Patent Publication Number: US-7903991-B2

Title: Method and apparatus for measuring nip width in an image production device

Description:
BACKGROUND 
     Disclosed herein is a method for measuring nip width in an image production device, as well as corresponding apparatus and computer-readable medium. 
     The nip width is the measured arc distance created by an intersection of a soft fuser roll and a hard pressure roll in an image production device, such as a printer, copier, multi-function device, etc. If the nip width is not set properly, media sheets will not be fused (fixed) properly and cause toner (dry ink) to rub off on the prints. In addition an inadequately set nip results in accelerated roll surface wear and non-optimum gloss levels on the prints. 
     In conventional image production devices, the current nip set up procedure requires the operator to manually load a blank piece of paper into the fuser nip to make an impression, dust the impression with toner, and then measure the nip width with a small scale. This manual process leads to nip width variability. Nip width variability inboard to outboard along the fuser and pressure rolls can cause fuser roll edge wear, which results in significant delta gloss variability. 
     SUMMARY 
     A method and apparatus for measuring nip width in an image production device is disclosed. The method may include receiving a signal to measure the nip width, the nip width being the distance of an arc length created by an intersection of the fuser roll and the pressure roll, positioning a nip width measuring device into the nip, measuring the nip width, determining if the measured nip width meets a required nip width, wherein if the measured nip width does not meet the required nip width, adjusting the nip width. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exemplary diagram of an image production device in accordance with one possible embodiment of the disclosure; 
         FIG. 2  is an exemplary block diagram of the image production device in accordance with one possible embodiment of the disclosure; 
         FIG. 3  is an exemplary diagram of the nip width measurement environment in accordance with one possible embodiment of the disclosure; and 
         FIG. 4  is a flowchart of an exemplary nip width measuring process in accordance with one possible embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Aspects of the embodiments disclosed herein relate to a method for measuring nip width in an image production device, as well as corresponding apparatus and computer-readable medium. 
     The disclosed embodiments may include a method for measuring nip width in an image production device. The method may include receiving a signal to measure the nip width, the nip width being the distance of an arc length created by an intersection of the fuser roll and the pressure roll, positioning a nip width measuring device into the nip, measuring the nip width, determining if the measured nip width meets a required nip width, wherein if the measured nip width does not meet the required nip width, adjusting the nip width. 
     The disclosed embodiments may further include an image production device that may include a nip width measurement unit that includes a nip width measuring device that measures the nip width, the nip width being the distance of an arc length created by an intersection of the fuser roll and the pressure roll, and a nip width adjustment unit that receives a signal to measure the nip width, positions the nip width measuring device into the nip, receives the nip width measurement from the nip width measuring device, determines if the measured nip width meets a required nip width, wherein if the nip width adjustment unit determines that the measured nip width does not meet the required nip width, the nip width adjustment unit adjusts the nip width. 
     The disclosed embodiments may further include a computer-readable medium storing instructions for controlling a computing device for measuring nip width in an image production device. The instructions may include receiving a signal to measure the nip width, the nip width being the distance of an arc length created by an intersection of the fuser roll and the pressure roll, positioning a nip width measuring device into the nip, measuring the nip width, determining if the measured nip width meets a required nip width, wherein if the measured nip width does not meet the required nip width, adjusting the nip width. 
     The disclosed embodiments may concern a method and apparatus for measuring nip width in an image production device. A measuring device such as a linear probe may contact the fuser roll nip exit from a datum to determine the nip ½ width. This procedure may be used for initial nip set up and nip checks after each fuser roll change or a periodic check, for example. The probe may have a mechanical display or an electronic output that could be sent to the user interface or be used for automatic nip adjustment. 
     The measuring device may use a spring loaded probe to measure the nip width on the inboard and outboard ends of the fuser roll to pressure roll nip. The probe may be either a simple mechanical scale or a linear transducer, for example, that produces a signal that could be used to adjust the nip width automatically. The probe may also be implemented in a single or double probe configuration. 
     The benefits of this process include:
         The process may not require opening and closing of the rolls set to imprint the nip.   The process may reduce the number of steps involved in the current procedure.   The process may reduce variation from the manual method.       

       FIG. 1  is an exemplary diagram of an image production device  100  in accordance with one possible embodiment of the disclosure. The image production device  100  may be any device that may be capable of making image production documents (e.g., printed documents, copies, etc.) including a copier, a printer, a facsimile device, and a multi-function device (MFD), for example. 
     The image production device  100  may include an image production section  120 , which includes hardware by which image signals are used to create a desired image, as well as a feeder section  110 , which stores and dispenses sheets on which images are to be printed, and an output section  130 , which may include hardware for stacking, folding, stapling, binding, etc., prints which are output from the marking engine. If the printer is also operable as a copier, the printer further includes a document feeder  140 , which operates to convert signals from light reflected from original hard-copy image into digital signals, which are in turn processed to create copies with the image production section  120 . The image production device  100  may also include a local user interface  150  for controlling its operations, although another source of image data and instructions may include any number of computers to which the printer is connected via a network. 
     With reference to feeder section  110 , the module may include any number of trays  160 , each of which may store a media stack or print sheets (“media”) of a predetermined type (size, weight, color, coating, transparency, etc.) and includes a feeder to dispense one of the sheets therein as instructed. Certain types of media may require special handling in order to be dispensed properly. For example, heavier or larger media may desirably be drawn from a media stack by use of an air knife, fluffer, vacuum grip or other application (not shown in the Figure) of air pressure toward the top sheet or sheets in a media stack. Certain types of coated media are advantageously drawn from a media stack by the use of an application of heat, such as by a stream of hot air (not shown in the Figure). Sheets of media drawn from a media stack on a selected tray  160  may then be moved to the image production section  120  to receive one or more images thereon. 
     In this embodiment, the image production section  120  is shown to be a monochrome xerographic type engine, although other types of engines, such as color xerographic, ionographic, or ink-jet may be used. In  FIG. 1 , the image production section  120  may include a photoreceptor which may be in the form of a rotatable belt. The photoreceptor may be called a “rotatable image receptor,” meaning any rotatable structure such as a drum or belt which can temporarily retain one or more images for printing. Such an image receptor can comprise, by way of example and not limitation, a photoreceptor, or an intermediate member for retaining one or more marking material layers for subsequent transfer to a sheet, such as in a color xerographic, offset, or ink-jet printing apparatus. 
     The photoreceptor may be entrained on a number of rollers, and a number of stations familiar in the art of xerography are placed suitably around the photoreceptor, such as a charging station, imaging station, development station, and transfer station. In this embodiment, the imaging station is in the form of a laser-based raster output scanner, of a design familiar in the art of “laser printing,” in which a narrow laser beam scans successive scan lines oriented perpendicular to the process direction of the rotating photoreceptor. The laser may be turned on and off to selectably discharge small areas on the moving photoreceptor according to image data to yield an electrostatic latent image, which is developed with marking material at development station and transferred to a sheet at transfer station. 
     A sheet having received an image in this way is subsequently moved through fuser section that may include a fuser roll  170  and a pressure roll  180 , of a general design known in the art, and the heat and pressure from the fuser nip causes the marking material image to become substantially permanent on the sheet. The nip width  190  is shown as the distance of an arc length created by an intersection of the fuser roll  170  and the pressure roll  180 . The sheet once printed, may then be moved to output section  130 , where it may be collated, stapled, folded, etc., with other media sheets in a manner familiar in the art. 
     Although the above description is directed toward a fuser used in xerographic printing, it will be understood that the teachings and claims herein can be applied to any treatment of marking material on a medium. For example, the marking material may comprise liquid or gel ink, and/or heat- or radiation-curable ink; and/or the medium itself may have certain requirements, such as temperature, for successful printing. The heat, pressure and other conditions required for treatment of the ink on the medium in a given embodiment may be different from those suitable for xerographic fusing. 
       FIG. 2  is an exemplary block diagram of the image production device  100  in accordance with one possible embodiment of the disclosure. The image production device  100  may include a bus  210 , a processor  220 , a memory  230 , a read only memory (ROM)  240 , a nip width adjustment unit  250 , a feeder section  110 , an output section  130 , a user interface  150 , a communication interface  280 , an image production section  120 , and a nip width measurement unit  295 . Bus  210  may permit communication among the components of the image production device  100 . 
     Processor  220  may include at least one conventional processor or microprocessor that interprets and executes instructions. Memory  230  may be a random access memory (RAM) or another type of dynamic storage device that stores information and instructions for execution by processor  220 . Memory  230  may also include a read-only memory (ROM) which may include a conventional ROM device or another type of static storage device that stores static information and instructions for processor  220 . 
     Communication interface  280  may include any mechanism that facilitates communication via a network. For example, communication interface  280  may include a modem. Alternatively, communication interface  280  may include other mechanisms for assisting in communications with other devices and/or systems. 
     ROM  240  may include a conventional ROM device or another type of static storage device that stores static information and instructions for processor  220 . A storage device may augment the ROM and may include any type of storage media, such as, for example, magnetic or optical recording media and its corresponding drive. 
     User interface  150  may include one or more conventional mechanisms that permit a user to input information to and interact with the image production unit  100 , such as a keyboard, a display, a mouse, a pen, a voice recognition device, touchpad, buttons, etc., for example. Output section  130  may include one or more conventional mechanisms that output image production documents to the user, including output trays, output paths, finishing section, etc., for example. The image production section  120  may include an image printing and/or copying section, a scanner, a fuser, etc., for example. 
     The image production device  100  may perform such functions in response to processor  220  by executing sequences of instructions contained in a computer-readable medium, such as, for example, memory  230 . Such instructions may be read into memory  230  from another computer-readable medium, such as a storage device or from a separate device via communication interface  280 . 
     The image production device  100  illustrated in  FIGS. 1-2  and the related discussion are intended to provide a brief, general description of a suitable communication and processing environment in which the disclosure may be implemented. Although not required, the disclosure will be described, at least in part, in the general context of computer-executable instructions, such as program modules, being executed by the image production device  100 , such as a communication server, communications switch, communications router, or general purpose computer, for example. 
     Generally, program modules include routine programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Moreover, those skilled in the art will appreciate that other embodiments of the disclosure may be practiced in communication network environments with many types of communication equipment and computer system configurations, including personal computers, hand-held devices, multi-processor systems, microprocessor-based or programmable consumer electronics, and the like. 
       FIG. 3  is an exemplary diagram of the nip width measurement environment in accordance with one possible embodiment of the disclosure. The nip width measurement environment  300  may be found in the image production section  120  and may include fuser roll  170 , pressure roll  180 , and nip width measurement unit  295 . The nip width measurement unit  295  may include any device that may automatically be positioned to measure the nip width  190 . In the exemplary embodiment shown, the nip width measurement unit  295  may include a linear probe  310  which may be extended by a spring  320 , for example. The probe  310  may be a mechanical scale or a linear transducer, for example. However, as one of skill in the art may recognize, other configurations of automatically measuring the nip width may be used. 
     The fuser roll  170  and pressure roll  180  are positioned at a fixed datum  330 . If the measurement process of the disclosed embodiments dictates, the nip width adjustment unit  250  may change the nip width  190  by adjusting the distance between the fuser roll  170  and the pressure roll  180 . Note however, that while the disclosed embodiments concern a nip width  190  the distance of an arc length created by an intersection of the fuser roll  170  and the pressure roll  180 , the disclosed process may be applied to any two rolls in an image production device  100  where the rolls must be properly adjusted to allow media to pass through without jamming. 
     The operation of components of the nip width adjustment unit  250 , the nip width measurement unit  295 , and the nip width measurement process will be discussed in relation to the flowchart in  FIG. 4 . 
       FIG. 4  is a flowchart of an exemplary nip width measurement process in accordance with one possible embodiment of the disclosure. The method begins at  4100 , and continues to  4200  where the nip width adjustment unit  250  may receive a signal to measure the nip width  190 . The nip width  190  may be measured automatically upon fuser roll  170  replacement or on a periodic basis, for example. At step  4300 , the nip width adjustment unit  250  may position the nip width measuring device  310  into the nip  190 . At step  4400 , the nip width measuring device  310  measures the nip width  190  and the nip width adjustment unit  250  receives the nip width measurement from the nip width measuring device  310 . The nip width  190  may be measured on at least each edge of the fuser roll  170  for example. 
     At step  4500 , the nip width adjustment unit  250  may determine if the measured nip width  190  meets a required nip width. If the nip width adjustment unit  250  determines that the measured nip width  190  meets the required nip width, the process may then go to step  4700  and end. If the nip width adjustment unit determines that the measured nip width  190  does not meet the required nip width, at step  4600 , the nip width adjustment unit  250  may adjust the nip width  190 . The nip width measurement may also be displayed on the user interface  150 , for example. The process may then go to step  4700  and end. 
     Embodiments as disclosed herein may also include computer-readable media for carrying or having computer-executable instructions or data structures stored thereon. Such computer-readable media can be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code means in the form of computer-executable instructions or data structures. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or combination thereof) to a computer, the computer properly views the connection as a computer-readable medium. Thus, any such connection is properly termed a computer-readable medium. Combinations of the above should also be included within the scope of the computer-readable media. 
     Computer-executable instructions include, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions. Computer-executable instructions also include program modules that are executed by computers in stand-alone or network environments. Generally, program modules include routines, programs, objects, components, and data structures, and the like that perform particular tasks or implement particular abstract data types. Computer-executable instructions, associated data structures, and program modules represent examples of the program code means for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described therein. 
     It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.