Abstract: In the case of a web breakage detector for web processing machines and more particularly for web feed printing machines, comprising a device for monitoring the web tension and adapted to produce a signal in the event of the web tension decreasing, a high degree of reliability and ease of operation are possible if said monitoring device is designed in the form of a pressure measuring device, which comprises a web pressure sensor for detecting the pressure in a gap delimited during normal operation on the one hand by the web and on the other hand by a stationary cover passed by the web, such sensor being adapted to produce a signal in the event of a pressure drop occurring in the gap.

Abstract: A carriage position control circuit which locates a carriage at a center position of a printing sheet regardless of the paper size to maintain the printing sheet in contact with the platen. The carriage position control circuit includes a sensor (30) which moves, together with the carriage (2), in parallel to a center axis of the platen (1) of a serial printer and senses a printing sheet (10), a sheet position detector (43) which detects left and right edge positions of the printing sheet based on the sensor output and a center position calculating circuit (45) which calculates the center position of the printing sheet based on the left and right edge positions. The detection of the left and right edge positions and the calculation of the center position are performed before the leading edge of the printing sheet reach the anti-floating device (3).

Abstract: An automatic document feeder for use with an electrophotographic copier, digital copier or similar image recorder capable of transporting ordinary documents in the form of separate sheets and a continuous document in the form of computer form (CF) paper which is formed with equally spaced sprocket holes, as desired. A sprocket hole sensor is disposed on an imaginary line along which the sprocket holes of the CF paper are moved. A control device reversibly controls the transport of the CF paper to a predetermined reference position on a glass platen in association with the number of sprocket holes being counted. The document feeder is capable of not only copying a desired page of the CF paper but also implementing jam recovery in the event when a paper sheet jams the image recorder.

Abstract: An automatic document feeder (ADF) for use with an electrophotographic copier, digital copier or similar image recorder for selectively feeding ordinary documents in the form of separates sheets and a continuous document in the form of computer form (CF) paper. Sprocket holes formed through the CF paper are sensed to controllably transport and stop the CF paper on the basis of the number of sensed holes. Even when the first print area of the CF paper is set on a platen by hand, the paper can be surely transported and stopped page by page to the last print area. Regarding the last print area, the stop position is determined on the basis of the number of sprocket holes having been counted until the trailing edge thereof has moved away from a sensor. Hence, whatever the deviation of a print area relative to the CF paper may be, all the print areas including the last print area can be accurately set on the platen to reproduce complete images.

Abstract: A chart recorder (10) is disclosed having an automatic paper loading system, an automatic tensioning system and an "odometer" system for determining the amount of paper moved through the chart recorder. The chart recorder (10) includes a print roller (34) and a feed roller (22), both in frictional contact with the paper in the recorder and both connected to and rotated by a motor. The feed roller (22) is connected to the motor through a one way clutch that allows the feed roller (22) to "free wheel" when the feed roller (22) is rotated at a faster rate, due to frictional contact with the paper, than the roller would be rotated by the motor (56). Dissipative forces in the one way clutch (68) and bearings (24) of the feed roller (22) cause it to resist being rotated which imparts tension to the paper and draws it into contact with a paper guide (14).

Abstract: The dot impact printer of the invention sets an optimum printing speed based on various factors, such as kanji or alphanumeric characters, and to set an optimum brake pulse and an optimum energizing energy corresponding to the set optimum printing speed. The printing mode is determined through a series of logic steps and optimum settings for the printing actions is selected according to the mode identified. Thus, in the invention, based on the print contents, a printing speed, an energizing period of time for the first dot, an energizing period of time for the following dots, a brake pulse width, a period of time till the generation of brake pulses and delay time, are changed.

Abstract: An automatic document feeder (ADF) for use with an electrophotographic copier, digital copier or similar image recorder for selectively feeding ordinary documents in the form of separate sheets and a continuous document in the form of computer form (CF) paper. Sprocket holes formed through the CF paper are sensed to controllably transport and stop the CF paper on the basis of the number of sensed holes. Even when the sprocket holes are partly deformed or practically lost due to breakage, the positions where they should exist are surely sensed to control the transport and stop of the CF paper. Sensors responsive to the sprocket holes do not have to be shifted in matching relation to the width of CF paper and, therefore, eliminates the need for a complicated structure.

Abstract: A printer improved in the accuracy of detection as to whether or not recording paper exists. The printer has a sensor provided upstream a printing head in a paper feed direction to detect whether or not recording paper exists, a device for measuring a paper feed quantity of the recording paper, a central processing unit that controls the measuring device and a printer control circuit, and a comparator that makes a comparison between the measured paper feed quantity and a predetermined value. When "paper empty" is detected by the sensor, the central processing unit judges it to be "real paper empty" when no "paper existence" is detected during the period that predetermined paper feed is conducted after the detection of the "paper empty", and then suspends the printing operation. Thus, it is possible to prevent the central processing unit from erroneously judging a printed portion of the recording paper to be the trailing end of the recording paper.

Abstract: Paper feed rollers are in a paper supply path before a printing unit. A paper detector is between the printing unit and the paper feed rollers for sensing the presence of paper in the path. A control of the paper transport is facilitated in the paper supply direction by a movement detector before the paper feed rollers, which is driven by the transported paper and produces a number of pulses proportional to the passage length of the paper. The paper detector comprises a magnet on a rotatable lever and a fixed unipolar Hall element. The movement detector comprises a rotatable wheel having multipole magnets on its periphery and a bipolar Hall element secured to respond to the rotating magnetic poles of the wheel.

Abstract: A transport device for use in a recording apparatus is disclosed. The transport device includes a conveyor belt having at least three layers. The upper layer of the belt is a conductive or semiconductive layer that is discriminable from a recording material by a detector. Below the first conductive or semiconductive layer is an insulating layer and below the insulating layer is a third conductive layer. The first layer has a volume resistivity value of from 10.sup.14 to 10.sup.17 .OMEGA.cm. The detectors are positioned upstream and downstream of the recording region and disposed downstream of that recording region is a cleaning blade and absorber which together work under control of a controller to clean ink from the conveyor before it soils the charging roller or the next recording sheet. The controller also controls the cleaning operation in accordance with the amount of ink that was unnecessarily jetted onto the conveyor belt.

Abstract: A sheet guide apparatus for a printer comprises a printing head, a platen arranged in opposed relation to the printing head, sheet feed tractor arranged upstream of the platen in a sheet delivering direction, a plurality of guide elements arranged downstream of a delivering direction of a sheet passing between the printing head and the platen, along an axis of the platen with the guide elements spaced from a surface of the platen, wire rope and pulley system for moving the printing head axially of the platen, and control unit for controlling the wire rope and pulley system such that, after a forward end of the sheet transported by the sheet feed tractor has been abutted against sheet engaging surfaces of the respective guide elements, the printing head is reciprocated along the platen axis.

Abstract: A thermal transfer recording device for recording an image on a recording sheet by means of an ink film. The device has a cassette accommodating recording sheets and a unit accommodating an ink film both of which are loadable into the main body of the device, and further has a first sensor for detecting the type of the cassette and a second sensor for detecting the type of the unit. The device alerts the operator when the type of the unit is judged to be incompatible with the type of the cassette according to the result of detection by the first and second sensors.

Abstract: A thermal printing device for printing an image data on a thermosensible paper includes a platen roller for conveying the thermosensible paper, a thermal head having a plurality of heater elements provided in opposition to the platen roller, a unit for pressing the thermal head against the platen roller with the thermosensible paper laid therebetween when the image data is printed on the thermosensible paper, a unit for controlling the pressing unit to release the thermal head out of a pressing state against the platen roller under predetermined conditions, and a unit for selectively actuating the heater elements in accordance with the image data.

Abstract: A thermal printer uses a thermal line head which, when paper having a width smaller than a predetermined width is supplied in error, is able to inhibit electric supply to the heat generating devices that are situated outside of the paper to thereby prevent the heat generating devices from shortening their life span due to the idle heating thereof. There is provided a device which can be moved in the width, or lateral, direction of paper to detect the side edges of the paper and, in accordance with the moving distance of the paper side edge detection units from the reference position thereof, it is possible to specify the block of the thermal line head to which electric supply is to be inhibited.

Abstract: A device for actuating a tilting lever used in sensing sheet-type recording media includes a tilting lever having first and second arms and being swingably mounted about a pivot axis attached to a frame, from a first reference position to a second reference position. A first permanent magnet cooperates with a magnetized contact region on the first tilting-lever arm and is arranged to rest against the magnetized contact region when the first arm is in the first reference position. A second permanent magnet cooperates with a further magnetized contact region on the second arm and is arranged to rest against the further contact region when the second arm is in the second reference position.

Abstract: In the determination of the length of a sheet that has been inserted in a printer, an optical sensor scans the length of the sheet as it is fed into the printer, and a counter is controlled to provide a count corresponding to the length of the sheet. When the sensor encounters a mark on the sheet, such as a line, it provides an output indicating that the sheet is not present. This erroneous output is corrected by moving the sensor laterally of the sheet to a position displaced from the mark to enable further sensing of the presence of the sheet in a region that does not include the mark.

Abstract: A printing apparatus includes a platen on which a printing medium is set, a carriage which is movable along the platen and having a guide for guiding the printing medium to the platen and a printing head for making a print on the printing medium which is set on the platen, a first motor for moving the carriage along the platen, a second motor for feeding the printing medium, and a controller for controlling the first motor so that the carriage is moved to a first position until a tip end of the printing medium passes between the printing head and the platen and the carriage is moved to a second position after the tip end of the printing medium passes between the printing head and the platen, where the first and second positions are mutually different positions.

Abstract: An image recording apparatus for recording to a recording medium comprises an ink sheet cassette to mount an ink sheet having an ink, a carriage to mount an ink sheet cassette, a platen to mount a recording medium, a recording head for transferring the ink of the ink sheet to the recording medium to thereby record to the recording medium, an alarm portion provided for the ink sheet in order to warn of the end of ink sheet in the cassette, and a sensor which is commonly used to detect both the size of recording medium set onto the platen and the alarm portion. The alarming portion is formed by adhering or printing a high reflectance material such as a metal foil to the end portion on the back surface of the ink sheet.

Abstract: There is disclosed a recording apparatus for image recording on a recording sheet, in which a releasing member is provided for releasing the recording head from the platen roller, and the sheet setting operation is conducted by the platen roller while the recording head is released, in order to reduce the load on the driving force of the platen roller. The releasing member can assume a locked position, in which the operator can use both hands for other operations, or an unlocked position, in which the recording head automatically returns to the recording position after sheet setting.

Abstract: The subject invention comprises a printer system for a serial printer having an optical sensor detection system for the alignment of images on a sheet of print media, the correction of misalignment as a result of inaccurate alignment of the print media and the determination of the orientation of print media in a printer.

Abstract: In a thermal printer having a small diameter drum, a sensor having an emitter and detector detects the lead edge of a receiver sheet just prior to its entry into the nip between the drum and a print head.

Abstract: A sheet feeder for a printer selectively feeds a continuous sheet and a cut sheet to a printing mechanism including a platen and a print head. The continuous sheet is fed by a pair of pin tractors and the platen while the cut sheet is fed only by the platen. At least one sheet presser roller is provided for guiding the feeding of the cut sheet, which moves toward the platen when the cut sheet is fed so as to hold the latter against the platen, and moves away from the platen when the continuous sheet is fed. A switching lever sets the sheet feed mode, which when moved to a first position causes to feed the cut sheet by rotating the platen and when moved to a second position causes to feed the continuous sheet by rotating both the pin tractors and the platen.

Abstract: Different print sheet sets are disclosed to receive printing by a thermal printer. A thermal image transfer sheet is removably attached to a print sheet having a score line across the same to form a zone for coded indicia and a zone to receive printing. Indicia are provided in the indicia zone to represent certain conditions, such as the optimum thermal printing energy to be applied to pixels forming a printing head, and such indicia are sensed by a sensing device to program various aspects of printing, such as the printing format. The print sheet may be divided, as by scoring, into different print fields so that it may be readily separated into separate display signs.

Abstract: A paper detecting apparatus for a printer which can be produced at a low cost. The paper detecting apparatus comprises a pivotal paper detecting member for detecting paper which passes a paper transport path, and a motion converting and transmitting mechanism for converting pivotal motion of the paper detecting member and transmitting the same to a remote location. The paper detecting apparatus further includes a sensor for converting linear movement transmitted thereto by the motion converting and transmitting mechanism into an electric signal.

Abstract: The elements of a printing mechanism, including a platen, print head and drive motors, are constructed and arranged to provide a clearance permitting an envelope to remain entirely in a flat condition in a plane tangent to the platen at the location of the printing line while the envelope is being printed by the print head. The housing of the printing mechanism is constructed with specially configured slots. First and second opposite end walls of the housing, and a third wall, extending from one end wall to the other, provide at least partial coverage of the print head and platen. The third wall has a slot extending from one end wall to the other, the slot being arranged to receive an envelope and to allow the envelope to be inserted in a flat condition between the print head and the platen. The end walls have parallel slots, meeting and continuous with the slot of the third wall.

Abstract: A printing apparatus includes a platen on which a printing medium is set, a carriage which is movable along the platen and having a guide for guiding the printing medium to the platen and a printing head for making a print on the printing medium which is set on the platen, a first motor for moving the carriage along the platen, a second motor for feeding the printing medium, and a controller for controlling the first motor so that the carriage is moved to a first position until a tip end of the printing medium passes between the printing head and the platen and the carriage is moved to a second position after the tip end of the printing medium passes between the printing head and the platen, where the first and second positions are mutually different positions.

Abstract: A printer having a printing unit for printing on a sheet and a sheet feeding control section for controlling continuous or cut sheet feeding is disclosed. The sheet feeding control section performs sheet feeding of a predetermined amount after the data corresponding to one page has been printed by the printing unit. The sheet detecting section detects whether or not the printing sheet exists in the vicinity of the printing unit. If no printing sheet is det4ected in the vicinity of the printing unit, the printing control section determines that no continuous-page sheet feeder has been mounted. On the other hand, if the printing sheet is detected, the printing control section determines that the continuous-page sheet feeder has been mounted. If it is found that no continuous-page sheet feeder is mounted, the printing operation is stopped temporarily. If it is found that the continuous-page sheet feeder has been mounted, the printing operation is continued.

Abstract: In the present invention, a long and narrow color ink ribbon in which ink supply portions are repeatedly formed with the same arrangement is formed, a ribbon carrying means which moves the color ink ribbon in its lengthwise direction is provided, positions discriminating marks which are parallel to the lengthwise direction of the color ink ribbon and of which lengths are set correspondingly to the respective ink supply portions are positioned on the same straight line and formed at one edge of the color ink ribbon, and a discrimination mark read-out means implemented by arranging two optical sensors on a straight line in the direction along which the color ink ribbon moves is provided at the position opposite the discrimination marks.

Abstract: An apparatus for determining the print region for individual sheets of paper for use in a printer is provided. A paper sheet feeder for feeding the individual sheets of paper is supported on the printer. A sensor detects the presence of a sheet of paper fed by the paper sheet feeder. A microprocessor measures the length of the individual sheet of paper based upon the detection from the detector and provides a measurement value. The microprocessor computes the size of a possible print region of each sheet paper based upon this measurement value and displays the size of a possible print region on a display. Memory associated with the printer stores the size of the possible print region for setting the internal condition of the printer upon the introduction of power to the printer.

Abstract: A continuous paper autoloading mechanism for a thermal printer comprises a continuous paper supply section, a paper feeder, a pitch sensor for detecting the pitch of labels or tags detachably attached to the continuous paper and for producing pitch signals, a paper guide and a printer section having a paper feeding capability, all disposed in succession in the direction of paper feed. The paper feeding functions provided by the paper feeder and the printer section are synchronized and controlled in response to the pitch signals for feeding the leading edge of a first label on the continuous paper into proper alignment with the printer head, in a manner which avoids wastage of labels and carbon ribbon during the autoloading process.

Abstract: A printer for printing on at least two types of recording sheet using a single print head arranged at a single printing section. The printer includes a first recording sheet forwarding path, a second sheet forwarding path, a first recording sheet forwarding mechanism, a second recording sheet forwarding mechanism, a printing section opening/closing mechanism, a first recording sheet path opening/closing mechanism, a second recording sheet path opening/closing mechanism, a single recording sheet detector, and a recording sheet blocking mechanism.

Abstract: A thermal printer wherein a sheet of recording paper is interposed between two drums provided on axially opposite sides of a shaft of a platen roll facing a line-type thermal head and an endless belt mounted on outer peripheries of the drum. One way clutches provided on a shaft of the drum will cause the paper to rotate together with the drums during recording and the recording paper is driven by the endless belt during paper feed and delivery operations to slide relative to the drums. The sheet of paper is fed to a lower portion of an open portion of the drums and is removed from an upper portion of the open portion of the drums so that the feed and delivery of the sheet of paper can be effected upon rotation of the drums in one direction, and the printing operation is started after a detection of a trailing end of the sheet of paper so that the printing operation can be reformed regardless of the length of the sheet of paper immediately after the feed of the sheet of paper.

Abstract: A passbook printer has a print head movable along a printing station and in opposed relation to a platen for printing data on the passbook. The printer has an optical reading head assembly which is movable independent of the print head and in a direction of the path of the passbook past the printing station. The optical reading head assembly is positioned at the printing station for reading page and line information from the passbook and then is moved to a position adjacent the printing station for permitting the print head to freely move along the printing station.

Abstract: An electronic, programmable check encoder (10) having a check guide (14) capable of receiving a check to be encoded. A plurality of sensors (40,42,44,46) locate the position of the check in the check guide (14). Following determination of the position of the check, the check is clamped and moved by a drive assembly to an encoder (80) and then moved out of the apparatus by an eject assembly. the structure and interrelationship of the check gudie (14), the sensors (40,42,44,46) the check drive assembly and the check eject assembly are such that the check processing speed is significantly increased.

Abstract: A printer comprising a frame, a platen for supporting printing paper, a carriage reciprocally movable along said platen and having a print head mounted thereon defining a print point, paper feed rollers for feeding said printing paper through said printing point, at least one back-up roller disposed at an upstream side of said printing point and rotationally abutted against one of said paper feed rollers, at least one discharge roller disposed at a downstream side of said printing point and movable toward and away from another of said paper feed rollers, and a discharge roller driver for moving said discharge roller toward and away from said roller, said discharge roller driver moving said at least one discharge roller toward said roller for nipping said printing paper therebetween prior to the release of a tail edge of said printing paper from between said at least one back-up roller and said paper feeder, a link disposed in parallel with said platen and having a first end portion and a second end portion, e

Abstract: A printing system comprises:(x.sub.1) a source of A data and B data to be separately printed; a first printer connected with that source to receive the A data for printing it on a first sheet, such as an envelope, and to pass the B data; and a second printer connected with the data source via the first printer, and to print the B data on a second sheet, such as a letter, the first printer including:(a) a feed plate adjacent which the first sheet is fed in a longitudinal feed direction,(b) a print head for printing the A data on the first sheet,(c) a first drive at one longitudinal side of the print head, and a second drive at the opposite longitudinal side of the print head, the drives adapted to move the first sheet longitudinally forwardly, and then longitudinally reversely, to enable the print head to print on relatively spaced zones on the sheet.

Abstract: A thermal printer comprises a pair of fixed frames for rotatably supporting a platen which is rotated by a motor and a head unit rotatably supported by the fixed frames through a pair of movable frames and for supporting a thermal head. A pair of pinch rollers are rotatably mounted on the fixed frames, which are selectively brought to a first operating state to feed a paper sheet to the region between the platen and the thermal head, and a second operating state to feed no paper sheet. The thermal head is selectively moved between a first position, in which it is pressed against the platen, and a second position in which it is disengaged from the platen. The thermal head is moved to the first position, at the same time the pinch rollers and moved to the second operating state, while the thermal head is moved to the second position, at the same time the pinch rollers are moved to the first operating state.

Abstract: A magnetic read/write head is supported on the carriage that carries the platen of a passbook printer. The passbook is moved to the printing station and a sensor is provided for detecting the presence of the passbook. A height adjusting member operates to move the read/write head into position for writing data into and for reading data from a magnetic stripe on the passbook.

Abstract: A lever projects into the space between two guide plates for a sheet data carrier and is journalled so as to upwardly pivotable in the transport direction of the carrier against the force of a spring. A Hall-element sensor is secured adjacent to a magnet secured to the journalled end of the lever so that the sensor is activated by translation or rotation of the lever effected by engagement of the lever with the feeding of the data carrier. The lever is arranged to initially translate to activate the sensor and rotated after the translation so that when the lever is returned to its position prior to translation, only rotation of the lever switches the state of the sensor to indicate the position of the trailing edge of the carrier.

Abstract: Sensor arm (5) detects paper (1) at the printing stations of a printer (13). The sensor arm is linked through shaft (37) to position ledge (43) where it encounters and extension (47) of spring clutch (31) to decouple the spring clutch. Sheetfeed (11) is both driven and controlled from the platen (3) of the printer. With the spring clutch deactivated by the presence of paper, pawl (39) continues to hold the sheetfeed in an inactive status. In the absence of paper, the sensor arm (5) moves past the printing region, moving the ledge (43) away from contact with the spring clutch. Backward movement of the platen then initiates a sheetfeed cycle by movement of gear (35) being transmitted through the spring clutch (31).

Abstract: An arrangement for position indication of an edge of a sheet, which is transported between a lower and an upper guide plate of a printing apparatus, can be simplified and improved with respect to its indication accuracy in that an elastic tape is provided, which extends in the transport direction, which projects with a bulged part into the space between the two guide plates and whose beginning part is fixed and whose end part is slidably journalled, a stationarily journalled electrical sensor being provided, which upon movement of the tape can be activated by its end.

Abstract: An apparatus for determining the print region for individual sheets of paper for use in a printer is provided. A paper sheet feeder for feeding the individual sheets of paper is supported on the printer. A sensor detects the presence of a sheet of paper fed by the paper sheet feeder. A microprocessor measures the length of the individual sheet of paper based upon the detection from the detector and provides a measurement value. The microprocessor computes the size of a possible print region of each sheet paper based upon this measurement value and displays the size of a possible print region on a display. Memory associated with the printer stores the size of the possible print region for setting the internal condition of the printer upon the introduction of power to the printer.

Abstract: In a printer enabling a user to select different forms-feed modes, a cut-forms automatic-feed unit (12) and a continuous-forms feed cassette (14) are detachably mounted on a printer main body (10) in its upper surface of a rear portion of the main body (10) and in its rear surface of the rear portion of the same (10), respectively, so that the user can selectively mount at least one of such feed units (12, 14). The printer has forms-feed modes corresponding to the mounted feed units (12, 14) and another forms-feed mode for manually feeding a cut-form to the printer. Each of the feed units (12, 14) can be manually mounted on the printer main body (10) as required. When a forms-feed mode set by the user is different from its preceding mode and a form according to the preceding mode remains in a form-driving unit (54, 102, 104, 106) in the printer main body (10), a sensor detects such remaining form.

Abstract: An electronic labeling machine is disclosed which includes a printing mechanism with a carriage adapted for horizontal travel across assemblies of identification devices to be imprinted. A web sensor is attached to the carriage for concurrent travel therewith. In traversing horizontally across the assembly, the web sensor provides a signal to a microprocessor which indicates the presence or absence of the assembly under the current position of the sensor. The microprocessor also receives a timing signal from the printing mechanism indicative of the position of the carriage. Based on the timing signal and the signal from the web sensor, the microprocessor measures a current width of the assembly. The assembly is especially adapted for use with the invention, and includes notched portions having a width difference than the nominal assembly width, each notched portion being in a fixed relative position with respect to one of the identification devices.

Abstract: A mechanism for automatically adjusting the gap between the platen and print head of a printer includes a paper thickness lever detecting lever pivotably mounted on the printer base so that one end selectively contacts the surface of the platen. The opposite end of the lever contacts a pressure sensitive conductive member or adjusts the amount of light striking a photosensitive member of a paper thickness detector to generate an initial signal. After paper is fed onto the platen the lever contacts the surface of the paper and the paper thickness detector generates a second paper thickness signal corresponding to the different position of the lever. A carriage control circuit receives this signal and controls a print head carriage guide to adjust the relative position between the carriage and the platen to provide a suitable distance for printing.

Abstract: An apparatus is presented for printing material on an extruded plastic tubing. An extruder forms the plastic tubing of the desired diameter and thickness. The tubing is then drawn through a cooling bath by a pulling mechanism, and cut into desired lengths. The tubing may be dried after the cooling process, and an ink jet printer is utilized to print on the tubing as it is being drawn to be cut. A computer controls the printing process in correlation with the tubing cutter to provide a print signal to the printer in accordance with the desired lengths of tubing. The print heads of the printer are also three-dimensionally adjustable so as to center the printed material on the desired size and length of tubing to be cut.

Abstract: A sheet feeding apparatus for feeding a sheet to a recording station by means of rollers, comprising an automatic OHP sheet feeder, wherein the fact whether a sheet being fed is an OHP sheet or a separating sheet is discriminated; if the sheet is the OHP sheet, the sheet is advanced by a predetermined amount, and is retracted by a predetermined amount into a waiting passage; then, another sheet is supplied and the fact that the another sheet is a separating sheet is confirmed; and thereafter, images or characters are recorded on the OHP sheet, while feeding the OHP sheet and the separating sheet altogether in an overlapped condition.

Abstract: A monitor (18,26,28) monitors movement of paper (12) through a printer (16). The paper movement sensors (18,26) comprise one central wheel (70) or a pair of spaced edge wheels (158) each operating an individual photo-optic wheel (164,76). By counting pulses from the photo-optic wheels (76,164) monitor logic (28) determines conditions of jam, over-feeding and skew within the printer (16) both on an instantaneous and on a short term cumulative basis. The system self-calibrates through an initializing routine and later, continuously during operation. Paper movement sensors (18,26) are provided in dust-protected housings which can be chained together to provide monitoring facilities at many points.

Abstract: A printer has a detection mechanism for detecting the absence of paper and the end position of the printhead upon start-up and reset. The detection mechanism includes a detection lever arm that is spring loaded and operationally positioned in a normal state. An optical sensor made up of an LED and a photo transistor that receives light from the LED, has the lower end of the detection lever arm operationally positioned in the normal state, between the LED and the photo transistor. The upper end of the detection lever arm is urged against the paper, by the spring. The platen supporting the paper has a groove formed therein which, in the absence of paper, receives the upper end of the detection lever arm, causing the lower end to move from its normal position between the LED and the photo transistor, the optical sensor then indicating a paper-out condition.

Abstract: In a high speed printing station, cut sheets are separated one by one sequentially and transferred through the printing station. When a sheet jamming occurs in the feeding unit all sheet transport means are stopped, the previous sheets remaining and moving in the printing and ejecting units are wasted and components in the printing unit are contaminated by toner powder. The control method of the present invention comprises steps of (a) detecting the sheet jamming occurring in the feeding unit by a first sensor, (b) stopping the transporting means in the feeding unit only, (c) continuing operation of other transport means until the second sensor in the ejecting unit detects an ejection of all previous sheets in the printing and ejecting units, and (d) stopping the other transport means. The sheets except the jammed one become available for use and the contamination by toner powder is avoided.