Abstract: The present invention relates to an image forming apparatus for carrying out image forming in any of a plurality of image forming modes by changing the relationship between the drive starting time of the document scanner and the time at which registration rollers feed paper to the image forming unit. The paper feeding unit is adapted to feed paper from a paper housing unit at predetermined time intervals, determined according to the sizes of paper. The time intervals at which the registration rollers feed paper to the image forming unit are equal to these predetermined time intervals. Such predetermined time intervals remain unchanged for all image forming modes. Further, the period of time during which paper is once stopped by the registration rollers remains unchanged even though the image forming mode is changed.

Abstract: A developing apparatus is provided with a developer bearing member for bearing developer including toner particles and carrier particles to feed the developer to a developing station. A regulating member is disposed in confronting relation to the developing bearing member and adapted to regulate an amount of the developer fed to the developing station. A voltage source outputs an alternating bias voltage to the developer bearing member and to the regulating member. A detecting element is disposed in the vicinity of the regulating member and in confronting relation to the developing bearing member. The detecting element is adapted to detect toner density in the developer born by the developer bearing member. An electrical shield member is disposed between the detecting member and the regulating member.

Abstract: An apparatus which develops an electrostatic latent image. A transport roll advances developer material from a chamber to a donor roll. The donor roll advances the toner particles to the latent image. The latent image attracts toner particles from the donor roll. In order to improve the speed with which toner particles removed from the donor roll are replaced, an alternating voltage is applied between the two rolls.The magnetic transport roll is driven to rotate at a surface velocity at least 2, but not more than 5 times that of the rotational surface velocity of the donor roll. Also, the compression pile height (CPH) vs the spacing between the spacing between the donor roll and the transport roller (DRS) is found to be optimal when meeting the ratio CPH:DRS=2:3.

Abstract: A multicolor printing method for printing multicolor picture images upon a material or object to be printed comprises the steps of, in accordance with a first embodiment of the invention, the formation of a multicolor toner image upon a flexible belt by means of electrophotographic printing methods or techniques, and the transfer of such multicolor toner image directly to the material or object to be printed, such as, for example, a container made of, for example, metal, paper, plastic, glass, or the like, by means of a thermo-transferring process. In accordance with a second embodiment of the invention, the multicolor toner image is formed upon a plastic film, which is laminated upon the flexible belt, by means of electrophotographic printing methods or techniques, and the plastic film is then transerred to and fused upon the container.

Abstract: A semimoist process copier for electrostatically forming a latent image on a photoconductive element and developing it by a liquid developer. When the temperature of the liquid developer or that of the photoconductive drum is lower than a predetermined temperature, the state of the copier just after the end of the previous copying operation is maintained. A person intending to operate the copier for a subsequent copying operation is capable of doing so immediately. The elimination of a waiting period after a drum cleaning operation is performed is achieved by allowing a drum cleaning blade to remain in contact with the drum when the temperature of the liquid developer or the drum is below a reference temperature. In this manner, when the drum or developer temperature is below the reference temperature, no waiting period is experienced by the user on subsequent attempts to copy.

Abstract: A photographic recording apparatus is provided having a housing body, and a process cartridge unit including a photoconductive drum and a developing device and which is removably mounted on the housing body. The cartridge unit includes a first and a second frame which are pivotable about a rotation axis of the drum relative to each other, and a biasing member for biasing the two frames to thereby hold the frames in a first relative angular position. The housing body includes a portion for holding the cartridge unit such that the two frames are held in a second relative angular position, which is established by pivoting the two frames from the first relative angular position against a biasing action of the biasing member. The first and second frames each having holes or openings that are initially misaligned, cooperate in an overlapping fashion to provide at least one opening through which a portion of the drum is exposed outside the frames, when the frames are placed in the second relative angular position.

Abstract: An image forming apparatus includes a main body having an original table on which an original set is placed, a cover mount portion located at one side of the original table, and an openable original cover having a portion to be mounted on the cover mount portion of the main body. The cover holds the original set on the table. Mounted on the cover mount portion of the main body are first to fourth engaging members, which are respectively engageable with first to fourth members to be engaged, all mounted on the cover portion to be mounted, the first and fourth members to be engaged being hooks and the second and third members to be engaged being pins. These pairs are inserted and engaged with each other when the original cover is moved in a direction perpendicular to a direction to open the cover.

Abstract: An image forming apparatus for forming an image by deflecting a light beam signal modulated by an image signal onto a photoconductive element by a polygonal mirror to electrostatically form a latent image and developing the latent image. A main scanning synchronization detector is located in the vicinity of the photoconductive element for setting up synchronization in the main scanning direction. A displacement detector detects a distance over which the photoconductive element has been displaced over a period of time associated with a subscanning pitch. Correcting control is driven in response to the output signals of the main scanning synchronization detector and displacement detector. The light beam signal is so deflected in the subscanning direction as to correct an error in the subscanning pitch.

Abstract: A developing device confronting a rotatably provided electrostatic latent image support member and including a rotatable developing roller confronting said electrostatic latent image support member, a flexible outer sleeve having a peripheral length larger than that of the developing roller so as to be loosely fitted around the developing roller, an urging member for depressing the outer sleeve against the developing roller so as to form a gap between the developing roller and the outer sleeve such that a peripheral surface of the outer sleeve is brought into contact, at a downstream side or an upstream side of its location having a maximum distance from an axis of the developing roller in a rotational direction of the outer sleeve, with the electrostatic latent image support member when the developing roller is rotated and a member for forming a toner layer on the peripheral surface of said outer sleeve.

Abstract: A method for copying relatively thin documents of semitransparent or thin stock which permit images on the reverse side to show through to other portions of the copy apparatus. A sensing system is employed to sense the density of the document and otherwise determine that background images may show through. The copier may automatically produce a black sheet for backing on the thin or semitransparent stock and the original copy using the copy lighter feature to eliminate the uniform gray background which would otherwise be produced. This can be done automatically or on command by the operator.

Abstract: An electrostatographic copier or printer includes front end apparatus for forming and developing copies of images electrostatically, and back end apparatus which include a multiple function fusing roller that also functions as an image transfer roller. The multi-function fusing apparatus selectively includes a contact fusing operation or a non-contact fusing operation. A vacuum roller holds the copy sheet while either a radiant fuser or a pressure nip fuser will fix a toner image onto the substrate. The vacuum roller may be internally heated and the pressure roller which creates the fusing nip is selectively moved into and out of contact with the vacuum roller dependent upon the operation selected.

Abstract: Document reproduction apparatus includes a plurality of sensors for acquiring real time diagnostic data. The acquired data is statistically compared to predetermined control limits or reference value(s) to predeict incipient problems before failure occurs so as to functionally and automatically optimize the reproduction apparatus. Operation of the document reproduction apparatus is functionally optimized in real time in response to differences between the acquired data and the predetermined control limits or reference value(s). The optimizing operation may be in response to detection that the acquired data is tending away from nominal by studying statistical variations in the data.

Abstract: An apparatus in which an electrostatic latent image recorded on a photoconductive belt is developed with toner. A donor belt is wrapped about a portion of a magnetic roll to define an extended loading zone. The magnetic roll advances a developer material comprising carrier and toner to the loading zone. At the loading zone, toner is deposited on the donor belt. A plurality of electrode wires are positioned in the space between the donor belt and the photoconductive belt. The electrodes are electrically biased to detach the toner from the donor belt so as to form a toner cloud in the space between the electrodes and photoconductive belt. Detached toner from the toner cloud develops the latent image.

Abstract: An electrophotographic copier/duplicator having a 17".times.11" wide endless photoconductor includes single imaging apparatus for forming and processing a single 17".times.11" image at a time, within a 17".times.11 " image frame of its photoconductor, and dual imaging apparatus for simultaneously forming and processing two 8.5".times.11" images at a time, within a 17".times.11" image frame of such photoconductor.

Abstract: A device for fixing a powder image on a receiving support using heat that consists of an image transfer roller internally provided with a first heating element having the same heat-generating power over the entire length of the image transfer roller, and a second heating element which has a higher heat-generating power in the edge zones of the image transfer roller than in the middle zone of the roller, and a pressure roller internally provided with a third heating element which like the second heating element has a higher heat-generating power in the edge zones than in the middle zone. The device may be in a warm-up condition in which the temperature of the rollers is not yet at the working level, stand-by condition in which the temperature is at the working level but in which no fixing is carried out, and a fixing condition in which fixing is carried out. During warm-up, all the heating elements generate the maximum power.

Abstract: A transmission densitometer determines the optical density of an electrically charged layer of toner material on a photoconductive layer by exposing the photoconductive layer to radiation through the toner layer such that the amount of exposure is characteristic of the density of the toner layer. The change in voltage on the surface of the toner layer caused by the exposure is detected, such that the change in detected voltage is characteristic of the density of the toner layer.The measurement of the change in the detected voltage is carried out by measuring the characteristic voltage on a toner layer developed upon a photoconductive layer using a first electrostatic voltmeter, discharging the characteristic voltage on the area of the photoconductor which was measured by the first electrostatic voltmeter using the exposing device, and measuring the remaining voltage in that area by using a second electrostatic voltmeter.

Abstract: An electrostatographic reproduction apparatus transfers a toner image from an image member to a receiver sheet by applying an electric field between the image member and the receiver sheet in a direction urging the toner image to the receiver sheet. A programmed power supply is adapted to (1) generate a pre-set constant current across the applied electric field during an adjustment period and (2) lock onto the voltage that supplies the set-point current for the reminder of a reproduction run. The value of the voltage is used to automatically adjust the value of an least one electrostatographic process element. The electrostatographic process element to be adjusted may be at least one of detack bias, detack duration, initial voltage V.sub.0, exposure E.sub.0, developement bias V.sub.B, copy sheet conditioning, and copy sheet drying.

Abstract: A printer for electrophotographically forming an image on a continuous-form recording paper. The printer has a transfer unit and a pair of heat fixing rollers which are brought into a withdrawn state, in a print stand-by state. Thus, the recording paper is out of contact with a photoconductive drum and a heat roll when the transfer unit and heat fixing rollers are in their withdrawn state. A pair of dust removing brushs are also brought into a withdrawn state in the print stand-by state so as to be out of contact with the recording paper.

Abstract: A multicolor image forming apparatus which includes an image forming drum which has a gap or though in its periphery used for securing the ends of a photoconductive sheet. A transfer roller engages the drum to receive a series of different color toner images in registration to form a multicolor image. The transfer roller is driven by engagement with the periphery of the drum in a pressure nip between the drum and roller. When the gap in the drum passes through the nip, an independent motor rotates the transfer roller to a home position, thereby reindexing the roller between each series of images.

Abstract: A method of controlling print positioning comprises the steps of: detecting the time which elapses until a sheet of paper reaches a given position; predicting the time which would elapse until the paper reaches an image transfer position on the basis of the time detected in the detection step; calculating the time difference between the predicted time and an elapse time calculated on the basis of a paper carrying speed pattern which is previously stored and has at least two speeds; and controlling the paper carrying speed so that the calculated time difference becomes zero, thereby preventing any misregistration between a toner image and the paper.