Patent Grant
9335703
The sound a sheet of hardcopy media makes as it moves along a hardcopy media transport path can be used to diagnose the condition of the hardcopy media. Quiet or uniform sounds can indicate a normal or problem-free passage of the hardcopy media along the hardcopy media transport path. Loud or non-uniform sounds can indicate a disruption in the passage of the sheet of hardcopy media such as a stoppage due to jamming or tearing or other physical damage of the hardcopy media.
As an example, in commonly assigned U.S. Pat. No. 4,463,607 a hardcopy media transport cylinder with a specialized profile is used to enhance the diagnostic qualities of the hardcopy media transport noise in order to detect hardcopy media wear. However, this specialized hardcopy media transport cylinder is designed to induce stresses into the hardcopy media that interfere with smooth hardcopy media transport at high transport speeds.
Other known methods of detecting jams include using optical or mechanical sensors in order to detect the times of the passage of a sheet of hardcopy media at various locations along the hardcopy media transport path. If the hardcopy media does not arrive at a given location at a given amount of time after the start of transport, a hardcopy media jam is inferred. The problem with this approach is that optical and mechanical sensors are highly localized in physical detection range, requiring the use of several such sensors situated along the hardcopy media transport path.
Commonly assigned U.S. Pat. No. 8,857,815 describes placing a microphone near the beginning of a hardcopy media feed path in order to detect the sound of a hardcopy media jam in progress. The signal from the microphone is processed by counting the number of sound samples above a given threshold within a sampling window of a given width. If the count is sufficiently large a hardcopy media jam is signaled. In this approach, no information is provided about the location of the hardcopy media as it moves along the transport path. Thus, although sound may be used to detect a jam in progress, information regarding the location of the jam that may be provided by optical or mechanical sensors as discussed above is unavailable.
There remains a need for a fast and robust technique to indicate hardcopy media jams along a hardcopy media transport path that uses a single hardcopy media sensor and processes the signals from the hardcopy media sensor simply, and in a way that incorporates the location of the hardcopy media along the hardcopy media transport path.
The present invention represents a method of indicating a medium jam along a medium transport path in a scanner or other media transport device. The scanner includes one or more rollers for use in conveying the medium along the medium transport path. One or more microphones are included in the scanner and detect the sound of the medium being transported. The microphones produce signals representing the sound, which are sent to a processor which produces sound values from the signals. Various sound amplitude maximum values are computed, including a pre-transport path maximum amplitude values responsive to the sound values from a plurality of microphones from a region before the medium transport path, transport path maximum amplitude values responsive to the sound values from a plurality of microphones from a region within the medium transport path, and post-transport path maximum amplitude values responsive to the sound values from a plurality of microphones from a region after the medium transport path. The processor analyzes these various computed sound values and indicates a medium jam responsive to the maximum amplitude values when the computed sound values go above what is expected for normal operation.
The processor may be included in a computer system that is part of, or in communication with, the scanner and microphones. The processor may execute computer program instructions stored on a non-transitory computer-readable medium which cause the processor to acquire sound signals from the plurality of microphones responsive to the sound generated by a medium being transported along a medium transport in the scanner. The computer-readable medium includes further instructions enabling the processor to determine whether a jam has occurred based on the sound signal values according to a detection method, as described in detail below.
Based on the sound signals received, the computer may change the detection method on-the-fly. For example, depending on where the sound values come from within a sound profile established from signals from the various microphones, loudness thresholds for indicating a jam may be adjusted.
The one or more microphones can detect the sound of a medium jamming over a larger physical area than optical or mechanical methods, which are localized in nature. As a result, one microphone can replace the need for several optical or mechanical sensors. By using multiple microphones, a larger area can be monitored and signals from the multiple microphones can be compared against each other to determine the location of the sound source better than one microphone could. Determining the location of the noise source may be helpful in determining the location of the jam, as it is typical for the jam to cause the detected noise, and thus the noise source is often the jam location. Additionally, the area covered by any one microphone depends on sound path from the sound source to the microphone, and structural features could block sound from reaching the microphone. Further, there could be noisy components such as the rollers that make it hard to decipher the sound beyond the roller. Thus, to provide full jam detection coverage, multiple microphones may be installed along the transport path. The sound values over the entire medium transport path and at specific locations along the medium transport path are processed, thereby improving medium jam detection accuracy and reliability. The sound value processing is simple as it comprises computing sums of the sound values produced from the microphone signals. More computationally intensive methods such as transformations into frequency space or signal processing methods such as median filtering are avoided, resulting in sound value processing that requires substantially less computation resources and processing time. In addition, training and calibration techniques may be applied in order to optimize and simplify parameter settings.
The present invention is directed to a media transport system, and in particular to a system and method for detecting media jams within the media transport system. The method may be carried out using a process stored as instructions on a computer program product. The computer program product can include one or more non-transitory, tangible, computer readable storage medium, for example; magnetic storage media such as magnetic disk (such as a floppy disk) or magnetic tape; optical storage media such as optical disk, optical tape, or machine readable bar code; solid-state electronic storage devices such as random access memory (RAM), or read-only memory (ROM); or any other physical device or media employed to store a computer program having instructions for controlling one or more computers to practice the method according to the present invention.
The input tray 110 is connected to the scanner base 100 with hinges, allowing the input tray 110 to be opened and closed as illustrated by an arrow A3. The input tray 110 may be opened at times of scanning and closed when the medium transport system 10 is not in use. When the input tray 110 is closed the footprint of the medium transport system 10 can be reduced. The input tray 110 allows hardcopy media 115 to be scanned to be placed into it. Examples of the hardcopy media are paper documents, photographic film, and magnetic recording media. Other examples of the hardcopy media 115 will be evident to those skilled in the art. The top hardcopy medium 117 is the medium at the top of the hardcopy media 115 and is the next document to be pulled into the scanner by the urging roller 120. The input tray 110 is provided with input side guides 130a and 130b which can be moved in a direction perpendicular to a transport direction of the hardcopy media 115. By positioning the side guides 130a and 130b to match with the width of the hardcopy media 115, it is possible to limit the movement of the hardcopy media 115 in the input tray 110 as well as set the position (left, right or center justified) of the top hardcopy medium 117 within the media transport path. The input side guides 130a and 130b may be referred to collectively as the input side guides 130. The input tray 110 may be attached to a motor (not shown) that causes the input tray 110 to raise top hardcopy medium 117 to the urging roller 120 for scanning or to lower the input tray 110 to allow additional hardcopy media 115 to be added to the input tray 110.
The output tray 190 is connected to the scanner pod 180 by hinges, allowing the angle of the output tray 190 to be adjusted as shown by the arrow marked A1. The output tray 190 is provided with output side guides 160a and 160b which can be moved in a direction perpendicular to a transport direction of the hardcopy media 115, that is, to the left and right directions from the transport direction of the hardcopy media 115. By positioning the output side guides 160a and 160b to match with the width of the hardcopy media 115, it is possible to limit the movement of the output hardcopy media 150 in the output tray 190. The output side guides 160a and 160b may be referred to collectively as the output side guides 160. An output tray stop 170 is provided to stop the top hardcopy medium 117 after being ejected from the output transport roller 140. When the output tray 190 is in the up state as shown in
The operator control panel 122 is attached to the scanner pod 180 and can be tilted as shown by the arrow marked A2 to allow optimal positioning for the operator. An operation input 125 is arranged on the surface of the operator control panel 122, allowing the operator to input commands such as start, stop, and override. The operation input 125 may be one or more buttons, switches, portions of a touch-sensitive panel, selectable icons on a visual operator display 128, or any other selectable input mechanism. The override command may allow the operator to temporarily disable multi-feed detection, jam detection, or other features of the scanner while scanning. The operator control panel 122 also includes an operator display 128 that allows information and images to be presented to the operator. As noted above, the display 128 could include selectable icons relating to commands and operations of the media transport device. The operator control panel 122 may also contain speakers and LEDs (not shown) to provide additional feedback to the operator.
The top surface of the scanner base 100 forms a lower media guide 294 of the media transport path 290, while the bottom surface of the scanner pod 180 forms and upper media guide 292 of the media transport path 290. A delta wing 185 may be provided which helps to guide the media from the input tray into the media transport path 290. As shown in
In
The first microphone 200a, second microphone 200b, and third microphone 200c are examples of sound detectors that detect the sound generated by the top hardcopy medium 117 during transport through the media transport path 290. The microphones generate and output analog signals representative of the detected sound. The microphones 200a and 200b are arranged to the left and right of the urging rollers 120 while fastened to the delta wing 185 at the front of the scanner pod 180. The microphones 200a and 200b are mounted so as to point down towards the input tray 110. To enable the sound generated by the top hardcopy medium 117 during transport of the media to be more accurately detected by the first microphone 200a and the second microphone 200b, a hole is provided in the delta wing 185 facing the input tray 110. The microphones 200a and 200b are mounted to the delta wing 185 using a vibration reducing gasket. The third microphone 200c is at the downstream side of the feed roller 223 and the separator roller 220 while fastened to the upper media guide 292. A hole for the third microphone 200c is provided in the upper media guide 292 facing media transport path 290. The microphone 200c is mounted in the upper media guide 292 using a vibration reducing gasket. As an example, the microphones may be MEMS microphones mounted flush to a baffle with isolator material to reduce vibration transferring from the baffle to the MEMS. By mounting the MEMS flush, the amount of internal machine noise behind the microphone that can be detected by the microphone is reduced.
The second media detector 210 is arranged at a downstream side of the feed roller 223 and the separator roller 220 and at an upstream side of the take-away rollers 260. The second media detector 210 detects if there is a hardcopy media present at that position. The second media detector 210 generates and outputs a second media detection signal which changes in signal value depending on whether hardcopy media is present at that position. The second media detector 210 can be of any form known to those skilled in the art including, but not limited to, contact sensors, motion sensor and optical sensors.
The ultrasonic transmitter 282 and the ultrasonic receiver 284, together forming an ultrasonic sensor 280, are arranged near the media transport path 290 of the top hardcopy medium 117 so as to face each other across the media transport path 290. The ultrasonic transmitter 282 transmits an ultrasonic wave that passes through the top hardcopy medium 117 and is detected by the ultrasonic receiver 284. The ultrasonic receiver then generates and outputs a signal, which may be an electrical signal, corresponding to the detected ultrasonic wave.
A plurality of ultrasonic transmitters 282 and ultrasonic receivers 284 may be used. In this situation, the ultrasonic transmitters 282 are positioned across the lower media guide 294 perpendicular to the transport direction as marked by arrow A4 while ultrasonic receivers 284 are positioned across the upper media guide 292 perpendicular to the transport direction as marked by arrow A4.
The pod image acquisition unit 230 has an image sensor, such as a CIS (contact image sensor) or CCD (charged coupled device). Similarly, the base image acquisition unit 234 has an image sensor, such as a CIS or CCD.
As the top hardcopy medium 117 travels through the media transport path 290, it passes the pod imaging aperture 232 and the base imaging aperture 236. The pod imaging aperture 232 is a slot in the upper media guide 292 while the base imaging aperture 236 is a slot in the lower media guide 294. The pod image acquisition unit 230 images the top surface of the top hardcopy medium 117 as it passes the pod imaging aperture 232 and outputs an image signal. The base image acquisition unit 234 images the bottom surface of the top hardcopy medium 117 as it passes the base imaging aperture 236 and outputs an image signal. It is also possible to configure the pod image acquisition unit 230 and the base image acquisition unit 234 such that only one surface of the top hardcopy medium 117 is imaged.
The top hardcopy medium 117 is moved along a media transport path 290 by sets of rollers. The sets of rollers are composed of a drive roller and normal force roller. The drive roller is driven by a motor which provides the driving force to the roller. The normal force roller is a freewheeling roller that provides pressure to capture the top hardcopy medium 117 between the drive roller and normal force roller. In the medium transport system 10, the initial drive and normal force rollers that grab the top hardcopy medium 117 within the media transport path 290 are referred to as take-away rollers 260. The additional drive and normal force roller pairs along the media transport path 290 are referred to as transport rollers 265. The roller may be driven by a single motor where all the rollers start and stop together. Alternatively the rollers may be grouped together where each group is driven by its own motor. This allows different motor groups to be started and stopped at different times or run at different speeds.
The medium transport system 10 may have an output transport roller 140. The output transport roller 140 is connected to a separate drive motor that either speeds-up the top hardcopy medium 117 or slows down the top hardcopy medium 117 for modifying the way the output hardcopy media 150 is placed into the output tray 190, as described in detail in U.S. Pat. No. 7,828,279.
Hardcopy media 115 placed on the input tray 110 is transported between the lower media guide 294 and the upper media guide 292 in the transport direction shown by arrow A4 by rotation of the urging roller 120. The urging roller 120 pulls the top hardcopy medium 117 out of the input tray 110 and pushes it into the feed roller 223. The separator roller 220 resists the rotation of the feed roller 223 such that when the input tray 110 has a plurality of hardcopy media 115 placed on it, only the top hardcopy medium 117 which is in contact with the feed roller 223 is selected for feeding into the media transport path 290. The transport of the hardcopy media 115 below the top hardcopy medium 117 is restricted by the separator roller 220 to prevent feeding more than one medium at a time which is referred to as a multi-feed.
The top hardcopy medium 117 is fed between the take-away rollers 260 and is transported through the transport rollers 265 while being guided by the lower media guide 294 and the upper guide 292. The top hardcopy medium 117 is sent past the pod image acquisition unit 230 and the base image acquisition unit 234 for imaging. The top hardcopy medium 117 is then ejected into the output tray 190 by the output transport roller 140. In addition to microphones 200a, 200b, and 200c, a microphone 297 may be provided near the exit of the transport path. This microphone 297 detects the sounds of the hardcopy media towards the end of the transport path, and as the media is output into the output tray 190. These detected sounds may be used to detect jams occurring in the output tray 190 or as documents are exiting the media transport device. A system processing unit 270 monitors the state of the medium transport system 10 and controls the operation of the medium transport system 10 as described in more detail below.
Although
The operator configures the image controller 440 to perform the required image processing on the captured images either through the operator control panel 122 or network interface 445. As the image controller 440 receives the captured images, it sends the captured images to the image processing unit 485 along with a job specification that defines the image processing that should be performed on the captured images. The image processing unit 485 performs the requested image processing on the captured images and outputs processed images. It will be understood that the functions of image processing unit 485 can be provided using a single programmable processor or by using multiple programmable processors, including one or more digital signal processor (DSP) devices. Alternatively, the image processing unit 485 can be provided by custom circuitry (e.g., by one or more custom integrated circuits (ICs) designed specifically for use in digital document scanners), or by a combination of programmable processor(s) and custom circuits.
The image controller 440 manages image buffer memory 475 to hold the processed images until the network controller 490 is ready to send the processed images to the network interface 445. The image buffer memory 475 can be internal or external memory of any form known to those skilled in the art including, but not limited to, SRAM, DRAM, or Flash memory. The network interface 445 can be of any form known to those skilled in the art including, but not limited to, Ethernet, USB, Wi-Fi or other data network interface circuit. The network interface 445 connects the medium transport system 10 with a computer or network (not shown) to send and receive the captured image. The network interface 445 also provides a means to remotely control the medium transport system 10 by supplying various types of information required for operation of the medium transport system 10. The network controller 490 manages the network interface 445 and directs network communications to either the image controller 440 or a machine controller 430.
A first sound acquisition unit 420a includes the first microphone 200a, a first sound analog processing 422a, and a first sound A/D Converter 424a, and generates a sound signal responsive to the sound picked up by the first microphone 200a. The first sound analog processing 422a filters the signal which is output from the first microphone 200a by passing the signal through a low-pass or band-pass filter to select the frequency band of the interest. The first sound analog processing 422a also amplifies the signal and outputs it to the first sound A/D converter 424a. The first sound A/D converter 424a converts the analog signal which is output from the first sound analog processing 422a to a digital first source signal and outputs it to the system processing unit 270. As described herein, outputs of the first sound acquisition unit 420a are referred to as the “left sound signal”. The first sound acquisition unit 420a may comprise discrete devices or may be integrated into a single device such as a digital output MEMS microphone.
A second sound acquisition unit 420b includes the second microphone 200b, a second sound analog processing 422b, and a second sound A/D Converter 424b, and generates a sound signal responsive to the sound picked up by the second microphone 200b. The second sound analog processing 422b filters the signal which is output from the second microphone 200b by a passing the signal through a low-pass or band-pass filter to select the frequency band of the interest. The second sound analog processing 422b also amplifies the signal and outputs it to the second sound A/D converter 424b. The second sound A/D converter 424b converts the analog signal which is output from the second sound analog processing 422b to a digital second source signal and outputs it to the system processing unit 270. As described herein, outputs of the second sound acquisition unit 420b outputs will be referred to as the “right sound signal”. The second sound acquisition unit 420b may comprise discrete devices or may be integrated into a single device such as a digital output MEMS microphone.
A third sound acquisition unit 420c includes the third microphone 200c, a third sound analog processing 422c, and a third sound A/D Converter 424c, and generates a sound signal responsive to the sound picked up by the third microphone 200c. The third sound analog processing 422c filters the signal which is output from the third microphone 200c by a passing the signal through a low-pass or band-pass filter to select the frequency band of the interest. The third sound analog processing 422c also amplifies the signal and outputs it to the third sound A/D converter 424c. The third sound A/D converter 424c converts the analog signal which is output from the third sound analog processing 422c to a digital third source signal and outputs it to the system processing unit 270. As described herein, outputs of the third sound acquisition unit 420c outputs will be referred to as the “center sound signal”. The third sound acquisition unit 420c may comprise discrete devices or may be integrated into a single device such as a digital output MEMS microphone.
Below, the first sound acquisition unit 420a, second sound acquisition unit 420b and the third sound acquisition unit 420c may be referred to overall as the sound acquisition unit 420.
The transport driver unit 465 includes one or more motors and control logic required to enable the motors to rotate the urging roller 120, the feed roller 223, the take-away rollers 260, and the transport rollers 265 to transport the top hardcopy medium 117 through the media transport path 290.
The system memory 455 has a RAM (random access memory), ROM (read only memory), or other memory device, a hard disk or other fixed disk device, or flexible disk, optical disk, or other portable storage device. Further, the system memory 455 stores a computer program, database, and tables, which are used in various control function of the medium transport system 10. Furthermore, the system memory 455 may also be used to store the captured images or processed images.
The system processing unit 270 is provided with a CPU (central processing unit) and operates based on a program which is stored in the system memory 455. The system processing unit 270 may be a single programmable processor or may be comprised of multiple programmable processors, a DSP (digital signal processor), LSI (large scale integrated circuit), ASIC (application specific integrated circuit), and/or FPGA (field-programming gate array). The system processing unit 270 is connected to the operator button 124, the operator display 128, first media sensor 205, second media sensor 210, ultrasonic sensor 280, pod image acquisition unit 230, base image acquisition unit 234, first sound acquisition unit 420a, second sound acquisition unit 420b, third sound acquisition unit 420c, image processing unit 485, image buffer memory 475, network interface 445, system memory 455, transport driver unit 465.
The system processing unit 270 controls the transport driver unit 465, controls the pod image acquisition unit 230 and base image acquisition unit 234 to acquire a captured image. Further, the system processing unit 270 has a machine controller 430, an image controller 440, a sound jam detector 450, a position jam detector 460, and a multi-feed detector 470. These units are functional modules which are realized by software operating on a processor. These units may also be implemented on independent integrated circuits, a microprocessor, DSP or FPGA.
The sound jam detector 450 executes the sound jam detection processing. In the sound jam detection processing, the sound jam detector 450 determines whether a jam has occurred based on a first sound signal acquired from the first sound acquisition unit 420a, a second sound signal acquired from the second sound acquisition unit 420b and/or a third sound signal acquired from the third sound acquisition unit 420c. Situations in which the sound jam detector 450 determines that a media jam has occurred based on each signal, or a combination of signals, may be referred to as a sound jam.
The position jam detector 460 executes the position jam detection processing. The position jam detector 460 uses second media detection signals acquired from the second media sensor 210, an ultrasonic detection signal acquired from the ultrasonic detector 280 and a timer unit 480, started when the transport driver unit 465 enables the urging rollers 120 and the feed rollers 223 to feed the top hardcopy medium 117, to determine whether a jam has occurred. The position jam detector 460 can also use pod image acquisition unit 230 and base image acquisition unit 234 to detect the lead-edge and trail-edge of the top hardcopy media 117. In this case the image controller 440 outputs a lead-edge and trail-edge detection signal which is combined with the timer unit 480 to determine whether a jam has occurred if the lead-edge and trail-edge detection signal are not asserted within a predefined amount of time. Situations in which the position jam detector 460 determines that a media jam has occurred based on the second media detection signal, the ultrasonic detection signal, pod image acquisition unit 230 or base image acquisition unit 234 may be referred to as a position jam.
The multi-feed detector 470 executes multi-feed detection processing. In the multi-feed detection processing, the multi-feed detector 470 determines whether the feed module 225 has allowed multiple hardcopy media to enter the media transport path 290 based on an ultrasound signal acquired from the ultrasonic detector 280. Situations in which the multi-feed detector 470 determines that multiple hardcopy media entered the media transport path 290 may be referred to as a multi-feed.
The machine controller 430 determines whether an abnormality condition, such as a medium jam, has occurred along a media transport path 290. The machine controller 430 determines that an abnormality has occurred when there is at least one of a sound jam, a position jam, and/or a multi-feed condition. When an abnormality is detected, the machine controller 430 takes action based on the operators predefined configuration for abnormality conditions. One example of a predefined configuration would be for the machine controller 430 to inform the transport driver unit 465 to disable the motors. At the same time, the machine controller 430 notifies the user of media jam using the operator control panel 122.
When a medium jam along a media transport path 290 has not occurred, the image controller 440 causes the pod imaging acquisition unit 230 and the base imaging acquisition unit 234 to image the top hardcopy medium 117 to acquire a captured image. The pod imaging acquisition unit 230 images the top hardcopy medium 117 via the pod image device 400, pod image A/D Converter 402, and pod pixel correction 404 while the base imaging acquisition unit 234 images the top hardcopy medium 117 via the base image device 410, base image A/D converter 412, and base pixel correction 414.
Detection of the sound of the top hardcopy medium 117 begins at points 600, 610 and 620 in
A sound jam detection window is used to define the region(s) of sound values in sound profiles shown in
In
The compute maximum loudness block 710 computes loudness B 740 which represents how much sound was produced or the intensity of sound produce from sound values B 560. The loudness B 740 can be computed by a high amplitude count from the sounds values B 560, as described in U.S. Patent Publication No. US2014/0251016. The loudness B 740 can be represented by, for example, the maximum peak-to-peak amplitude or peak amplitude of the sound values B 560. The loudness B 740 may also be represented by any other comparison of characteristics or qualities of sound values B 560. A moving window may be used to partition the sound values B into frames that are collectively used together in the compute maximum loudness block 710. The moving window computes loudness B 740 from the most recent N2 sound values B 560 within the jam detection region for sound profile B 640 where N2 is typically 1024. The compute maximum loudness block 710 begins at 610 and continues until a medium jam is detected or the end of the sound values B 560 has been reached or the end of the jam detection window is reached. When the urging roller 120 and feed roller 223 initial start rotating, they produce a spike of noise, as shown in region B of the sound profile B 640. This spike is referred to as mechanical noise and is due to the mechanical parts of the urging roller 120 and feed roller 223 going from stationary to a rotating motion. The compute maximum loudness block 710 ignores the sound values B 560 within region A or region B of the sound profile B 640 to avoid producing a false jam based on the mechanical noise. Alternatively the compute maximum loudness block 710 may weight the sound values B 560 within region A or region B of the sound profile B 640 to reduce the chance of producing a false jam.
The compute maximum loudness block 720 computes loudness C 750 which represents how much sound was produced or intensity of sound produce from sound values C 570. The loudness C 750 can be computed by a high amplitude count from the sounds values C 550, as described in U.S. Patent Publication No. US2014/0251016. The loudness C 750 can be represented, for example, by the maximum peak-to-peak amplitude or peak amplitude of the sound values C 570. The loudness C 750 may also be represented by any other comparison of characteristics or qualities of sound values C 550. A moving window may be used to partition the sound values C into frames that are collectively used together in the compute maximum loudness 720. The moving window computes loudness C 750 from the most recent N3 sound values C 570 within the jam detection region for sound profile C 650 where N3 is typically 1024. The compute maximum loudness block 720 begins at 620 and continues until a medium jam is detected or the end of the sound values C 570 has been reached or the end of the jam detection window is reached. When the urging roller 120 and feed roller 223 initial start rotating, they produce a spike of noise, as shown in region B of the sound profile C 650. This spike is referred to as mechanical noise and is due to the mechanical parts of the urging roller 120 and feed roller 223 going from stationary to a rotating motion. The compute maximum loudness block 720 ignores the sound values C 570 within region A or region B of the sound profile C 650 to avoid producing a false jam based on the mechanical noise. Alternatively the compute maximum loudness block 720 may weight the sound values C 570 within region A or region B of the sound profile A 650 to reduce the chance of producing a false jam.
It should be noted that compute maximum loudness block 700, 710 and 720 do not have to use the same method to compute the loudness of the sound values 550, 560 and 570. A different method may be used for each microphone.
If the loudness value B 740 is greater than the loudness threshold TB1, a jam 770 is indicated. If the loudness value B 740 is not greater than the loudness threshold TB1 then the jam test moves to block 820 which compares the loudness value C 750 to loudness threshold TC1.
If the loudness value C 750 is greater than the loudness threshold TC1, a jam 770 is indicated. If the loudness value C 750 is not greater than the loudness threshold TC1 then the jam test moves to block 830 which compares the loudness value A 730 to loudness threshold TA21 and compares the loudness value B 740 to loudness threshold TB21.
If the loudness value A 730 is greater than the loudness threshold TA21 and loudness value B 740 is greater than loudness threshold TB21, a jam 770 is indicated. If the loudness value A 730 is not greater than the loudness threshold TA21, or loudness value B 740 is not greater than the loudness threshold TB21 then the jam test moves to block 840 which compares the loudness value A 730 to loudness threshold TA22 and loudness value C 750 to loudness threshold TC22.
If the loudness value A 730 is greater than the loudness threshold TA22 and loudness value C 750 is greater than loudness threshold TC22, a jam 770 is indicated, if the loudness value A 730 is not greater than the loudness threshold TA22, or loudness value C 750 is not greater than the loudness threshold TC22, then the jam test moves to block 850 which compares the loudness value B 740 to loudness threshold TB23 and loudness value C 750 to loudness threshold TC23.
If the loudness value B 740 is greater than the loudness threshold TB23 and loudness value C 750 is greater than loudness threshold TC23, a jam 770 is indicated. If the loudness value B 740 is not greater than the loudness threshold TB23, or loudness value C 750 is not greater than the loudness threshold TC23 then the jam test moves to block 860 which compares the loudness value A 730 to loudness threshold TA3, loudness value B 740 to loudness threshold TB3 and loudness value C 750 to loudness threshold TC3.
If the loudness value A 730 is greater than the loudness threshold TA3 and loudness value B 740 is greater than loudness threshold TB3, and loudness value C 750 is greater than loudness threshold TC3, a jam 770 is indicated. If the loudness value A 730 is not greater than the loudness threshold TA3, or the loudness value B 740 is not greater than the loudness threshold TB3, or the loudness value C 750 is not greater than the loudness threshold TC3 then the jam test moves to continue 780.
In a document scanner, many jams are the result of poor preparation where the operator does not ensure that the multiple hardcopy media 115 are attached together before it is placed into the input tray 110. The hardcopy media 115 can be attached together with staples, paper clips or adhesive. Other examples of how the hardcopy media 115 can be attached together will be evident to those skilled in the art.
A hardcopy media jam is most likely to occur when the top hardcopy medium 117 is being selected from the stack of hardcopy media 115 in the input tray 110 by the feed module 225 and is being fed into the media transport path 290 by the feed roller 223. During this time the third microphone 200c is ideally positioned for detecting a media jam behind the feed roller 223. Once the lead-edge of the top hardcopy medium 117 passes the take-away roller 260 the probability of a media jam is reduced. As the trail-edge of the top hardcopy medium 117 approaches urging roller 120 the chance of a trail-edge jam begin increasing. During this time the first microphone 200a and the second microphone 200b are ideally positioned for detecting a media jam along the trail-edge of the top hardcopy medium 117.
As the trail-edge of a hardcopy media passes the feed module 225, the trail edge of the hardcopy media may make a snapping sound that creates a sharp impulse in the sound signal value C 570. This sharp impulse may be referred to as the trail-edge snap. To reduce the probability of false jam detection on the trail-edge, the compute maximum loudness block 720 favors regions A, B and C of the sound profile C 650 while weighting the sound values C 570 from the other regions less. This effectively creates a low sensitivity region as the top hardcopy medium 117 is transported though the media transport path 290. The compute maximum loudness blocks 700 and 710 favor regions C, D and E of the sound profile A 630 and sound profile B 640 which allows trail-edge media jams to be detected without increasing the risk of false jams due the trail-edge snap as it passes over the point of feeding at the contact between feed rollers 223 and the separator rollers 220.
Since the top hardcopy medium 117 is attached to the next hardcopy media 1210 on the trail-edge, the trail-edge of the top hardcopy medium 117 starts to pull the trail-edge of the next hardcopy media 1210 towards the media transport path 290. This has the effect of lifting up the trail-edge of the top hardcopy medium 117 and the next hardcopy media 1210 at the staple 1220. As top hardcopy medium 117 is pulled further into the media transport path 290 the trail-edge of top hardcopy medium 117 and the next hardcopy media 1210 at the staple 1220 strikes the delta wing at labeled B2 as shown in
The distance that the lead-edge of the top hardcopy medium 117 travels into the media transport path 290 and the distance the staple is located from the lead-edge can be determined by monitoring the second media sensor 210 along with the ultrasonic sensor 280. This can be used to provide additional information regarding how the top hardcopy medium 117 is bound to the hardcopy media below it. For example, if the trail-edge of top hardcopy medium 117 is attached to the next hardcopy media 1210 then the machine controller 430 could signal the transport driver unit 465 to reverse the motors to so that rollers return the top hardcopy medium 117 and the next hardcopy media 1210 to the input tray 110.
Over time the sound profiles 630, 640, 650 as shown in
The initial thresholds TA1, TB1, TC1, TA21, TB21, TA22, TC22, TB23, TC23, TA3, TB3 and TC3 may be computed through a training process. The sound profiles 630, 640 and 650 of the sound values from microphones 200a, 200b and 200c are captured from the normal passage of hardcopy media 115 through the media transport path 290 to create a library of sound profiles. The library consists of a collection of sound profiles 630, 640 and 650 for N4 hardcopy media 115 where N4 is typically 250. The training process then analyzes the sound profile 630, 640 and 650 for each hardcopy media 115 in the library and computes the maximum sound value for microphones 200a, 200b and 200c over the library of sound profiles. To find the thresholds used for multiple threshold tests 830-860, the sound profiles for the microphones are compared to each other to find the sound values that produce the maximum loudness for the microphones together. The process is repeated while all but one of the microphone's sound value is held constant. While holding one microphone's sound value constant, the other microphone(s) sound profiles are searched for sound values that produce a loudness that is greater than the previous loudness found. If a greater loudness is found then that sound value for the microphone replaces the current loudness for that microphone. The process continues searching the sound profiles of each microphone while holding the other microphone sound value constant.
These maximum sound values are then used to set the thresholds TA1, TB1, TC1, TA21, TB21, TA22, TC22, TB23, TC23, TA3, TB3 and TC3. Since a library of sound profiles was created using the normal passage of hardcopy media 115 through the media transport path 290, a jam 770 would be indicted anytime the sound value A 550, B 560 and C 570 produced a loudness A 730, loudness B 740 or loudness C 750 which exceeded the threshold tests as described in
The operator may put the medium transport system 10 into a training mode to allow for optimization of thresholds to match the type of hardcopy media 115 being loaded into the input tray 110. The thresholds TA1, TB1, TC1, TA21, TB21, TA22, TC22, TB23, TC23, TA3, TB3 and TC3 can be generic thresholds meaning that the thresholds will work for wide range of types of hardcopy media 115. They may also be custom thresholds meaning that thresholds TA1, TB1, TC1, TA21, TB21, TA22, TC22, TB23, TC23, TA3, TB3 and TC3 are defined for a specific type of hardcopy media 115. For example, a medium transport system 10 may be processing only 130 NCR media. In this case the training would be done using only 130 NCR media in order to optimize the thresholds for this type of media. Whenever a media transport system restricts its use to a particular set of types of media, the training may be done using only those media types to optimize the thresholds. Alternatively each microphone's thresholds may be set as a mixture of generic and custom thresholds across the entire sound profile thereby allowing the sound detection process 450 to use custom thresholds specific to a type hardcopy media in specific regions of the sound profile 630, 640 and 650.
In addition, the thresholds can be set specifically for each medium transport system 10. In this case each medium transport system 10 may produce a sound profile for hardcopy media 115 that is unique to that system. Alternatively, the thresholds TA1, TB1, TC1, TA21, TB21, TA22, TC22, TB23, TC23, TA3, TB3 and TC3 can be global thresholds meaning that the thresholds will be applied across the entire sound profile. They may also be local thresholds meaning that thresholds TA1, TB1, TC1, TA21, TB21, TA22, TC22, TB23, TC23, TA3, TB3 and TC3 are defined for a specific region A-E, thereby handling unique characteristics of the various sections of the media transport path 290. Unique characteristics of the media transport path 290 can be of any form known to those skilled in the art including, but not limited to, change in roller material, rollers speed, bends or curves within the media transport path 290.
This application claims the benefit of U.S. Provisional Application No. 62/064,858, filed Oct. 16, 2014, and hereby incorporates by reference the provisional application in its entirety.
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