Media alignment devices and methods
By calculating the midpoint between sensor data threshold crossings and compensating for error assumptions, the method achieves precise media alignment with improved accuracy, addressing the inaccuracies in existing media alignment technologies.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- ZEBRA TECHNOLOGIES CORP
- Filing Date
- 2024-12-27
- Publication Date
- 2026-07-02
AI Technical Summary
Existing media alignment devices and methods suffer from inaccuracies in determining the location of demarcation features on media elements due to environmental variables and noise in sensor data, leading to alignment errors of +/-1 mm or more.
The method analyzes the midpoint between the points where the sensor data crosses a threshold, compensating for errors by assuming similar error values at these points, and calculates the advance distance based on the known spacing of media elements to achieve precise alignment.
Improves alignment accuracy to less than +/-0.5 mm or +/-0.3 mm by accurately determining the midpoint between sensor data thresholds, reducing alignment errors and enhancing media processing precision.
Smart Images
Figure CN2024143012_02072026_PF_FP_ABST
Abstract
Description
MEDIA ALIGNMENT DEVICES AND METHODSBACKGROUND
[0001] Media processing devices, namely printers or other systems, can process media from a roll of media, such as a roll of adhesive labels on a release liner. When printing or processing such media formats, alignment of each respective media element with respect to the printing device may ensure printed indicia is properly positioned on each media element.SUMMARY
[0002] In a first embodiment, the technology of the present disclosure is provided by a media processing device, defining a media process path, the media processing device including a drive train configured to advance a web of media along the media process path, the web of media including individual media elements overlaying portions of a liner, each individual media element spaced at predetermined intervals, a sensor configured to observe the web of media at a first process point of the media process path and output a readout signal, and a processing platform. The processing platform is configured to receive the readout signal from the sensor, identify a first time index of the readout signal where data of the readout signal first exceeds a predetermined threshold, identify a second time index of the readout signal where the data of the readout signal first recedes below the predetermined threshold after the first time index, determine a third time index, the third time index being a midpoint between the first time index and the second time index, and control the drive train to advance the web of media along the media process path such that a predetermined location index on the web of media corresponding to the third time index aligns with a second media process point along the media process path at a predetermined time.
[0003] In an example aspect of the first embodiment, the predetermined location index on the web of media is selected from the group consisting of a leading edge of a media element, a trailing edge of a media element, a midpoint of a media element, a leading edge of a gap between two sequential media elements, a trailing edge of a gap between two sequential media elements, a midpoint of a gap between two sequential media elements, a printable area of a media element, and a midpoint of a gap between two sequential media elements.
[0004] In an example aspect of the first embodiment, the processing platform is configured to calculate compensation distance to advance the web of media based on a feed rate of the web of media along the media process path and an amount of time elapsed between the first time index and the second time index.
[0005] In an example aspect of the first embodiment, the media processing device is a thermal printer.
[0006] In an example aspect of the first embodiment, the second media process point is a heat line of the media processing device.
[0007] In an example aspect of the first embodiment, the sensor is an optical sensor configured to detect an amount of light which passes through the web of media as the web of media is advanced along the media process path.
[0008] In an example aspect of the first embodiment, the drive train is configured to advance the web of media by driving a roller which contacts the web of media.
[0009] In an example aspect of the first embodiment, the web of media is a web of adhesive labels overlaying portions of a release liner.
[0010] In an example aspect of the first embodiment, the web of media is configured such that each individual media element is arranged end-to-end in a linear configuration.
[0011] In a second embodiment, the technology of the present disclosure is provided by a method of media alignment for a media processing device, wherein the media processing device is configured to process a web of media along a media process path, the web of media including individual media elements overlaying portions of a liner, each individual media element spaced at predetermined intervals, the method including receiving a readout signal from a sensor observing the web of media at a first process point of the media process path, identifying a first time index of the readout signal where data of the readout signal first exceeds a predetermined threshold, identifying a second time index of the readout signal where the data of the readout signal first recedes below the predetermined threshold after the first time index, determining a third time index, the third time index being a midpoint between the first time index and the second time index, controlling the media processing device to advance the web of media along the media process path such that a predetermined location index on the web of media aligns with a second media process point along the media process path at a predetermined time.
[0012] In an example aspect of the second embodiment, the predetermined location index on the web of media is selected from the group consisting of a leading edge of a media element, a trailing edge of a media element, a midpoint of a media element, a leading edge of a gap between two sequential media elements, a trailing edge of a gap between two sequential media elements, a midpoint of a gap between two sequential media elements, a printable area of a media element, and a midpoint of a gap between two sequential media elements.
[0013] In an example aspect of the second embodiment, the method includes calculating a compensation distance to advance the web of media based on a feed rate of the web of media along the media process path and an amount time elapsed between the first time index and the second time index.
[0014] In an example aspect of the first embodiment, the media processing device is a thermal printer.
[0015] In an example aspect of the first embodiment, the second media process point is a heat line of the media processing device.BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 illustrates a media processing device, according to embodiments of the present disclosure.
[0017] FIG. 2 illustrates a roll of media elements which are processable by the media processing device of FIG. 1, according to embodiments of the present disclosure.
[0018] FIG. 3 illustrates media elements of the roll of media elements of FIG. 2 interacting with a sensor of the media processing device of FIG. 1.
[0019] FIG. 4 illustrates a sensor readout and an ideal readout relative to a section of media, according to embodiments of the present disclosure.
[0020] FIG. 5 illustrates a flowchart detailing a method of aligning media elements, according to embodiments of the present disclosure.
[0021] FIG. 6 illustrates a diagram including media elements, a sensor, and a sensor readout, according to embodiments of the present disclosure.DETAILED DESCRIPTION
[0022] Embodiments of the present disclosure now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the disclosure are shown. Indeed, the embodiments of the present disclosure can have many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
[0023] Previously proposed media alignment devices and methods have analyzed sensor data to identify demarcation features on media elements. Generally, such devices and methods apply a threshold condition to the sensor data to identify points at which the sensor data crosses the threshold and correlates the point at which the data crosses the threshold to the demarcation feature. Generally, a demarcation feature (e.g., a leading and / or trailing edge of a label) produces a “spike” or pulse in the sensor data. Typically, the point at which the rising edge of the spike crosses the threshold is identified as the trailing edge of a label, and the point where the falling edge of the spike crosses the threshold is identified as the leading edge of the subsequent label. Certain factors, such as the spacing between the media and the sensor, and other imperfections in the sensor data can result in errors or noise in the sensor data. To account for this, the threshold condition must be adjusted to account for error or noise. The narrowest tolerances for such methods typically yield alignment accuracies of + / -1 millimeter (mm) .
[0024] The devices and methods of the present disclosure seek to reduce the error (or improve the accuracy) in determining the location of the demarcation feature and decrease the tolerances. As an example, the devices and methods of the present disclosure can have improved accuracy and tolerances as compared to conventional detection of demarcation features. In one example, embodiments of the devices and methods described herein can have an alignment accuracy that is less than + / -1 mm, less than or equal to + / -0.5 mm, or less than or equal to + / -0.3 mm. The methods and devices described herein analyze the “spike” or pulse in the sensor data to determine a midpoint between the point where a first edge of the spike crosses the threshold and the point where a second edge of the spike crosses the threshold. While it is assumed that there exits error in these two points (e.g., the points at which the edges of the spike cross the threshold are offset relative to a position of leading and trailing edges of a demarcation feature) , it can also be assumed that the unknown values of the error of each point is very similar, thus the midpoint between these two points can correspond to a midpoint on the media between the leading edge and trailing edges of demarcation features. As the spacing of the media elements is known, a distance to advance the media may be calculated, such that the media can be aligned for processing.
[0025] Media processing devices may be configured to process media elements in various forms, however this disclosure is primarily concerned with those media processing devices which process media elements which are configured on a continuous web, which may be wound into a roll, where many processable media elements are secured to the continuous web, e.g., a single, or otherwise unified backing or liner. An example of such media includes printable adhesive labels on a release liner, although other forms of media are contemplated.
[0026] FIG. 1 illustrates a block diagram of an example media processing device 100, such as a printer, in accordance with embodiments of the present disclosure. The media processing device 100 can include a housing 102. The housing 102 contains or supports one or more components of the media processing device 100 including, for example, a logic circuit 104 (e.g., processing platform) , memory 106, a communication interface 108 (e.g., for wired and wireless communication) , input / output (I / O) devices 110 (e.g., a display, switches, buttons, speakers, microphone, etc. ) , a printhead 112, a radiofrequency encoder / reader 114, a motor 116, a drive train 118, a platen roller 120, and a sensor 122, (e.g., formed by an emitter 122a and a receiver 122b) . The printhead 112 and the platen roller 120 can form a nip. In some embodiments, (e.g., for thermal transfer printing) , the media processing device 100 can include a ribbon supply spindle 128 and a ribbon take up spindle 130 for supporting an ink ribbon 132. For direct thermal embodiments, the media processing device 100 can be devoid of the ribbon supply spindle 128, the ribbon take-up spindle 130, and the ink ribbon 132. The housing 102 can also be configured to contain a media supply 134 containing media 136 (e.g., a continuous web with media elements disposed thereon) . As an example, the housing 102 can include a media chamber to store the media supply 134 as it is consumed by the media processing device 100. The logic circuit 104 can include one or more processors, one or more coprocessors, one or more microprocessors, one or more controllers, one or more digital signal processors (DSPs) , one or more application specific integrated circuits (ASICs) , one or more field programmable gate arrays (FPGAs) , one or more microcontroller units (MCUs) , one or more hardware accelerators, one or more special-purpose computer chips, and one or more system-on-a-chip (SoC) devices. The memory 106 is a non-transitory computer-readable medium that can include, for example, volatile (e.g., RAM, DRAM, SRAM, etc. ) and / or non-volatile memory (e.g., ROM, PROM, EPROM, EEPROM, Flash memory device, optical memory device, magnetic memory device) .
[0027] The logic circuit 104 of the media processing device 100 can be operatively coupled to the memory 106, the communications interface 108, the I / O devices 110, the printhead 112, the radiofrequency encoder / reader 114, the motor 116, and / or the sensor 122. The platen roller 120 can be driven by the motor 116 via a drive train 118 to rotate the platen roller 120 about an axis of rotation in a first direction (e.g., counterclockwise in the orientation shown in FIG. 1) to pull the media 136 through the feed path in a direction indicated by arrow 140 and output the media from the media processing device via a media exit 138 formed in the housing 102 and can be driven by the motor 116 via the drive train 118 to rotate the platen roller 120 about the axis of rotation in a second direction (e.g., clockwise in the orientation shown in FIG. 1) to retract the media 136 (in an opposite direction than the arrow 140) . In some examples, the drive train 118 is configured to advance the web of media 136 by driving the platen roller 120 which contacts the media 136. In one example, the logic circuit 104 can be configured to execute code stored in the memory 106 to perform operations and functions of the media processing device 100, (e.g., by communicating with and / or controlling one or more of the components of the media processing device 100) . The logic circuit 104 can execute the code stored memory 106 to implement a printing operation or function that controls the motor 116 to rotate the platen roller 120 to feed the media 136 past the printhead 112, controls the printhead 112 to print on the media 136 (either directly or by transferring an ink from a ribbon to the media) , and / or controls the RF encoder / reader 114 to encode and / or read radiofrequency circuits (e.g., RFID or NFC tags or inlays) included in or on the media 136. For thermal transfer printing, the printable surface of the media 136 is configured to receive a pigment (e.g., resin, wax-resin, etc. ) that is transferred from the ink ribbon 132 installed on the ribbon supply and take-up spindles 128 and 130, respectively, via an operation of the printhead 112. For direct thermal printing, the printhead 112 of the media processing device 100 can selectively heat the printable surface of the media 136 triggering a chemical or physical change in a thermally sensitive dye covering at least a portion of the printable surface of the media 136. After printing on the media 136, the media can be further advanced and output from media processing device 100 by the operation of the platen roller 120.
[0028] FIG. 2 illustrates a media supply 134 configured as roll of media 136, including media elements 200 disposed on a liner 202, according to embodiments of the present disclosure. The media 136 is an example of media which is processable by the media processing device 100. Each media element 200 (e.g., individual media element) is disposed on the release liner 202 at a predetermined interval (e.g., overlaying portions of the liner 202, each individual media element 200 spaced at predetermined intervals, arranged end-to-end in a linear configuration) , such that there exists a gap 204 of a known dimension between each media element 200 on the liner 202, e.g., where the gap 204 can form a demarcation feature to facilitate alignment of the media elements 200 relative to the printhead 112.
[0029] Each media element includes a media leading edge 206 opposed to a media trailing edge 208. The media leading edge 206 and media trailing edge 208 may not be inherent to each media element 200 but rather determined based on the feed direction (e.g., shown by arrow 140) of the media processing device 100 by which the media 136 is being processed. In the illustrated embodiments, the media trailing edge 208 of a media element 200 also demarcates a gap leading edge 207 of the gap 204 and the media leading edge 206 of a subsequent media element 200 also demarcates the gap trailing edge 209 of the gap 204. In various examples, media elements 200 may have alternate demarcation features which may be detected or observed by a sensor (e.g., an embodiment of the sensor 122) . As an example, the media 136 can include a black mark, a notch, or other demarcation features.
[0030] FIG. 3 illustrates a detailed view of the media 136 (illustrated in a side profile view) interacting with the sensor 122 according to embodiments of the present disclosure. In the present example embodiment, the sensor 122 includes the emitter 122a and the receiver 122b configured in a transmissive sensor configuration. However, in other example embodiments, the emitter 122a and the receiver 122b can be configured in a reflective sensor configuration. The sensor 122 can be an optical sensor, where the emitter 122a can be, for example, a photodiode that emits electromagnetic energy in the light spectrum (e.g., a light signal) and receiver 122b can be a photodetector that detects the presence or absence of the emitted electromagnetic energy (e.g., the light signal) impinging on the receiver 122b and / or can detect variation in the intensity or power of the electromagnetic energy (e.g., the light signal) impinging on the receiver 122b. The sensor 122 can continuously output the sensor output.
[0031] FIG. 4 illustrates a section of media 136, a sensor readout 400 which is an example sensor output when detecting the section of media 136 (e.g., as illustrated in FIG. 3) , and an ideal readout 450 representing a theoretical sensor output when detecting the section of media 136, according to embodiments of the present disclosure.
[0032] The ideal readout 450 appears as rectangular wave or pulse, instantly changing between a low output value 452 and a high output value 454 corresponding to when the sensor detects a media element 200 on the liner 202 versus when the sensor 122 detects the liner 202 alone (e.g., a gap 204) . Furthermore, under these theoretical and ideal conditions, the media trailing edge 208 would be represented by a vertical line 456 and the media leading edge 206 would be represented by vertical line 457, each edge having distinct points in the sensor output corresponding to the media leading edge 206 and the media trailing edge 208 (e.g., or other demarcation features) . However, in real world conditions, the sensor 122 may be affected by several environmental variables, such as distance between the emitter 122a and the receiver 122b, and whether the media 136 is closer to the emitter 122a or the receiver 122b, electrical and / or optical noise inserted into the sensor, response delays, and variations and tolerances in the manufacturing processes of the media. As a result, the sensor output may be more accurately represented by the sensor readout 400.
[0033] In the sensor readout 400, when the sensor 122 observes a media element 200 overlaying the liner 202, the sensor output is generally defined in a low value range 402, and when the sensor 122 detects the liner 202 alone (e.g., the gap 204 between the media trailing edges 208 and media leading edges 206 of adjacent media 200) , the sensor output is generally in a high value range 404. The sensor 122 is preferably calibrated such that the highest variability in the low range does not overlap with the lowest variability in the high range. Moreover, the media trailing edges 208 (or gap leading edges 207) appear as rising slopes 406 and the media leading edges 206 of adjacent media 200 (or gap trailing edge 207) appear as a falling slopes 407, the rising slopes 406 and falling slopes 407 defined between the high value range 404 and the low value range 402. Thus, the actual location of the media trailing edge 208 or the media leading edge 206 (or the gap leading edge 207 or gap trailing edge 209) with respect to the readout 400 is less definite compared to the theoretical ideal case, as due to tolerances, the actual location of the media trailing edge 208 or media leading edge 206 (or the gap leading edge 207 or gap trailing edge 209) can only be restricted to the range in which the slope 406 appears, and not to a specific point in the sensor readout 400. It is this indefiniteness which leads to error when detecting the exact location of the media leading edge 206 or media trailing edge 208 (or the gap leading edge 207 or gap trailing edge 209) based on the readout 400.
[0034] FIG. 5 illustrates a flowchart detailing a method 500 for aligning media elements (e.g., media elements 200) e.g., relative to a printhead (e.g., printhead 112) , according to embodiments of the present disclosure. FIG. 6 illustrates a sensor readout 622 (e.g., from the sensor 122) vertically aligned with a section of media 136 such that the sensor readout 622 directly corresponds to the section of media 136 as observed by the sensor 122, according to embodiments of the present disclosure. FIG. 6 is intended to illustrate concepts and features discussed with respect to FIG. 5 and the method 500. FIGS. 5 and 6 are discussed concurrently in the following.
[0035] Block 510 describes a step of the method 500 in which a sensor readout 622 is received, according to embodiments of the present disclosure. In some examples, the sensor readout 622 from the sensor 122 is received by a logic circuit 104, which may include a processor, or processing platform. The sensor readout 622 is output by the sensor 122 and corresponds to the media 136 passing by the sensor 122. As discussed in reference to FIG. 4, when the sensor 122 observes the media element 200, the corresponding data in the sensor readout 622 is in a first range (e.g., a low range) , and the when the sensor observes a gap 204, the corresponding data in the senor readout is in a second range (e.g., a high range) , or vice versa.
[0036] Block 520 describes a step of the method 500 in which a first time index (T1) is identified, according to embodiments of the present disclosure. In some examples, the logic circuit 104, or other processor, analyzes the sensor readout 622 and applies a threshold 602 condition in order to identify a first edge (e.g., a rising edge) of the “spike” in the readout 622 corresponding to the detection of a leading edge of the gap 204 in the media 136 between two media elements 200. The logic circuit determines the T1 where the sensor readout 622 first exceeds the threshold 602.
[0037] The threshold is generally configured to be between the first range (e.g., the low range) and the second range (e.g., the high range) , such that any environmental variability does not result in detection, and any detection is nearly certain to correspond to a media leading edge 206 or media trailing edge 208, within certain tolerances. Thus, T1 corresponds to the media trailing edge 208 of a first media element 200 (or the leading edge of the gap 204) with an unknown error of E1, which is defined as the distance between the media trailing edge 208 of the media element 200 (or the leading edge of the gap 204) and the detected T1.
[0038] Block 530 describes a step of the method 500 in which a second time index (T2) is identified, according to embodiments of the present disclosure. In some examples, the logic circuit 104, or other processor, analyzes the sensor readout 622 under the threshold 602 condition and identifies the T2 where the sensor readout 622 first recedes below the threshold 602 following the T1, which defines a second edge (e.g., a falling edge) of the spike. Thus, T2 corresponds to the media leading edge 206 of a second, subsequent media element 200 (or the trailing edge of the gap 204) with an unknown error of E2, which is defined as the distance between the media leading edge 206 of the media element 200 (or the trailing edge of the gap 204) and the detected T2.
[0039] In some examples, the steps of blocks 520 and 530 may be modified, such that T1 is identified to correspond to media leading edge 206 of a given media element 200 and that T2 is identified to correspond to a media trailing edge 208 of the given media element 200.
[0040] While real-world variables may have substantial effects on the values of E1 and E2 across an entire roll of media 136 (e.g., the given tolerance) , it is assumed that the possible variance in the difference between a subsequent E1 and E2 is less than the possible variance of the value of E1 or of E2, due to the close proximity of media elements 200. Said differently, the variables which effect E1 and E2 likely effect subsequent measurements to a similar degree. As an example, the media 136 may be relatively closer to the emitter 122a and relatively farther away from the receiver 122b when T1 is detected, which produces an error or variance in E1. It is reasonable to assume that over the space of the gap 204, that the media 136 does not drastically change its orientation relative to the emitter 122a and the receiver 122b, the gap being 1 centimeter or less, as an example. A large change in positioning of the media would likely develop over the course of processing many media elements 200. Thus, it can be assumed that E1 is very similar to E2. E1 and E2 may vary in size from, for example, -3 millimeters to 3 millimeters. The difference of E1 and E2 between subsequent media elements 200 may be less than, for example, 1 mm, but certainly less than the 6 mm tolerance above for the present example.
[0041] Block 540 describes a step of the method 500 in which a third time index (T3) is computed, according to embodiments of the present disclosure. In some examples, prior to computing T3, the distance between T1 and T2 must be computed, which is done by simply subtracting T2 from T1. The T3 is a computed midpoint between T1 and T2, referred to as the compensation distance (DC) and is computed by halving the distance between T2 and T1. Assuming that E1 and E2 are nearly identical in size, it can be assumed that T3 corresponds to the midpoint of the gap 204 between the adjacent media elements 200. This assumption is made with greater certainty (e.g., within smaller tolerances) than the assumption that T1 is directly aligned with the media trailing edge 208 or that T2 is directly aligned the media leading edge 206.
[0042] As the gap 204 on the media 136 is of a fixed size, and of known dimensions, the distance to the midpoint of the gap 204 from a media leading edge 206 or media trailing edge 208 (DG) is known. Furthermore, the location from the sensor to the heat line of the printhead 112 (DS) is known, and the feed rate of the printer (e.g., the speed at which media is advanced past the sensor and / or printhead) is known.
[0043] Block 550 describes a step of the method 500 in which the media web is aligned, e.g., relative to the printhead according to T3, according to embodiments of the present disclosure. In this step of the method 500, the drive train 118 of the media processing device 100 is controlled to advance the web of media 136 along the media process path such that a predetermined location index on the web of media aligns with a second media process point along the media process path at a predetermined time.
[0044] DC, which is initially calculated in units of time (e.g., the amount of time elapsed between T1 and T2) , can be converted into distance units based on the feed rate of the printer. Thus DC (distance) is given by DC (time) X feed rate. In order to align a portion of a media element, such a leading edge of a media element (e.g., with the heat line of the printhead 112) a distance to advance the media 136 must be calculated. The advancement distance (DA) is given by DS –DC + DG at the moment that T2 is detected. Advancing the media by DA will align the media leading edge 206 of the media element 200 to be processed with the heat line of the printhead 112.
[0045] Various predetermined location indices are contemplated, as once the location of the midpoint of the gap has been determined, any location on the web of media 136 with a known location relative to (e.g., a known distance from) the midpoint of the gap 204 can be calculated into the DA. The predetermined location index is referenced to the midpoint of the gap 204, and T3. As such, the predetermined location index may be a media leading edge 206, a media trailing edge 208, a midpoint of a media element 200, a printable area of the media element 200 having a predetermined margin from a media leading edge 206 or media trailing edge 208, and a midpoint of the gap.
[0046] Similarly, any feature along the process path of the media processing device may serve as the second media process point for alignment, so long as the distance between the sensor 122 and the second media process point is known. As such, the second media process point may the printhead 112, the heat line of the printhead, a print line of the media processing device 100, or another point which is a predetermined distance from the sensor 122 or printhead 112.
[0047] In the illustrated embodiment, the predetermined location index is the media leading edge 206 of the media element 200 and the second media process point is the heat line of the printhead 112.
[0048] After the step described by block 550, the method 500 may be concluded, or repeated for subsequent media elements 200 in the web of media 136.
[0049] In various examples, the method 500 may be executable the media processing device 100.
[0050] In the illustrated embodiments, the method 500 is directed towards aligning the media 136 based on determining the location of a midpoint of the gap 204 between two media elements 200. One skilled in the art will recognize that the method 500 may be performed in similar fashion to align the media 136 based on a determined the location of a midpoint of a media element 200. In such an example, T3 would be computed between a T1 correlated with a media leading edge 206 of a given media element 200 and a T2 correlated with a media trailing edge 208 of the given media element 200.
[0051] In the foregoing specification, specific embodiments have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present teachings.
[0052] The benefits, advantages, solutions to problems, and any element (s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.
[0053] Moreover in this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises, ” “comprising, ” “has” , “having, ” “includes” , “including, ” “contains” , “containing” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises, has, includes, contains a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises …a” , “has …a” , “includes …a” , “contains …a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises, has, includes, contains the element. The terms “a” and “an” are defined as one or more unless explicitly stated otherwise herein. The terms “substantially” , “essentially” , “approximately” , “about” or any other version thereof, are defined as being close to as understood by one of ordinary skill in the art, and in one non-limiting embodiment the term is defined to be within 10%, in another embodiment within 5%, in another embodiment within 1%and in another embodiment within 0.5%. The term “coupled” as used herein is defined as connected, although not necessarily directly and not necessarily mechanically. A device or structure that is “configured” in a certain way is configured in at least that way, but may also be configured in ways that are not listed.
[0054] Certain expressions may be employed herein to list combinations of elements. Examples of such expressions include: “at least one of A, B, and C” ; “one or more of A, B, and C” ; “at least one of A, B, or C” ; “one or more of A, B, or C” . Unless expressly indicated otherwise, the above expressions encompass any combination of A and / or B and / or C.
[0055] It will be appreciated that some embodiments may be comprised of one or more specialized processors (or “processing devices” ) such as microprocessors, digital signal processors, customized processors and field programmable gate arrays (FPGAs) and unique stored program instructions (including both software and firmware) that control the one or more processors to implement, in conjunction with certain non-processor circuits, some, most, or all of the functions of the method and / or apparatus described herein. Alternatively, some or all functions could be implemented by a state machine that has no stored program instructions, or in one or more application specific integrated circuits (ASICs) , in which each function or some combinations of certain of the functions are implemented as custom logic. Of course, a combination of the two approaches could be used.
[0056] Moreover, an embodiment can be implemented as a computer-readable storage medium having computer readable code stored thereon for programming a computer (e.g., comprising a processor) to perform a method as described and claimed herein. Examples of such computer-readable storage mediums include, but are not limited to, a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a ROM (Read Only Memory) , a PROM (Programmable Read Only Memory) , an EPROM (Erasable Programmable Read Only Memory) , an EEPROM (Electrically Erasable Programmable Read Only Memory) and a Flash memory. Further, it is expected that one of ordinary skill, notwithstanding possibly significant effort and many design choices motivated by, for example, available time, current technology, and economic considerations, when guided by the concepts and principles disclosed herein will be readily capable of generating such software instructions and programs and ICs with minimal experimentation.
[0057] The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.
Claims
1.A media processing device, comprising:a drive train configured to advance a web of media along a media process path, the web of media comprising individual media elements overlaying portions of a liner, each individual media element spaced at predetermined intervals;a sensor configured to observe the web of media at a first process point of the media process path and output a readout signal; anda logic circuit, configured to:receive the readout signal from the sensor,identify a first time index of the readout signal where data of the readout signal crosses a predetermined threshold,identify a second time index of the readout signal where the data of the readout signal subsequently crosses the predetermined threshold after the first time index,determine a third time index, the third time index being a midpoint between the first time index and the second time index, andcontrol the drive train to advance the web of media along the media process path such that a predetermined location index on the web of media referenced relative to the third time index aligns with a second media process point along the media process path at a predetermined time.2.The media processing device of claim 1, wherein the predetermined location index on the web of media is selected from the group consisting of a leading edge of a media element, a trailing edge of a media element, a midpoint of a media element, a leading edge of a gap between two sequential media elements, a trailing edge of a gap between two sequential media elements, a midpoint of a gap between two sequential media elements, a printable area of a media element, and a midpoint of a gap between two sequential media elements.3.The media processing device of claim 1, wherein the processing platform is configured to calculate a compensation distance to advance the web of media based on a feed rate of the web of media along the media process path and an amount of time elapsed between the first time index and the second time index.4.The media processing device of claim 1, wherein the media processing device is a thermal printer.5.The media processing device of claim 1, the second media process point it the heat line of the media processing device.6.The media processing device of claim 1, wherein the sensor is an optical sensor configured to detect an amount of light which passes through the web of media as the web of media is advanced along the media process path.7.The media processing device of claim 1, wherein the drive train is configured to advance the web of media by driving a roller which contacts the web of media.8.The media processing device of claim 1, wherein the web of media is a web of adhesive labels overlaying portions of a release liner.9.The media processing device of claim 1, wherein the web of media is configured such that each individual media element is arranged end-to-end in a linear configuration.10.A method of media alignment for a media processing device, wherein the media processing device is configured to process a web of media along a media process path, the web of media comprising individual media elements overlaying portions of a liner, each individual media element spaced at predetermined intervals, the method comprising:identifying a first time index of a readout signal from a sensor where data of the readout signal crosses a predetermined threshold, the sensor observing the web of media at a first process point of the media process path,identifying a second time index of the readout signal where the data of the readout signal subsequently crosses the predetermined threshold after the first time index,determining a third time index, the third time index being a midpoint between the first time index and the second time index, andcontrolling the media processing device to advance the web of media along the media process path such that a predetermined location index on the web of media aligns with a second media process point along the media process path at a predetermined time.11.The method of claim 10, wherein the predetermined location index on the web of media is selected from the group consisting of a leading edge of a media element, a trailing edge of a media element, a midpoint of a media element, a leading edge of a gap between two sequential media elements, a trailing edge of a gap between two sequential media elements, a midpoint of a gap between two sequential media elements, a printable area of a media element, and a midpoint of a gap between two sequential media elements.12.The media processing device of claim 10, further comprising calculating a compensation distance to advance the web of media based on a feed rate of the web of media along the media process path and an amount time elapsed between the first time index and the second time index.13.The method of claim 10, wherein the media processing device is a thermal printer.14.The method of claim 10, wherein the second media process point is a heat line of the media processing device.