PATENT DOCUMENT

Publication Number: US-10870261-B2
Application Number: US-201715803481-A
Country: US
Kind Code: B2

Title: Structured glass for an electronic device

Abstract:
An electronic device can include a three-dimensional glass feature. In one embodiment, the three-dimensional glass feature is a cavity formed on the inside portion of a cover glass of an electronic device.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a glass structure defining:
 a first glass surface; 
 a second glass surface that is opposite the first glass surface; 
 a cavity formed into the second glass surface in a region of the glass structure having a first thickness, the cavity defined by:
 a stepped region having a second thickness that is less than the first thickness and defined by a third glass surface; and 
 a bottom region having a third thickness that is less than the second thickness and defined by a fourth glass surface; 
 
 
 an enclosure coupled to the glass structure; 
 a processing unit within the enclosure; and 
 a camera operationally connected to the processing unit and extending at least partially into the cavity; wherein: 
 the first glass surface defines a portion of an exterior of the electronic device. 
 
     
     
       2. The electronic device of  claim 1 , wherein:
 the cavity defines an optical lens; 
 the glass structure defines:
 a first portion having a first index of refraction; and 
 a second portion having a second index of refraction; and 
 
 the glass structure is a cover glass of the electronic device. 
 
     
     
       3. The electronic device of  claim 1 , wherein:
 the glass structure is a monolithic glass structure formed by fusing a first glass layer to a second glass layer. 
 
     
     
       4. The electronic device of  claim 1 , wherein:
 the cavity is positioned over a logo; and 
 the cavity optically magnifies the logo. 
 
     
     
       5. The electronic device of  claim 1 , wherein:
 the cavity is a first cavity; and 
 the glass structure further defines:
 a second cavity; and 
 a structural rib separating the first cavity from the second cavity. 
 
 
     
     
       6. A method of manufacturing a glass structure of an electronic device, comprising:
 placing a set of glass layers; 
 fusing the set of glass layers to form a monolithic glass structure defining:
 a first glass surface; and 
 a second glass surface that is opposite the first glass surface, the monolithic glass structure forming a cover glass for an electronic device; 
 
 forming a cavity in a region of the monolithic glass structure having a first thickness, the cavity defined by:
 a stepped region having a second thickness that is less than the first thickness and defined by a third glass surface; and 
 a bottom region having a third thickness that is less than the second thickness and defined by a fourth glass surface. 
 
 
     
     
       7. The method of  claim 6 , further comprising pre-stressing the set of glass layers before the operation of forming the cavity. 
     
     
       8. The method of  claim 6 , wherein forming the cavity occurs after fusing the set of glass layers. 
     
     
       9. The method of  claim 6 , wherein the cavity is formed by chemical etching. 
     
     
       10. The method of  claim 6 , further comprising applying an optical coating to a perimeter of the monolithic glass structure. 
     
     
       11. The method of  claim 6 , wherein the cavity forms a logo. 
     
     
       12. The method of  claim 6 , further comprising applying a sealant to a surface of the cavity. 
     
     
       13. The method of  claim 6 , wherein the set of glass layers are of differing sizes. 
     
     
       14. The electronic device of  claim 5 , wherein the structural rib protrudes beyond the second glass surface of the glass structure. 
     
     
       15. The electronic device of  claim 1 , further comprising a mask layer on the third glass surface. 
     
     
       16. The electronic device of  claim 15 , wherein the mask layer is an opaque mask layer. 
     
     
       17. The electronic device of  claim 1 , wherein the glass structure is a front cover of the electronic device. 
     
     
       18. The electronic device of  claim 6 , wherein the structural rib has a fourth thickness that is greater than the first thickness. 
     
     
       19. The electronic device of  claim 1 , wherein the electronic device is a mobile phone.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a nonprovisional patent application of and claims the benefit of U.S. Provisional Patent Application No. 62/417,989, filed Nov. 4, 2016 and titled “Structured Glass for an Electronic Device,” the disclosure of which is hereby incorporated herein by reference in its entirety. 
    
    
     FIELD 
     The described embodiments relate generally to electronic devices. More particularly, the present embodiments relate to structured glass in electronic devices. Still more particularly, the present invention relates to three-dimensional structured glass as a component or feature included in an electronic device. 
     BACKGROUND 
     Many electronic devices, such as smart telephones, laptop computers, and tablet computing devices include a glass element or a glass portion. The glass may be used in a variety of ways, to include screens and coverings. Conventional glass applications in electronic devices have a flat interior cross-section and have been functionally limited by traditional manufacturing techniques and by conventional glass geometries. 
     The cover glass used in many electronic devices is illustrative of limitations imposed by typical glass geometries. Most cover glasses are planar sheets of glass and provide no internally-facing functionalities. That is, while the externally-facing cover glass commonly provides a touch-screen interface, the internal surface presents a restrictive planar design constraint for internal device electronics. However, a cover glass that provides a structured glass feature on the internally-facing portion reduces design constraints and may provide unique functionalities. For example, a three-dimensional lens may be formed on the internally-facing cover glass disposed over a camera, thereby providing an enhanced feature for the electronic device. 
     SUMMARY 
     In one aspect, a glass device configured for use with an electronic device is disclosed, the glass device comprising: a first surface; a second surface disposed opposite the first surface, the first and the second surfaces defining a first thickness; and a structured glass feature forming a cavity within the first thickness, the cavity having a perimeter on the second surface and an interior cavity surface; wherein the second surface faces an interior of the electronic device; wherein at least a portion of the interior cavity surface is optically masked. 
     In another aspect, the optically masked portion comprises the perimeter. In another aspect, the electronic device as in claim  14 , wherein the glass device comprises a set of fused glass layers comprising a first layer with a first index of refraction and a second layer with a second index of refraction. In another aspect, at least a portion of the optically-masked portion is engaged with an optical coating. In another aspect, the glass device is a cover glass of the electronic device. In another aspect, the electronic device comprises a portable telephone. In another aspect, the cover glass comprises sapphire. 
     In one aspect, a method of manufacturing a glass device for use with an electronic device is disclosed, the method comprising: obtaining a glass layer with a first thickness; fixturing the glass layer; removing a portion of the glass layer to form a structured glass feature within the first thickness, the structured glass feature having a perimeter and a surface extending from the perimeter; and optically masking the perimeter wherein the perimeter is not visible to a naked eye. 
     In another aspect, the fixturing operation provides a guide to forming the structured glass feature during the operation of removing the portion of the glass layer. In another aspect, the method further comprises polishing the surface after the operation of removing the portion of the glass layer. In another aspect, the method further comprises pre-stressing the glass layer before the operation of removing the portion of the glass layer. In another aspect, the operation of removing the portion of the glass layer includes at least one of machining, etching, or lasering. In another aspect, the operation of optically masking the perimeter comprises application of an optical coating to the perimeter. In another aspect, the structured glass feature is an optical lens. In another aspect, the optical lens is configured for use with a camera of the electronic device. In another aspect, the method further comprises: pre-stressing the glass layer before the operation of removing the portion of the glass layer; and polishing the surface after the operation of removing the portion of the glass layer; wherein: the glass device is a sapphire cover glass of the electronic device; and the structured glass feature is an optical lens. 
     In one aspect, a method of manufacturing a cover glass for use with an electronic device is disclosed, the method comprising: obtaining a first glass layer with a first thickness; obtaining a second glass layer with a second thickness and an aperture formed within an interior of the second glass layer, the aperture defining a perimeter; coupling the first glass layer with the second glass layer; and fusing the first and the second glass layers to form a single monolithic structure; wherein the single monolithic structure includes a structured glass feature comprising the perimeter. 
     In another aspect, the method further comprises optically masking at least a portion of a surface extending from the perimeter. In another aspect, the method further comprises polishing a surface extending from the perimeter. In another aspect, the operation of fusing the first and the second glass layers includes at least one of heat fusion and pressure fusion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention are better understood with reference to the following drawings. The elements of the drawings are not necessarily to scale relative to each other. Identical reference numerals have been used, where possible, to designate identical features that are common to the figures. 
         FIG. 1A  illustrates a front view of one example of an electronic device with example features including cameras, a home button, a logo, vertical edge cuts and a toothed linear hinge; 
         FIG. 1B  depicts a rear view of the electronic device shown in  FIG. 1A ; 
         FIG. 1C  depicts a side view of the electronic device shown in  FIG. 1A ; 
         FIG. 2A  is a sample cross-section view of the electronic device of  FIGS. 1A and 1B , taken along line A-A in  FIG. 1A  and showing one embodiment of a structured glass feature disposed over a camera; 
         FIG. 2B  is a sample cross-section view of the electronic device of  FIGS. 1A and 1B , taken along line A-A in  FIG. 1A  and showing another embodiment of the structured glass feature disposed over a camera; 
         FIG. 3A  is a sample cross-section view of the electronic device of  FIGS. 1A and 1B , taken along line B-B in  FIG. 1A  and showing one embodiment of a structured glass feature disposed over two cameras; 
         FIG. 3B  is a sample cross-section view of the electronic device of  FIGS. 1A and 1B , taken along line B-B in  FIG. 1A  and showing one embodiment of a three-dimensional rib feature disposed between two cameras with a pair of structured glass features disposed over each camera; 
         FIG. 4  is a sample cross-section view of the electronic device of  FIGS. 1A and 1B , taken along line A-A in  FIG. 1A  and showing one embodiment of a three-dimensional lens feature; 
         FIG. 5  is a sample cross-section view of the electronic device of  FIGS. 1A and 1B , taken along line C-C in  FIG. 1A  and showing one embodiment of a three-dimensional input/output cavity feature; 
         FIG. 6  is a sample cross-section view of the electronic device of  FIGS. 1A and 1B , taken along line D-D in  FIG. 1A  and showing one embodiment of a three-dimensional logo cavity feature; 
         FIG. 7  is a sample cross-section view of a portion of the electronic device of  FIGS. 1A and 1B , taken along line E-E in  FIG. 1A  and showing one embodiment of a three-dimensional hinge feature; 
         FIG. 8A  is a sample detail view A-A of the electronic device of  FIGS. 1A and 1B  and showing one embodiment of a three-dimensional retention feature; 
         FIG. 8B  is a sample detail view A-A of the electronic device of  FIGS. 1A and 1B  and showing another embodiment of the three-dimensional retention feature; 
         FIG. 9  is a sample process for manufacturing a structured glass feature in a glass layer; 
         FIG. 10  is another sample process for manufacturing a structured glass feature in a glass layer; and 
         FIG. 11  depicts example components of an electronic device in accordance with the embodiments described herein. 
     
    
    
     DETAILED DESCRIPTION 
     Structured glass, meaning glass formed to provide structured glass features, enables novel and unique geometries and features when used in electronic devices. For example, a structured glass may allow more efficient use of interior space, increase operating efficiencies of electronic components, and enable new optical features and mechanical functions. 
     Generally, embodiments described herein may take the form of an electronic device incorporating a glass structure defining structured glass features. Typical glass structures for computing devices, such as cover glasses, input surfaces, buttons, and the like, are generally planar. This is especially true with respect to an interior surface of a glass structure, e.g., the portion of the glass structure facing an interior of an electronic device. Embodiments may include and/or create structured glass features on or in glass structures, and particularly interior surfaces of glass structures, to enhance functionality of the glass structure and/or associated electronic devices. 
     A “structured glass feature,” as used herein, is a three-dimensional structure formed in a glass substrate. The structured glass feature may extend from the glass substrate, as in the examples of a protrusion, boss, convex lens, raised logo or image, and the like. Alternatively, a structured glass feature may extend into the glass substrate, as in the examples of a concave lens, a recess, aperture, receptacle, or the like. The glass substrate may be formed from multiple layers that are bonded to one another. In some embodiments, the structured glass feature may be formed on, in, or by some, but not all, of the layers; in other embodiments, all layers may cooperate to form the structured glass feature. 
     As one example, a structured glass feature may be formed in a glass structure to provide additional space for a component of an electronic device. The structured glass feature may be a recess (or other type of aperture) sized or otherwise configured to accept the component or a portion of the component. The recess may be formed to minimize or eliminate undesirable optical effects, such as transitions between the recess portion and the nominal portions of the glass. 
     As another example, a structured glass feature may be formed in a glass structure to provide increased structural support and construct varied structural framing. A three-dimensional glass portion may form a structural rib within an electronic device to increase stiffness along a specified axis. More comprehensively, a glass structure may include framing components such as trusses to provide defined structural properties, such as stiffness, along identified glass portions. 
     As another example, a structured glass feature may be formed in a glass structure to provide an integrated lens in optical communication with a device component. The lens may be formed in a glass structure disposed above a camera to alter the nominal focal plane of the camera. 
     As another example, a structured glass feature may be formed in a glass structure to provide for increased device sensor functionality or increased efficiency. The structured glass feature may form a cavity to reduce the distance between an interior sensor, such as a capacitive-based sensor, and an exterior input, such as a user touch. 
     As another example, a structured glass feature may be formed in a glass structure to provide optical enhancement to an embedded interior logo. For example, the structured glass feature may optically magnify the logo. The glass structure may form an interior cavity to house a three-dimensional logo, or form a cavity with optical properties so as to present a planar logo as a dimensioned logo, or provide a logo with several material properties to create a unique visual appearance to a user. 
     As another example, a structured glass feature may be formed in a glass structure to create a mechanical hinge, flexure, or controlled break point. The glass structure may form a linear (or other) sequence of trenches or cuts separated by an elastic material such that the glass structure may bend along an identified axis. 
     As another example, a structured glass feature may be formed in a glass structure as a sequence of vertical cuts in the glass edge which provide increased adhesion to (or mechanical interlocking with) adjacent components. The vertical cuts enable additional volume of adhesive to reside along contact surfaces between the glass and a surface such as a device frame, thereby increasing bonding strength. 
     A structured glass feature may be formed in a glass structure in any of several ways. As one example, a glass layer may be obtained and fixtured. A structured glass feature, such as a three-dimensional cavity, may be formed into the glass layer. A portion of the structured glass feature may then be optically coated to optically mask at least a portion of the structured glass feature, such as a perimeter surrounding the structured glass feature and/or a sidewall defining a portion of the structured glass feature. 
     As another example, a structured glass feature may be formed by combining two or more glass layers. A first and a second substrate may be obtained. A structured glass feature, such as an aperture, is formed into the second substrate. The first and the second substrate are then coupled and fused together, forming a single monolithic structure. In some embodiments, the first and second substrates (such as two glass layers) may be of different sizes, such that a first portion of the first substrate is fused to the second substrate while a second portion is not. The aperture may be optically coated to optically mask at least a portion of the aperture, such as a perimeter surrounding the aperture and/or sidewall defining the aperture. The perimeter may form a boundary of a surface of the structured glass feature. 
     “Monolithic,” as used herein, refers to a structure, set of layers, or the like that are fused together such that material of adjacent layers or pieces intermingle with one another. A “monolithic” structure or element need not lack any physical indication of the separate layers, elements, or pieces from which it is constructed; some monolithic structures may have melt zones, fusing zones, or the like between layers. (Some monolithic structures may lack any such indication to the unaided eye, however.) Rather, monolithic structures formed from separate layers, pieces, or elements have intermingled materials between such layers, pieces, or elements such that their edges (or other portions abutting one another) are not separate. 
     These and other embodiments are discussed below with reference to  FIGS. 1-10 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting. 
       FIGS. 1A-1C  show front, rearm and side views, respectively of one example of an electronic device  100 . The electronic device  100  may include features such as one or more cameras, a home button, a logo, vertical edge cuts and a toothed linear hinge. These features are only example features and some or all may be omitted and/or reside in other locations. Other features are possible. The electronic device  100  includes a first camera  102 , a second camera  104 , a third camera  106 , a fourth camera  108 , an enclosure  110 , an input/output (I/O) member  112 , a display  114 , a light source for the camera or cameras  116 , logo  118 , toothed hinge  120 , and speaker or microphone  122 . The electronic device  100  can also include one or more internal components (not shown) typical of a computing or electronic device, such as, for example, one or more processing units, memory components, network interfaces, and so on. 
     In the illustrated embodiment, a cover glass  124  is disposed over display  114  of the electronic device  100 . The cover glass  124  can be made of any suitable material, including, but not limited to, glass, plastic, acrylic, sapphire, and various combinations thereof. One or more portions of the cover glass  124  can define an input region for a touch sensing device and/or a force sensing device. The cover glass  124  can include one or thinner regions or portions spanning particular components, such as spanning one or more of the cameras, the speaker and/or a microphone  122 , the logo  118  and the I/O member  112 . More specifically, a structured glass feature may be formed within the cover glass  124  to provide additional space for a component of an electronic device, such as one or more cameras. Such a structured glass feature is discussed in more detail below with respect to  FIGS. 2 and 3 . The cover glass  124  may also be configured to include one or more thicker regions or portions. For example, the cover glass  124  may form one or more structural ribs. Such a three-dimensional structural feature is discussed in more detail below with respect to  FIG. 3B . 
     In the illustrated embodiment, the cover glass  124  is positioned over the entire front surface of the electronic device  100 . Thus, the cover glass  124  is disposed over the display, the first camera  102 , the second camera  104 , the third camera  106 , and the enclosure  110 . In other embodiments, a cover glass  124 ′ can be disposed over, or form, one or more portions of other surfaces of the electronic device, such as a top case of the electronic device  100 . 
     As shown in  FIGS. 1A-1C , the electronic device  100  is implemented as a mobile telephone. Other embodiments, however, are not limited to this type of electronic device. Other types of computing or electronic devices include a laptop computer, desktop computer, netbook, a phone, a tablet computing device, a wearable computing or display device such as a watch or glasses, a digital camera, a printer, a scanner, a video recorder, a desktop computer, server, touchscreen, a copier, and so on. 
     The enclosure  128  can form an outer surface or partial outer surface and protective case for the internal components of the electronic device  100 , and may at least partially surround the display  114 . The enclosure  128  can be formed of one or more components operably connected together, such as a front piece and a back piece. Alternatively, the enclosure  128  can be formed of a single piece operably connected to the display  114 . 
     The I/O member  112  can be implemented with any type of input or output member. By way of example only, the I/O member  112  can be a switch, a button, a capacitive sensor, or other input mechanism. The I/O member  112  allows a user to interact with the electronic device  100 . For example, the I/O member  112  may be a button or switch to alter the volume, return to a home screen, and the like. The electronic device can include one or more input members or output members, and any or each member can have a single I/O function or multiple I/O functions. In one embodiment, the cover glass  124  is shaped above the I/O member to provide a reduced thickness between an external input (such as a user touch) and an internal device sensor, thereby increasing sensor performance. Such an embodiment is discussed in greater detail below with respect to  FIG. 5 . 
     The cover glass  124  of  FIGS. 1A-B  may additionally or alternatively be configured to provide vertical edge cuts, a toothed linear hinge and/or a three-dimensional logo cavity feature. The vertical edge cuts, which may enhance coupling or adhesion of the cover glass to the device enclosure, is detailed below with respect to  FIG. 8 . The toothed hinge feature, which may allow controlled bending of the cover glass, is described below with respect to  FIG. 7 . And the three-dimensional logo cavity feature, which may provide a holographic presentation of a logo, is described below with respect to  FIG. 6 . 
     The display  114  can be operably or communicatively connected to the electronic device  100 . The display  114  can be implemented with any type of suitable display, such as a retina display or an active matrix color liquid crystal display. The display  114  can provide a visual output for the electronic device  100  or function to receive user inputs to the electronic device. For example, the display  114  can be a multi-touch capacitive sensing touchscreen that can detect one or more user touch and/or force inputs. 
       FIGS. 2A-B  are sample cross-section views of the electronic device  100  of  FIGS. 1A and 1B , taken along line A-A in  FIG. 1A  and showing embodiments of a structured glass feature  201  forming a cavity disposed over a camera. As shown in  FIG. 2A , a cover glass  200  is disposed over a substrate  240  of the electronic device  100 . The structured glass feature  201  may be of any geometry and configuration. The cover glass  200  can be made of any suitable material such as sapphire, glass, plastic, and various combinations of materials. 
     The cover glass  200  has an upper or externally facing or first surface  231  and a lower or internally facing or second surface  233 . The second surface  233  is opposite the first surface  231 . The first surface  231  and the second surface  233  define a nominal thickness T 1  of the cover glass  200 . The cover glass  200  has a thinned region  202  with a thickness T 2 , as compared to a remainder  206  of the cover glass  200 , which has a thickness T 1 . Generally and as shown, thickness T 1  is greater than thickness T 2 . The second surface  233  of the cover glass  200  forms an interior cavity surface  237 . The interior cavity surface  237  has a portion parallel with the first surface  231  that defines a thickness T 2  of cover glass  200 . The interior cavity surface  237  has a perimeter  235  that bounds the thinned region  200  and region  204  (e.g., a surface of the structured glass feature). A sidewall extends from the perimeter and defines an edge of the aperture. 
     In one embodiment of the structured glass feature  201 , cover glass  200  transitions between thickness T 2  of region  202  to thickness T 1  of other areas of the cover glass  200  by way of region  204 . Region  204  is defined by radius R 1  and radius R 2 ; these radiuses, taken together, define a sidewall. Sidewall region  204  begins from, and is bounded by, perimeter  235 . Radius R 1  begins from the perimeter  235  of the second surface  233  of the cover glass  200 . Radius R 2  begins from a cover glass  200  portion of thickness T 2 . Radius R 1  and radius R 2  intersect tangentially. Radius R 1  and radius R 2  cooperate to form transition region of the interior cavity surface  237 , bounded by the perimeter  235 . In one embodiment, the sidewall or transition region  204  is a cover glass  200  defined by only one of R 1  or R 2 , such that one end point of sidewall region  204  forms a step and the other forms a curve. In another embodiment, the sidewall region  204  includes a vertical portion connecting to (and/or terminating at) either of cover glass portion of thickness T 1  or to cover glass portion of thickness T 2 , with the other terminus of the vertical portion connecting to a curved portion. Other configurations and geometries of sidewall region  204  are possible, to include a ramp between cover glass portion  206  of thickness T 1  and cover glass portion  202  of thickness T 2 . 
     In one embodiment, the geometry of transition region  204  is defined by the method of manufacturing of the structured glass feature  201 . The method of manufacturing the structured glass feature  201  is detailed below, but in one embodiment, the tool used to create the structured glass feature  201  defines the transition region  204 . For example, if the structured glass feature  201  is formed using a computer numerical controlled (“CNC”) grinding and polishing technique, the geometry of the CNC grinding tool may define a CNC tool radius between portion  202  of thickness T 2  and the remaining portion  206  of thickness T 1 . Such a CNC tool radius would define radius R 2  in  FIG. 2A  joining portion  202  and remaining portion  206 . 
     Interior cavity surface  237 , to include region  202  of thickness T 2 , is formed over a device  100  component, such as a camera  207 . In one embodiment, the thinner region  202  of thickness T 2  may be disposed over the light-receiving region  206  of a camera  208 . Region  202  can have any given shape and dimension, to include the planar configuration of  FIG. 2A . In some embodiments, the region  202  is coincident with the light-receiving region  206 , centered about the light-receiving region  206  and/or centered about a center-line axis of the camera  208 . In some embodiments, the region  202  can have a size and/or shape that positions the region  202  over some or all of the non-light receiving regions of the camera  208 . 
     The sidewall or transition region  204  of the cover glass  200  provides additional space  210  for the camera  208  and/or other devices, such as second lens, polarizing filter, etc. In some embodiments, a higher quality camera can be included in the electronic device  100  when the additional space  210  is present than might be possible if the cover glass lacks the structured glass feature. For example, a higher quality camera can include a larger sensor, higher quality lenses, an autofocus feature, and/or a flash module. In some embodiments, a front-facing camera (e.g., camera  102 ) can be of equal or near-equal quality as a rear-facing camera (e.g., camera  108 ). 
     The structured glass feature  201  may be formed over device  100  components other than a camera. For example, the structured glass feature  201  may be formed over all or part of a logo  118 , a speaker/microphone  122 , and/or internal electronic components of the device  100 , such as the main logic board. The additional vertical distance  218  provided by the structured glass feature  201  may enable, for example, a larger and more capable main logic board to be installed in the device  100 . In some embodiments, the structured glass feature may be contoured to match, mimic, parallel, or otherwise roughly follow contours of one or more internal components of the electronic device. 
     One or more brackets  212  can engage with or attach to the camera  207 . The bracket or brackets  212  can have any given configuration and size, and can be positioned at any location. The one or more brackets  212  may be positioned below or adjacent the perimeter  235 . Any suitable attachment mechanism can be used to attach the camera  207  to the bracket(s)  212  and/or to the frame. By way of example only, an adhesive material and/or a fastener can be used to attach the camera  207  to the bracket(s)  212  and/or to the frame. 
     In some embodiments, the one or more mounting brackets  212  may provide additional or alternative functions, such as structural support or structural enhancement in the transition regions between varied thickness regions of the cover glass. That is, the mounting brackets may provide structural support at the edge of the transition region  204  from the region  206  of thickness T 1  and the region  202  of thickness T 2 . The mounting brackets may also be configured with optical properties to draw attention to the outline of the structured glass feature  201 , or to draw attention away from, or otherwise optically mask, the outline region. Optical masking is disclosed below. 
     In some embodiments, the one or more mounting brackets  212 , if engaged with or replaced with one or more actuators, may provide a means to point or position a device  100  component, such as a camera  207 , disposed below the cover glass. For example, the brackets may allow a lens of the camera  207  to extend vertically into the structured glass feature  201 , providing an additional functionality to the camera  207 . Alternatively or additionally, the brackets  212  may allow the camera  207  to be pointed by rotation of the camera frame or rotation of a camera lens. 
     In some embodiments, the structured glass feature  201  may be filled with a gas to increase or adjust device performance, such a performance of the camera. For example, the structured glass feature  201  may be filled with a temperature-controlled gas to reduce a temperature differential between the device exterior and the camera, thereby enabling performance of the camera in an extended temperature range, that is, in relatively colder or warmer external temperatures. 
     The embodiment shown in  FIG. 2B  is similar to the embodiment shown in  FIG. 2A  except that the structured glass feature  201  of the cover glass  200  transitions between a region  202  of thickness T 2  and a remaining region  206  of thickness T 1  by way of steps within transition/sidewall region  204 . That is, the sidewall region  204  is not defined by a radius R 1  and a radius R 2 , as in the embodiment of  FIG. 2A , but rather by a first step of thickness T 3  and a second step of thickness T 4 . 
     The first surface  231  and the second surface  233  define a nominal thickness T 1  of the cover glass  200 . The cover glass  200  has a set of thinned regions of thickness T 2  and T 2  plus T 4 . The second surface  233  of the cover glass  200  forms an interior cavity surface  237 . The interior cavity surface  237  has a first portion parallel with the first surface  231  that defines a thickness T 2  of cover glass  200 , and a second portion parallel with the first surface  231  that defines a thickness T 2  plus T 4  of the cover glass  200 . The interior cavity surface  237  has a perimeter  235  that begins from second surface  233  and that forms a boundary of the interior cavity surface. It should be appreciated that the interior cavity surface is stepped, as shown in the figure. 
     In one embodiment, at least a portion of the interior cavity surface  237 , such as the perimeter  235  and/or one or more steps (as depicted in  FIG. 2B ) are configured to be invisible to the naked eye. Stated another way, least a portion of the interior cavity surface  237  is configured such that the change in thickness is not perceptible to the naked human eye. In one embodiment, the steps of the sidewall region  204  are optically masked such that the transition regions are not visible to the naked human eye. In one embodiment, at least a portion of the interior cavity surface  237  is optically masked such that the transition regions are not visible to the naked human eye. 
     The optical masking of the sidewall region  204  of the structured glass feature  201  may be achieved in any of several ways, to include through geometric methods and material methods. That is, the sidewall region  204  may be made visually imperceptible by relative dimensioning and shaping of the sidewall region  204  and/or through design of optical properties of the materials forming the sidewall region  204 . 
     The human eye interprets received light waves to provide vision, to include color differentiation and depth perception. Adjustment to received light waves will adjust vision. The most common corrective eye glasses adjust or bend incoming light waves to adjust the eye&#39;s interpretation of otherwise uncorrected incoming light waves. Such eye glasses use refraction to adjust the incoming light waves. Refraction is the change in direction of propagation of a wave due to a change in its transmission medium. The refractive index, also known as the index of refraction, is a dimensionless number that describes the degree to which light is bent or refracted within a transmission medium. Functionally, eye glasses place a lens in front of the wearer&#39;s eyes. The lens has refractive optical properties to appropriately adjust the incoming light waves, so as to alter the light waves before receipt by the wearer, thereby improving the wearer&#39;s vision. 
     Refraction may be applied to optically mask the sidewall region  204  of the structured glass feature  201  such that the sidewall region  204  is imperceptible to the device  100  user. With respect to a user looking at a target object through a clear piece of glass, a user&#39;s eye receives light reflected off the target object that passes essentially unchanged through the clear glass. That is, the target object light passes through the clear glass without a change in direction. However, if the clear glass has an imperfection, such as a change in density, some of the target object light will be altered in direction, and the target object will not be seen as clearly. That is, the object may appear blurred. 
     Returning to the sidewall region  204  of the structured glass feature  201 , the sidewall region  204 , depending on geometry and dimension, may adjust some target object light akin to an imperfection in clear glass. However, this optical effect, e.g. the distortion or re-direction of light passing through the sidewall region  204 , may be mitigated and/or eliminated by re-directing the altered light to correct for the undesirable distortion. Such a correction or optical masking may be achieved in any of several ways. For example, a portion of glass within the sidewall region  204  of the structured glass feature  201  may be configured with a different index of refraction than the remaining glass portion. For example, a first glass layer may have a first index of refraction and a second glass layer may have a second index of refraction. Thus, as a wave, such as an optical wave, passes from the first glass layer into the second glass layer, the wave will change direction. This change of direction may conceal, correct for, or otherwise remove any optical distortion caused by sidewall region  204  geometries (such as the stepped geometry of  FIG. 2B , or the curved geometry of  FIG. 2A ). Specifically, in regards to the sidewall region  204  of the structured glass feature  201 , the transition region may be configured with layers of glass of varied indexes of refraction, so as to provide a perceived optical wave of the same character as that emitted from a portion of glass outside, or not bounded by, the sidewall region  204 . Put another way, multiple glass layers having different indices of refraction may cooperate to optically mask a structured glass feature. 
     In one embodiment, the sidewall or transition region  204  of the structured glass feature  201 , including portions with varied refractive properties, is formed through stacked layers of glass. That is, the curved area defined by radius R 1  of transition portion  204  of  FIG. 2A  may be formed of layers of glass with a first index of refraction, such that target light is refracted to adjust or correct for the distortion of light caused by the curved radius R 1  portion. Similarly, the curved area defined by radius R 2  of transition portion  204  of  FIG. 2A  may be formed of layers of glass with a second index of refraction, such that target light is refracted to adjust or correct for the distortion of light caused by the curved radius R 2  portion. The stacked layers of glass may form a set of fused glass layers that create a single monolithic structure. 
     In another embodiment, the optical masking of the sidewall region  204  of the structured glass feature  201  is achieved through application of one or more optical films with defined refractive properties. For example, with respect to the sidewall region  204  of the structured glass feature  201 , with reference to the sidewall portion  204  of  FIG. 2A  defined by a radius R 1  and a radius R 2 , a first film with refractive index one may be applied to all or a portion of the surface of sidewall region  204  defined by radius R 1 , and a second film with a refractive index two may be applied to all or a portion of the surface of the transition region defined by radius R 2 . Each of the first film and the second film function to reduce or eliminate the refractive distortion caused by the respective radius R 1  and radius R 2  features, thereby reducing or eliminating a user&#39;s optical perception of the sidewall region  204 . 
     The optical effects of the sidewall region  204  as described above may also be used to amplify or magnify, rather than eliminate, optical distortions, or items below the structured glass feature. Such an application is described below with respect to the embedded logo  118  of  FIG. 6 . 
       FIG. 3A  is a sample cross-section view of the electronic device  100  of  FIGS. 1A and 1B , taken along line B-B in  FIG. 1A  and showing one embodiment of a structured glass feature  301  disposed over two cameras. The embodiment shown in  FIG. 3A  is similar to the embodiment shown in  FIG. 2A  except that the cover glass  300  has a thinned region spanning a set of electronic device  100  components, such as a first camera  306  and a second camera  308 . 
     The cover glass  300  has a first surface  331  and a second surface  333 . The first surface  331  and the second surface  333  define a nominal thickness T 1  of the cover glass  300 . The cover glass  300  has a thinned region  302  with a thickness T 2 , as compared to a remainder  314  of the cover glass  300 , which has a thickness T 1 . Generally and as shown, thickness T 1  is greater than thickness T 2 . The second surface  333  of the cover glass  300  forms an interior cavity surface  337 . The interior cavity surface  337  has a portion parallel with the first surface  331  that defines a thickness T 2  of cover glass  300 . The interior cavity surface  337  has, and is bounded by, a perimeter  335  that begins from second surface  333 . 
     Cover glass  300  transitions between thickness T 2  of region  302  to thickness T 1  of other areas of the cover glass  300  by way of region  304 . One or both of first camera  306  and second camera  308  may engage brackets  312 . Similar to the brackets discussed above with respect to  FIGS. 2A-B , the brackets  312  may comprise actuators which may adjust, move or direct one or both of first camera  306  and second camera  308 . Brackets  312  are positioned below or adjacent to perimeter  335 . 
     The embodiment of  FIG. 3B  is similar to the embodiment shown in  FIG. 3A  except that the cover glass  300  has both thinned regions and a thickened region spanning a set of electronic device components, such as a first camera  306  and a second camera  308 . The cover glass  300  has a first surface  331  and a second surface  333 . The first surface  331  and the second surface  333  define a nominal thickness T 1  of the cover glass  300 . The second surface  333  of the cover glass  300  forms an interior cavity surface  337 . The interior cavity surface  337  has a portion parallel with the first surface  331  that defines a thickness T 2  of cover glass  300 . The interior cavity surface  337  has a perimeter  335  that begins from second surface  333 . The perimeter  335  forms a boundary of the interior cavity surface  337 . 
     Two structured glass features  301  are formed over each camera, and a three-dimensional thickened or protruding region feature  316  (e.g., a structural rib) is formed between the features  301 . A pair of thin regions  318  of thickness T 6  are disposed above each of first camera  306  and second camera  308 . The thin regions  318  are thinner than most other areas  314  of cover glass  314 . Cover glass  300  transitions to thin regions  318  by way of sidewall regions  320 . Sidewall regions  320  may be formed in any of several geometries, to include one or more radii and one or more steps. Disposed between the paired thinned regions  318  is a thicker region  316  of thickness T 5 . A transition region  322  transitions from each thinner region  318  to the thicker region  316 , and may be formed in any of several geometries, to include one or more radii and one or more steps. It should be appreciated that the protruding structural rib  316  is bounded by a second perimeter  339 . One or more brackets  312  and  314  may engage one or more of first camera  306  and second camera  308 . 
     The structured glass feature  303 , including relatively thicker region  316 , may form a structural rib within an electronic device to increase structural strength or stiffness along a specified axis of the device  100 . The structured glass feature  303  forms a second perimeter  339  at each of the structured glass features  301 . 
     The formed structural rib of the structured glass feature  303  may vary in cross-section along its length. That is, the width may vary along the axis of the formed structural rib. Such a configuration enables varied structural strength along the structural rib, which may be desirable in order to design structural strength as a function of varied loading within the device  100 . For example, a relatively heavier component (such as a battery) in a first portion of the device  100  may require additional structural strength relative to an area with lighter components. The portion of the device  100  requiring increased strength would be designed with a structured glass feature  303  configured as a structural rib of increased thickness (relative to the cavities and the overall cover glass structure  300 ) and/or increased depth T 5 . 
     In other embodiments, the structured glass feature  303  is a set of structured glass features  303  that form a glass framing structure for all or a portion of the device  100 . That is, the structured glass feature  303  comprises primary framing components such as trusses to provide defined structural properties, such as stiffness, along identified glass portions or along large portions of the device  100 . In one embodiment, a set of structured glass features  303  form the primary enclosure of the device. In such embodiments, the structured glass features  303  comprise portions of one or more different widths  316  and thicknesses T 1 . 
     Methods of manufacturing the structured glass features, such as structured glass feature  303 , are detailed below with respect to  FIGS. 9-10 . In one embodiment, the structured glass feature  303  is formed through placing and fusing of multiple layers of glass. In such a method, the multiple layers of glass may exhibit varied structural properties and thus may serve as design vehicles to form glass structural components of varied strength. That is, some portions of the device may be configured with structured glass of higher strength than others, or with different impact resistance. For example, the portions of cover glass at an edge of a device  100  may be engineered to have increased resistance to cracking or shattering, and thus may be formed from layers of tempered glass. In contrast, an interior portion of a device  100  may be formed of stacks or layers of non-tempered glass. 
     In some embodiments, the structured glass feature  303  may be formed with an airtight internal cavity filled with a gas to provide for temperature control of the device  100 . For example, a gas contained within the internal cavities may be cooled to prevent overheating of the device, or heated to allow device operation in colder external temperatures than would otherwise be allowed. As such, the external operational temperature range of the device  100  is expanded. In one embodiment, such internal cavities may be formed by placing and fusing, or thermoforming, glass layers. That is, the set of glass layers may contain portions with internal gaps or trenches or may be partial layers such that, when stacked with companion layers, an internal channel or cavity is formed. 
       FIG. 4  is a sample cross-section view of the electronic device  100  of  FIGS. 1A and 1B , taken along line A-A in  FIG. 1A  and showing one embodiment of a three-dimensional lens feature  401 . The cover glass  400  has a first surface  431  and a second surface  433 , the second surface  433  opposite the first surface  431 . The first surface  431  and the second surface  433  define a nominal thickness T 1  of the cover glass  400 . The cover glass  400  has a thickened region  402  with a maximum thickness T 7 . The second surface  433  of the cover glass  400  forms an interior cavity surface  437 . The interior cavity surface  437  has a perimeter  435  that begins from second surface  433 . 
     The cover glass  400  of the electronic device  100  has a region  402  that is thicker than other areas  414  of the cover glass  400  and forms an optical lens  404 . Region  402  is curved so as to form a lens of maximum cover glass thickness T 7 . The formed lens  404  is disposed over camera  406 . In some embodiments, the lens  404  may be coated or treated with a film, such as an anti-reflection film. In some embodiments, the lens may be stacked or disposed adjacent an optical filter, such as a polarization filter. 
     In one alternate embodiment, rather than a concave lens as shown in  FIG. 4 , a convex lens is formed, wherein the maximum thickness T 7  of the cover glass is less than the thickness T 1  of the other areas  414  of the cover glass  400 . In some embodiments, the lens  404  is any type of known optical lens, including compound lens such as a biconvex and biconcave lens. The lens  404  may be in optical communication with the light-receiving region of the camera  406 . 
     The camera  406  is may be mounted or engaged with one or more brackets  412 . In some embodiments, the brackets  412  function to position the camera  406 . In alternate embodiments, the brackets  412  function to adjust the three-dimensional lens feature  401 . The brackets  412  may comprise actuators that finely apply pressure to the lens  401  such that the shape of the lens is slightly altered to, for example, improve focus of the camera. Such fine adjustment of the lens  401 , typically limited to a sub-wavelength of the light band of interest, is known in the optical sciences as adaptive optics. Generally, in adaptive optics, fine adjustments to the shape of an optical lens serve to calibrate the incoming light to remove known external light distortions, such as distortion caused by atmospheric effects. 
     In one embodiment, the lens  401  is constructed through placing and fusing of multiple layers of glass, as described above further detailed with respect to  FIGS. 9-10  below. In such a method of manufacture, in one embodiment, at least one layer of glass is intentionally stacked with a sub-wavelength gap relative to an adjacent layer. 
     In one embodiment, a conventional lens is positioned within a three-dimensional cavity, such as the cavity  202  of  FIG. 2A , and engaged with actuators such that the lens may be adjusted within the cavity. The adjustment may comprise vertical position adjustment and/or tilt or angular position. Alternatively or additionally, the lens may be adjusted in curvature using the adaptive optics discussed above. In one embodiment, the cavity containing the lens is a sealed cavity such that a gas may be inserted and maintained. The gas may enhance or adjust lens properties, based on type of gas, pressure of gas, or temperature of gas. Thus, adjustment of the gas characteristics provide a way to adjust characteristics of the lens without removing the lens. 
       FIG. 5  is a sample cross-section view of the electronic device  100  of  FIGS. 1A and 1B , taken along line C-C in  FIG. 1A  and showing one embodiment of a three-dimensional input/output cavity feature  501 . In the embodiment of  FIG. 5 , a cover glass  500  of the electronic device has a region  508  forming at least part of the input/output  112  of the device  100 . The region  508  may form a thinned concave depression in the cover glass  500  to a minimum thickness of T 2  within a region  508  of thickness T 1 . One or more trenches  504  of height T 8  may also be formed below the region  508 . The trenches  504  may be fitted with sensors and/or electronics disposed at surface  506  which are aided by a closer or reduced vertical distance to the surface of region  508 . For example, a reduced distance to the surface of the input/output  112  may increase sensitivity of some sensors and/or reduce power requirements to operate some sensors. Also, a region  508  formed within the cover glass  500  may be water tight, thereby eliminating a water entry area common in traditional input/output  112  configurations. 
     In one embodiment, the trenches  504  are fitted with one end of an induction charging system, which is configured to receive an inductive charge from a device positioned near or within input/output cavity feature  501 . Because inductive charging efficiency is increased with a reduction in distance between charging elements, the efficiency of the inductive charging increases because the transmitting inductive charging source may be positioned within the cavity feature  501 . A similar increase in efficiency would occur with magnetic connections, that is, the strength of a magnetic connection between a magnet disposed on surface  506  and an external magnet increases when the external magnet is positioned within cavity feature  501 . 
     In another embodiment, the efficiency of haptic communications between the device  100  and a device user increases due to the input/output cavity feature  501 . A haptic communication, such as a vibration, may be more efficient or effective if the distance between the vibration source and the haptic receiver is reduced. For example, the cavity  501  may be subject to enhanced and/or localized flexure, insofar as the trenches  504  may change the local stiffness of the feature  501 . Accordingly, a haptic output applied to an under surface of the cavity feature  501  may cause the cavity feature  501  to flex more (with respect to the same force) than if the trenches  504  were absent. This enhanced deflection may be more readily felt by a user touching the cavity feature  501 , as described below. 
     The input/output cavity feature  501  allows a user to position her (curved) fingertip within the (curved) input/output cavity feature  501 , thereby reducing the distance between a vibration source disposed at  504  and the user&#39;s fingertip. Thus, a given vibration energy may be produced with reduced power, given the reduced distance between the user and the vibration source. Or, a given power may yield a higher effective level of vibration energy given the reduced distance between the user and the vibration source. 
       FIG. 6  is a sample cross-section view of the electronic device  100  of  FIGS. 1A and 1B , taken along line D-D in  FIG. 1A  and showing one embodiment of a three-dimensional logo cavity feature  601 . In the embodiment of  FIG. 6 , a cover glass  500  of the electronic device has a region  602  disposed over a logo  118  of the electronic device  100 . The region  602 , of thickness T 2 , is thinner than other areas  608  of the cover glass  600 , of thickness T 1 . The three-dimensional logo cavity feature  601  may be of any configuration and size. For example, the three-dimensional logo cavity feature  601  may form a rectangular cross-section as shown in  FIG. 6 , but may also form a rounded cavity such as that of  FIG. 2A , or a stepped cavity such as that shown in  FIG. 2B . 
     Logo  118  comprises a first logo area  604  and a second logo area  606 . The second logo area  606  has different optical properties than the first logo area  604 . Logo  118  is disposed in the opening or aperture formed in the cover glass  600  wherein when viewed, the logo  118  appears holographic or three-dimensional. In some embodiments, the logo is formed by a liquid, such as ink. In some embodiments, the logo  118  is a solid material, such as a metal. 
     The logo  118 , separately or in combination with the three-dimensional logo cavity feature  601 , may present unique optical characteristics to a user of the electronic device  100 . Generally, optical properties of the logo  118  and/or the three-dimensional logo cavity feature  601  may be designed to present optical effects including color variation and magnification. Such optical effects may be achieved through application of refraction and diffraction, for example. 
     As briefly discussed above with regard to  FIGS. 2A-B , the optical concepts employed to mask user perception of the sidewall region  204  may also be used to magnify rather than eliminate optical properties, such as the size of the logo  118   s . With respect to the logo  118  disposed below the three-dimensional logo cavity feature  601 , refraction may be employed to provide optical features of the three-dimensional logo cavity feature  601  and/or logo  118 . 
     In one embodiment, one or more portions of the logo  118 , such as the first logo area  604  and a second logo area  606 , may be comprised of materials with varied reflective properties. That is, first logo area  604  may comprise a material with a first index of refraction and the second logo area may comprise a second area  606  with a second index of refraction. Thus, the two logo areas will refract or bend incoming light in different ways, and thus will be perceived by a user differently. In one embodiment, the different indices of refraction result in different colors perceived by a user of the electronic device  100 . The varied refractive indices may be achieved in any of several ways, to include through application of an optical film and through glass layering (as discussed above with respect to  FIGS. 2A-B .) 
     In another embodiment, the optical diffraction characteristics of the three-dimensional logo cavity feature  601  are used to enable optical features of the logo  118  disposed below the three-dimensional logo cavity feature  601 . Diffraction is a change in direction of waves when passing through an opening or around a barrier. With respect to  FIG. 6 , light emitted from logo  118  may be diffracted in passing through the three-dimensional logo cavity feature  601 . For example, if the interior of three-dimensional logo cavity feature  601  were configured with angled features, light emitted from logo  118  would be diffracted (and at least partially reflected) resulting in an optical effect viewable by the user. 
     In some embodiments, the logo disposed in the three-dimensional logo cavity feature  601  is fitted with one or more actuators to effect movement of the logo or to adjust its optical properties. For example, the logo may be engaged with a vibration source to allow vibration of the logo. In some embodiments, the logo is heat sensitive such that when engaged with a heat source, the logo changes in characteristics, such as color or shape. In one embodiment, the three dimensional cavity feature  601  is airtight and filled with a gas. The gas may be pressurized or temperature controlled to effect optical properties of logo  118 . 
     In other embodiments, the logo  118  may be formed by creating the three-dimensional cavity in the structured glass and coating the cavity walls with an ink, foil, solid, or other suitable material. The cavity need not be filled by the coating material. Rather, since the cavity walls are coated, from the outside the logo may appear to be a solid mass of material filling the cavity even though it is not. This may permit the space within the cavity to house all or part of an internal component, as described above, while the cavity itself (e.g., the structured glass feature) creates the logo  118 . 
     Although embodiments are discussed with respect to a logo, it should be appreciated that any character, symbol, shape or the like may be formed and implemented as described herein. Thus, letters, words, numbers and the like may be formed in certain embodiments. 
       FIG. 7  is a sample cross-section view of the electronic device  100  of  FIGS. 1A and 1B , taken along line E-E in  FIG. 1A  and showing one embodiment of a three-dimensional hinge feature  701 . The three-dimensional hinge feature  701  is enabled by a linear sequence of tooth structures formed in glass, the teeth separated by an elastic material. When a bending force is applied to the glass along the axis defined by the sequence of teeth, the elastic material is compressed and the glass bends or hinges, without damage to the surrounding glass. The three-dimensional hinge feature  701  may take any of several forms and configurations. 
     In the embodiment of a three-dimensional hinge or joining feature  701  depicted in  FIG. 7 , a cover glass  700  of the electronic device  100  has a region  706  forming a set of teeth elements  120 , for example at a split of a mobile telephone as shown in  FIG. 1C . In other embodiments the hinge or joining feature  701  can join top and bottom portions of a laptop, such that the top portion may be pivoted with respect to the bottom portion, as an example. The set of teeth elements  120  are generally rectangular in cross-section with width  702 , and separated relative to an adjacent tooth by a distance  704 . The teeth  120  are of height so as to form a thinner region of thickness T 2  above a particular tooth. The gap (of width  704 ) formed between teeth is fitted with a material with elastic properties, such as a rubber material. The sequence of teeth relative to an adjacent tooth form a line in the cover glass with increased elasticity which allows for controlled bending of the cover glass  700  without fracture or cracking of the cover glass  700 . In some embodiments, the hinge or joining feature  701  permits two portions of the device  100  joined by the feature to flex or move relative to one another. In others, the feature  701  joins the two portions without permitting movement. 
     In another embodiment of the three-dimensional hinge or joining feature  701 , the set of regions of distance  704  formed between the set of teeth elements  120  are generally of rounded cross-section, or of rounded cross section with extended planer edges. Such geometry may be readily formed through use of a CNC machine to cut the regions between the teeth. 
     In one embodiment, the three-dimensional hinge feature  701  is engineered to fail at a specified bending angle, such that user operation of the hinge below the specified bending angle will not result in cracking or breakage of the cover glass. The specified bending angle may be determined through structural properties and geometries of the three-dimensional hinge feature  701 . For example, an elastic material with increased elasticity fitted within distance  704  of the three-dimensional hinge feature  701  would provide an increase in maximum bending angle. 
     In another embodiment, the three-dimensional hinge feature  701  is not used as a hinge but instead is employed to provide controlled flexibility of or near a component of the electronic device  100 . For example, mounting brackets  212  of  FIGS. 2A-B  may be constructed of glass with a three-dimensional hinge feature such that the brackets may flex, move or the like, thereby allowing actuation (such as motion or positional adjustment) of, for example, an adjacent camera  207  positioned on a substrate  240 . In one embodiment, the three-dimensional hinge feature is constructed of several stacked layers of glass, the layers of glass with slightly different thermal expansion properties, such that when a heat source is applied to the three-dimensional hinge feature, the three-dimensional hinge feature slightly expands such that the three-dimensional hinge feature moves or actuates. 
       FIGS. 8A-B  are sample detail views A-A of the electronic device  100  of  FIGS. 1A and 1B  and showing embodiments of a three-dimensional retention feature  801 . The sequence of vertical cuts in the glass edge provides increased adhesion to adjacent components by providing additional space to contain adhesive material and to provide increased surface area for the adhesion. That is, the increase in surface area afforded by the three-dimensional retention feature  801  allows an increase in contact surface area between the edge of the cover glass  800  and the enclosure  128 . The increase in contact surface area between the bonded surfaces increases adhesion strength because adhesion strength increases with contact surface area. The increased availability of adhesive, as contained in the cavities of the vertical cuts of the three-dimensional retention feature  801 , helps to ensure that adhesive is provided between all contact surface areas. Conventional bonding between two planar surfaces commonly contain portions of a contact surface area with little or no adhesive, resulting in an undesirable non-uniform bond and a localized area of weaker bonding strength. 
     The three-dimensional retention feature  801  may take any of several geometric shapes or configurations. The shape of the three-dimensional retention feature  801  may be, for example, circular, rectangular, or a combination thereof. The grooves may be of any dimension. The sequence of three-dimensional retention features  801  may be uniform or non-uniform. That is, the sequence of three-dimensional retention features  801  may be laterally spaced in a uniform pattern, or may decrease in separation in areas in need of additional adhesion and therefore provide increased strength. 
     In the embodiment of  FIG. 8A , the edge of a cover glass  800  adjacent the enclosure  128  of the electronic device  100  comprises a set of uniform grooves or cuts of height T 7 . The shape of the three-dimensional retention feature  801  is generally circular with extended planar tangential edges. Such a groove shape of the three-dimensional retention feature  801  may be created by use of a CNC tool applied against the edge of the cover glass  800 . Each groove has a width  804  and is separated from an adjacent groove by distance  802 . The enclosure defines a set of projections or protrusions  806  that are received within the three-dimensional retention features. These projections  806  may mate with the edge features  801  to join the enclosure  128  to the cover glass  800 , or otherwise mechanically interlock or retain the two in a position or alignment with respect to one another. An adhesive or the like may facilitate such interlocking and/or retention, although the adhesive may be omitted in many embodiments. 
     In the embodiment of  FIG. 8B , generally similar to the embodiment shown in  FIG. 8A , the set of three-dimensional retention features  801  include a trench feature to provide an additional cavity to hold adhesive. The trench is of width  812  of a groove of width  810  and relative separation to adjacent grooves of distance  808 . The grooves are of height T 7 . In some embodiments, the trenches of  FIG. 8B  are formed by way of laser undercutting. Here, the three-dimensional retention features  801  are undercut to form a mushroom cross-section, such that a head of each retention feature is larger in cross-section than a channel of each retention feature. Thus, when material of the enclosure  128  (or any other suitable material) is placed within the head and channel of the three-dimensional retention features  801 , the combination of enclosure and cover glass  800  may resist separation. It should be appreciated that the enclosure  128  may be metal, plastic, ceramic, and/or another layer of glass that is affixed to, mechanically interlocked with, or fused with the cover glass at the set of three-dimensional retention features. 
     The three-dimensional retention feature  801  may serve any of several additional functions in addition to aiding adhesion or mechanical interlocking. For example, the grooves may provide a space to engage or secure an elastic material that is positioned between the edge of the cover glass  800  and the enclosure  128 . Such an elastic material may provide impact absorption in the event of an impact to the electronic device  100 , such as caused by dropping of the electronic device  100 . In another example, the three-dimensional retention feature  801  may function to engage or secure an electrical component of the electronic device  100 , such as an antenna, or a three-dimensional glass feature such as a colored glass three-dimensional glass feature. Such a colored glass structured glass feature may function to bring attention to the edge of the electronic device, for design or aesthetic purposes. 
     The above embodiments and/or features of structured glass may be manufactured or produced in any of several ways. The following methods, alone or in combination, may be used: computer numeric control (CNC) grinding, followed by chemical and/or mechanical polishing; etching, to include masked etching; ultrasonic machining optionally with ultrasonic machining; laser ablation, laser machining, and/or laser polishing; vacuum forming optionally with vacuum polishing; and glass bonding. In some embodiments, the cover glass is a homogeneous and/or a monolithic glass. 
     Sample, but not exhaustive, manufacturing processes will now be discussed. It should be appreciated that various operations described below may be combined with other operations (described herein or otherwise) to form a structured glass feature in a structured glass element. Accordingly, combinations of processes, operations, and the like that are set out herein are contemplated. Further, the various operations, processes, and methods discussed herein may be used, singly or in various combinations, to form any feature and/or structure discussed herein, as well as other such features and/or structures. 
       FIG. 9  depicts an example process  900  that may be used to manufacture a structured glass feature. The operation of process  900  may be performed, for example, to form the structured glass features described above with respect to  FIGS. 1-8 . 
     In operation  902 , a glass layer is obtained. The glass layer may be of any optical substrate made of glass, to include thin and ultra-thin glass wafers. In one embodiment, the glass layer is a sapphire glass. 
     In operation  904 , the glass layer is fixtured. The substrate may be fixtured as a whole, for example by being clamped or otherwise retained along its edges, corners, on a major surface area of the glass, and so on. However, it may be useful to locally fixture the glass in the region in which the structured glass feature is to be formed. The fixture may serve as a guide or mask to prevent over-removal of material. Further, local fixturing may ensure that the glass is well supported at or around the area in which the structured glass feature is formed. In some embodiments, a support may abut, retain, and/or fixture the glass within millimeters, or even microns, of an edge of the area removed to form the structured glass feature. 
     In operation  906 , the structured glass feature is formed. The structured glass feature may form a cavity surface defining a perimeter, the cavity surface and perimeter formed within a first thickness of the substrate. 
     Any of several methods may be used to form the structured glass feature into a thickness of the glass layer. For example, some structured glass features may be formed by mechanically removing portions of a glass layer. For example, a grinder, router, CNC machine, or the like may be used to mechanically remove material from the glass layer to form the structured glass feature (and thus, shape the substrate into a glass structure). Similarly, a laser may ablate material to form the structured glass feature. Some embodiments may chemically etch the glass layer to form it into a structured glass (e.g., glass having a structured glass feature). The chemical etch may be locally applied and may be neutralized once the structured glass feature is formed. For example, the glass layer may be masked around the region in which the structured glass feature is formed, in order to prevent the etchant from removing excess material. The etchant may be applied by spraying, vapor deposition, as a bath, a stream, and so on. 
     Machining, etching, and lasering processes may yield a relatively rough surface, a surface with micro-cracks or micro-voids defined therein, or both. Generally, the rougher a surface, the less optically transparent it is. When the surface is placed above a camera, even small flaws, cracks, voids, and the like may be readily apparent in images captured through the structured glass insofar as the camera may magnify these flaws. Likewise, even small imperfections in a structured glass feature above a graphical display may be readily apparent; the underlying display may cause the imperfection to refract or reflect light, thereby drawing attention to the imperfection. These imperfections may cause a sparkling effect, haze, or translucency in the glass over the display. Also, for aesthetic reasons, it may be undesirable to optically cover or mask the perimeter formed around a structured glass feature. Generally, the perimeter and/or the imperfections that may be created during operation  906  may be mitigated or removed by operation  908 . 
     In operation  908 , all or a portion of the structured glass feature may be optically masked. The optical masking operation may be performed in any of several ways, alone or in combination. For example, the structured glass feature may be polished in one or more operations. Each polishing operation may use a subsequently finer polishing material and/or head to progressively reduce the size of imperfections. Similarly, the surfaces defining the structured glass feature may be ground or otherwise abrasively treated to reduce imperfections. 
     In some embodiments, an optically clear sealant, adhesive, or the like (collectively, “sealant”) may be applied to one or more surfaces defining the structured glass feature. Typically this sealant is applied after the feature is formed and its surfaces are polished or otherwise processed, although the sealant can be applied at any time. The sealant may fill in any remaining micro-cracks or other imperfections, thereby strengthening the structured glass feature and reducing a risk of mechanical failure. The sealant may have other properties, such as acting as a light filter, a polarizer, a color shifter, or the like. For example, the sealant may enhance images taken by a camera within (or partially within) the structured glass feature. In this manner, the sealant may cooperate with an internal component to enhance operation of some facet of the associated electronic device. 
     As previously discussed, some embodiments may apply ink, metal, or another opaque coating to some portion of the structured glass feature, or parts of the structured glass adjacent the structured glass feature. The ink may conceal imperfections in the glass or may be used to provide the illusion that the structured glass feature is fully filled with a material when only its edges, walls, or the like are coated. 
     Further, some embodiments may mechanically pre-stress the glass layer prior to mechanically cutting, or lasering, it. Pre-stressing the glass layer may reduce surface imperfections formed when material is removed. The fixturing structure may pre-stress the glass layer, as appropriate, or it may be separately pre-stressed. 
       FIG. 10  depicts an example process  1000  that may be used to manufacture a structured glass feature. The operation of process  1000  may be performed, for example, to form the structured glass features described above with respect to  FIGS. 1-8 . 
     In operation  1002  a first glass layer is obtained. Operation  1002  is similar to operation  902  of example process  900 . 
     In operation  1004 , a second glass layer is obtained. The second glass layer includes an aperture. The aperture may be formed through the second glass layer or form a cavity within a thickness of the second glass layer. The aperture may be formed by in a similar manner to that described with respect to operation  906  of example process  900 . 
     In operation  1006 , the first and the second substrates are coupled or positioned adjacent one another (e.g., such that they are touching or nearly touching one another, or in any event sufficiently close to be fused to one another in subsequent operations). The substrates may be coupled in a precise manner with aid of a fixturing device, as described above with respect to operation  904  of example method  900 . For example, the second substrate may include a three-dimensional aperture that forms a cavity intended to be positioned below a precise location of the first substrate, such that ultimately the cavity is positioned below a sensor component of a host electronic device. 
     In operation  1008 , the first and the second substrate are fused to form a single substrate. The resulting single substrate may form a single monolithic structure. The fusion of the first and the second substrate may be performed in any of several ways. For example, some embodiments may fuse the substrates by a thermoforming process to fuse the glass layers into a single monolithic structure. Several glass layers, sheets or the like may be stacked to form an outline of a structured glass feature (or multiple features). The glass layers may be subject to heat and/or pressure to fuse them into a single mass or single monolithic structure. In some embodiments, a mold or similar structure may define the structured glass feature to ensure the glass does not slump or flow into inappropriate areas. In other embodiments, no mold or the like is used. 
     Further, some embodiments may mechanically pre-stress one or more of the set of glass layers prior to fusing them together and/or forming a structured glass feature. Pre-stressing the glass layer(s) may reduce surface imperfections formed when material is removed. The fixturing device may pre-stress the glass layer(s), as appropriate, or they may be separately pre-stressed. 
     The operations of example method  900  and example method  1000  may be combined. For example, the optical masking operation  908  of example method  900  may be applied in the example method  1000 . 
     It should be appreciated that the glass layers need not all be flat. Likewise, the glass layers need not all have a uniform size or any single uniform dimension; different layers may be of different sizes. By using differently-sized glass layers, a variety of structured glass features may be formed in a variety of different shapes and with different dimensions. Further, in many embodiments, multiple pieces of glass may be used to form any given layer. In some embodiments, a first glass layer may be larger than a second, adjacent glass layer. Accordingly, a first portion of the first glass layer may be fused to the second glass layer while a second portion is not. Additionally, one or more material properties (such as strength, stiffness, elasticity, impact resistance, opacity, indices of refraction, and the like) may vary between two or more glass layers. 
       FIG. 11  depicts example components of an electronic device in accordance with the embodiments described herein. The schematic representation depicted in  FIG. 11  may correspond to components of any device described above, such as a laptop computer, tablet computing device, mobile phone, digital media player, and so on. However,  FIG. 11  may also more generally represent other types of electronic devices having substrates (particularly glass layers) with structured glass features formed therein and/or thereon. 
     The device  1100  generally includes processing circuitry  1140 , such as one or more processing units. The processing circuitry  1140  is operatively connected to components of the device  1100 . The processing circuitry  1140  is configured to detect input, initiate output, and generally control various operations and/or functions of the electronic device  1100 . 
     In addition the processing circuitry  1140  may be operatively connected to computer memory  1142 . The processing circuitry  1140  may be operatively connected to the memory  1142  component via an electronic bus or bridge. The processing circuitry  1140  may include one or more computer processing units or microcontrollers that are configured to perform operations in response to computer-readable instructions. The processing circuitry  1140  may include a central processing unit (CPU) of the device  1100 . Additionally or alternatively, the processing circuitry  1140  may include other processing units within the device  1100  including application specific integrated chips (ASIC) and other microcontroller devices. The processing circuitry  1140  may be configured to perform functionality described in the examples above. 
     The memory  1142  may include a variety of types of non-transitory computer-readable storage media, including, for example, read access memory (RAM), read-only memory (ROM), erasable programmable memory (e.g., EPROM and EEPROM), or flash memory. The memory  1142  is configured to store computer-readable instructions, sensor values, and other persistent software elements. 
     The memory  1142  can store electronic data that can be used by the signal generator  1150 . For example, the memory  1142  can store electrical data or content, such as timing signals, algorithms, and one or more different electrical signal characteristics that the signal generator  1150  can use to produce one or more electrical signals. The electrical signal characteristics include, but are not limited to, an amplitude, a phase, a frequency, and/or a timing of an electrical signal. The processing circuitry  1140  can cause the one or more electrical signal characteristics to be transmitted to the signal generator  1150 . In response to the receipt of the electrical signal characteristic(s), the signal generator  1150  can produce an electrical signal that corresponds to the received electrical signal characteristic(s). 
     In this example, the processing circuitry  1140  is operable to read computer-readable instructions stored on the memory  1142 . The computer-readable instructions may adapt the processing circuitry  1140  to perform the operations or functions described herein. The computer-readable instructions may be provided as a computer-program product, software application, or the like. 
     The device  1100  may also include a battery  1152  that is configured to provide electrical power to the components of the device  1100 . The battery  1152  may include one or more power storage cells that are linked together to provide an internal supply of electrical power. The battery  1152  may be operatively coupled to power management circuitry that is configured to provide appropriate voltage and power levels for individual components or groups of components within the device  1100 . The battery  1152 , via power management circuitry, may be configured to receive power from an external source, such as an alternating current power outlet. The battery  1152  may store received power so that the device  1100  may operate without connection to an external power source for an extended period of time, which may range from several hours to several days. 
     In some embodiments, the device  1100  also includes a display  1104  that renders visual information generated by the processing circuitry  1140 . The display  1104  may include a liquid-crystal display, light-emitting diode, organic light emitting diode display, organic electroluminescent display, electrophoretic ink display, or the like. If the display  1104  is a liquid-crystal display or an electrophoretic ink display, the display may also include a backlight component that can be controlled to provide variable levels of display brightness. If the display  1104  is an organic light-emitting diode or organic electroluminescent type display, the brightness of the display  1104  may be controlled by modifying the electrical signals that are provided to display elements. 
     In some embodiments, the device  1100  includes one or more input devices  1154 . The input device  1154  is a device that is configured to receive user input. The input device  1154  may include, for example, a push button, a touch-activated button, biometric sensor, force sensor, or the like. In some embodiments, the input devices  1154  may provide a dedicated or primary function, including, for example, a power button, volume buttons, home buttons, scroll wheels, and camera buttons. Generally, a biometric input device and a force sensor may also be classified as input components. 
     The device  1100  may also include a haptic actuator  1156 . The haptic actuator  1156  may be implemented as described above, and may be a ceramic piezoelectric transducer. The haptic actuator  1156  may be controlled by the processing circuitry  1140 , and may be configured to provide haptic feedback to a user interacting with the device  1100 . 
     The device  1100  may also include a communication port  1146  that is configured to transmit and/or receive signals or electrical communication from an external or separate device. The communication port  1146  may be configured to couple to an external device via a cable, adaptor, or other type of electrical connector. In some embodiments, the communication port  1146  may be used to couple the device  1100  to another computing device. 
     Various embodiments have been described in detail with particular reference to certain features thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the disclosure. And even though specific embodiments have been described herein, it should be noted that the application is not limited to these embodiments. In particular, any features described with respect to one embodiment may also be used in other embodiments, where compatible. Likewise, the features of the different embodiments may be exchanged, where compatible. For example, although the embodiments shown in  FIGS. 2-4  depict the front-facing first camera  102  ( FIG. 1A ), those skilled in the art will recognize that the invention can be used with the rear-facing second camera  108 . Additionally, a cover glass arrangement can include multiple thinner or multiple thicker regions formed in a cover glass.

Metadata:
Filing Date: 20171103
Publication Date: 20201222
Grant Date: 20201222
Priority Date: 20161104
Inventors: ZHANG, LI
RAFF, JOHN
OW, FLORENCE W.
ZHANG, GUANGTAO
KIM, SOYOUNG
LUZZATO, VICTOR
SARGENT, DANIEL B.
Assignee: APPLE INC
CPC Classifications: [{"code": "C03B23/203", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1633", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B17/06", "inventive": true, "first": true, "tree": "[]"}, {"code": "C03B23/203", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1633", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B17/06", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/041", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "C03B9/03", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/041", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B17/06", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "C03B9/03", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1633", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "C03B23/203", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 62065049