Abstract:
Systems and methods for determining the edge step and edge form of a test belt during production are provided. A gauge on a test belt provides belt edge information. A belt edge determination controller for a testing device determines the edge step and edge form of the test belt to stabilize or eliminate the steps on subsequently produced belts. The testing device includes a sensor mounted at one end of the belt module which sends sensor signals to the belt edge determination controller to determine the edge step and edge form of the belt. The belt edge determination controller then determines whether the determined edge step and edge form are appropriate for subsequent production. As the belt edge information varies, the belt edge determination controller compares the belt edge data to acceptable values and initialize the production values as the acceptable values to stabilize or eliminate the step during production

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     This invention relates to methods and systems that measure the edge step and edge form of a belt. 
     2. Description of Related Art 
     Electrophotography, a method of copying or printing documents, is performed by exposing a light image representation of a desired original image onto a substantially uniformly charged photoreceptor, such as a belt. In response to that light image, the photoreceptor discharges to create a latent image of the desired image on the photoreceptor&#39;s surface. Developing material, or toner, is then deposited onto the latent image to form a developed image. The developed image is then transferred to a final substrate, such as paper. The surface of the photoreceptor is then cleaned of residual developing material and recharged in preparation for the production of another image. 
     If the photoreceptor is an endless belt, the belt may be produced by aligning the two opposite edges of a planar sheet of photoreceptor material and then sealing together the aligned edges. The sealed area is called the seam. 
     SUMMARY OF THE INVENTION 
     As shown in FIG. 1, seams may be produced containing a step that is a discontinuous, or uneven, change in the belt edge profile. That is, the two edges of the belt to be sealed together may not be perfectly aligned due to, for example, waviness of the planar sheet. This edge step and the underlying waviness in edge form, if greater than a given acceptable value, could increase undesired registration offsets between color separation images in a developed multi-color image formed during a print run. 
     Registration offsets in a developed image are undesirable because, when the developed image is transferred to a final substrate, the final transferred image will include the registration offsets. That is, each different color separation image will be slightly misregistered, or offset, relative to the other color separation images and/or the receiving substrate. These registration offsets, even if only a few mils or tens of microns, are well within the visual acuity of the human eye. 
     Thus, the quality of the resulting image suffers greatly even for small steps and small amounts of waviness in the edge forms of the belt that are greater than the acceptable values. Without learning the edge step and edge form of the belt, the degree of registration between the color separation images cannot approach the level of quality necessary for good image production. Complex, independent control systems are employed to ensure good belt production. 
     This invention provides systems and methods for determining the edge step and edge form of a belt. 
     This invention separately provides at least one sensor on a test belt that is capable of providing belt edge information for producing subsequent belts. 
     This invention separately provides a belt edge determination controller for a testing device that uses the determined edge step and edge form of the test belt to reduce or eliminate the edge steps and waviness in edge forms on subsequently produced belts. 
     This invention separately provides systems and methods that determine edge information of a test belt along a belt moving direction during a test run to adjust the production data to remove or reduce the edge steps and waviness in edge forms during production. 
     The systems and methods of this invention separately provide sensors which provide feedback signals indicating the edge step and edge form of the test belt during a test run. 
     The systems and methods of this invention separately provide a controller that determines the differences between sensor feedback values to obtain belt edge data and compares the belt edge data to acceptable values, and to initialize the production data as the acceptable values to reduce or eliminate the step and waviness in edge form of during production of subsequent belts. 
     Various exemplary embodiments of the systems of this invention include a testing device that includes sensors mounted at one side of the belt module. The sensor signals are sent to a belt edge determination controller to determine the edge step and edge form of the test belt. Then, the belt edge determination controller determines whether a determined edge step and edge form data are appropriate for subsequent production. 
     In accordance with the systems and methods of this invention, problems in registration during a print run, such as misalignment, are reduced or eliminated. 
     These and other features and advantages of the systems and methods of this invention are described in or are apparent from the following detailed description o exemplary embodiments of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be described in relation to the following drawings, in which reference numerals refer to like elements, and wherein: 
     FIG. 1 shows an exemplary test belt; 
     FIG. 2 shows one exemplary embodiment of system including a testing system in accordance with this invention; 
     FIG. 3 shows in greater detail a front view of one exemplary embodiment of the belt testing device of FIG. 1; 
     FIG. 4 shows in greater detail a top view of one exemplary embodiment of the belt testing device of FIG. 1; 
     FIGS. 5-9 illustrate one exemplary embodiment of a method for mounting the test belt onto the belt testing device of FIGS. 3 and 4; 
     FIG. 10 shows in greater detail one exemplary embodiment of the test belt in a mounted position; 
     FIG. 11 shows in greater detail a top view of one exemplary embodiment of the test belt in a loaded position; 
     FIG. 12 shows in greater detail a front view of one exemplary embodiment of the test belt in a loaded position; 
     FIG. 13 shows in greater detail one exemplary embodiment of the belt testing device and the belt edge determining circuit shown in FIG. 1; and 
     FIG. 14 is a flowchart outlining one exemplary embodiment of the method for testing the test belt. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIG. 2 shows one exemplary embodiment of a system including a testing system  200  in accordance with this invention. As shown in FIG. 2, the testing system  200  includes a controller  210 , an input/output interface  220 , a memory  230 , a belt edge determining circuit  240 , a belt testing device  300  and a production system  400 , each of which is interconnected by a control and/or data bus  250 . An input device  120  is connected to the input/output interface  220  over a link  122 . Control and/or data signals from the input device  120  are input through the input interface  220 , and, under control of the controller  210  are stored in the memory  230  and/or provided to the controller  210 . 
     The input device  120  can be any known or later developed device for providing control information from a user to the testing system  200 . Thus, the input device  120  can be a control panel of the testing system  200 , or could be a control program executing on a locally or remotely located general purpose computer, or the like. The link  122  can be any known or later developed device for transmitting control signals and data input using the input device  120  from the input device  120  to the testing system  200 . 
     The memory  230  preferably has at least an alterable portion and may include a fixed portion. The alterable portion of the memory  230  can be implemented using static or dynamic RAM, a floppy disk and disk drive, a hard disk and disk drive, flash memory, or any other known or later developed alterable volatile or non-volatile memory device. If the memory includes a fixed portion, the fixed portion can be implemented using a ROM, a PROM, an EPROM, and EEPROM, a CD-ROM and disk drive, a writable optical disk and disk drive, or any other known or later developed fixed or non-volatile memory device. 
     The belt edge determining circuit  240  inputs the determined data stored in the memory  230  for a desired edge profile of a test belt in the belt testing device  300 , adjusts the test belt to the desired testing position by adjusting the position of one or more rollers of the belt testing device  300  on which the test belt is mounted, and obtains an indication whether the belt edge data for the test belt is appropriate for production of subsequent belts. The belt edge determining circuit  240  then outputs the indication to the production system  400  over the control and/or data bus  250 . 
     While FIG. 2 shows the belt edge determining circuit  240 , the belt testing device  300  and the production system  400  as portions of an integrated system, the belt edge determining circuit  240  could be provided as a separate device from the belt testing device  300  and the production system  400 . That is, the belt edge determining circuit  240  may be a separate device attachable to a physically independent belt testing device  300  and/or a physically independent production system  400 . For example, the belt edge determining circuit  240 , and at least one edge sensor  357  and seam sensor  356  as shown in FIG. 3, may be devices which interface with the belt testing device  300  and/or the production system  400 . 
     Furthermore, the belt edge determining circuit  240  may be implemented as software executing on the testing system  200 . Other configurations of the elements shown in FIG. 2 may be used without departing from the spirit and scope of this invention. 
     It should be understood that the production system  400  can be any system that is capable of producing belts using the belt edge data generated according to the invention. 
     FIGS. 3 and 4 show one exemplary embodiment of the belt testing device  300  according to this invention. FIG. 3 shows a front view of the belt testing device  300  while FIG. 4 shows a top view of the belt testing device  300 . As shown in FIG. 3, the belt testing device  300  includes a plurality of stationary rollers  310  and a movable roller  320 . During a test run, a test belt  350  can be mounted around the rollers  310  and  320  to determine the belt edge profile of that test belt  350 . The belt edge profile is determined using at least one edge sensor  357 , and seam sensor  356  mounted around the test belt  350 . Each edge sensor  357  includes at least one in-board sensor  357   a  and at least one out-board sensor  357   b . The belt edge determining circuit  240  adjusts the test belt  350  to the desired testing position by adjusting the position of the movable roller  320 . As shown in FIG. 3, the position of movable roller  320  is adjusted by moving at least one of the ends of the movable roller  320  in a plane perpendicular to the moving direction of the test belt  350 . As shown in FIG. 4, the test belt  350  travels laterally with respect to the direction of the width of the belt width due to the movement of the movable roller  320 . 
     It should be appreciated that although FIGS. 3 and 4 show the belt testing device  300  as having three stationary rollers  310 , any number of stationary rollers  310  may be used. In particular, the number of stationary rollers  310  may be varied in accordance with the belt size. For example, for a smaller test belt  350 , only two stationary roller  310  may be needed. Thus, any number of stationary rollers  310  may be used in accordance with the methods and systems of this invention. 
     FIGS. 5-9 show one exemplary embodiment of mounting systems and methods for mounting the test belt  350  onto the belt testing device  300  according to this invention when at least two stationary rollers  310  are used. As shown in FIG. 5, at least one stationary extension  312  and at least one movable extension  322  are respectively attached to the ends of the rollers  310  and  320  outside of the belt testing device  300 . The extensions  312  and  322  are attached to the end of the rollers  310  and  320  by slipping the extensions  312  and  322  over bearings (not shown) at one end of the rollers  310  and  320 . The test belt  350  is loaded over the extensions  312  and  322  outside of the belt testing device  300 . 
     FIG. 6 shows in greater detail one exemplary embodiment of the stationary extension  312  while FIG. 7 shows in greater detail one exemplary embodiment of the movable extension  322 . As shown in FIG. 6, a stationary extension  312  may comprise a single arm. The stationary extension  312  is attached to an end of a roller  310  or  320  by slipping one end of the extension  312  over a bearing at one end of the roller  310  or  320 . The end of the stationary extension  312  which is to be attached to the roller  310  or  320  may have a pocket to receive the bearing. 
     As shown in FIG. 7, a movable extension  322  may comprise two arms connected in parallel. The movable extension  322  is attached to an end of one of the rollers  310  and  320  by slipping one end of one of the two arms of the extension  322  over a bearing at one end of the one roller  310  or  320 . The end of the movable extension  322  on the arm which is to be attached to the one roller  310  or  320  may have a pocket to receive the bearing. The end of the movable extension  322  on the arm which is not attached to the one roller  310  or  320  may also have a pocket to receive a bearing of the other roller  310  and  320 . 
     While FIGS. 5-7 show that the extension  312  is attached to one end of the roller  310  while the extension  322  is attached to one end of the roller  320 , it should be appreciated that the extensions  312  are  322  can be attached to the rollers  310  and/or  320  in any desirable orientation. That is, it should be appreciated that the extension  312  may be attached to the movable roller  320  and the extension  322  may be attached to a fixed roller  310 . 
     FIGS. 8 and 9 show in greater detail an exemplary embodiment of how the belt is mounted on and tightened on the belt testing device  300  according to the systems and methods of this invention. As shown in FIG. 8, as the test belt  350  is loaded onto the extensions  312  and  322 , the movable extension  322  is in a loading position away from the roller  310  or  320 . After the test belt  350  is loaded on the extensions  312  and  322 , the extension  322  is rotated into a vertical, mounting, position, slipping the pocket of the unattached arm over the bearing of the other of the rollers  310  and  320 . As shown in FIG. 9, when the extension  322  is rotated into the mounting position, the test belt  350  is tightened on the extensions  312  and  322  and locked into position before it is slid onto the rollers  310  and  320  inside the belt testing device  300 . 
     As shown in FIGS. 10-12, after tensioning, the test belt  350  is then pushed back onto the rollers  310  and  320  of the belt testing device  300  and locked into position ready for testing. FIG. 10 shows the positioning of the test belt  350  before and after being pushed back onto rollers  310  and  320 . As shown in FIG. 11, after the test belt  350  is pushed back onto rollers  310  and  320 , the extensions  312  and  322  are removed. The belt  350  can then be tested. Because the test belt  350  is first loaded onto the extensions  312  and  322  outside the belt testing device  300 , mounting the test belt  350  onto the rollers  310  and  320  is facilitated and damage to the test belt  350  can be reduced. 
     As discussed above, it should be appreciated that any number of stationary rollers  310  may be applied. Accordingly, it should be appreciated that any number of the mounting extensions  312  and  322  corresponding to the rollers  310  and  320  may be used in accordance with the methods and systems of this invention. 
     It should also be appreciated that though FIGS. 5 and 6 show the extensions  312  and  322  as arms, the extensions  312  and  322  are not limited to this feature. Accordingly, it should be appreciated that any extensions that are capable of mounting and tightening the test belt  350  outside the belt testing device  300  may be used as the extensions  312  and  322  in accordance with the methods and systems of this invention. 
     As shown in FIGS. 3,  4  and  13 , the belt testing device  300  further includes at least one edge sensor  357  positioned on the test belt  350 , and a seam sensor  356 . Each registration sensor  357  can include, for example, one or more in-board sensors  357   a  and one or more out-board sensors  357   b . The seam sensor  356  senses the position of the seam  351  on the test belt  350  at a fixed position. Each belt edge sensor  357  output signals indicative of the edge profile of the test belt  350  over the control and/or data bus  250  to the belt edge determining circuit  240 . Similarly, the sensor  356  output signals indicative of the seam  351  of the test belt  350  over the control and/or data bus  250  to the belt edge determining circuit  240 . The belt edge determining circuit  240  then determines the edge profile of the test belt  350  at the particular belt edge sensor positions, respectively. 
     The in-board sensor  357   a  detects a first edge of the test belt  350  while the out-board sensor  357   b  detects a second edge of the test belt  350 . Differences in the components between the one or more in-board sensors  357   a  and the one or more out-board sensors  357   b  may be used by the belt edge determining circuit  240  to determine the edge step and edge form of the test belt  350 . 
     The edge determining circuit  240  determines the edge step and edge form by comparing the differences in components between the one or more in-board sensors  357   a  and the one or more out-board sensors  357   b  along test belt  350 . By obtaining the difference in components at separate locations along the test belt, a jump in variance can be determined. The jump in variance is determined as the edge step of the test belt  350 . That is, at the edge step of the belt  350 , there is an abnormality in the data collected. Thus, this abnormality will provide a jump in the variance. The edge form of the test belt  350  is determined as the variance data collected along the test belt  350 . 
     The belt edge determining circuit  240  relies on its knowledge of the moving direction position of the test belt  350 , relative to the seam detected using the seam sensor  356  and the values determined using the at least one belt edge sensor  357 , to both learn the edge step and edge form of the test belt  350 . For the belt edge determining circuit  240  to work properly, the detected values of the test belt  350  must be synchronized with the moving-direction position of the test belt  350 . 
     Using the determined differences in the edge profile detected by the at least one belt edge sensor  357 , the belt edge determining circuit  240  generates a plot of the differences for each rotation of the test belt  350 . The belt edge determining circuit  240  controls the lateral movement of the test belt  350  in order to obtain the accurate determination of the edge step and edge form. In one exemplary embodiment, the belt edge determining circuit  240  compares two consecutive plots for exactness to determine whether the movement of the test belt  350  is zero. That is, when one plot is laid on top of the other plot, the two plots are compared for exactness to determine whether the movement of the test belt  350  is zero. The belt edge determining circuit  240  then controls a motor which controls the movement of the movable roller  320  to obtain the desired position of the test belt  350  where lateral movement of the test belt  350  is zero. 
     The edge step and edge form data is collected when the test belt  350  is adjusted so that is lateral movement is zero, i.e., under a controlled condition. In one exemplary embodiment, the belt edge determining circuit  240  generates an edge profile table. These measurements of the edge profile, which are used to determine the edge step and edge form of the test belt  350 , are stored in the edge profile table for each position of the test belt  350  along the moving-direction relative to the seam  351 . 
     The edge profile table is obtained during a test run of the testing system  200 . During the test run, the belt edge determining circuit  240  collects data on the nominal profile of the edge of the test belt  350  at the at least one belt edge sensor  357  for each position along the test belt  350  with respect to the detected seam  351 . The belt edge determining circuit  240  stores the nominal profile in the edge profile table. The edge profile table has one entry for each sample position along the test belt  350 . 
     FIG. 13 shows in greater detail one exemplary embodiment of the belt testing device  300  and the belt edge determining circuit  240  shown in FIG.  1 . As shown in FIG. 13, the belt edge determining circuit  240  includes a belt edge determination controller  242 , an input controller  244 , and an output controller  246 . The output controller  246  controls the output to the movable roller  320  to adjust the position of the test belt  350 . The input controller  244  receives the signals output from the at least one belt edge sensor  357  and the seam sensor  356 . 
     The at least one belt edge sensor  357  senses the edge profile of the edge of the test belt  350  at the two positions. The sensed edge profile is input to the input controller  244 . The seam sensor  356  senses the arrival of the seam  351  on the test belt  350  and outputs a seam sensor signal to the input controller  244 . 
     Upon the seam sensor signal indicating the arrival of the seam  351  at the predetermined position, the seam sensor signal is input to the input controller  244  and the belt edge determination controller  242  determines the actual lateral movement of the test belt  350  based on the determined position of the test belt  350  at the at least one belt edge sensor  357  relative to the position of the seam  351 . The belt edge determination controller  242  then uses the data to generate a plot for each rotation of the test belt  350  and to compare two consecutive plots for exactness. The output controller  246  then controls the motor to the movable roller  320  to control the position of the belt to obtain two exact consecutive plots. That is, the output controller  246  adjusts the movement of the test belt  350  to a controlled condition of zero movement. At this point of controlled condition, the belt edge determination controller  242  uses the latest plot or next plot to obtain the edge step and edge form. 
     FIG. 4 shows one exemplary embodiment of the at least one belt edge sensor  357 . As shown in FIG. 4, a laser beam is directed from the top edge to the bottom edge of the sensor  357 . As the test belt  350  passes between the two edges of the sensor  357 , the loss in light is detected. Because the loss in light varies with the various positions on the test belt  350 , the difference in light loss at two separate locations can be detected. Thus, in plotting the data of the detection result, the jump in variance is detected as the edge step of the test belt  350 . Furthermore, because the data plot represents the waviness in the test belt  350 , the data plot represents the edge form of the test belt  350 . 
     FIG. 14 is a flowchart outlining one exemplary embodiment of the method for testing the test belt. Beginning at step S 100 , control continues to step S 110 , where the arrival of the seam is determined. Next, in step S 120 , the belt edge values of the belt are measured. Then, in step S 130 , a current data plot is generated based on the measured belt edge values at the position relative to the seam. Control then continues to step S 140 . 
     In step S 140 , the current data plot is stored. In step S 150 , a determination is made whether the current plot is the first plot. If the current plot is the first plot, control returns to step S 100 . Else, there is a previous plot, and control continues to step S 160 . Next, in step S 160 , the previous plot is input. Then, in step S 170 , the current data plot is compared to the previous data plot to determine whether the current data plot matches the previous data plot. If the data plots match, the control condition is obtained and control jumps to step S 190 . Else, control continues to step S 180 , 
     In step S 180 , the belt position is adjusted to the control position. Control then returns to step S 110 . 
     In step S 190 , the edge form and edge step are measured. Then, in step S 200 , the edge form and edge step are compared to acceptable values and an indicator is output which indicates whether the production data is acceptable. Control then continues to step S 210 , where the method ends. 
     As shown in FIG. 1, the testing system  200  is preferably implemented on a programmed general purpose computer. However, the testing system  200  can also be implemented on a special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit elements, an ASIC or other integrated circuit, a digital signal processor, a hardwired electronic or logic circuit such as a discrete element circuit, a programmable logic device such as a PLD, PLA, FPGA or PAL, or the like. In general, any device, which is capable of implementing the finite state machine that is in turn capable of implementing the flowchart shown in FIG. 6, can be used to implement the testing system  200 . 
     This invention has been described in connection with the preferred embodiments. However it should be understood that there is no intent to limit the invention to the embodiments described above. On the contrary, the intent to cover all alternatives, modification, and equivalents as may be included within the spirit and scope of the invention. 
     While this invention has been described in conjunction with the exemplary embodiments outlined above, it is evident that may alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the exemplary embodiments of the invention, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention. 
     For example, it should be appreciated that this invention need not only be used to determine edge steps and edge forms for a photoreceptor belt. Thus, it should be appreciated that various other modifications and changes may occur to those skilled in the art without departing from the spirit and scope of this invention.