Abstract: A packaging machine which unwinds a bottom film web from a supply roll and conveys it intermittently or continuously along the packaging machine and in a forming station, forms into the bottom film web packaging cavities, which are then filled with a product to be packaged. In a sealing station, a top film web is sealed to the bottom film web, wherein the bottom and top film web are respectively unwound from a supply roll and the bottom and top film web are respectively tensioned by means of a dancer roll. The supply roll is driven by means of a motor, the parameters of which, in particular rotation speed and/or torque, can be set on the basis of the parameters of the respective supply roll.

Abstract: Example implementations relate to determining a correction factor that converts a measured sensor distance (228) to a calibrated sensor distance (222). The measured sensor distance may be based on an amount of substrate advancement through a web printing press (202) between detecting a mark (226-1, . . . , 226-N) on the substrate (204) at a first sensor (212) and detecting the mark at a second sensor (214). The calibrated sensor distance (222) may be the separation between the first sensor and the second sensor.

Abstract: Systems and methods for utilizing a trimming device to trim an edge of a plastic card having round corners, are provided. The plastic card has an overlay laminated on a major surface of the plastic card. The periphery of the overlay overhangs the edge of the plastic card. The trimming device trims the overhanging part of the laminated overlay by moving the trimming device along the edge of the personalized document in a direction generally parallel to the major surface of the plastic card.

Abstract: A method for automatically adapting a write cycle to a movement of a web-shaped medium in a digital printing machine, as a function of the thickness of the web-shaped medium guided around first and second transport or guide rollers, includes providing the first and second transport or guide rollers having a known diameters, the diameter of the second being different from the diameter of the first. A rotational speed ratio N(T) between the first and second transport or guide rollers (9, 11) is determined while the printing material (6) is guided around the transport or guide rollers (9, 11). The write cycle is determined at least with the use of the previously determined rotational speed ratio N(T).

Abstract: Disclosed is a printer including a transverse tension sensor for detecting that a sheet being discharged has deviated in a paper width direction orthogonal to a discharging direction. The conveyance of the sheet is stopped based on a detection signal of the transverse tension sensor.

Abstract: A moving unit causes a relative movement of a web and a mark detecting unit for detecting a ground color of the web and a mark color in a predetermined direction. A measuring unit measures a measurement value corresponding to a moving amount of the mark detecting unit with respect to the web in a time from when a detected color is switched from the ground color to the mark color till when a detected color is back to the ground color. A setting unit sets a threshold used for determining whether the color detected is the ground color or the mark color on the basis of the mark color detected by the mark detecting unit at the time when the mark detecting unit is moved in a reverse direction for a distance of half the measurement value since the color detected is back to the ground color.

Abstract: A device includes a conveying roller configured to convey a recording medium, a follower roller configured to press the recording medium against the conveying roller, a detector configured to detect a direction of skew of the conveyed recording medium, and a changer configured to change a state of contact between the recording medium and the conveying roller in accordance with a result of the detection by the detector such that a length of a portion of the conveying roller that is in contact with the recording medium in a conveyance direction is larger on a side toward which the recording medium is skewed than on an opposite side.

Abstract: A web processing assembly including first, second and third fixed spaced apart pairs of nip rollers moving the web respectively at a first, second and third speeds, the first and third speeds being constant and similar, the second speed being variable with a mean speed similar to the first and third speeds, a first idler roller engaging the web between the first and second pair of rollers and a second idler roller engaging the web between the second and third pair of rollers, each idler roller maintaining the web in constant tension by moving along a restrained path perpendicular to its axis to compensate for a difference between the variable second speed and the respective one of the constant first and third speeds. A method for processing a web and system for conveying a web are also disclosed.

Abstract: An inkjet printer includes a conveyance belt including a groove, a conveyance mechanism, a cutting mechanism, a control unit, and a judgment unit. After the cutting mechanism cuts the printing medium, the judgment unit judges whether or not a cut position of the printing medium will be located in a predetermined region of the conveyance belt if the conveyance mechanism drives the conveyance belt to convey the printing medium in the direction opposite to the conveyance direction. The predetermined region of the conveyance belt includes the groove. When the judgment unit judges that the cut position of the printing medium will be located in the predetermined region, the control unit controls the conveyance mechanism to convey the printing mechanism on the conveyance belt in the conveyance direction and subsequently controls the cutting mechanism to cut the printing medium.

Abstract: An apparatus for deflecting a printing material web coming from a printing press that is cut into at least two individual webs to laterally arranged processing devices. The apparatus includes a respective load-bearing frame for each individual web. A respective deflection rod and a respective longitudinal regulation roller for each individual web is supported on the load bearing frame. The deflection rods and longitudinal regulation rollers are adjustable relative to the load-bearing frame in a direction transverse to or parallel to a running direction of the respective individual web.

Abstract: An inkjet printer includes a conveyance belt including a groove, a conveyance mechanism, a cutting mechanism, a control unit, and a judgment unit. After the cutting mechanism cuts the printing medium, The judgment unit judges whether or not a cut position of the printing medium will be located in a predetermined region of the conveyance belt if the conveyance mechanism drives the conveyance belt to convey the printing medium in the direction opposite to the conveyance direction. The predetermined region of the conveyance belt includes the groove. When the judgment unit judges that the cut position of the printing medium will be located in the predetermined region, the control unit controls the conveyance mechanism to convey the printing mechanism on the conveyance belt in the conveyance direction and subsequently controls the cutting mechanism to cut the printing medium.

Abstract: A feeder for the surface mounting device is disclosed. The feeder includes a feeding unit being installed at one side of a main frame, having a plurality of armature coils and a circular permanent magnetic unit facing the plurality of armature coils to generate a rotation/reverse rotation force and carry a tape at a pitch interval and having a position sensing unit and a position detecting disk capable of sensing the position of the circular permanent magnetic unit, a vinyl separation unit carrying the vinyl removed from the tape by the rotation force or re-carrying the vinyl by the reverse rotation force, and a vinyl recovery unit recovering the vinyl by winding the same by the rotation force or discharging the vinyl by the reverse rotation force.

Abstract: A method for self-adjusting color and cut register control in rotary printing machines having individual or a plurality of webs is specified, according to which the amount of relative web stretching of the individual web sections is calculated from the operating points of the drives driving the web and the correcting variables for color and cut registers are derived from the production-dependent combination of all the stretching values.

Abstract: A preprinted web having a plurality of first repeating images is reprinted with a plurality of second repeating images which are in register with the first images. A register mark is printed on the web for each of the first images. When the web is reprinted, the positions of the register marks are sensed and compared with the positions of the second images, and the unwind tension of the web is adjusted to maintain the relative positions substantially constant.

Abstract: A film transporting apparatus for transporting forwards and backwards a film with a plurality of images recorded thereon in a predetermined direction, whereby the position of each image is stored and placed in a predetermined position on the basis of the position of multiplicity of position differentiating marks provided on the film in the predetermined direction at regular pitches, the predetermined direction at regular pitches, including, a mark detecting device for detecting the marks on the film, an image detecting device for detecting the images on the film, a rear edge detecting device for detecting the rear edge of the film, and a control device for controlling the mark detecting device so as not to detect marks from the rear edge of the film to a reference portion on the film.

Abstract: In a continuous form printer, a passage of the leading edge of the sheet is detected by a top sensor located along a feeding path thereof. If the top sensor detects the leading edge of the sheet while the sheet is fed in a reverse direction, the control unit of the printer determines whether the detection of the leading edge by the top sensor is correct or not, by feeding the sheet once in the forward direction and then feeding the sheet in the reverse direction and by checking whether the top sensor again detects the leading edge of the sheet being fed in the reverse direction.

Abstract: A detector assembly for detecting registration marks on a printed sheet when different color printing on different colored sheets is present has a pair of light sources and a light sensor. The light sources are of different colors selected to be complimentary such that one light source or the other will be capable of detecting a substantial range of contrasting registration marks placed on sheets that can be of various colors. Controls are used for selecting the light source that provides an output sensed by a light sensor when passing over the registration marks.

Abstract: A cascaded loop controller is used to control register or repeat lengths and web tension on laminating machines where the inner control loop utilizes register-length sensors near the unwind end of the laminating machine to make rapid adjustments in web tension that are necessary immediately following a reel splice and an outer control loop that provides a remote register-length set-point to the inner loop based upon a desired repeat length as measured near the rewind end of the laminating machine.

Abstract: A system and method for incorporating, in the production of a continuous stream of images, by an image transfer device upon a moving web, post-production operations upon the web at various locations. Locations of a web, having a plurality of images placed thereon, output from an image transfer device are tracked. Specific operations at various locations upon the web are performed by a post-production device as the web passes through it. The web is directed from the image transfer device to the post-production device. In response to the tracking of locations upon the web, the point when a location has entered the post-production device is determined. In response to this determination, the post-production device is commanded to perform its specific operation at a connect location.

Abstract: A processing control system in a processing apparatus, for repetitive processing of a plurality of marked sections of uniform length forming a continuous elongate material, the processing controller outputting a corrected material feed length signal for maintaining registration between marks on the sections and processing positions on the sections within a tolerance.

Abstract: An electrophotographic printer is capable of using a plurality of types of continuous form recording media having different page lengths, respectively. In the printer, a photoconductive member is charged and exposed to light carrying image data to form a latent image. In operation, one of the plurality of types of recording media is selected, and a portion of the photoconductive member corresponding to a page of the selected one of the plurality of types of recording media is exposed to light. In another embodiment, a laser beam printer utilizes a continuous-form recording sheet, wherein two control members are provided for, respectively, controlling the recording sheet so as to be discharged from the printing device after a printing operation, and for controlling the recording sheet so as to be located at a position from which a printing operation is restarted. Thus, recording sheets are not wasted when printer output is started.

Abstract: A web error recovery divert system is provided. A web is printed and scanned for errors. An error is identified in a grouping of sections or pages. A replacement grouping of sections or pages is printed. The replacement grouping includes an identifying mark or banner page indicating the presence of a replacement section. The web is redirected through a cutter and diverter that identifies the banner page and, at the appropriate locations, cuts and removes the grouping having the error. The replacement grouping and the remainder of the web is driven to a post-processing unit for further operations.

Abstract: An electrophotographic printer is capable of using a plurality of types of continuous form recording media having different page lengths, respectively. In the printer, a photoconductive member is charged and exposed to light carrying image data to form a latent image. In operation, one of the plurality of types of recording media is selected, and a portion of the photoconductive member corresponding to a page of the selected one of the plurality of types of recording media is exposed to light. In another embodiment, a laser beam printer utilizes a continuous-form recording sheet, wherein two control members are provided for, respectively, controlling the recording sheet so as to be discharged from the printing device after a printing operation, and for controlling the recording sheet so as to be located at a position from which a printing operation is restarted. Thus, recording sheets are not wasted when printer output is started.

Abstract: A system and method for incorporating, in the production of a continuous stream of images, by an image transfer device upon a moving web, post-production operations upon the web at various locations. Locations of a web, having a plurality of images placed thereon, output from an image transfer device are tracked. Specific operations at various locations upon the web are performed by a post-production device as the web passes through it. The web is directed from the image transfer device to the post-production device. In response to the tracking of locations upon the web, the point when a location has entered the post-production device is determined. In response to this determination, the post-production device is commanded to perform its specific operation at a connect location.

Abstract: A printing system having a plurality of printing stations in series is provided with a web width sensor system that detects the change in width of a paper web by monitoring the position of both edges of the sheet after it leaves a printing station to determine the change in position of each side edge and thereby the change in width of the web.

Abstract: A device for positioning a tip portion of a continuous form provided in a laser printer when the continuous form is set in the laser printer. The device includes a pair of fixing rollers provided at a position separated by a predetermined interval from a photosensitive drum, a tractor unit, a feed sensor, a tip sensor, and a control unit. The tractor unit is provided between the fixing rollers and the photosensitive drum to feed the continuous form toward the fixing rollers, the feed sensor outputs feed pulses in accordance with an amount fed of the continuous form, the tip sensor senses the tip portion of the continuous form. The control unit counts the number of feed pulses sensed by the feed sensor to feed one page of the continuous form so as, to discharge one page from the outlet mouth of the printer when a positioning of the tip portion is needed.

Abstract: A system of incrementally moving a foil, or other flexible and elastic elongated web, through a work station, by contacting and registering the foil on both sides of the work station. An example of such a work station is a hot stamping press that transfers optical images from the foil to other substrates. A drive mechanism, with an associated foil registration device, is provided at each of the entrance to the work station and the exit from it. Each registration device optically detects registration marks provided on the foil along its length, and is used to stop its associated drive mechanism after a predetermined number of marks have passed. This dual drive system maintains registration of the foil or other web throughout an extended work station. It is particularly advantageous for use with those hot stamping presses that either have a large number of die or whose multiple die are widely separated, since the multiple images carried along the foil are then all properly registered with the die.

Abstract: A system and method in the manufacture of plastic bags for accurately registering a web having graphic material printed repetitively thereon with respect to a transverse cutting and sealing device comprise detecting the passage of an eyemark printed on the web by a certain location at an initial part of a web index, calculating the initial length travelled by the web from the start of the web index to the detection of the eyemark, and then adjusting a predetermined draw length of the web based upon that calculated initial length.

Abstract: A register control system, particularly one that registers marks on a printed web to a function cylinder, produces proportional and integral gains each independently variable to control the take over point of the integral gain with respect to the proportional gain. The accumulating integral gain is zeroed out after cross over if the proportional gain exceeds a preset percentage of the integral error band. The overall system gain is varied with the line speed independently of the proportional and integral gains to provide speed-insensitive control. The direction of automatic correction is always selected to return the system to register in the shortest distance possible. High frequency clock pulses are counted between encoder pulses to interpolate with high accuracy the angular position measurement of the marks and a homing pulse.

Abstract: An apparatus and method for sensing gaps between labels adhered to a backing material in longitudinally spaced-apart positions as the backing material travels along the print path of a thermal printer. An array of light-emitting diodes oriented transverse to the print path illuminates the backing material. A fiber optic detects the light transmitted through the backing material and passes the light to a photodiode. The photodiode produces an analog electrical signal indicative of the amount of light transmitted, which varies depending on whether the light has passed through only the backing material or through both the backing material and the print media it carries. The analog signal is converted to a digital signal which is processed by a microprocessor to monitor and control the advancement of the print media and backing material through the printer.

Abstract: An off-line web finishing system performs plural functions on a pre-printed and rewound web at a series of pieces of equipment arranged in a line. Tension in the web is set at a variable infeed at a substantially constant value that is sufficient to facilitate handling of the web. A common web-transport system drives all draw rolls in the line in unison, at substantially the same speed, and without slippage between the web and the rolls. A second drive system, preferably one using a second drive shaft, rotates the function cylinders of one or more registration sensitive pieces of equipment in unison. A continuously adjustable variable transmission is operatively connected between the secondary line shaft and a main line shaft for the web transport. A control system adjusts the variable transmission. It includes a central microprocessor, an optical scanner associated with each function cylinder, and an encoder to measure the speed of rotation of the function cylinder.

Abstract: A roll feed apparatus of the type including a pair of rolls for clamping a workpiece therebetween and for intermittently feeding the workpiece, comprises a differential gear, operatively connected to at least one of the rolls, for rotating the roll(s). A mechanical feeding mechanism is connected to the deferential gear for outputting a rotational output thereof to the differential gear for effecting the intermittent feeding.

Abstract: A method for incorporating, in the production of a continuous stream of images, by an image transfer device upon a moving web, post-production operations upon the web at various locations. Locations of a web, having a plurality of images placed thereon, output from an image transfer device are tracked. Specific operations at various locations upon the web are performed by a post-production device as the web passes through it. The web is directed from the image transfer device to the post-production device. In response to the tracking of locations upon the web, the point when a location has entered the post-production device is determined. In response to this determination, the post-production device is commanded to perform its specific operation at a connect location.

Abstract: A film registration gate assembly has a gate with focal positioning location for focal positioning of an image frame of a strip film with edge perforations. Undersized first and second pins enter a pair of transversely aligned perforations to register the image frame with the positioning location. An undersized third pin enters a third perforation spaced along the film from the second pin and then pulls the film obliquely to a reference line extending between the first and second pins to nest against the first and second pins the perforations thereat and register the image frame precisely at the aperture. A plate with a window registering with the image frame and aperture clamps the film against the gate. The window, positioning location and image frame are of corresponding size and shape. The pins register the image frame precisely with the positioning location, and the plate maintains the image frame in precise focal position thereat.

Abstract: A film registration and ironing gate assembly has a gate with a positioning location or aperture for focal positioning of an image frame of a strip film with edge perforations. Undersized first and second pins enter a pair of transversely aligned perforations of the film to register the image frame with the aperture. An undersized third pin enters a third perforation spaced along the film from the second pin and then pulls the film obliquely to a reference line extending between the first and second pins to nest against the first and second pins the perforations thereat and register the image frame precisely at the positioning location or aperture. A pair of flexible bands extending along the film edges adjacent the positioning location move progressively into incrementally increasing contact with the film to iron it and clamp its perforations against the gate. The pins register the image frame precisely with the positioning location, and the bands maintain the image frame in precise focal position thereat.

Abstract: A web conveyor drive system, for example of the suction box type, employs independent motor drives for each of the plurality of drive rollers in the suction drive. Web tension drive loads are equalized across the drive rollers by controlling the individual motor drive current to a value substantially equal to the average of all the motor drive currents in the conveyor drive.

Abstract: An apparatus for measuring and controlling lengths of movement of a continuous stock material strip which is intermittently fed by feed rollers along a predetermined path of travel to a machine which includes a reciprocally operable carriage having tooling for acting upon the strip. The apparatus comprises a strip measuring mechanism for engaging with and sensing a length of movement of the strip and generating a first signal representative of the length of movement of the strip. A controller receives the first signal from the strip measuring mechanism, and comparing the first signal to a second signal representative of a predetermined desired length of movement of the strip. The controller generates a shut-down signal to the machine if the difference between the first and second signals exceeds a predetermined shut-down limit range and generates a length error signal representing the difference between the first and second signals.

Abstract: A system for feeding and positioning articles being processed comprises: a conveying device for driving and conveying the articles; a passage detecting component for detecting the passage of a part to be detected of one part of an article, which is being thus conveyed and driven, past a forward mark point which has been set at a position spaced apart by a specific distance immediately in front of an ultimate objective stopping position; a position pulse counter for counting the timing of the passage of the part to be detected past the forward mark point; an additional feed quantity setting component for setting the quantity of feeding of an article up to the ultimate objective stopping position in accordance with the timing of passage of the part to be detected past the forward mark point; and a feed quantity control component for controlling the driving quantity of the conveying device in accordance with the said quantity feeding thus set.

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: An off-line web finishing system performs plural functions on a pre printed and rewound web at a series of pieces of equipment arranged in a line. Tension in the web is set at a variable infeed at a constant value that is sufficient to facilitate handling of the web. A common web-transport system drives all draw rolls in the line in unison, at the same speed, and without slippage between the web and the rolls. In the preferred form, a second drive line rotates in unison the function cylinders of pieces of equipment that are registration sensitive. The second line is driven by a main line shaft of the web transport system via a variable transmission that is adjusted in response to at least one optical scanner that senses misregistrations between the printed pattern on the web and the function cylinders. The registration sensitive function cylinders operate on the web only intermittently.

Abstract: A system for incorporating, in the production of a continuous stream of images, by an image transfer device upon a moving web, post-production operations upon the web at various locations. Locations of a web, having a plurality of images placed thereon, output from an image transfer device are tracked. Specific operations at various locations upon the web are performed by a post-production device as the web passes through it. The web is directed from the image transfer device to the post-production device. In response to the tracking of locations upon the web, the point when a location has entered the post-production device is determined. In response to this determination, the post-production device is commanded to perform its specific operation at a connect location.

Abstract: In a method and apparatus for cutting either a single sheet or a lay-up of sheets of material to derive pattern pieces or the like from the material, the material is cut segment-by-segment by bringing a fresh segment to a cutting station after a preceding segment has been entirely cut. Discontinuities, which may translate into points of non-clean cutting, which might otherwise occur in cut lines as they pass to one segment to another, because of accidental shifting or mispositioning of the material during advancement, are avoided or reduced by acquiring the start and finish X and Y coordinates of an index point on the material and then using such coordinates with the cutting instructions used in the cutting of the subsequent segment, the use of the coordinates being such that accidental shifting or mispositioning of the material is taken into account and compensated for in the cutting of the second segment.

Abstract: An off-line web finishing system performs plural functions on a pre-printed and rewound web at a series of pieces of equipment arranged in a line. Tension in the web is set at a variable infeed at a constant value that is sufficient to facilitate handling of the web. A common web-transport system drives all draw rolls in the line in unison, at the same speed, and without slippage between the web and the rolls. In the preferred form, a second drive line rotates in unison the function cylinders of pieces of equipment that are registration sensitive. The second line is driven by a main line shaft of the web transport system via a variable transmission that is adjusted in response to at least one optical scanner that senses misregistrations between the printed pattern on the web and the function cylinders. The registration sensitive function cylinders operate on the web only intermittently.

Abstract: A microprocessor controlled thermal printer particularly usable in a hand-held labeler for printing labels on a composite web detects indices on the web and utilizes the detected indices to position the labels relative to the print head. The printer utilizes an improved index detection system that compensates for variations in index size and density and for variations in sensor sensitivity by detecting both the leading and trailing edges of an index and utilizing the distance between the detected leading and trailing edges to determine the length of the index. By dividing the length thus determined by two, and by advancing the web by this amount after the detection of the leading edge of an index, the center of the index can be accurately located, and the web can be accurately registered at any desired position relative to the center of the index.

Abstract: A microprocessor controller thermal printer particularly usable in a hand-held labeler for printing labels on a composite web detects indices on the web and automatically adjusts the distance that the web is advanced based on a measurement of the distance between indices made during a paper loading sequence. The printer includes automatic jam detection that measures the length of time that one of the indices is being detected and provides a jam indication if it is detected for more than a predetermined time period. A solenoid operated braking mechanism retains the web in position upon completion of a printing cycle to prevent the web from being moved relative to the print head while the label is being applied.

Abstract: A bag machine includes a programmed logic controller intermittently actuating a web feed draw roll motor for controlled web feed during the inoperative period of a cycled seal bar. The controller has separate inputs for the seal bar periods and a web length and establishes a control program of a preferred motion profile, with acceleration and deceleration of the fixed rolls to match the bag length to the available time using the total time available, with acceleration to a maximum and deceleration to reference, with or without a constant speed period. The bag length and time is monitored each machine cycle to calculate the next motion profile and permit changes in the bag length without machine shut-down. A programmed registered mode of control responds to a web mark spacing relative to the seal bar. In the registered mode, a photoscanner detects the mark during a constant speed web feed period prior to the end of the available time and actuates the web feed accordingly.

Abstract: In a thermal transfer type color printer, an ink film on which plural color inks are sequentially painted in its longitudinal direction is sequentially transported forward between an ink film supply roll and winding roll, while a printing paper is repeatedly transported forward and backward in order to print out a color image by overlapping plural color inks. In color printing, the printing paper and ink film are partially overlapped and wound around a platen roller, and a thermal head is pressed against the platen roller by sandwiching the ink film and printing paper therebetween so that the thermal head transfers the color inks on the printing paper. In order to prevent wrinkles from being formed on the ink film, tension applying means applies tension force to the ink film by temporarily controlling or stopping revolution of the ink film supply roll.

Abstract: A method and apparatus for measuring the relaxed length of a moving web includes forming a plurality of detectable marks along the length of the web at a repeated length interval. First and second detectors positioned along the web path are separated by a known distance S. A first tensioning force is applied to the moving web, and a first tensioned repeat length of the web is measured by detecting a mark moving past the first detector and then detecting the next mark moving past the second detector. The time separating the detections is determined. A second tensioning force of a known proportional relationship with the first tensioning force is applied to the moving web. A second tensioned repeat length is measured. The speed of the moving web is measured, and a relaxed length is calculated from the first tensioned repeat length, the second tensioned repeat length, and the proportional relationship between the first and second tensioning forces.

Abstract: A method and apparatus for measuring the repeat length (L) of a moving web includes forming a plurality of detectable marks along the length of the web at a repeated length interval. First and second detectors positioned along the web path are separated by a known distance (S). The repeat length of the web is obtained by detecting a mark moving past the first detector and then detecting a mark moving past the second detector, determining the time (t) separating the detections, and measuring the speed of the moving web (V), wherein the repeat length is calculated using the formula L=S+Vt.

Abstract: In a printer for printing information onto a continuous form, at least one of opposite side edges of the continuous form is detected by a side-edge detecting arrangement. It is judged that a traveling abnormality of the continuous form occurs, when a detecting signal representative of the at least one side edge of the continuous form detected by the side-edge detecting arrangement continues for a preset period of time and more. If the continuous form is provided therein with sprocket holes, the side-edge detecting arrangement may include a pair of side-edge detectors each for detecting the sprocket holes in a corresponding one of opposite side edge portions of the continuous form. In this case, it is judged that the traveling abnormality of the continuous form occurs, when the detecting signal representative of the sprocket holes in each side edge portion of the continuous form is not continuously outputted within a preset period of time and more.