PATENT DOCUMENT

Publication Number: US-11867650-B2
Application Number: US-202117223674-A
Country: US
Kind Code: B2

Title: Enclosure detection for reliable optical failsafe

Abstract:
Optical component integrity monitoring circuitry monitors an optical component integrity sensing path in an optical component. If a rise in resistance of the sensing path is detected, the circuitry prevents the optical component from emitting light. The optical component may have a light-emitting device that emits light through an optical element. The sensing path may have a first path that is used to detect damage to the optical element and a second path that is coupled to a package covering the optical element and light-emitting device. The first path may have a segment formed from a metal trace on the optical element and a segment formed from a wire bond, providing mechanical compliance to tolerate strains expected in the use case. The second path ensures that the package is present to constrain movement of the optical element and its wires within a safe envelope defined by the package interior.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a housing; 
 a printed circuit in the housing; 
 an optical component coupled to the printed circuit, comprising:
 an optical element; 
 a laser configured to emit light through the optical element; 
 a package in which the optical element and laser are mounted; and 
 an optical element integrity sensor path having a first segment formed from a metal trace on the optical element and a separate second segment coupled between the printed circuit and the first segment; and 
 an optical component package integrity sensor path in the package that is connected in series with the optical element integrity sensor path. 
 
 
     
     
       2. The electronic device defined in  claim 1  further comprising control circuitry configured to monitor a resistance of the optical element integrity sensor path and the optical component package integrity sensor path. 
     
     
       3. The electronic device defined in  claim 2  wherein the optical element integrity sensor path is configured to increase in resistance in response to damage to the optical element. 
     
     
       4. The electronic device defined in  claim 3  wherein the optical component package integrity sensor path is configured to detect movement of the package relative to the printed circuit due to contact between the optical element and the package. 
     
     
       5. The electronic device defined in  claim 4  wherein the second segment comprises a wire bond. 
     
     
       6. The electronic device defined in  claim 5  wherein the optical component package integrity sensor path comprises a conductive structure that is connected to a contact on the printed circuit with solder. 
     
     
       7. The electronic device defined in  claim 6  wherein the package comprises polymer and wherein the conductive structure comprises a metal member that is embedded in the polymer. 
     
     
       8. The electronic device defined in  claim 7  wherein the optical element comprises a diffuser. 
     
     
       9. The electronic device defined in  claim 1  wherein the optical element comprises an optical element selected from the group consisting of: a diffuser, a grating, a layer with at least one lens, and a filter. 
     
     
       10. The electronic device defined in  claim 1  further comprising:
 a switch coupled in series with the laser; and 
 control circuitry configured coupled to the optical component package integrity sensing path and the optical element integrity sensing path and configured to open the switch in response to a detected resistance rise in a path formed from the optical component package integrity sensing path and the optical element integrity sensing path. 
 
     
     
       11. The electronic device defined in  claim 10  further comprising a display configured to emit light through a transparent portion of the housing, wherein the optical component is configured to emit the light through the transparent portion of the housing. 
     
     
       12. The electronic device defined in  claim 10  wherein the housing has a front and opposing rear, the electronic device further comprising a display at the front, wherein the optical component is configured to emit the light from the rear. 
     
     
       13. An electronic device, comprising:
 a housing; 
 a printed circuit in the housing; and 
 an optical component coupled to the printed circuit, comprising:
 an optical element having a metal trace forming a damage sensing resistor; 
 a laser configured to emit light through the optical element; 
 a wire bond connected between the damage sensing resistor and the printed circuit; and 
 a package having a conductive path that is electrically connected to the printed circuit with solder joints, wherein the conductive path, the damage sensing resistor, and the wire bond are connected in series to form an optical component integrity monitoring path. 
 
 
     
     
       14. The electronic device defined in  claim 13  further comprising optical component integrity monitoring circuitry configured to detect changes in resistance in the optical component integrity monitoring path. 
     
     
       15. The electronic device defined in  claim 14  further comprising a switch coupled in series with the laser, wherein the optical component integrity monitoring circuitry is configured to open the switch in response to detecting that the resistance of the optical component integrity monitoring path has risen. 
     
     
       16. The electronic device defined in  claim 15  wherein the optical element comprises a diffuser. 
     
     
       17. The electronic device defined in  claim 16  wherein the laser comprises an infrared laser diode. 
     
     
       18. The electronic device defined in  claim 16  further comprising a display covered by a transparent portion of the housing, wherein the optical component is an infrared flood illuminator that is configured to emit the light through the transparent portion of the housing. 
     
     
       19. An electronic device, comprising:
 an optical component having an optical element, a light-emitting device configured to emit light through the optical element, and a package; and 
 control circuitry configured to make resistance measurements on an optical component integrity path that includes a trace on the optical element, a wire bond, and a path that passes through the package. 
 
     
     
       20. The electronic device defined in  claim 19  further comprising a printed circuit, wherein the path that passes through the package is coupled to the printed circuit with solder joints.

Description:
FIELD 
     This relates generally to electronic devices, and, more particularly, to electronic devices with optical components. 
     BACKGROUND 
     Electronic devices such as tablet computers, cellular telephones, and other equipment are sometimes provided with optical components. These optical components may include light-emitting devices and corresponding optical elements sensors such as diffusers. To ensure that the optical components are operated within desired limits, failsafe mechanisms may be deployed. 
     SUMMARY 
     Electronic devices may have optical components. For example, a portable electronic device such as a cellular telephone, tablet computer, or other device may have an optical component that emits light. The optical component may have an optical element such as a diffuser or other optical element and may have a laser that emits light through the optical element. 
     The electronic device may have optical component integrity monitoring circuitry that monitors an optical component integrity sensing path in the optical component. If a rise in resistance of the sensing path is detected, the circuitry can prevent the optical component from emitting light. 
     The sensing path may have a first path that is used to detect damage to the optical element and a second path that is coupled to a package covering the optical element and light-emitting device to detect movement of the optical element. The first path may have a segment formed from a metal trace on the optical element and a segment formed from a wire bond. The second path may include solder joints. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic diagram of an illustrative electronic device in accordance with an embodiment. 
         FIG.  2    is a cross-sectional side view of an illustrative electronic device in accordance with an embodiment. 
         FIG.  3    is a side view of an illustrative optical component in accordance with an embodiment. 
         FIG.  4    is a perspective view of an illustrative optical component in accordance with an embodiment. 
         FIG.  5    is a cross-sectional side view of an illustrative optical component in accordance with an embodiment. 
         FIG.  6    is a side view of an illustrative optical component in accordance with an embodiment. 
         FIG.  7    is a cross-sectional side view of an illustrative optical component in which an optical element has moved and is contacting a package portion of the component in accordance with an embodiment. 
         FIG.  8    is a top view of an illustrative optical component illustrating how rotational movement of an optical element in the component will be detected by contact between the optical element and a package portion of the component in accordance with an embodiment. 
         FIG.  9    is a circuit diagram of illustrative optical component integrity monitoring circuitry in accordance with an embodiment. 
         FIGS.  10  and  11    are side views of illustrative optical components with integrity monitoring circuitry in accordance with an embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     A schematic diagram of an illustrative electronic device that may include one or more optical components is shown in  FIG.  1   . Electronic device  10  of  FIG.  1    may be a computing device such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wristwatch or other device worn on a user&#39;s wrist, a pendant device, a headphone or earpiece device, a head-mounted device such as eyeglasses, goggles, or other equipment worn on a user&#39;s head, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, equipment that implements the functionality of two or more of these devices, or other electronic equipment. Illustrative configurations in which device  10  is a portable device such as a cellular telephone or tablet computer of may sometimes be described herein as an example. 
     As shown in  FIG.  1   , electronic device  10  may have control circuitry  16 . Control circuitry  16  may include storage and processing circuitry for supporting the operation of device  10 . The storage and processing circuitry may include storage such as hard disk drive storage, nonvolatile memory (e.g., flash memory or other electrically-programmable-read-only memory configured to form a solid state drive), volatile memory (e.g., static or dynamic random-access-memory), etc. Processing circuitry in control circuitry  16  may be used to control the operation of device  10 . The processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, application specific integrated circuits, etc. Control circuitry  16  may include communications circuitry for supporting wired and/or wireless communications between device  10  and external equipment. For example, control circuitry  16  may include wireless communications circuitry such as cellular telephone communications circuitry and wireless local area network communications circuitry. 
     Input-output circuitry in device  10  such as input-output devices  12  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output devices  12  may include buttons, joysticks, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers, tone generators, haptic output devices, cameras, light-emitting diodes and other status indicators, data ports, etc. A user can control the operation of device  10  by supplying commands through input-output devices  12  and may receive status information and other output from device  10  using the output resources of input-output devices  12 . 
     Input-output devices  12  may include one or more displays such as display  14 . Display  14  may be an organic light-emitting diode display, a display formed from an array of crystalline semiconductor light-emitting diode dies, a liquid crystal display, or other display. Display  14  may be a touch screen display or a display that is insensitive to touch. 
     As shown in  FIG.  1   , input-output devices  12  may include sensors  18 . Sensors  18  may include capacitive sensors, light-based proximity sensors, magnetic sensors, accelerometers, force sensors, touch sensors, temperature sensors, pressure sensors, inertial measurement units, accelerometers, gyroscopes, compasses, microphones, radio-frequency sensors, three-dimensional image sensors (e.g., structured light sensors with light emitters such as infrared light emitters configured to emit structured light and corresponding infrared image sensors, three-dimensional sensors based on pairs of two-dimensional image sensors, etc.), cameras (e.g., visible light cameras and/or infrared light cameras with or without associated flood illuminators and/or flash systems), light-based position sensors (e.g., lidar sensors), monochrome and/or color ambient light sensors, and other sensors. Sensors  18  such as ambient light sensors, image sensors, optical proximity sensors, lidar sensors, optical touch sensors, and other sensors that use light and/or components that emit light such as status indicator lights and other light-emitting components may sometimes be referred to as optical components. If desired, sensors  18  may include integrity monitoring (failsafe) sensors. 
     A cross-sectional side view of an illustrative electronic device is shown in  FIG.  2   . As shown in  FIG.  2   , device  10  may include housing  22 . Housing  22 , which may sometimes be referred to as an enclosure or case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. In the example of  FIG.  2   , device  10  has a front F and an opposing rear R. Display  14  may be mounted at front F and may be covered by a transparent portion of housing  22  such as display cover layer  22 C. 
     As shown in the cross-sectional side view of device  10  of  FIG.  2   , housing  22  (including portion  22 C) may separate an interior region of device  10  such as interior region  30  from an exterior region surrounding device  10  such as exterior region  32 . Housing  22  may be formed using a unibody configuration in which some or all of housing  22  is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). If desired, a strap may be coupled to a main portion of housing  22  (e.g., in configurations in which device  10  is a wristwatch or head-mounted device). 
     Optical components  36  and/or other internal electrical components (e.g., integrated circuits, discrete components, light sources, light detectors, cameras, and other optical components, etc.) for forming control circuitry  16  and input-output devices  12  may be mounted in interior  30  of housing  22  (e.g., on one or more substrates such as printed circuit  38 ). In some configurations, components may be mounted in interior  30  adjacent to display  14  and/or adjacent to a rear housing wall portion of housing  22  at rear R. For example, one or more front-facing optical components such as component  36 F may be mounted under a portion of display cover layer  22 C and may be configured to operate in a front-facing arrangement and/or one or more rear-facing optical components such as component  36 R may be mounted under a transparent rear housing wall in housing  22 , under a rear-facing optical window, etc. Components such as optical components  36 F and  36 R may be formed in any suitable portion of device  10  and may be mounted to one or more printed circuits such as printed circuit  38 . The example of  FIG.  2    is illustrative. 
     Optical components  36  may include components that emit and/or detect light (see, e.g., light-based components in sensors  18 ), may include flood illuminators for image sensors and/or other sensors (e.g., flood illuminators that emit flood infrared illumination), may include gaze tracking sensors (e.g., light emitters that create glints for a gaze tracker), may include components that emit structured light (e.g., arrays of lasers covered with optical elements that split emitted beams into additional beams), may include optical proximity sensors that emit and detect infrared light, may include time-of-flight sensors, lidar sensors, and/or other optical components.  FIG.  3    is a cross-sectional side view of an illustrative optical component. As shown in  FIG.  3   , optical component  36  may include a light source such as light-emitting device  36 L and an optical element such as optical element  36 D. Device  36 L and element  36 D may be mounted in an enclosure such as optical component package  36 P. Package  36 P may be formed from polymer and/or other materials. 
     Light-emitting device  36 L may be, for example, a laser device having one or more semiconductor lasers (e.g., one or more vertical cavity surface-emitting lasers and/or other laser diodes). Optical element  36 D may be a diffractive optical element, a diffuser, a lens, a prism, a mirror, a lens array, a layer of meta lenses, a filter, and/or other optical element that reflects, focuses, diffuses, diffracts, refracts, and/or otherwise modifies light emitted by device  36 L. In an illustrative configuration, which may sometimes be described herein as an example, device  36 L is a laser and optical element  36 D is a diffuser (e.g., a laser and diffuser used together in providing infrared flood illumination for an infrared camera). In general, however, device  36 L may be any component that emits light and element  36 D may be any light-modifying optical structure. 
     To ensure eye safety for users of device  10 , optical component  36  is provided with redundant safety mechanisms. For example, component  36  may be powered by current limiting circuitry. This circuitry dynamically monitors the current flowing through laser  36 L and prevents excess current from flowing, thereby restricting the magnitude of emitted light from laser  36 L. Failsafe mechanisms based on failsafe resistors and/or other integrity monitoring signal paths are also incorporated into component  36  to ensure that physical damage to component  36  does not result in undesired operating modes. These failsafe features may, for example, detect whether optical element  36 D has become damaged or dislodged. 
     Damage to optical element  36 D may include cracking or chipping that results when device  10  is dropped or otherwise exposed to excessive stress by a user. A drop event or other excessive force event may also potentially dislodge element  36 D from support structures on which element  36 D has been mounted. To detect both of these types of potential damage, the failsafe mechanism of device  10  can incorporate multiple integrity sensing paths. These paths, which are sometimes called integrity paths, integrity sensing lines, integrity monitoring signal paths, sensing resistors, sense traces, sensing lines, sensors, etc., may include a first path (sometimes called an optical element integrity sensing path) that is used to detect damage to optical element  36 D such as chipping and/or cracking and a second path (sometimes called an optical component package integrity sensing path) that is used to detect whether package  36 P has been dislodged (e.g., due to contact with a dislodged optical element within package  36 P). 
     Optical integrity monitoring circuitry (e.g., circuitry forming some or all of an integrated circuit and/or other circuitry in control circuitry  16  of  FIG.  1   ) may be used to continually monitor the states of the first and second sensing paths. If the paths experience a change in resistance (e.g., if either or both of the paths becomes an open circuit or otherwise exhibits an increase resistance above a desired nominal value), current to component  36  can be blocked. 
       FIG.  4    is a perspective view of optical component  36  in an illustrative configuration in which package  36 P has the shape of a box with an outwardly facing opening  40 . Optical element  36 D may be mounted within the interior of package  36 P in alignment with opening  40 . During operation, device  36 L may emit light that passes through optical element  36 D and opening  40 . This light may exit device  10  through the front or rear of device  10  (see, e.g., components  36 F and  36 R of  FIG.  2   , as examples). 
     As shown in the cross-sectional side view of  FIG.  5   , package  36 P may have an open bottom. This allows package  36 P to serve as an enclosure that covers both element  36 D and device  36 L. Support structures  42  (e.g., posts, a ring-shaped member, and/or other supporting structures) may be used to support element  36 D on printed circuit  38 . Printed circuit  38  may be a rigid printed circuit, a flexible printed circuit (e.g., a printed circuit formed from a sheet of polyimide or other flexible polymer layer), or other printed circuit onto which circuitry in addition to component  36  is mounted and/or may be a printed circuit that is used to form part of component  36 . Support structures  42  may be attached at joints  44  (e.g., adhesive joints, welds, fastener joints, etc.). Device  36 L may be electrically and physically mounted to contacts  46  on printed circuit  38  using electrical connects  48  (e.g., solder joints). 
     Zig-zag thin-film metal traces and/or other integrity monitoring path(s)  36 DT- 1  may be formed on element  36 D. Path  36 DT-1 may, as an example, include thin metal lines that are nominally unbroken, but which will break when cracks or chips are present on element  36 D. This allows the state of path  36 DT- 1  to serve as part of a sensing path (sometime referred to as a failsafe resistor) that can detect whether element  36 D has been damaged. Path  36 DT- 1  may be connected to path(s)  36 DT- 2  at connections  54 . In an illustrative configuration, path  36 DT- 2  is a wire bond path and connections  54  are wire bonds. The wires of path  36 DT- 2  may be coupled to contacts  52  on printed circuit 38 (e.g., using wire bond connections). Together, path segment  36 DT- 1  and path segment  36 DT- 2 , which are coupled in series, form a first optical component integrity monitoring path. This first path is used to monitor for potential damage (chips, cracks, etc.) to element  36 D and may therefore be referred to as an optical element integrity sensing path or optical element damage sensing path. 
     During severe drop events and other undesired high-stress events, element  36 D may become dislodged from support structure  42  and may therefore move within package  36 P. Motion of element D could impact the alignment of element  36 D relative to device  36 L. The use of wires or other compliant failsafe structures can provide resilience against strains imposed during a drop event, but may allow motion of element  36 D. When package  36 P is present and intact, movement of device  36 D is constrained to be safe. To ensure satisfactory failsafe operation in the event that device  10  is dropped or otherwise causes element  36 D to move, movement may be monitored using a second optical component integrity monitoring path. This second path detects when element  36 D moves sufficiently to contact adjacent portions of package  36 P and thereby dislodge package  36 P from printed circuit  38 . In particular, package  36 P may have a metal member or other structure (e.g., a metal trace, etc.) that forms optical component package integrity sensing path  36 PT. Path  36 PT may be electrically and physically coupled to printed circuit  38  using connections  56 . Connections  56  may be, for example, solder joints that couple terminals at two opposing ends of path  36 PT to respective contacts  50  on printed circuit  38 .  FIG.  6    is a side view of component  36  of  FIG.  5    viewed along the X axis of  FIG.  5   . As shown in  FIG.  6   , path  36 PT may be formed from a conductive metal member that is insert molded within a polymer material forming package  36 P. The ends of the metal member may be electrically connected to contacts  50  on printed circuit  38  using solder joints (connections  56 ). 
     The first and second sensing paths in this type of arrangement have different characteristics. 
     The relatively long lengths of wire bond path  36 DT- 2  in the first sensing path make the wire bond portions of the first sensing paths compliant (e.g., the wire bonds may have slack that allows the wire bonds to bend and expand slightly due to movement of element  36 D without failing). As a result, paths  36 DT- 2  allow element  36 D to move somewhat without prematurely forming open circuits. The use of wire bonds or other compliant electrical connections in forming electrical connections between contacts  52  and path  36 DT- 1  on optical element  36 D therefore helps to enhance reliability when monitoring for damage in optical element  36 D using path  36 DT- 1  on element  36 D. 
     With the second sensing path, the metal member of path  36 PT is coupled to contacts  50  using solder joints  56 . Solder joints (e.g., solder joints of about 25-80 microns in thickness) are relatively brittle and are therefore less compliant than wire bonds. As a result, joints  56  will not exhibit significant slack. It may take significant force from element  36 D contacting package  36 P to break solder joints  56 . But while joints  56  may withstand considerable force, the non-compliant nature of joints  56  will ensure that joints  56  fail before allowing package  36 P to move enough that it no longer constrains the motion envelope of element  36 D. 
     As shown in  FIG.  7   , for example, if element  36 D becomes dislodged from support structures  42  and tilts upwards, element  36 D will span the nominal gap between element  36 D and the facing inner surface of package  36 P and will therefore contact package  36 P. So long as solder joints  56  are intact, package  36 P will constrain undesired further motion of package  36 P to ensure safety. In the event that excessive force is applied by element  36 D to package  36 P, joints  56  will fail and package  36 P will become dislodged from printed circuit  38 . The use of a brittle (less compliant) path design for the second sensing path helps ensure that element  36 D is not able to move excessively without detection. As shown in the top view of component  36  of  FIG.  8   , the inner surface of package  36 P may, if desired, be configured to permit a finite amount of rotational motion of element  36 D relative to printed circuit  38  before package  36 P is dislodged. 
     The size of the gaps between element  36 D and package  36 P can be configured to establish a desired permitted amount of movement (e.g., tilting, shifting, and/or rotation) in element  36 D relative to printed circuit  38 . Further movement of element  36 D after element  36 D contacts package  36 P is constrained by package  36 P and joints  56 , which hold package  36 P in place on printed circuit  38 . In the event that solder joints  56  are overstressed and package  36 P begins to move, joints  56  will open and this open circuit will be detected. If, as an example, the gaps between element  36 D and package  36 P are small, the second sensing path will be sensitive to movement of element  36 D beyond this relatively small distance. On the other hand, if the gaps are larger, the second sensing path will permit more movement of element  36 D. As one example, the minimum distance between element  36 D and package  36 P may be set to a value between 50 and 200 microns. In general, the gaps may be at least 20 microns, at least 50 microns, at least 100 microns, at least 300 microns, less than 500 microns, less than 250 microns, less than 150 microns, or other suitable size. 
     The strength with which path  36 PT is embedded within package  36 P must exceed the strength of joints  56 , ensuring that any movement of package  36 P will break the circuit. 
       FIG.  9    is a circuit diagram showing how control circuitry  16  may include optical component integrity monitoring circuitry that monitors for damage to element  36 D and that monitors for movement of element  36 D. Power source  70  may be a battery and/or other source of power and may optionally include current limiting circuitry to enhance safety (e.g., circuitry to help limit the maximum current through device  36 L and thereby limit the maximum power of the light beam emitted from device  36 L). If desired, source  70  may open switch  72  or take other action to prevent excessive light emission from device  36 L in response to detecting more than a desired amount of current flow through device  26 L. 
     During normal operation, switch  72  is closed and current flows through device  36 L from power source  70  so that device  36 L emits light. Control circuitry such as resistance monitoring circuitry  74  measures the optical component integrity sensor paths such as the first path associated with the trace on optical element  36 D and the second path associated with package  36 P. The first path includes a first path segment  36 DT- 1  formed from metal traces on element  36 D that form a failsafe resistor that can detect cracks or other damage to element  36 D and includes a second path segment  36 DT- 2  formed from compliant signal lines such as wire bonds to help ensure a reliable connection to the first path segment. The use of the compliant path segment in the first path helps ensure that optical element damage monitoring can be performed reliably without premature detections due to small permissible amounts of movement of element  36 D. The second path  36 PT monitors whether package  36 P has become dislodged from printed circuit  38  due to excessive movement of element  36 D (e.g., movement exceeding the gap-related threshold amount of movement), thereby ensuring that undesired movement of element  36 D is detected (e.g., so that excessive movement of element  36 D will be detected even though such movement might not cause the compliant wire bonds of the second path segment  36 DT- 2  to break). 
     The resistances of first and second paths may be measured separately or, as shown in  FIG.  9   , the first and second paths may be connected in series, thereby allowing circuitry  74  to monitor the total resistance of both paths simultaneously. If an open circuit or other unexpected rise in resistance becomes present in either the first or the second path, the entire combined series-connected first and second paths will also experience an open circuit or unexpected resistance rise that can be detected by circuitry  74 . In response to detecting an open circuit or other abnormal increase in resistance (e.g., an increase in resistance above a threshold or other resistance change indicative of a fault), circuitry  74  can apply a control signal to switch  72  that causes switch  72  to open and thereby block current flow to device  36 L. In this way, light output from device  36 L may be blocked in response to detection of a fault in optical component  36 . 
     If desired, the first and second paths may be formed using other types of integrity monitoring paths.  FIG.  10    shows an illustrative arrangement in which support structures  42  include conductive structures  80  (e.g., metal members, thin-film coatings, wires, metal traces formed using laser-direct structuring, and/or other suitable conductive paths). Conductive structures  80  form vertical conductive paths through support structures  42 . At the lower end each of structures  80 , a solder connection  82  is formed with a mating contact pad on printed circuit  38 . If desired, solder connections between signal paths in support  42  and board  38  may be used to detect movement of support  42 . At the upper end of each of structures  80 , a wire bond connection is formed with a respective wire bond  84 . The other ends of wire bonds  84  are connected to the terminals of the integrity sensing path formed from thin-film metal trace  86  on optical element  36 D. With this arrangement, wire bonds  84  may be shorter than the wire bonds of paths  36 DT- 2  of  FIG.  4   , thereby ensuring that wire bonds  84  will be sufficiently sensitive to movement of element  36 D. At the same time, wire bonds  84  are more compliant than brittle solder connections, which can help enhance the reliability of the sensing operations performed using trace  86  (e.g., so that cracks, chips, and other damage in element  36 D can be detected without risk of premature failure of the electrical connection to trace  86  from small permitted movements in element  36 D). 
     In the example of  FIG.  11   , two short sets of wire bonds  80 ′ and  84  are used to couple the circuitry of printed circuit  38  to trace  86 . As with the illustrative arrangement of  FIG.  9   , the relatively short length of wire bonds  84  may help to ensure satisfactory detection of undesired amounts of movement of element  36 D with respect to printed circuit  38  while the compliance of wire bonds  84  ensures satisfactory reliability of the connection with trace  86 . 
     In general, wire bonds in the optical component integrity monitoring circuit paths of component  36  may have any suitable length (e.g., 750 microns, at least 200 microns, at least 500 microns, less than 1.5 mm, less than 1 mm, less than 600 microns, less than 300 microns, etc.). 
     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. 
     
       
         
           
               
             
               
                   
               
               
                 Table of Reference Numerals 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                 10 
                 Electronic device 
               
               
                 12 
                 Input-output devices 
               
               
                 14 
                 Display 
               
               
                 18 
                 Sensors 
               
               
                 16 
                 Control circuitry 
               
               
                 22 
                 Housing 
               
               
                      22C 
                 Display cover layer 
               
               
                 R 
                 Rear 
               
               
                 F 
                 Front 
               
               
                 36 
                 Components 
               
               
                 38 
                 Printed circuit 
               
               
                 30 
                 Interior 
               
               
                 32 
                 Exterior 
               
               
                 36, 36F, 36R 
                 Components 
               
               
                 40 
                 Opening 
               
               
                  36P 
                 Package 
               
               
                 36DT-1, 
                 Paths 
               
               
                 36DT-2, 
               
               
                 36PT 
               
               
                 56, 44, 48, 54 
                 Connections 
               
               
                 50, 52, 46 
                 Contacts 
               
               
                 42 
                 Support structure 
               
               
                 70 
                 Power source 
               
               
                 72 
                 Switch 
               
               
                 74 
                 Circuitry 
               
               
                 80′, 84 
                 Wire bonds 
               
               
                 80 
                 Conductive structures 
               
               
                 82 
                 Connections 
               
               
                 86 
                 Trace

Metadata:
Filing Date: 20210406
Publication Date: 20240109
Grant Date: 20240109
Priority Date: 20210406
Inventors: MCCORD, MICHAEL K.
MO, STACY H.
Assignee: APPLE INC
CPC Classifications: [{"code": "G01N27/041", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01N27/045", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01R31/2635", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01R31/2635", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01N27/041", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01N27/045", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01R31/2635", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 83449613