LED head drive energy with which the additional raster lines are printed are set independently of each other.

Abstract: An optical device for forming a latent image on the surface of a photosensitive member by an optical head, developing the latent image and transferring the developed toner image onto a transfer sheet at a transferring section. The transfer sheet is transported at least at the transfer section in a direction inclined relative to a direction perpendicular to the rotation axis of the photosensitive member at an angle of distortion of the latent image which occurs when the optical head forms the latent image on the surface of the photosensitive member, thereby toner particles in the transfer section receive twisting force and the distortion of the latent image is corrected when the latent image is transferred to the transfer sheet.

Abstract: The present invention is a multiple spot laser assembly, comprising a plurality of laser diodes, and a plurality of mounts, which include a support surface, upon which the laser diode are permanently affixed. The mounts, including the base plate and/or heat sink, further include a mating feature along an edge thereof for aligning a first mount with an adjacent mount, the two mounts abutting along at least one common edge. The mating features assure the accurate alignment of the laser diodes on the adjacent mounts when the mounts are assembled into a multispot laser light source.

Abstract: An optical print head in an image forming apparatus includes linearly arranged blocks and integrated circuits for driving disposed at one or both ends of the line of blocks. Each of the blocks includes a plurality of light emitting diodes. Positionally corresponding light emitting diodes in each block are connected to one of a plurality of meandering individual signal lines which are connected to the integrated circuits and each block is further connected to a corresponding common signal electrode to which power is selectively applied, thereby making possible illumination and drive of light emitting diodes in each block. The head may include a housing containing the blocks, individual signal lines and common signal electrodes and further include a flexible substrate located outside of the housing connected to and supplying power to the common signal electrodes.

Abstract: A method and an apparatus for driving an edge emission type line head having a plurality of edge emission type EL elements grouped in blocks. Each group of the edge emission type EL elements has a channel electrode connected to a channel driver and has a common electrode connected via a matrix circuit to common terminals of a common driver. The channel driver outputs voltages while the common driver outputs alternately a positive and a negative high voltage. If something happens to stop the function of the line head in operation, the output of the common driver is stopped after a pair of a positive and a negative high voltage is output by one common terminal, or after one-line output is effected by the common driver. This helps prolong the service life of the edge emission type EL elements constituting the line head.

Abstract: This invention relates to an image forming apparatus based on the electrophotographic process, more particularly to the image forming apparatus having an exposure member inside of a photoreceptor member, which develops upon receiving light exposed with the exposure member. The image forming apparatus features to include the exposure member having a plurality of LED elements arrayed along a main scanning line of the photoreceptor member which is exposed with the LED elements in a time sharing manner by n bits unit, and the photoreceptor means having the photoconductive layer formed of amorphous silicon compounds for receiving the light. The photoreceptor member is electrified through brushing contact of the developer carried by the toner support member, and wherein the exposure portion of the exposure means is located in the developer brushing contact region.

Abstract: A method for printing an image including the step of generating a basic line timing signal and an additional line timing signal providing timings between respective timings of the basic line timing signal, producing a matrix by a video signal of a number of lines corresponding to a ratio of a resolution of the video signal to a resolution of a printing portion, producing one dot of a grayscale data signal having grayscale information of dots of the matrix, and driving a printing head by head drive energy determined according to the grayscale data signal, when an image is printed by using the printing head having a resolution in the raster direction less than the resolution of the video signal for forming the image to be printed. Although a number of dots for forming the image is reduced, amount of information is not reduced since dot information is converted into the grayscale information, so that high-quality printing is possible at a time of printing for grayscale.

Abstract: There is disclosed an optic system for illuminating a spatial light modulator array in a xerographic printing process consisting of an array of LED emitters constructed to efficiently replace the conventional tungsten source used in prior art. The array of LED emitters can be geometrically configured or electrically operated by strobing or varying the brightness of individual pixels to compensate for other system optical deficiencies and results in improved printing process. By exposure strobing the LED source correction for fuzzy line edges can be achieved.

Abstract: A plurality of light-emitting diode chips (2) densely packed in the form of rows is associated with driver chips (34) and associated drive chips (3) on both sides. The printing information is supplied from a printer control (6) via a bus system (4, 4' and 5, 5'). Each light-emitting diode chip is subdivided into n groups of light-emitting diodes (for example LED1, LED3, LED5 . . . LED31 and LED98, LED100 . . . LED128), which are arranged geometrically offset with respect to one another transversely to the main direction of the diode row. Each drive chip contains a switching unit (32) for generating internal sequence control signals (for example SWE1, SWE2, I-CLK) and n part-circuits (33/0 to 33/3) associated with the n groups of light-emitting diodes for the simultaneous processing of the printing information into temporally staggered drive signals (DS).

Abstract: A linear printhead writer assembly includes a linear source of radiation such as an LED printhead, and an elongated linear focusing device such as a linear lens array, and a support housing for supporting both the source of radiation and focusing device in a fixed relation with respect to each other and to an exposure locus. A positioning bar is supported by the support housing and engages a web image member to position the image member with respect to the exposure locus. The writer is preferably used with an image member having a radiation-sensitive layer on a side opposite the writer and is particularly adapted for exposing a charged image member already containing a toner image as part of a process to create a two-color image on the image member. The focusing device is held in the writer assembly by a coupling with a pair of end supports, each coupling allowing thermal expansion of the lens support and also isolating the lens support from vibration transmitted through the support housing.

Abstract: In an electrophotographic image forming apparatus, a potential measurement device for measuring the surface potential of the electrostatic latent image and a reflective density measurement device for measuring the density of a visible image developed from the latent image are made movable, in mutually synchronized manner, along the axial direction of the rotating photosensitive member. In this manner the image forming ability can be measured over the entire surface of the photosensitive member, and the process conditions can be suitably regulated according to the results of measurements.

Abstract: In an electrophotographic device, a main body is divided into a lower body and a swingable upper body. A process unit formed of at least a toner holder, a charger, and a developer is detachably mounted in the lower body. The position of the process unit (particularly, the photosensitive member) relative to the lower body (particularly, a member driving gear) is controlled by placing a shaft of the member through a groove in a side wall of the lower body at one end of the member, and by bringing a lower end of the side wall of the process unit supporting the member into contact with an upper end of a support member supporting the member driving gear. An exposure unit mounted in the upper body is positioned to the photosensitive member with a predetermined distance therebetween by bringing a contact portion of the exposure head into contact with the side wall of the lower body supporting the member.