PATENT DOCUMENT

Publication Number: US-11437861-B2
Application Number: US-201916546201-A
Country: US
Kind Code: B2

Title: Test object holder

Abstract:
A testing assembly comprising a test object and a test object holder. The test object holder includes a body with an aperture defined therethrough. The test object is located in the aperture and an adhesive sheet is positioned over the aperture and the test object to retain the test object in place during testing.

Claims:
What is claimed is: 
     
       1. A testing assembly for testing a performance of at least one wireless power transfer device to be tested in the presence of a foreign object, the testing assembly comprising:
 a test object representing a foreign object that might be found in the presence of a wireless power system, wherein the test object comprises a first face, a second face opposite the first face, and a thickness between the first face and the second face; and 
 a test object holder, the test object holder comprising:
 a body having an aperture defined therethrough, wherein the body has a first face, a second face opposite the first face, and a thickness between the first face of the body and the second face of the body, and wherein the thickness of the body is less than or equal to the thickness of the test object, and the test object is located within the aperture during testing; and 
 an adhesive sheet positioned over the aperture and the test object; 
 wherein the test object holder holds and retains the test object in a specified test position relative to the at least one wireless power transfer device to be tested. 
 
 
     
     
       2. The testing assembly of  claim 1 , wherein the at least one wireless power transfer device to be tested is a wireless power transmitting device and the testing assembly further comprises a wireless power receiving device and the test object is located between the wireless power transmitting device and the wireless power receiving device. 
     
     
       3. The testing assembly of  claim 1 , wherein the adhesive sheet comprises polyimide or Kapton tape. 
     
     
       4. The testing assembly of  claim 1 , wherein the test object is made of steel. 
     
     
       5. The testing assembly of  claim 1 , wherein the test object is made of aluminum. 
     
     
       6. The testing assembly of  claim 1 , wherein the test object is a ring having an outer diameter between 21.8 mm and 22 mm and an inner diameter between 19.8 mm and 20 mm. 
     
     
       7. The testing assembly of  claim 1 , further comprising a temperature sensor that measures the temperature of the test object. 
     
     
       8. The testing assembly of  claim 7 , wherein the temperature sensor is a thermocouple. 
     
     
       9. The testing assembly of  claim 1 , wherein the thickness of test object is between 0.9 mm and 1 mm and the thickness of the body is between 0.6 mm and 1 mm. 
     
     
       10. The testing assembly of  claim 9 , wherein the thickness of the body is 0.8 mm. 
     
     
       11. The testing assembly of  claim 1 , wherein the thickness of the test object is less than or equal to 0.5 mm and the thickness of the body is between 0.04 mm and 0.2 mm. 
     
     
       12. The testing assembly of  claim 11 , wherein the thickness of the test object is between 0.1 mm and 0.2 mm. 
     
     
       13. The testing assembly of  claim 12 , wherein the thickness of the test object is 0.13 mm. 
     
     
       14. The testing assembly of  claim 1 , wherein the test object holder comprises one or more indexing features. 
     
     
       15. The testing assembly of  claim 14 , wherein the indexing features comprise one or more notches at an edge of the test object holder. 
     
     
       16. The testing assembly of  claim 15 , wherein the one or more notches comprise three equally-spaced notches. 
     
     
       17. The testing assembly of  claim 1 , wherein the test object is a disk. 
     
     
       18. The testing assembly of  claim 17 , wherein the test object has a diameter between 14.8 mm and 15 mm. 
     
     
       19. The testing assembly of  claim 17 , wherein the test object has a diameter between 19.8 mm and 20 mm. 
     
     
       20. The testing assembly of  claim 17 , wherein the test object has a diameter between 21.8 mm and 22 mm. 
     
     
       21. The testing assembly of  claim 1 , wherein the body comprises a rigid material. 
     
     
       22. The testing assembly of  claim 21 , wherein the body is formed from FR-4. 
     
     
       23. The testing assembly of  claim 21 , wherein the body comprises glass fibers. 
     
     
       24. The testing assembly of  claim 23 , wherein the body comprises epoxy. 
     
     
       25. The testing assembly of  claim 1 , wherein the test object holder further comprises a support frame adapted to support the body. 
     
     
       26. The testing assembly of  claim 25 , wherein the support frame is formed from FR-4. 
     
     
       27. The testing assembly of  claim 25 , wherein the support frame comprises glass fibers. 
     
     
       28. The testing assembly of  claim 27 , wherein the support frame comprises epoxy. 
     
     
       29. The testing assembly of  claim 25 , wherein the body comprises a sheet of resilient polymer material. 
     
     
       30. The testing assembly of  claim 29 , wherein the polymer material is biaxially-oriented polyethylene terephthalate. 
     
     
       31. The testing assembly of  claim 29 , wherein the polymer material is cellulose acetate. 
     
     
       32. A testing assembly for testing performance of at least one wireless power transfer device to be tested in the presence of a foreign object, the testing assembly comprising:
 a conductive test object representing a foreign object that might be found in the presence of a wireless power system, the test object having a thickness defined by opposing first and second faces; and 
 a test object holder, the test object holder comprising:
 a rigid body having an aperture defined therethrough and having a thickness defined by opposing first and second faces with the thickness of the body being less than or equal to the thickness of the test object, wherein the test object is disposed within the aperture during testing; and 
 a non-conductive adhesive sheet positioned over the aperture and the test object to secure the test object relative to the test object holder; 
 wherein the test object holder retains the test object in a specified test position relative to the at least one wireless power transfer device. 
 
 
     
     
       33. The testing assembly of  claim 32 , further comprising a temperature sensor configured to measure the temperature of the test object. 
     
     
       34. The testing assembly of  claim 32 , wherein the at least one wireless power transfer device to be tested is a wireless power transmitting device and the testing assembly further comprises a wireless power receiving device and the test object is located between the wireless power transmitting device and the wireless power receiving device. 
     
     
       35. The testing assembly of  claim 32 , wherein the rigid body is formed from FR-4. 
     
     
       36. The testing assembly of  claim 32 , wherein the adhesive sheet comprises polyimide or Kapton tape. 
     
     
       37. The testing assembly of  claim 32 , wherein the thickness of test object is between 0.9 mm and 1 mm and the thickness of the body is between 0.6 mm and 1 mm. 
     
     
       38. The testing assembly of  claim 32 , wherein the test object is a disk having a diameter selected from one of the following ranges:
 14.8 mm to 15 mm; 
 19.8 mm to 20 mm; and 
 21.8 mm to 22 mm. 
 
     
     
       39. The testing assembly of  claim 32 , wherein the test object is a ring having an outer diameter between 21.8 mm and 22 mm and an inner diameter between 19.8 mm and 20 mm. 
     
     
       40. The testing assembly of  claim 32 , wherein the rigid body comprises glass fibers. 
     
     
       41. The testing assembly of  claim 40 , wherein the rigid body comprises epoxy. 
     
     
       42. The testing assembly of  claim 32 , wherein the test object holder comprises one or more indexing features. 
     
     
       43. The testing assembly of  claim 42 , wherein the indexing features comprise one or more notches at an edge of the test object holder. 
     
     
       44. The testing assembly of  claim 43 , wherein the one or more notches comprise three equally-spaced notches. 
     
     
       45. A testing assembly for testing a performance of at least one wireless power transfer device to be tested in the presence of a foreign object, the testing assembly comprising:
 a conductive test object representing a foreign object that might be found in the presence of a wireless power system, the test object having a thickness defined by opposing first and second faces; and 
 a test object holder, the test object holder comprising:
 a resilient polymer sheet having an aperture defined therethrough and having a thickness defined by opposing first and second faces with the thickness of the resilient polymer sheet being less than or equal to the thickness of the test object, wherein the test object is disposed within the aperture during testing; 
 a rigid frame that supports the resilient polymer sheet; and 
 a non-conductive adhesive sheet positioned over the aperture and the test object to secure the test object relative to the test object holder; 
 wherein the test object holder retains the test object in a specified test position relative to the at least one wireless power transfer device. 
 
 
     
     
       46. The testing assembly of  claim 45 , further comprising a temperature sensor configured to measure the temperature of the test object. 
     
     
       47. The testing assembly of  claim 45 , wherein the at least one wireless power transfer device to be tested is a wireless power transmitting device and the testing assembly further comprises a wireless power receiving device and the test object is located between the wireless power transmitting device and the wireless power receiving device. 
     
     
       48. The testing assembly of  claim 45 , wherein the rigid frame that supports the resilient polymer sheet is formed from FR-4. 
     
     
       49. The testing assembly of  claim 45 , wherein the resilient polymer sheet is biaxially-oriented polyethylene terephthalate. 
     
     
       50. The testing assembly of  claim 45 , wherein the resilient polymer sheet is cellulose acetate. 
     
     
       51. The testing assembly of  claim 45 , wherein the adhesive sheet comprises polyimide or Kapton tape. 
     
     
       52. The testing assembly of  claim 45 , wherein the test object is a disk having a diameter selected from one of the following ranges:
 14.8 mm to 15 mm; 
 19.8 mm to 20 mm; and 
 21.8 mm to 22 mm. 
 
     
     
       53. The testing assembly of  claim 45 , wherein the test object is a ring having an outer diameter between 21.8 mm and 22 mm and an inner diameter between 19.8 mm and 20 mm. 
     
     
       54. The testing assembly of  claim 45 , wherein the rigid frame that supports the resilient polymer sheet comprises glass fibers. 
     
     
       55. The testing assembly of  claim 54 , wherein the rigid frame that supports the resilient polymer sheet comprises epoxy. 
     
     
       56. The testing assembly of  claim 45 , wherein the thickness of the test object is less than or equal to 0.5 mm and the thickness of the is between 0.04 mm and 0.2 mm. 
     
     
       57. The testing assembly of  claim 56 , wherein the thickness of the test object is between 0.1 mm and 0.2 mm. 
     
     
       58. The testing assembly of  claim 57 , wherein the thickness of the test object is 0.13 mm. 
     
     
       59. The testing assembly of  claim 45 , wherein the test object holder comprises one or more indexing features. 
     
     
       60. The testing assembly of  claim 59 , wherein the indexing features comprise one or more notches at an edge of the test object holder. 
     
     
       61. The testing assembly of  claim 60 , wherein the one or more notches comprise three equally-spaced notches.

Description:
This patent application claims the benefit of provisional patent application No. 62/880,870, filed on Jul. 31, 2019, and provisional patent application No. 62/721,415, filed on Aug. 22, 2018, which are hereby incorporated be reference herein in their entireties. 
    
    
     FIELD 
     This relates generally to wireless power transfer and, more particularly, to foreign object detection for wireless power transfer devices. 
     BACKGROUND 
     In wireless power transfer systems, a wireless power transmitting device wirelessly transmits power to a wireless power receiving device. The wireless power receiving device receives the wirelessly transmitted power and provides power to charge an internal battery or to power the receiving device. 
     Wireless power transmitting devices may include one or more transmitting coils which generate a magnetic field and define a charging region (for example, transmitting devices with a charging surface or a charging volume). Provided the receiving device is located in sufficient proximity to the charging area or zone, wireless power transfer may be achieved. 
     Foreign objects, such as metallic objects like coins or rings, located in proximity to the magnetic field of such wireless power systems may intercept wireless power intended for a receiving device. Also, the magnetic field may induce eddy currents in the foreign object. Wireless power systems, and in particular transmitting devices, may be tested to determine what effect they have on the wireless charging experience. 
     Accordingly, various standards have been outlined to enable such testing of wireless power systems. For example, the standards outlined in the Wireless Power Consortium (WPC) Qi Specification v1.2.3 and IEC 62368-1 (Edition 3). Qi Specification v1.2.3 specifies a test which includes positioning a representative foreign object between the test transmitting device and test receiving device and then measuring the temperature of the representative foreign object over a period of time as power is transmitted by the test transmitting device. As the test is highly dependent on the location of the representative foreign object relative to the test transmitting device and test receiving device, a holder frame that allows tests to be reliably and consistently repeated without influencing the outcome is desired. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an illustrative wireless power system in accordance with some embodiments. 
         FIG. 2  is a schematic diagram of an illustrative wireless power system including a foreign object. 
         FIG. 3  is a schematic diagram of an illustrative testing system in accordance with some embodiments. 
         FIG. 4  is a perspective view of a test object according to one embodiment. 
         FIG. 5  is a perspective view of a test object according to one embodiment. 
         FIG. 6  is a perspective view of a test object according to one embodiment. 
         FIG. 7  is a top view of a test object holder according to one embodiment. 
         FIG. 8  is cross-sectional view of the test object holder of  FIG. 7 , including a test object and a sensor. 
         FIG. 9  is a top view of a test object holder according to another embodiment. 
         FIG. 10  is a cross-sectional view of the test object holder of  FIG. 9 , including a test object and a sensor. 
         FIG. 11  is a side view of a testing system according to one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     A wireless power system has a wireless power transmitting device that transmits power wirelessly to a wireless power receiving device. The wireless power transmitting device is a device such as a wireless charging mat, wireless charging puck, wireless charging stand, wireless charging table, or other wireless power transmitting equipment. The wireless power transmitting device may be a stand-alone device or built into other electronic devices such as a laptop or tablet computer, cellular telephone or other electronic device. The wireless power transmitting device has one or more coils that are used in transmitting wireless power to one or more wireless power receiving coils in the wireless power receiving device. The wireless power receiving device is a device such as a cellular telephone, watch, media player, tablet computer, pair of earbuds, remote control, laptop computer, electronic pencil or stylus, other portable electronic device, or other wireless power receiving equipment. 
     During operation, the wireless power transmitting device supplies alternating-current signals to one or more wireless power transmitting coils. This causes the coils to transmit alternating-current electromagnetic signals (sometimes referred to as wireless power signals) to one or more corresponding coils in the wireless power receiving device. Rectifier circuitry in the wireless power receiving device converts received wireless power signals into direct-current (DC) power for powering or charging the wireless power receiving device. 
     Wireless power transmitting and receiving devices can be designed to cooperate specifically with each other. For example, the size, shape, number, dimensions and configuration of coils of one or both of the devices may be selected based on the other device. Magnetic elements may also be included in the transmitting and/or receiving device, and the size, shape, number, dimensions and configuration of the magnetic elements may be selected based on the other device. 
     In some cases, wireless power transmitting and receiving devices can be designed to be closely coupled to each other. Typically, this is achieved by arranging the coils of the transmitting and receiving devices such that they are aligned with and close to each other in use. Systems in which the transmitting and receiving devices can be closely coupled to each other in use are sometimes referred to as inductive power transfer systems. Transmitting and receiving devices that can be closely coupled to receiving devices are sometimes referred to as inductive power transfer devices. 
     Wireless power transmitting and receiving devices can also be designed to cooperate with each other in particular orientations, positions or other spatial relationships. For example, some receiving devices may have a preferred position or orientation with respect to a transmitting device. This preferred position or orientation may allow for good power transfer, minimum leakage of the charging field and other advantageous effects. The transmitting and/or receiving devices may have visual markings to indicate where or in what orientation to place the receiving device, engaging elements to hold the receiving device in a particular position or orientation, magnetic couplings or other biasing elements to urge the receiving device towards a particular position or orientation, or other arrangements. 
     Wireless power transmitting and receiving devices can also be used with other devices without being specifically designed to cooperate with them. For example, a wireless power transmitting device can operate with many different types of receiving devices having different coil arrangements, different (or no) magnetic elements, sizes, shapes and other characteristics. A wireless power receiving device can operate with many different types of transmitting devices having different coil arrangements, different (or no) magnetic elements, sizes, shapes and other characteristics. 
     Wireless power transmitting and receiving devices can also be used in various orientations, positions or other spatial relationships. For example, wireless power transmitting or receiving devices may be provided without visual markings, engaging elements, magnetic couplings or other biasing elements, or other arrangements. Alternatively, transmitting or receiving devices may have these arrangements but still operate in various other orientations and positions. 
     An illustrative wireless power system is shown in  FIG. 1 . As shown in  FIG. 1 , a wireless power system  8  includes a wireless power transmitting device  12  and one or more wireless power receiving devices such as wireless power receiving device  10 . Device  12  may be a stand-alone device such as a wireless charging mat, may be built into furniture, laptop or tablet computers, cellular telephones or other electronic devices, or may be other wireless charging equipment. Device  10  is a portable electronic device such as a wristwatch, a cellular telephone, a tablet computer, an electronic pencil or stylus, or other electronic equipment. Illustrative configurations in which device  12  is a tablet computer or similar electronic device and in which device  10  is an electronic accessory that couples with the tablet computer or similar electronic device during wireless power transfer operations may sometimes be described herein as examples. Illustrative configurations in which device  12  is a mat or other equipment that forms a wireless charging surface and in which device  10  is a portable electronic device or electronic accessory that rests on the wireless charging surface during wireless power transfer operations may also sometimes be described herein as examples. 
     During operation of system  8 , a user places one or more devices  10  on or near the charging region of device  12 . Power transmitting device  12  is coupled to a source of alternating-current voltage such as alternating-current power source  50  (e.g., a wall outlet that supplies line power or other source of mains electricity), has a battery such as battery  38  for supplying power, and/or is coupled to another source of power. A power converter such as AC-DC power converter  40  can be included to convert power from a mains power source or other AC power source into DC power that is used to power control circuitry  42  and other circuitry in device  12 . During operation, control circuitry  42  uses wireless power transmitting circuitry  34  and one or more coils  36  coupled to circuitry  34  to transmit alternating-current electromagnetic signals  48  to device  10  and thereby convey wireless power to wireless power receiving circuitry  46  of device  10 . 
     Power transmitting circuitry  34  has switching circuitry (e.g., transistors in an inverter circuit) that are turned on and off based on control signals provided by control circuitry  42  to create AC current signals through appropriate coils  36 . As the AC currents pass through a coil  36  that is being driven by the switching circuitry, a time varying electromagnetic field (wireless power signals  48 ) is produced, that is received by one or more corresponding coils  14  electrically connected to wireless power receiving circuitry  46  in receiving device  10 . If the time varying electromagnetic field is magnetically coupled to coil  14 , an AC voltage is induced and a corresponding AC currents flows in coil  14 . Rectifier circuitry in circuitry  46  can convert the induced AC voltage in the one or more coils  14  into a DC voltage signals for powering device  10 . The DC voltages are used in powering components in device  10  such as display  52 , touch sensor components and other sensors  54  (e.g., accelerometers, force sensors, temperature sensors, light sensors, pressure sensors, gas sensors, moisture sensors, magnetic sensors, etc.), wireless communications circuitry  56  for communicating wirelessly with control circuitry  42  of device  12  and/or other equipment, audio components, and other components (e.g., input-output devices  22  and/or control circuitry  20 ) and/or are used in charging an internal battery in device  10  such as battery  18 , or to charge subsequent devices, either wired or wirelessly. 
     Devices  12  and  10  include control circuitry  42  and  20 . Control circuitry  42  and  20  may include storage and processing circuitry such as analogue circuitry, microprocessors, power management units, baseband processors, digital signal processors, field-programmable gate arrays, microcontrollers, application-specific integrated circuits with processing circuits and/or any combination thereof. Control circuitry  42  and  20  is configured to execute instructions for implementing desired control and communications features in system  8 . For example, control circuitry  42  and/or  20  may be used in sensing for foreign or other non-receiver objects (e.g. metallic objects such as coins or RFID tags within electronic devices), determining power transmission levels, processing sensor data, processing user input, processing other information such as information on wireless coupling efficiency from transmitting circuitry  34 , processing information from receiving circuitry  46 , using information from circuitry  34  and/or  46  such as signal measurements on output circuitry in circuitry  34  and other information from circuitry  34  and/or  46  to determine when to start and stop wireless charging operations, adjusting charging parameters such as charging frequencies, coil assignments in a multi-coil array, and wireless power transmission levels, and performing other control functions. Control circuitry  42  and/or  20  may be configured to perform these operations using hardware (e.g. dedicated hardware or circuitry) and/or software (e.g. code that runs on the hardware of system  8 ). Software code for performing these operations is stored on non-transitory computer readable storage media (e.g. tangible computer readable storage media). The software code may sometimes be referred to as software, data, program instructions, instructions, or code. The non-transitory computer readable storage media may include non-volatile memory such as non-volatile random-access memory (NVRAM), one or more hard drives (e.g., magnetic drives or solid state drives), one or more removable flash drives or other removable media, other computer readable media, or combinations of these computer readable media or other storage. Software stored on the non-transitory computer readable storage media may be executed on the processing circuitry of control circuitry  42  and/or  20 . The processing circuitry may include application-specific integrated circuits with processing circuitry, one or more microprocessors, or other processing circuitry. 
     Device  12  and/or device  10  may communicate wirelessly. Devices  10  and  12  may, for example, have wireless transceiver circuitry in control circuitry  42  and  20  (and/or wireless communications circuitry such as circuitry  56  of  FIG. 1 ) that allows wireless transmission of signals between devices  10  and  12  (e.g., using antennas that are separate from coils  36  and  14  to transmit and receive unidirectional or bidirectional wireless signals, using coils  36  and  14  to transmit and receive unidirectional or bidirectional wireless signals, etc.). For example, device  12  and/or device  10  may communicate using in-band communications injected or combined into the wireless power signals  48  such as proposed in the Wireless Power Consortium Qi specification 1.1, which is incorporated herein by reference. Alternatively, a separate Bluetooth®, RFID, NFC, Zigbee, WiFi, RF or other communication system may be employed. 
     As previously described, foreign objects may sometimes be located in proximity to the wireless power system.  FIG. 2  shows the illustrative wireless power system  8  of  FIG. 1  in which a foreign object  58  is present. The foreign object  58  may be, for example, a metallic object like a coin, ring or metallic foil wrapper. The foreign object  58  may have been placed on or near the transmitting device  12  before the device  12  started operating or it may have been introduced after the device  12  started operating. During operation of the wireless power transmitting device  12 , the presence of the foreign object  58  may impact the user experience. For example, for a metallic foreign object located in the time varying electromagnetic field  48 , a current may be induced in the foreign object  58 . This may affect charging efficiency. This also may affect the temperature of foreign object  58 . If the foreign object  58  is a coin, for example, a user may be surprised if the coin is heated by the transmitting device. 
       FIG. 3  shows an illustrative testing system  60  for testing the effect of a foreign object in the presence of a device to be tested, for example a device of a wireless power system. The testing system  60  includes a test transmitting device  62  and test receiving device  64 . The test transmitting device  62  may have some or all of the features of the transmitting device  12  described above in relation to  FIG. 1 . The test transmitting device may include a charging surface or a charging volume. Similarly, the test receiving device  63  may have some or all of the features of the receiving device  10  described above in relation to  FIG. 1 . The test transmitting device  62  and test receiving device  64  are located in a test environment  66 . For example, the test environment may be a laboratory, hutch or other suitable room or enclosure. The environment may have stable environmental conditions (e.g., air temperature, air mass flow rate and/or pressure). The test transmitting device  62  and test receiving device  64  are positioned relative to each other so during operation of the test transmitting device  62  wireless power may be transmitted to the test receiving device  64 . For example, where the test transmitting device  62  is a charging surface, the test receiving device  64  may be placed onto the charging surface (with possibly the test object positioned therebetween). In another example, where the test transmitting device  62  is a charging volume, the test receiving device  64  may be placed into the charging volume. In both examples, the relative position and orientation of the test receiving device  64  may be specified by the testing standard. 
     The testing system  60  includes a test object  68 . The test object  68  represents a foreign object which might be found in the presence of a wireless power system. The test object may be one of a number of different test objects specified for testing purposes, some of which are described below. The test object  68  is located in a test position. Depending on the type of testing being carried out, the test object may be positioned between the test transmitting device  62  and test receiving device  64  or it may be positioned in another test position specified by the testing standard. 
     The testing system  60  includes a test object holder  70 . As described in more detail below, the test object holder  70  is configured to hold and retain the test object  68  in the test position. While the test object holder  70  in  FIG. 3  is shown as distinct from the test object  68 , in some example embodiments the test object  68  may also be considered as part of the test object holder  70  (for example, where the test object  68  and test object holder  70  are formed together). 
     The testing system  60  includes a measurement device  72 . The testing system  60  may include various sensors  71 ,  73  to detect and measure test variables, such as, for example test object temperature and environment temperature. Sensor  71  is shown in  FIG. 3  as being within the measurement device  72  and sensor  73  is shown as being provided inside the test object holder  70 . Sensor  73  may be a thermometer (for example, a thermocouple) provided on or inside the test object holder  70  to enable measurement of the temperature of the test object  68 . 
     The testing system  60  may be used to carry out testing in accordance with existing testing standards, for example the testing standards specified in WPC Qi Specification v1.2.3 and IEC 62368-1 (Edition 3). Alternatively, or in addition, the testing system  60  may be used to carry out testing in accordance with new testing standards, which may be variants of existing standards or entirely new standards. 
       FIGS. 4 to 6  show some possible test objects. The shape, size and/or material of the test objects may be specified in a testing standard. In  FIG. 4  the test object  68  is a disk  74 . The disk  74  is circular. The disk may represent a coin that may be placed in the proximity of a wireless power system. The disk  74  is substantially planar, including a top face  76 , a bottom face  78  and a side face  80 . The disk  74  may be made of a metallic material such as steel, aluminum, or other specified material. The disk  74  may have a diameter, indicated by arrow  82 , between about 10 and 20 mm, 12 and 18 mm, 14 and 16 mm, 14.8 and 15 mm, or that may be about 15 mm. In one example, the disk is constructed of steel and has a diameter in this range. Alternatively, the disk may have a diameter between about 15 and 30 mm, 20 and 25 mm, 21.8 and 22 mm, or that may be about 22 mm. In one example, the disk is constructed of aluminum and has a diameter in this range. The disk  74  may have a thickness between the top face  76  and the bottom face  78 , indicated by arrow  84 , between about 0.1 and 2.0 mm, 0.3 and 1.5 mm, 0.5 and 1.2 mm, 0.9 mm and 1 mm, or that may be about 1 mm. 
     In  FIG. 5  the test object  68  is a ring  86 . The ring may represent, for example, a piece of jewelry that may be placed in the proximity of a wireless power system. The ring  86  is substantially planar, including a top face  88 , a bottom face  90 , an internal side face  92  and an external side face  94 . The ring  86  may include a stub  96  projecting from the external side face  94 . A similar stub may also be provided on the disk  74  of  FIG. 4 . The ring  86  may be made of a metallic material such as steel or aluminum, as well as other specified materials prone to absorb electromagnetic waves emitted from a wireless power transmitting device. The ring  86  may have an inner diameter, indicated by arrow  98 , between about 10 and 30 mm, 15 and 25 mm, 19 and 21 mm, 19.8 and 20.2 mm, or that may be about 20 mm. The ring  86  may have an outer diameter, indicated by arrow  100 , between about 12 and 32 mm, 17 and 26 mm, 19 and 24 mm, 21.8 and 22 mm, or that may be about 22 mm. The ring  86  may have a thickness between the top face  88  and the bottom face  90 , indicated by arrow  102 , between about 0.1 and 2.0 mm, 1.3 and 1.5 mm, 0.5 and 1.2 mm, 0.9 and 1 mm, or that may be about 1 mm. 
     In  FIG. 6  the test object  68  is a foil disk  104 . The disk may represent, for example, a foil that may be placed in the proximity of a wireless power system. The disk  104  is substantially circular. The foil disk  104  is substantially planar, including a top face  106 , a bottom face  108 . Due to the thinness of the foil disc, the side face is not visible in  FIG. 6 . The foil disk  104  may be made of metallic foil such as steel foil, aluminum foil, or other specified material. The foil disk  104  may have an adhesive backing. The foil disk  104  may be a single layer of foil or it may be made of layers of foil stacked together. The foil disk  104  may be made of a single piece of foil folded in half to form two layers. In the case that the foil disk is made of a single piece of foil folded in half, the disk may be substantially circular but with a flat edge at the fold. The foil disk  104  may have a diameter, indicated by arrow  110 , between about 10 and 30 mm, 15 mm and 25 mm, 18 mm and 22 mm, 19.8 mm and 20 mm, or that may be about 20 mm. The foil disk  104  may have a thickness between the top face  106  and the bottom face  108  between about 0.01 mm and 1.0 mm, 0.05 mm and 0.5 mm, 0.1 mm and 0.2 mm, or that may be about 0.13 mm. In the case where a sensor is located adjacent the foil disk  104 , or between two layers of the foil disk  104 , the foil disk may have, in the region of the sensor, a thickness between the top face  106  and the bottom face  108  between about 0.02 mm and about 1 mm, 0.1 mm and 0.8 mm, 0.2 mm and 0.5 mm, or that may less than or equal to 0.5 mm. 
     While the test objects described in relation to  FIGS. 4 to 6  are substantially cylindrical (the disk  74  being a solid cylinder, the ring  86  being a hollowed cylinder and the foil disk being a very short solid cylinder), other shapes of test objects may be specified. Other test objects may include, for example, disks of different dimensions to represent various coins from different currencies. 
     The test objects may be arranged to thermally couple with sensor  73  so that the sensor can detect and measure the temperature of the test object. For example, in embodiments where the sensor  73  is a thermocouple, the side face of the test object may include a hole into which the sensing junction of a thermocouple may be inserted. The hole may be filled with a suitable thermally conductive compound, for example thermal paste. The depth and diameter of the hole may be specified in the relevant testing standard. In the case of the foil disk  104 , if there are multiple layers of foil the sensor may be placed between the layers of foil. A thermally conductive compound, for example thermal paste, may be provided between the layers of foil. 
       FIG. 7  shows a top view of a test object holder  70  according to an example embodiment. The test object is not shown. The test object holder  70  includes a body  120  which in the embodiment shown is generally elongate. The body  120  defines a space or aperture  122  therethrough. The aperture  122  is sized to receive to the test object (not shown in this figure). For example, the aperture  122  may be made larger than the test object such that the test object can be located within the aperture  122  without touching the body  120 . Alternatively, the aperture size may be approximately the same as, or slightly smaller than, the diameter of the test object to provide some contact between the test object and the test object holder  70 . The test object holder  70  of  FIG. 7  includes protrusions  130  that protrude inwardly from the edge of the aperture  122 . The protrusions  130  may assist centering of the test object in the aperture  122 . Various types and numbers of protrusions could be provided. For example, the holder  70  could include a single protrusion, or two or more protrusions spaced around the aperture edge. In the example of  FIG. 7 , there are three protrusions  130 . The protrusions in this example are sized to make contact with a test object to be located in the aperture  122 . In this example, the protrusions  130  are equally spaced around the edge of the aperture  122 . The protrusions  130  could be formed from the same material as the rest of the body  120  or from a different material. In this example, the protrusions  130  are the same material as the rest of the body  120 . The protrusions could be formed separately from, or integrally with, the rest of the body. In this example, the protrusions  130  are formed integrally with the rest of the body  120 . 
     The test object holder may also include a sheet configured to retain the test object in a desired position relative to the body during testing. The sheet may be an adhesive sheet that adheres to the test object during testing. An adhesive sheet may also adhere to the body of the test object holder. In  FIG. 7 , an adhesive sheet  128  is shown positioned over the aperture  122 . This may allow a test object to be placed within the aperture  122  and in contact with, and thereby adhered to, the adhesive sheet  128 . In this example, the adhesive sheet  128  is also placed over a channel  126  provided in the body  120  for a sensing element such as wires of a thermocouple, as described in more detail below. The adhesive sheet  128  can be in the form of adhesive tape. The adhesive sheet  128  may be formed of an electrically insulating material. This may prevent the induction of eddy currents in the adhesive sheet  128  during testing. This may also prevent current induced in the test object from flowing through the adhesive sheet  128 . These phenomena may otherwise reduce the reliability or accuracy of test results. 
     The adhesive sheet  128  should be able to withstand testing conditions. As test objects can heat up during testing, the adhesive sheet  128  may be formed of a heat-resistant material. The heat-resistant material may be configured to withstand temperatures of at least 70° C. The adhesive sheet  128  may be formed from a polymer material. Polymers may provide high strength and flexibility. One suitable class of polymers are polyimides. In the example of  FIG. 7 , the adhesive sheet  128  is formed from polyimide tape or Kapton tape. 
     The body  120  of the test object holder  70  may be formed of a relatively rigid or resilient material. This may help support the test object and retain the test object in desired position during testing. The body may be formed from an electrically non-conductive material. The body may be formed from a material with low magnetic permeability. For example, the body  120  could be formed of a composite material or a polymer material. The material could comprise glass fibers, which could be woven or non-woven. The body could comprise epoxy. In one example, the body  120  is formed from glass-reinforced epoxy or fiberglass. In one example, the body is formed from a circuit board substrate such as the material referred to as the National Electrical Manufacturers Association (NEMA) designation FR-4. In other examples, the body may be formed from wood; 3D-printer materials such as polyether ether ketone (PEEK); or phenolic board or phenolic paper or materials referred to as the NEMA designations CEM-1, CEM-2, CEM-3, CEM-4, CEM-5 or G-10. 
     The test object holder  70  may also include one or more indexing features. These may allow the holder  70  to be retained in one or more desired positions during testing. For example, in a testing system in which the test object holder is held in place by a clamp, the clamp may have one or more corresponding indexing features that engage with the indexing feature(s) of the holder. The indexing feature(s) may be one or more notches or holes formed in the body. In the test object holder  70  of  FIG. 7 , three indexing features  124  in the form of notches are provided in the body  120  at the end furthest from the aperture  122 . The indexing features  124  may be equally spaced from each other. 
     The test object holder  70  may also include a feature for receiving or retaining a part of a sensor. The part of the sensor may be retained on or in the test object holder  70 . For example, the sensor may include one or more wires that lie along a surface of the test object holder  70  or within a channel formed in the test object holder  70 . The part of the sensor may also be retained on or in the test object holder  70  by an adhesive sheet such as tape. In the example of  FIG. 7 , the body  120  of the test object holder  70  has a channel  126  for a wire of the sensor. The channel  126  in this example extends from an outer edge of the body  120  to an edge of the aperture  122 . Tape may also be applied over the channel  126  and the wire to retain the wire during testing. 
       FIG. 8  shows a cross-sectional view of a testing assembly  160  including the test object holder  70  of  FIG. 7 , the cross section being taken along line A-A of  FIG. 7 . In order to show the different elements clearly, certain dimensions in the figure have been exaggerated. In this figure, a test object is shown located in the aperture  122  and a sensor  132  is shown within a channel  126  in the body. In this example, the test object is the disk  74  of  FIG. 4 , although the holder  70  could be used with the test object of  FIG. 5  or another test object. As can be seen, the test object (in this example, disk  74 ) has a greater thickness than that of the body  120  of the test object holder. Specifically, the disk  74  has a first face (e.g. top face  76 ), a second face (e.g. bottom face  78 ), and a distance  84  between the first and second faces, referred to herein as the thickness. The body  120  of the test object holder  70  has a first face  134 , a second face  136  and a distance  138  between the first and second faces, referred to herein as the thickness. The thickness  84  of the disk  74  is greater than the thickness  138  of the body  120  of the test object holder  70 . This may allow the test object (in this case, disk  74 ) to be placed in close proximity to a test transmitting device and/or test receiving device during testing. The thickness  138  of the body  120  may be between about 0.05 and 2 mm, between about 0.2 and 1.5 mm, between about 0.6 and 1 mm, or may be about 0.8 mm. 
     In this example, the sensor is a thermocouple  132  that extends into a hole in the disk  74 . The thermocouple  132  is located within a channel  126  in the body  120  of the test object holder  70  and exits the channel  126  at the edge of the aperture  122 . The thermocouple  132  traverses part of the aperture  122  from the edge to the disk  74 . Providing the thermocouple  132  within the channel  126  may enable the total thickness of the test object holder  70  to be kept relatively low due to the thickness of the thermocouple  132  not contributing to the total thickness. In  FIG. 7 , tape  128  is provided over the test object (in this example, disk  74 ) in the region of the aperture  122  and over the channel  126  and thermocouple  132 . The tape (or other adhesive sheet)  128  may have a thickness between about 0.02 and 0.1 mm, 0.04 and 0.07 mm, or that may be about 0.05 mm. The combined thickness of the body  120  and the tape  128  may therefore be less than or equal to the thickness  84  of the disk  74 , and also less than the combined thickness of the disk  74  and tape  128 . 
       FIG. 9  shows an alternative example of the test object holder  70 . In this example, the test object holder  70  includes a body in the form of a first sheet  140 , a support frame  142  and a second sheet  128 . The first sheet  140  includes an aperture  144  in which a test object is to be placed during testing. The first sheet  140  may be formed from a heat-resistant material in order to withstand temperatures attained during testing with a test object. The first sheet  140  may be formed of a thermally insulating material. This may reduce conduction of heat away from the test object during testing, which may otherwise reduce the reliability or accuracy of test results. The first sheet  140  may be formed of an electrically insulating material. This may prevent the induction of eddy currents in the first sheet during testing. This may also prevent current induced in the test object from flowing through the first sheet  140 . These phenomena may otherwise reduce the reliability or accuracy of test results. The first sheet  140  may be formed from a natural, synthetic or semi-synthetic polymer. Suitable classes of polymers include polyesters and acetates. In one example, the first sheet  140  is formed from biaxially-oriented polyethylene terephthalate, sometimes marketed under the name Mylar. In other examples, the first sheet  140  may be formed from other polyethylene terephthalate (PET) materials. In another example, the first sheet  140  is formed from cellulose acetate. The thickness of the first sheet  140  may be between about 0.04 and 0.2 mm, 0.08 and 0.15 mm, or may be about 0.1 mm. 
     The frame  142  is provided at the edges of the first sheet  140 . The frame  142  supports the first sheet  140 . The frame  142  may be formed of a relatively rigid or resilient material. This may help support the first sheet  140  and test object during testing. For example, the frame  142  could be formed of a composite material or a polymer material. The material could comprise glass fibers, which could be woven or non-woven. The frame  142  could comprise epoxy. In one example, the frame  142  is formed from glass-reinforced epoxy or fiberglass. In one example, the frame  142  is formed from material used for circuit board substrates, such as the material referred to as the National Electrical Manufacturers Association (NEMA) designation FR-4. The thickness of the frame  142  may be between about 0.05 and 2 mm, between about 0.2 and 1.5 mm, between about 0.6 and 1 mm, or may be about 0.8 mm. 
     The second sheet is configured to retain the test object in place on the first sheet in the first sheet  140  during testing. In particular, it retains the test object in the aperture  144 . The sheet may be an adhesive sheet that adheres to the test object during testing. An adhesive sheet may also adhere to the first sheet  140  of the test object holder  70 . In  FIG. 9 , an adhesive sheet  128  is shown positioned over the aperture  144  in the first sheet  140  such as to retain a test object during testing. In this example, the adhesive sheet  128  is also placed over part of the first sheet  140  and part of the frame  142  to retain a sensing element such as wires of a thermocouple, as described in more detail below. The adhesive sheet  128  can be in the form of adhesive tape. The adhesive sheet  128  may be formed of an electrically insulating material. This may reduce the induction of eddy currents in the second sheet during testing. This may also reduce the flow of current induced in the test object through the adhesive sheet  128 . These phenomena may otherwise reduce the reliability or accuracy of test results. The adhesive sheet  128  may be the same tape discussed with reference to  FIGS. 7 and 8 . 
     The test object holder  70  of  FIG. 9  also includes indexing elements  124  as described with respect to the test object holder of  FIG. 7 . 
       FIG. 10  shows a cross-sectional view of a testing assembly  160  including the test object holder  70  of  FIG. 9 , the cross section being taken along line A-A of  FIG. 9 . In this figure, a test object is shown located adjacent the first sheet  140  and a sensor  132  is shown between two layers of the test object. In this example, the test object is the foil disk  104  of  FIG. 6 , but the test object holder  70  could be used with other test objects. In order to show the different elements clearly, certain dimensions in the figure have been exaggerated. In this example, the sensor is a thermocouple  132  that extends along the surface of the first sheet  140  to the foil disk  104 . In  FIG. 10 , the second sheet, in the form of adhesive tape  128 , is provided over the foil disk  104  and over the thermocouple  132 . Also visible in this figure are the frame  142  and one of the indexing notches  124 . 
     As can be seen in  FIG. 10 , the first sheet  140 , which forms the body of the test object holder  70 , has a thickness  146 . The test object has a thickness  150 . As can be seen in this example, the thickness of the test object (in this example, foil disk  104 ) is greater than the thickness of the first sheet  140 . In the case where the test object is the foil disk  104 , there may be a sensing junction of a thermocouple adjacent the foil disk  104  or between two layers of the foil disk  104 . In this scenario, the greatest thickness of the foil disk would be in the region of the thermocouple. 
       FIG. 11  shows an example of a testing system  170 . The testing system includes a test object holder  70  and a clamp  172  configured to hold the test object holder. This figure also shows a test object transmitting device  62 . The clamp  172  includes one or more indexing features  174  that cooperate with an indexing feature of the test object holder  70 . This may enable the test object holder  70  to be retained in one or more discrete positions during testing. By extension, this may enable the test object  68  to be retained in one or more discrete positions with respect to test devices such as the test transmitting device  62 . This may improve the repeatability and reproducibility of tests, as the test object holder  70  may easily and accurately placed in one of the discrete positions with respect to the clamp  172 , either manually by a human operator or by a machine. The indexing features  174  of the clamp  172  may include one or more pins or other protrusions. These would be arranged to cooperate with one or more notches, holes or recesses of the test object holder  70 . The indexing features  174  of the clamp  172  may include one or more holes, notches or other recesses. These would be arranged to cooperate with one or more pins or other protrusions of the test object holder  70 . For example, the test object holder  70  may include three notches as shown in  FIG. 7  or  FIG. 9 . The clamp may include a pin which, in use, is located in one of the notches of the test object holder  70 . This provides three different positions for the test object holder  70  relative to the clamp  172 . A handle or other grip may be provided on the test object holder  70  for gripping by a human operator or a machine. 
     The indexing features of the clamp and test object holder may facilitate use in an automated testing environment. The test object holder may be able to be quickly and accurately located in the clamp in the correct position because the discrete relative positions allowed by the indexing features may prevent, or at least reduce the likelihood of, the test object holder being placed in an incorrect position with respect to the clamp. 
     The foregoing is merely illustrative and various modifications can be made to the described embodiments. The foregoing embodiments may be implemented individually or in any combination, and elements from one embodiment may be combined with others.

Metadata:
Filing Date: 20190820
Publication Date: 20220906
Grant Date: 20220906
Priority Date: 20180822
Inventors: KAPOOR, Daman
ZHAO, Fei
Tamashiro, Matthew A
Dong, Jiahui J
LOUIS, JEFFREY DOUGLAS
PAAUWE, MICHAEL VICTOR
Zhang, Ryllian
Assignee: APPLE INC
CPC Classifications: [{"code": "G01K1/14", "inventive": true, "first": true, "tree": "[]"}, {"code": "H02J50/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/60", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01K7/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01K7/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01K13/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/60", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01D21/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01K1/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01K7/021", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01D11/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02J50/60", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01K1/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01K7/02", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 69586601