Systems and methods for card reader overlay detection

Abstract

A card reader is provided. The card reader includes a light sensor configured to generate a captured light signal based on the captured light. The card reader further includes a controller. The controller is configured to generate an average light signal by averaging the captured light signal according to an averaging cycle. The controller is configured to generate an average light threshold based on the average light signal. The controller is configured to determine an overlay condition based on the captured light signal and the average light threshold.

Description

SYSTEMS AND METHODS FOR CARD READER OVERLAY DETECTIONCross-Reference to Related Applications

[0001] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 559,337, filed on February 29, 2024, and titled “Systems and Methods for Card Reader Overlay Detection,” which application is herein incorporated by reference in its entirety.Field of the Disclosure

[0002] The present disclosure relates generally to payment card readers, and more particularly to systems and methods for card readers to detect overlays.Background

[0003] A common method of stealing payment card information is surreptitiously installing an overlay onto a card reader. The overlay may appear to be part of the card reader and can be difficult for a layperson to detect. When a user wishes to use a card reader to process a transaction, they may unknowingly insert their card into the overlay, allowing the overlay to extract the payment card information and provide it to a malicious third party. Accordingly, there is a need for systems and methods to detect an overlay installed on a card reader.Summary of the Disclosure

[0004] Generally, in one aspect, a card reader is provided. The card reader includes a light sensor. The light sensor is configured to capture light. The light sensor is further configured to generate a captured light signal based on the captured light.

[0005] The card reader further includes a controller. The controller is configured to generate an average light signal by averaging the captured light signal according to an averaging cycle.

[0006] The controller is configured to generate an average light threshold based on the average light signal.

[0007] The controller is configured to determine an overlay condition based on the captured light signal and the average light threshold.

[0008] According to an example, the overlay condition is generated if the captured light signal is less than the average light threshold for a detection period. The detection period may be at least three minutes.

[0009] According to an example, the average light threshold varies over time.

[0010] According to an example, the controller is further configured to: (1) generate a baseline signal based on the captured light signal, wherein the baseline signal is periodically updated according to a baseline cycle; and (2) determine the overlay condition based on the baseline signal and a baseline threshold.

[0011] According to an example, the baseline cycle is at least 24 hours.

[0012] According to an example, the average light signal remains substantially constant during a dark condition.

[0013] According to an example, the dark condition corresponds to the captured light signal being less than the average light signal.

[0014] According to an example, the average light threshold remains substantially constant during the dark condition.

[0015] According to an example, the light sensor is configured to capture the light via a light pipe.

[0016] According to an example, the light pipe is configured to convey light generated by a light-emitting diode (LED).

[0017] According to an example, the light pipe conveys at least a portion of the light generated by the LED to an indicator window.

[0018] According to an example, the averaging cycle is at least 0.5 seconds.

[0019] According to an example, the controller is further configured to determine a nighttime condition based on the captured light signal and a nighttime threshold.

[0020] According to an example, the controller is disabled from determining the overlay condition based on the captured light signal and the average light threshold during the nighttime condition.

[0021] According to an example, the average light threshold is generated to be less than the average light signal.

[0022] Generally, in another aspect, a method of overlay detection is provided. The method includes capturing light via a light sensor of a card reader.

[0023] The method further includes generating, via the light sensor, a captured light signal based on the captured light.

[0024] The method further includes generating, via a controller coupled to the light sensor, an average light signal by averaging the captured light signal according to an averaging cycle.

[0025] The method further includes generating, via the controller, an average light threshold based on the average light signal.

[0026] The method further includes determining, via the controller, an overlay condition based on the captured light signal and the average light threshold.

[0027] According to an example, the method may further include generating, via the controller, a baseline signal based on the captured light signal. The baseline signal is periodically updated according to a baseline cycle.

[0028] The method may further include determining, via the controller, the overlay condition based on the baseline signal and a baseline threshold.

[0029] According to an example, the method may further include (1) determining, via the controller, a nighttime condition based on the captured light signal and a nighttime threshold; and (2) disabling the controller from determining the overlay condition based on the captured light signal and the average light threshold during the nighttime condition.

[0030] According to an example, the overlay condition may be generated if the captured light signal is less than the average light threshold for a detection period.

[0031] According to an example, the average light signal may remain substantially constant during a dark condition, and wherein the dark condition corresponds to the captured light signal being less than the average light signal.

[0032] It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. It should also be appreciated that terminology explicitly employed herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.

[0033] These and other aspects of the various embodiments will be apparent from and elucidated with reference to the embodiment s) described hereinafter.Brief Description of the Drawings

[0034] FIG. 1 is an isometric view of a card reader, according to aspects of the present disclosure.

[0035] FIG. 2 is a partially exploded view of a card reader, according to aspects of the present disclosure.

[0036] FIG. 3 is a further partially exploded view of a card reader, according to aspects of the present disclosure.

[0037] FIG. 4 is a functional block diagram of aspects of a card reader, according to aspects of the present disclosure.

[0038] FIG. 5 is a further functional block diagram of aspects of a card reader, according to aspects of the present disclosure.

[0039] FIG. 6 is a plot of a captured light signal and corresponding signals and thresholds when an overlay has been installed, according to aspects of the present disclosure.

[0040] FIG. 7 is a plot of a captured light signal and corresponding signals and thresholds when an overlay has been installed under dark conditions, according to aspects of the present disclosure.

[0041] FIG. 8 is a plot of a captured light signal and corresponding signals and thresholds when a headlight shines on a light sensor of a card reader, according to aspects of the present disclosure.

[0042] FIG. 9 is a plot of a captured light signal and corresponding signals and thresholds when a bright light shines on a light sensor of a card reader and an overlay is installed, according to aspects of the present disclosure.

[0043] FIG. 10 is a plot of a captured light signal and corresponding signals and thresholds during a transaction, according to aspects of the present disclosure.

[0044] FIG. 11A is an isometric view of a portion of a payment terminal having a card reader, according to aspects of the present disclosure.

[0045] FIG. 1 IB is an exploded isometric view of a privacy shield being installed around a keypad of a payment terminal, according to aspects of the present disclosure.

[0046] FIG. 12A is an isometric view of a portion of a payment terminal having a card reader, according to aspects of the present disclosure.

[0047] FIG. 12B is an exploded isometric view of a privacy shield being installed around a keypad of a payment terminal, according to aspects of the present disclosure.

[0048] FIG. 13 is a flowchart of a method of overlay detection, according to aspects of the present disclosure.

[0049] FIG. 14 is a flowchart of a further method of overlay detection, according to aspects of the present disclosure.Detailed Description

[0050] The present disclosure is generally directed to systems and methods for card reader overlay detection. Generally, the card reader includes a light sensor. In some examples, the light sensor is arranged within a housing of the card reader and receives light via a light pipe optically connecting the light sensor to the environment proximate to the housing. The light pipe may also convey light generated by one or more indicator light emitting diodes (LEDs) arranged within the housing. The card reader includes a controller configured to process a captured light signal generated by the light sensor to determine if an overlay condition exists, meaning that an overlay may have been surreptitiously installed on the card reader.

[0051] In one example, the processing of the captured light signal includes generating an average light signal by averaging the captured light signal according to an averaging cycle, such as 0.5 seconds. The average light signal is used to generate an average light threshold which is offset from the average light signal. If the captured light signal is less than the average light threshold for a detection period (such as three minutes), an overlay condition exists. As the average light signal varies over time, the average light threshold similarly varies, unless a dark condition has been triggered by the captured light signal being less than the average light threshold. Varying the average light threshold according to the average light signal allows the system to compensate for gradual changes in captured light, only triggering an overlay condition in the event of a drastic decrease in captured light.

[0052] In another example, the processing of the light signal further includes generating a baseline signal and a baseline threshold. While the average light threshold is used to detect sudden and drastic decreases in captured light, the baseline threshold is used to detect significant decreases in captured light over a long period. For example, the baseline signal may be generated based on the light captured daily at the same time. If the baseline signal drops below the baseline threshold, an overlay condition exists. The overlay condition may be the result of an overlay being installed on the card reader when the light level is low due to the time of day or other factors. Accordingly, the card reader may implement two independent thresholds in order to trigger an overlay condition.

[0053] FIG. 1 illustrates a non-limiting example of a card reader 10. In particular, FIG. 1 shows the card reader 10 as including a card insertion slot 12, three indicator windows 14a, 14b, 14c, and a housing 16. The card insertion slot 12 is configured to receive a payment card (such as a bank card, credit card, debit card, electronic benefit transfer (EBT) card, etc.) to process a transaction. The indicator windows 14a, 14b, 14c are configured to illuminate invarious colors to indicate the progress of the transaction. In some examples, the top indicator window 14a may emit red light, the middle indicator window 14b may emit yellow light, and the bottom indicator window 14c may emit green light. The housing 16 may be manufactured from a metal or substantially metal material. In the example of FIG. 1, the card reader 10 is embodied as an outdoor card reader, such as for use on a fuel dispenser at a gas station. However, in other examples, the card reader 10 may be used with any type of device configured to capture payment card information. For example, the card reader 10 may be used with an indoor payment terminal, such as a payment terminal for use in a checkout line of a grocery store or retail shop.

[0054] FIG. 2 illustrates a rear partially exploded view of the card reader 10 of FIG. 1. In particular, FIG. 2 illustrates how the three indicator windows 14a, 14b, 14c receive light via three light pipes 18a, 18b, 18c. The first light pipe 18a may convey red light to the top indicator window 14a, the second light pipe 18b may convey yellow light to the middle indicator window 14b, and the third light pipe 18c may convey green light to the bottom indicator window 14c.

[0055] FIG. 3 illustrates additional aspects of the card reader 10 of FIGS. 1 and 2. The card reader 10 includes three LEDs 20a, 20b, 20c. The first LED 20a may be a red LED, the second LED 20b may be a yellow LED, and the third LED 20c may be a green LED. The red light generated by the first LED 20a may be conveyed from the first light pipe 18a to the top indicator window 14a. The yellow light generated by the second LED 20b may be conveyed from the second light pipe 18b to the middle indicator window 14b. The green light generated by the third LED 20c may be conveyed from the third light pipe 18c to the bottom indicator window 14c. While this non -limiting example describes red, green, and blue LEDs, any appropriate colors of LEDs may be used.

[0056] Further, FIG. 3 illustrates a light sensor 22 arranged within the housing 16 of the card reader 10 and next to the third LED 20c. Like the third LED 20c, the light sensor 22 is also arranged within the third light pipe 20c. Accordingly, the light sensor 22 may receive light, such as ambient light, via the third light pipe 20c and the bottom indicator window 14c to generate a corresponding captured light signal. The captured light may include natural light generated by the sun. The captured light may also include artificial light, such as light generated by indoor or outdoor luminaires (incandescent, fluorescent, LED, etc.) installed proximate to the card reader 10. The artificial light may also include light generated by moving objects, such as headlights from a vehicle driving up to the card reader 10. The captured light could also include light generated for the purpose of overlay detection, such as an LED providing light tothe light sensor 22 unless obstructed by an overlay. Therefore, if an overlay has been installed over the card reader 10 such that the light received by the light sensor 22 is significantly reduced, the captured light signal will indicate the presence of the overlay. The light sensor 22 is coupled to a microcontroller which receives a captured light signal corresponding to the captured light.

[0057] Further, while FIG. 3 illustrates an example where the light sensor 22 receives light via the third light pipe 20c, in other examples, the light sensor 22 may be arranged such that it receives or captures light without using a light pipe. For example, the light sensor 22 could be embedded within the housing 16 of the card reader 10 such that the light sensor 22 directly captures light incident upon the housing 16 of the card reader 10. This example is shown in FIGS. 11A-12B.

[0058] FIG. 4 is a block diagram showing detection of an overlay condition based on averaging light captured by the light sensor 22 via aspects of a microcontroller 100. The light sensor 22 generates a captured light signal 24 based on the light received via a light pipe 18. An average generator 111 generates an average light signal 102 by averaging the captured light signal 24 according to an averaging cycle 116. In some examples, the averaging cycle 116 may be 0.5 seconds.

[0059] The average light signal 102 is then provided to a threshold generator 113 to determine an average light threshold 104. The average light threshold 104 may be initially offset from the average light signal 102. In some examples, the average light threshold 104 may be 20% less than the average light signal 102. Further, the threshold generator 113 is configured to adjust the average light threshold 104 to account for gradual light increases or decreases, such as gradual variations in daylight. By adjusting the average light threshold 104 in this way, only sudden decreases in captured light will trigger an overlay condition 106.

[0060] The average overlay detector 115 is configured to detect two conditions based on the captured light signal 24 and the average light threshold 104. If the captured light signal 24 falls below the average light threshold 104 for any period of time, a dark condition signal 108 is generated. The dark condition signal 108 is provided to the average generator 111 to temporarily stop the average generator 111 from adjusting the average light signal 102. Accordingly, the average light threshold 104, offset from the average light signal 102, also stops updating.

[0061] Further, the average overlay detector 115 is also configured to generate an overlay condition signal 106. The overlay condition signal 106 is indicative of an overlay beinginstalled over the card reader 10. The overlay condition signal 106 is generated if the captured light signal 24 is less than the average light threshold 104 for a detection period 118, such as three minutes.

[0062] In some examples, the average overlay detector 115 may be enabled and / or disabled by a nighttime detector 121. The nighttime detector 121 compares the captured light signal 24 to a nighttime threshold (NTT) 122 to determine if the light captured by the light sensor 22 corresponds to nighttime conditions where little to no natural light is present. The nighttime threshold 122 will be lower than the average light threshold 104. If the captured light signal 24 is less than the NTT 122, the nighttime detector 121 generates a nighttime signal 120 indicative of nighttime conditions. The nighttime signal 120 may be provided to the average overlay detector 115 to disable the average overlay detector 115 from generating the overlay condition signal 106 during nighttime conditions. Accordingly, the overlay condition signal 106 will only be generated if the captured light signal 24 is both less than the average light threshold 104 and greater than the nighttime threshold 122 for the detection period 118.

[0063] Once generated, the overlay condition signal 106 may be used in a variety of ways. In some examples, the overlay condition signal 106 may be used to trigger one or more of the LEDs 20a, 20b, 20c to illuminate, thereby conveying to an observer that an overlay has been installed. In other examples, the overlay condition signal 106 may trigger a display (such as a touch screen display) to show text or images indicating that an overlay has been installed. In further examples, the overlay condition signal 106 may cause a notification of overlay detection to be transmitted to a centralized management system via wired or wireless communication.

[0064] FIG. 5 is a block diagram showing detection of an overlay condition according to a baseline signal 110. While the previously described average light signal 102 was used to analyze sudden changes in captured light to detect an overlay condition, the baseline signal 110 is used to periodically check the captured light level to detect dramatic changes over a significant time period, such as one day. This process may be used to detect the installation of an overlay in dark conditions. This process may also detect an overlay installed in such a manner that the captured light signal 24 decreases very gradually, imitating dusk-like conditions.

[0065] As shown in FIG. 5, the light sensor 22 provides the captured light signal 24 to a baseline generator 117 to generate a baseline signal 110. The baseline signal 110 may be updated according to a baseline cycle 112, such as every 24 hours (or once per day). The baseline signal 110 is then provided to a baseline overlay detector 119. The baseline overlaydetector 119 compares the baseline signal 110 to a baseline threshold 114. If the baseline signal 110 is less than the baseline threshold 114, the baseline overlay detector 119 generates the overlay condition signal 106, indicative of the installation of an overlay. Critically, the baseline overlay detector 119 may generate the overlay detection signal 106 even if the nighttime detector 121 of FIG. 4 has detected nighttime conditions.

[0066] In some examples, the baseline threshold 114 is stored in a non-volatile memory such that the baseline threshold 114 is retained in the event of intentional or unintentional power loss. The baseline threshold 114 may be calibrated upon initial set-up of the card reader 10, and retained for future use. In the example of a card reader 10 arranged in an outdoor environment, this calibration may occur post-sunset and in the presence of consistent artificial lighting.

[0067] In some examples, the average light threshold 104 and / or the baseline threshold 114 may be finetuned to detect an overlay with holes or apertures corresponding to the indicator windows 14a, 14b, 14c. Despite the presence of the holes or apertures, the thickness of the overlay around the windows 14a, 14b, 14c may still result in a reduction of captured light detectable by the various aspects of the microcontroller 100.

[0068] FIG. 6 is a chart showing how the various signals and thresholds may be used to detect an overlay condition in terms of intensity (lumens) over time (seconds). In particular, the chart of FIG. 6 shows the captured light signal 24, the average light signal 102, the average light threshold 104, the baseline signal 110, and the baseline threshold 114. FIG. 6 corresponds to a situation where an individual walks up to the card reader 10 and installs an overlay. Installing the overlay obscures the indicator window 14 associated with the light sensor 22, thereby limiting the amount of light the light sensor 22 may capture.

[0069] As shown in FIG. 6, the captured light signal 24 and the average light signal 102 are relatively close until the 38 second mark. Further, the average light threshold 104, offset from the average light signal 102, fluctuates along with the average light signal 104 as the light signal 24 varies. At 38 seconds, an individual walks up to the card reader 10, blocking the light sensor 22 from capturing light, and causing the captured light signal 24 to drop. While the average light signal 102 (and therefore the average light threshold 104) initially drops along with the captured light signal 24, the average light signal 102 enters a steady state once the captured light signal 24 is less than the average light threshold 104. The individual installs the overlay between the 55 and 67 second marks, further decreasing the captured light signal 24. The individual then walks away between the 67 and 76 second marks, causing the captured lightsignal 24 to slightly increase. However, once the overlay is in place, the captured light signal 24 remains less than the average light threshold 104 for a sufficient period of time for the card reader 10 to identify that an overlay has been installed.

[0070] FIG. 7 is a chart corresponding to a situation where an overlay is installed over a card reader 10 under dark conditions. As illustrated in FIG. 7, the captured light signal 24 briefly drops when the individual walks past the card reader 10. The captured light signal 24 then drops significantly when lights proximate to the card reader 10 are turned off. The overlay is installed over the card reader 10 while the lights remain off. The lights are then turned back on at a time of lower daylight. As with the example of FIG. 6, the captured light signal 24 remains less than the average light threshold 104 for a sufficient period of time for the card reader 10 to identify that an overlay has been installed.

[0071] FIG. 8 is a chart corresponding to a situation where a headlight shines directly on the light sensor 22 of the card reader 10. In this example, an overlay is not installed, and therefore should not be detected. In this example, the headlight shines on the light sensor 22 at the 41 -second mark, causing the captured light signal 24 (and therefore the average light signal 102 and the average light threshold 104) to increase significantly. The headlight stops shining on the light sensor 22 at the 82 second mark, causing the captured light signal 24 to decrease. Because the average light signal 102 and the average light threshold 104 automatically adjust along with the captured light signal 24, an overlay is not falsely detected, despite the significant reduction in captured light.

[0072] FIG. 9 is a chart corresponding to a situation where an active bright light is turned off when an overlay is installed over the card reader 10. As shown in FIG. 9, the captured light signal 24 (and therefore the average light signal 102 and the average light threshold 104) rapidly increase when the bright light is turned on, and then rapidly decrease when the bright light is turned off. As with the examples of FIG. 6 and 7, the captured light signal 24 remains less than the average light threshold 104 for a sufficient period of time for the card reader 10 to identify that an overlay has been installed.

[0073] FIG. 10 is a chart corresponding to a situation where a transaction occurs without an overlay being installed. As shown in FIG. 9, the captured light signal 24 dips below the average light threshold 104 when the transaction is being performed due to the individual performing the transaction blocking ambient light from the light sensor 22. The captured light signal 24 then rises back above the average light threshold 104 when the individual walks away.Accordingly, the captured light signal 24 does not remain below the average light threshold 104 for enough time to trigger overlay detection.

[0074] FIG. 11A is an isometric view of a portion of a payment terminal 1 having a card reader 10. As shown in FIG. 11 A, the payment terminal 1 may be configured to be used in a checkout line of a grocery store or retail shop. The card reader 10 includes a card insertion slot 12 and a keypad 26. The keypad 26 enables a customer to enter a wide array of information, such as a PIN number corresponding to a payment card inserted into the card insertion slot 12. The keypad 26 is partially surrounded by a wall 28. In the example of FIG. 11 A, the wall 28 is angled relative to the keypad 26. The angle of the wall 28 relative to the keypad 26 may range from approximately 90 degrees to approximately 135 degrees. Further, as shown in FIG. 11 A, light sensor 22 is embedded within the wall 28 to directly capture light incident upon the payment terminal 1. Arranging the light sensor 22 in this position allows the card reader 10 to detect overlays arranged over the keypad 26 to surreptitiously capture information regarding both the payment card in the card insertion slot 12 as well as user inputs to the keypad 26.

[0075] FIG. 1 IB is an exploded isometric view of a variation of the payment terminal 1 of FIG. 11 A further including a privacy shield 30. The privacy shield 30 may be installed around the keypad 30 to prevent third parties from observing user inputs entered into the keypad. The privacy shield 30 further includes a notch 32. The notch 32 prevents the privacy shield 30 from obstructing the light sensor 22 embedded within the wall 28 around the keypad 26, thereby enabling the light sensor 22 to capture light indicative of the presence of an overlay.

[0076] FIG. 12A is an isometric view of a portion of a further example of payment terminal 1 having a card reader 10. In this example, the light sensor 22 is embedded within the keypad 26. Like the example of FIG. 11 A, arranging the light sensor 22 in this position allows the card reader 10 to detect overlays arranged over the keypad 26. Further, FIG. 12B shows a privacy shield 30 be installed around the keypad 30. Unlike the example of FIG. 11B, this privacy shield 30 does not require a notch 32 to expose the light sensor 22.

[0077] FIG. 13 is a flowchart of a method 900 of overlay detection. The method 900 includes, in step 902, capturing light via a light sensor of the card reader.

[0078] The method 900 further includes, in step 904, generating, via the light sensor, a captured light signal based on the captured light.

[0079] The method 900 further includes, in step 906, generating, via a controller coupled to the light sensor, an average light signal by averaging the captured light signal according to an averaging cycle.

[0080] The method 900 further includes, in step 908, generating, via the controller, an average light threshold based on the average light signal.

[0081] The method 900 further includes, in step 910, determining, via the controller, an overlay condition based on the captured light signal and the average light threshold.

[0082] According to an example, the method 900 may further include, in optional step 912, generating, via the controller, a baseline signal based on the captured light signal. The baseline signal is periodically updated according to a baseline cycle.

[0083] The method 900 may further include, in optional step 914, determining, via the controller, the overlay condition based on the baseline signal and a baseline threshold.

[0084] FIG. 14 is a variation of the method 900 shown in FIG. 13. The method 900 includes, in optional step 916, determining, via the controller, a nighttime condition based on the captured light signal and a nighttime threshold.

[0085] The method 900 further includes, in optional step 918, disabling the controller from determining the overlay condition based on the captured light signal and the average light threshold during the nighttime condition.

[0086] As described herein, the various computer systems may include one or more computer processors, machine-readable memory, interface buses, and / or system buses that contain conductive circuit pathways through which instructions (e.g., machine-readable signals) may travel to effectuate communication, tasks, storage and the like. Each of the one or more processors may include a high-speed data processor adequate to execute the operations described herein and / or various specialized processing units. In some examples, one or more of the processors may be a single processor, multiple processors, or multiple processor cores on a single die. In some examples, an interface bus may include a network interface configured to connect one component or device to a communications network, which can include a direct interconnection, the Internet, a local area network (“LAN”), a metropolitan area network (“MAN”), a wide area network (“WAN”), a wired or Ethernet connection, a wireless connection, and similar types of communications networks, including combinations thereof. In certain examples, the memory described herein can be variously embodied in one or more forms of machine-accessible and machine-readable memory, and can include, but is not limited to, a non-transitory storage medium, a magnetic disk storage, an optical disk storage, an array of storage devices, a solid-state memory device, and the like, including combinations thereof. According to another embodiment, certain memory components can be distributed remotely, such as in various cloud computing applications, among other configurations.

[0087] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0088] The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[0089] The phrase “and / or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and / or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements can optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified.

[0090] As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.”

[0091] As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements can optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified.

[0092] It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.

[0093] In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively.

[0094] The above-described examples of the described subject matter can be implemented in any of numerous ways. For example, some aspects can be implemented using hardware, software or a combination thereof. When any aspect is implemented at least in part in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single device or computer or distributed among multiple device s / computers .

[0095] The present disclosure can be implemented as a system, a method, and / or a computer program product at any possible technical detail level of integration. The computer program product can include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present disclosure.

[0096] The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium can be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire.

[0097] Computer readable program instructions described herein can be downloaded to respective computing / processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and / or a wireless network. The network can comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and / or edge servers. A network adapter card or network interface in each computing / processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing / processing device.

[0098] Computer readable program instructions for carrying out operations of the present disclosure can be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, statesetting data, configuration data for integrated circuitry, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++, or the like, and procedural programming languages, such as the “C” programming language or similar programming languages. The computer readable program instructions can execute entirely on the user’s computer, partly on the user's computer, as a stand-alone software package, partly on the user’s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider). In some examples, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) can execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present disclosure.

[0099] Aspects of the present disclosure are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to examples of the disclosure. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer readable program instructions.

[0100] The computer readable program instructions can be provided to a processor of a, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks. These computer readable program instructions can also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and / or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function / act specified in the flowchart and / or block diagram or blocks.

[0101] The computer readable program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus, or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0102] The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various examples of the present disclosure. In this regard, each block in the flowchart or block diagrams can represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the blocks can occur out of the order noted in the Figures. For example, two blocks shown in succession can, in fact, be executed substantially concurrently, or the blocks can sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and / or flowchart illustration, and combinations of blocks in the block diagrams and / or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.

[0103] Other implementations are within the scope of the following claims and other claims to which the applicant can be entitled.

[0104] While various examples have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and / or structures for performingthe function and / or obtaining the results and / or one or more of the advantages described herein, and each of such variations and / or modifications is deemed to be within the scope of the examples described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and / or configurations will depend upon the specific application or applications for which the teachings is / are used. Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific examples described herein. It is, therefore, to be understood that the foregoing examples are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, examples can be practiced otherwise than as specifically described and claimed. Examples of the present disclosure are directed to each individual feature, system, article, material, kit, and / or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and / or methods, if such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent, is included within the scope of the present disclosure.

Claims

CLAIMSWhat is claimed is:

1. A card reader, comprising: a light sensor configured to capture light and generate a captured light signal based on the captured light; and a controller configured to: generate an average light signal by averaging the captured light signal according to an averaging cycle; generate an average light threshold based on the average light signal; and determine an overlay condition based on the captured light signal and the average light threshold.

2. The card reader of claim 1, wherein the overlay condition is generated if the captured light signal is less than the average light threshold for a detection period.

3. The card reader of claim 1, wherein the average light threshold varies over time.

4. The card reader of claim 1, wherein the controller is further configured to: generate a baseline signal based on the captured light signal, wherein the baseline signal is periodically updated according to a baseline cycle; and determine the overlay condition based on the baseline signal and a baseline threshold.

5. The card reader of claim 4, wherein the baseline cycle is at least 24 hours.

6. The card reader of claim 1, wherein the average light signal remains substantially constant during a dark condition.

7. The card reader of claim 6, wherein the dark condition corresponds to the captured light signal being less than the average light signal.

8. The card reader of claim 7, wherein the average light threshold remains substantially constant during the dark condition.

9. The card reader of claim 1, wherein the light sensor is configured to capture the light via a light pipe.

10. The card reader of claim 9, wherein the light pipe is configured to convey light generated by a light-emitting diode (LED).

11. The card reader of claim 10, wherein the light pipe conveys at least a portion of the light generated by the LED to an indicator window.

12. The card reader of claim 1, wherein the averaging cycle is at least 0.5 seconds.

13. The card reader of claim 1, wherein the controller is further configured to determine a nighttime condition based on the captured light signal and a nighttime threshold.

14. The card reader of claim 13, wherein the controller is disabled from determining the overlay condition based on the captured light signal and the average light threshold during the nighttime condition.

15. The card reader of claim 1, wherein the average light threshold is generated to be less than the average light signal.

16. A method of overlay detection, comprising: capturing light via a light sensor of a card reader; generating, via the light sensor, a captured light signal based on the captured light; generating, via a controller coupled to the light sensor, an average light signal by averaging the captured light signal according to an averaging cycle; generating, via the controller, an average light threshold based on the average light signal; and determining, via the controller, an overlay condition based on the captured light signal and the average light threshold.

17. The method of claim 16, further comprising: generating, via the controller, a baseline signal based on the captured light signal, wherein the baseline signal is periodically updated according to a baseline cycle; and determining, via the controller, the overlay condition based on the baseline signal and a baseline threshold.

18. The method of claim 16, further comprising: determining, via the controller, a nighttime condition based on the captured light signal and a nighttime threshold; and disabling the controller from determining the overlay condition based on the captured light signal and the average light threshold during the nighttime condition.

19. The method of claim 16, wherein the overlay condition is generated if the captured light signal is less than the average light threshold for a detection period.

20. The method of claim 16, wherein the average light signal remains substantially constant during a dark condition, and wherein the dark condition corresponds to the captured light signal being less than the average light signal.

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