PATENT DOCUMENT

Publication Number: US-8558977-B2
Application Number: US-55819309-A
Country: US
Kind Code: B2

Title: Electronic device display structures with alignment features

Abstract:
Electronic devices such as handheld electronic devices may have display modules. The display modules may be covered with a layer of protective cover glass. Peripheral portions of the cover glass may be coated with an opaque masking layer to block interior portions of the device from view. An opening in the opaque masking layer can be formed over an active portion of the display module. To facilitate alignment of the display module active area with the opening in the cover glass masking layer, the display module may be provided with alignment marks. The alignment marks may be formed in opposing corners at an end of the display module. The alignment marks may be formed from metal structures on one of the glass layers in the display module. An opaque masking layer that blocks stray backlight may have openings that are formed over the metal structures.

Claims:
What is claimed is: 
     
       1. A display module comprising:
 first and second glass layers; 
 an opaque masking layer between the first and second glass layers; 
 an alignment mark formed from an alignment structure and portions of the opaque masking layer that define at least one opening over the alignment structure; and 
 a third glass layer overlying the first glass layer, the third glass layer including a second opaque layer hiding the alignment mark from view. 
 
     
     
       2. The display module defined in  claim 1  further comprising liquid crystal display structures interposed between the first and second glass layers. 
     
     
       3. The display module defined in  claim 2  further comprising an additional alignment mark, wherein the alignment mark and the additional alignment mark are located at opposing corners of the display module. 
     
     
       4. The display module defined in  claim 1  wherein the first and second glass layers comprise upper and lower glass layers, wherein the opaque masking layer is formed on the upper glass layer, and wherein the alignment structure is formed on the lower glass layer. 
     
     
       5. The display module defined in  claim 1  wherein the opaque masking layer is formed on the first glass layer and wherein the alignment structure is formed on the second glass layer, the display module further comprising an integrated circuit mounted on the second glass layer. 
     
     
       6. The display module defined in  claim 1  wherein the first and second glass layers have opposing inner surfaces and wherein the opaque masking layer is formed on one of the inner surfaces. 
     
     
       7. The display module defined in  claim 6  wherein the alignment structure comprises a metal structure that is adjacent to the opening and that is formed on another one of the inner surfaces. 
     
     
       8. Display structures, comprising:
 a first transparent layer; 
 a second transparent layer; 
 at least some active pixel structures between the first transparent layer and the second transparent layer; 
 a third transparent layer overlying the first transparent layer; and 
 alignment marks on the second transparent layer hidden from view by a mask layer of the third transparent layer, the alignment marks facilitating alignment of the first, second and third transparent layers; wherein 
 said first and second transparent layers comprise liquid crystal display module glass layers; and 
 the display structures further comprise polarizer layers that surround the first and second transparent layers. 
 
     
     
       9. The display structures defined in  claim 8  further comprising an opaque masking layer on the first transparent layer, wherein the alignment marks are formed from alignment structures and openings in the opaque masking layer adjacent to the alignment structures through which the alignment structures are viewed. 
     
     
       10. The display structures defined in  claim 8 , further comprising a backlight structure that emits light that is at least partly blocked by the opaque masking layer. 
     
     
       11. The display structures defined in  claim 8  further comprising a backlight structure that emits light that is at least partly blocked by the opaque masking layer. 
     
     
       12. The display structures defined in  claim 8  further comprising a display driver integrated circuit mounted to the second transparent layer. 
     
     
       13. The display structures defined in  claim 8  further comprising a flex circuit attached to the second transparent layer. 
     
     
       14. The display structures defined in  claim 13  wherein the alignment marks comprise metal alignment structures formed at corners of the second transparent layer. 
     
     
       15. The display structures defined in  claim 8  wherein the alignment marks comprise metal alignment structures formed at corners of the second transparent layer. 
     
     
       16. The display structures defined in  claim 15  further comprising an opaque masking layer on the first transparent layer, wherein the alignment marks are formed from the metal alignment structures and openings in the opaque masking layer adjacent to the metal alignment structures through which the metal alignment structures are viewed.

Description:
BACKGROUND 
     This relates generally to electronic devices, and more particularly, to alignment of display structures within electronic devices. 
     Electronic devices such as handheld electronic devices often include displays. For example, a cellular telephone may have color touch screen display. To protect the display from damage, the display may be covered with a protective layer of glass. This layer, which is typically referred to as the cover glass, helps prevent scratches from damaging sensitive display structures. 
     A cover glass layer may be provided with a peripheral opaque mask. The mask may have a transparent opening though which the underlying display may be viewed. The mask itself may be formed from a black ink. Use of the opaque mask may help improve device aesthetics, because unsightly interior portions of the device are hidden from view by the mask. However, the presence of the mask may make it difficult or impossible to satisfactorily align the display underneath the cover glass. 
     It would therefore be desirable to be able to provide improve alignment techniques for displays in electronic devices. 
     SUMMARY 
     Electronic devices such as handheld electronic devices may have display modules. The display modules may be based on liquid crystal display technology. Active display pixels may be formed in an active area of the display module. Opposing glass layers may encase the display pixels. The lower surface of the uppermost glass layer may be provided with an opaque masking layer to block stray light from a backlight structure in the device. The upper surface of the lowermost glass layer may be provided with metal alignment structures. Openings may be formed in the opaque masking layer to allow the alignment structures to be visually inspected during alignment and assembly operations. 
     A display module in a device may be protected with a layer of cover glass. Peripheral portions of the cover glass may be coated with an opaque masking layer to block interior portions of the device from view. A rectangular opening in the opaque masking layer can be formed over the active portion of the display module to allow an image that is formed in the active portion of the display module to be viewed by a user of the device. To facilitate alignment of the display module active area with the opening in the cover glass masking layer, the alignment marks may be visually inspected using an alignment and assembly tool. Once the alignment marks have been placed into alignment with the edge of the opening in the opaque masking layer on the cover glass, the cover glass may be attached to the display module using adhesive. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device that includes a display with alignment structures in accordance with an embodiment of the present invention. 
         FIG. 2  is a perspective view of an illustrative cover glass and an illustrative display module with alignment structures in accordance with an embodiment of the present invention. 
         FIG. 3  is a cross-sectional side view of a system that may be used to align and assemble a display for an electronic device in accordance with an embodiment of the present invention. 
         FIG. 4  is a top view of a display module with alignment marks showing how the alignment marks may be located outside of the active display area in accordance with an embodiment of the present invention. 
         FIG. 5  is a cross-sectional side view of a portion of an electronic device showing how cover glass structures may be aligned to a display module with alignment features in accordance with an embodiment of the present invention. 
         FIG. 6  is a top view of a portion of an illustrative display module having a triangular alignment structure that is visible through a triangular opening in an opaque display module masking layer in accordance with an embodiment of the present invention. 
         FIG. 7  is a top view of a portion of an illustrative display module having a cross-shaped alignment structure that is visible through a cross-shaped opening in an opaque display module masking layer in accordance with an embodiment of the present invention. 
         FIG. 8  is a flow chart of illustrative steps involved in aligning and attaching a cover glass structure and a display module with alignment features using a system of the type shown in  FIG. 3  in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Alignment features may be provided for displays in electronic devices. 
     The electronic devices may desktop computers, televisions, or other consumer electronics equipment. The electronic devices may also be portable electronic devices such as laptop computers or small portable computers of the type that are sometimes referred to as ultraportables. If desired, portable electronic devices may be somewhat smaller devices. Examples of smaller portable electronic devices include wrist-watch devices, pendant devices, headphone and earpiece devices, and other wearable and miniature devices. With one suitable arrangement, the portable electronic devices may be handheld electronic devices. 
     Handheld electronic devices and other electronic devices may include displays. An illustrative electronic device of the type that may have a display is shown in  FIG. 1 . Device  10  of  FIG. 1  may be, for example, a handheld electronic device such as a cellular telephone with circuitry that runs email and other communications applications, web browsing applications, media playback applications, games, etc. 
     Device  10  may have housing  12 . Antennas for handling wireless communications may be housed within housing  12  (as an example). Housing  12  may be formed of any suitable materials including, plastic, glass, ceramics, metal, other suitable materials, or a combination of these materials. Bezel  14  may be formed from a conductive material and may serve to hold display  16  on device  10 . Bezel  14  may also form an aesthetically pleasing trim around the edge of device  10 . If desired, displays such as display  16  may be mounted in housing  12  without using bezel  14 . 
     Display  16  may be a liquid crystal display (LCD), an organic light emitting diode (OLED) display, a plasma display, an electronic ink display, or any other suitable display. A protective outer layer of plastic or glass may be provided over the outermost surface of display  16  to protect display  16  from damage. This layer is sometimes referred to herein as a cover glass layer. If desired, touch screen functionality may be integrated into display  16  or may be provided using a separate touch pad device. An advantage of integrating a touch screen into display  16  to make display  16  touch sensitive is that this type of arrangement can save space and reduce visual clutter. 
     Display screen  16  (e.g., a touch screen) is merely one example of an input-output device that may be used with electronic device  10 . If desired, electronic device  10  may have other input-output devices. For example, electronic device  10  may have user input control devices such as button  20 , input-output connectors for signal ports, a speaker such as speaker  18 , and other input-output devices. 
     In the example of  FIG. 1 , display  16  is shown as being mounted on the front face of handheld electronic device  10 , but display  16  may, if desired, be mounted on the rear face of handheld electronic device  10 , on a side of device  10 , on a flip-up portion of device  10  that is attached to a main body portion of device  10  by a hinge (for example), or using any other suitable mounting arrangement. 
     Display  16  may have an active portion that contains image pixels and an inactive portion. In inactive portions  30 , no image is created. In active portion  32  of display  16 , image pixels can be controlled to display a desired image. In the example of  FIG. 1 , active portion  32  of display  16  lies within dashed rectangle  24 . Peripheral inactive portion  30  of display  16  lies outside of rectangle  24 . Upper region  20  and lower region  22  may be inactive display regions. Portion  26  along the right hand boarder of display  16  and portion  28  along the left hand boarder of display  16  may also be inactive regions. These inactive portions form a peripheral inactive boundary (inactive area  30 ) that surrounds rectangular active region  32 . 
     To block internal structures in the inactive regions of display  16  from view by a user of device  10 , the cover glass of display  16  may be provided with an opaque mask. The opaque mask may be formed from a black ink or other substance that blocks visible light. The opaque mask may be formed over the inactive portions of display  16 . For example, the periphery of the cover glass of display  16  may be provided with an interior coating of black ink. The portion of the cover glass that overlaps active region  32  may be uncovered with ink so that this region remains transparent. 
     The structure in display  16  that is used in generating images is sometimes referred to as a display module. Display  16  may, for example, have an LCD display module that produces images using LCD technology (as an example). A microprocessor and other control circuitry in device  10  may supply the display module with image data using a cable. The cable may be formed from conductive traces on a flexible printed circuit board substrate such as a printed circuit board substrate formed from polyimide or other polymers (i.e., a flex circuit cable). The flex circuit cable may be connected to the display module using conductive adhesive. 
     Display driver circuitry may be provided in the form of one or more integrated circuits mounted in the display module. The flex circuit may supply signals to the display driver circuitry. The display driver circuitry may, in turn, drive image signals into an array of thin film transistors in the display. These transistors may be used in generating an electric field that controls the orientation of the liquid crystal material in the display module. As the orientation of the liquid crystal material changes, the polarization of the liquid crystal material changes. Polarizer layers and backlight structures that are associated with the display module may be used to convert polarization changes into a displayed image. 
     Display modules have an active area that contains image pixels. For example, an LCD display module may contain a central rectangular region in which the thin film transistors and liquid crystal material form image pixels. Other types of displays such as plasma displays, organic light-emitting diodes displays, and electronic ink displays also have active areas in which image pixels are formed. These active areas are generally surrounded by inactive areas. 
     During assembly, it is generally desirable to align the active portion of the display module with the transparent opening in the opaque mask of the cover glass. This alignment process is illustrated in  FIG. 2 . As shown in  FIG. 2 , display  16  may include cover glass structures  44  and display module  52 . Structures for providing display  16  with touch sensor functionality (e.g., a layer of transparent indium-tin oxide electrodes for a capacitive touch sensor array) may be attached to the underside of the cover glass in display  16  and are therefore sometimes considered to form part of cover glass structures  44 . Because structures  44  generally include a layer of cover glass, cover glass structures  44  are sometimes referred to as cover glass  44 . 
     The periphery of cover glass  44  may have a masking layer  50 . Masking layer  50  may be formed from black ink or other opaque masking material. This opaque material may be formed on the underside of cover glass  44  around the periphery of cover glass  44  (i.e., in the general shape of inactive area  30  of  FIG. 1 ). Central opening  54  of cover glass  44  (i.e., the rectangular portion of cover glass  44  that lies within dashed line  24 ) has the general shape of active area  32  of  FIG. 1  and is not covered by opaque mask  50 . 
     A central rectangular region that lies within dashed line rectangle  56  may form active region  42  of display module  52 . The rectangle formed by dashed line  56  may have approximately the same size and shape as the rectangle formed by dashed line  24  (i.e., the active area of display module  52  may be approximately the same size as opening  54  in cover glass  44 ). The portions of display module  52  that lie outside of rectangle  56  may form inactive portions  46  of display module  52 . 
     During assembly, display module  52  and cover glass  44  may be attached to each other using adhesive (e.g., clear pressure sensitive adhesive). To ensure that masking layer  50  does not inadvertently obscure active portions  42  of display module  52 , display module  52  and cover glass  44  may be aligned. For example, cover glass  44  and module  52  may be aligned along lateral dimensions  38  and  40  (i.e., parallel to the width and length of cover glass  44 ). Cover glass  44  and display module  52  may also be aligned about rotational axis  34  (i.e., to control the relative angle A). Cover glass  44  and module  52  may also be moved relative to each other along vertical dimension  36  parallel to the height of cover glass  44  (e.g., when it is desired to attach cover glass  44  to module  52 ). 
     When cover glass  44  and display module  52  are properly aligned, the edges of mask  50  will be aligned with the edges of inactive area  56  and the edges of clear opening  54  will therefore be aligned with the edges of active display area  42 . Aligning active display area  42  of display module  52  with opening  54  in mask  50  on cover glass  44  in this way ensures that active area  42  will be visible to a user of device  10  through opening  54  (i.e., there will be no skew between active area  42  and opening  54  that might otherwise block part of the edges of active area  42  from view). 
     It may be difficult or impossible to visually identify the location of the boundary of active region  42  when display module  52  is not powered, particularly when display module  52  is formed using normally-black display technology. It may therefore be desirable to include one or more alignment features in display module  52 . For example, alignment marks such as alignment marks  48  may be formed on display module  52 . These alignment structures can be fabricated in alignment with the edges of active area  42 , so alignment between display module  52  and cover glass  44  can be achieved by aligning the alignment marks on display module  52  with cover glass  44  (e.g., by aligning marks  48  with the edges of opening  54 ). 
     Alignment operations can be performed with the aid of an alignment and assembly system. A side view of an illustrative alignment and assembly system that may be used to align the edges of active area  42  of display module  44  so that they are parallel with the edges of opening  54  in mask  50  of cover glass  44  is shown in  FIG. 3 . As shown in the  FIG. 3  example, alignment and assembly tool  58  may have a control unit such as control unit  60 . Control unit  60  may be based on a computer or other suitable computing equipment and may have a user interface that allows tool  58  to be operated by a user. The user interface may be used in controlling system  58  with the computing equipment of unit  60 . The user interface may include, for example, a display, a keyboard, a mouse or other pointing device, etc. The mechanical components of tool  58  such as positioning stage components may also be controlled manually (e.g., by physically positioning these components using adjustment knobs or other mechanically adjustable translation and rotation controls). 
     The relative position between cover glass  44  and display module  52  may be adjusted using positioning equipment  62  and  64 . Positioning equipment  62  may include a vacuum chuck mounted to an x-y-z translation stage. A rotational mechanism may be used to control rotational alignment between cover glass  44  and display module  52 . Positioning equipment  64  may be fixed or may include translation and rotational stages. Using the user interface in control unit  60 , a user may operate control unit  60  and system  58 . For example, the user may provide commands that direct control unit  60  to adjust the relative position between cover glass  44  and display module  52 . Control unit  60  may make these adjustments by issuing analog or digital commands to positioning equipment  62  and  64 . Manual user adjustments (e.g., using adjustment knobs on equipment  62  and  64 ) may also be used. 
     A user may visually align cover glass  44  to display module  52 . Light sources such as light source  66  may be used to provide light  68  that illuminates cover glass  44  and display module  52 . The user may view cover glass  44  and display module  52  using a microscope (e.g., a stereo microscope), using an unaided eye, using camera  70  (e.g., a microscope-based camera or other camera), using a combination of these visual inspection devices, or other suitable equipment. Images from camera  70  may be displayed on a monitor such as monitor  72  in control unit  60 . 
     Alignment marks such as alignment mark  48  can be used to help the user ascertain the position of display module  52  (i.e., to determine the angle of orientation of the boundary that lies between active region  42  and inactive region  46  of display module  52 ). The angle of orientation of the edges of opening  54  in opaque mask layer  50  on cover glass  44  can be determined by visual inspection (e.g., using camera equipment such as camera  70 ). The location of the boundary between the active and inactive areas of display module  52  can be difficult to discern visually without alignment marks such as alignment marks  48 . The presence of alignment marks  48  provides readily discernable visual feedback on the orientation of the display module active area and thereby facilitates the alignment process. Alignment marks may also be used on cover glass  44  (e.g., on the underside of layer  50 ), but such alignment marks are generally not needed to discern the edges of opening  54  because mask  50  (and therefore the edges of opening  54 ) can be viewed through transparent cover glass  44 . 
     Once system  58  has been used to align cover glass  44  and display module  52 , cover glass  44  and display module  52  may be attached to each other. For example, a layer of transparent pressure sensitive adhesive may be interposed between cover glass  44  and display module  52 . Positioning equipment  62  and  64  (e.g., computer-controlled equipment that is controlled using control unit  60 ) may be used to lower cover glass  44  onto the surface of display module  52  after alignment has been achieved. Once cover glass  44  and display module  52  have been attached to each other in this way, the combined structure may be mounted in device  10 . This operation may be performed as part of a separate assembly step. During this assembly step, a flex circuit cable or other cable that handles display data for display module  52  may be used to connect display module  52  to a main logic board in device  10 . 
     A top view of display module  52  showing a possible location at which a flex circuit cable may be connected to the display module is shown in  FIG. 4 . As shown in  FIG. 4 , flex circuit cable  74  may be connected to display module  52  in an end portion of inactive area  46  (as an example). Alignment marks  48  may also be formed within this portion of inactive area  46  if desired. Alignment marks  48  may define an axis (axis  116 ) that is parallel to edge  114  of active area  42 . Components such as integrated circuit  78  (e.g., a display driver chip) may be mounted in area  46  adjacent to the termination location for flex cable  74 . 
     In conventional display modules, patterned metal features were formed on the upper side of the lower glass layer in the region of the lower glass layer that was not covered by the upper glass layer. This region of the lower glass layer was covered by black tape to prevent light leakage. The black tape included a hole over the patterned metal features to allow the patterned metal features to be viewed. This type of arrangement exposed the patterned metal features to potential damage and allowed light to escape through the holes in the black tape. 
       FIG. 5  is a cross-sectional side view of an illustrative display module and cover glass structure showing how alignment marks may be formed in the display module to assist in the alignment process. The cross-section of  FIG. 5  is taken along line  102  of  FIG. 1  and is viewed in direction  76  of  FIG. 1 . As shown in  FIG. 5 , cover glass structures  44  may include cover glass layer  98 , opaque mask layer  50 , pressure sensitive adhesive  80 , and touch sensor layer  82  (sometimes referred to as “touch glass”). Pressure sensitive adhesive  84  may be used to mount cover glass structures  44  to display module  52 . Display module  52  may be mounted in the interior of housing  12  using plastic support structures  110 . 
     Display module  52  may be based on LCD technology (as an example). LCD modules generally have upper and lower polarizer layers such as upper polarizer layer  86  and lower polarizer layer  104 . Upper polarizer  86  may be formed above the upper surface of upper glass layer  88 . Lower polarizer  104  may be formed below the lower surface of lower glass layer  96 . Liquid crystal display structures  94  may be formed between glass layers  88  and  96 . Liquid crystal display structures  94  may include thin film transistors, liquid crystal material, and other structures that form image pixels for display  16 . The portion of structures  94  to the left of dashed line  56  correspond to active area  42  of display module  52  (i.e., active image pixel structures). The portion of the structures to the right of dashed line  56  correspond to inactive area  46 . 
     An LCD display module may be provided with a backlight. In the example of  FIG. 5 , display module  52  is backlit using light source  108  (e.g., a light-emitting diode light source) and backlight structures  106 . Source  108  provides light to backlight structures  106 . Backlight from structures  106  passes upwards through the active elements of display module  52  for viewing by a user. To prevent stray backlight from becoming visible to the user, display module  52  may be provided with an opaque masking layer such as a layer of black ink. For example, display module  52  may be provided with a masking layer such as masking layer  90  around the periphery of the underside of glass layer  88  (i.e., in inactive area  46 ). 
     Alignment marks such as alignment mark  48  may be formed within the interior of display module  52 . For example, alignment mark  48  may be formed from a layer of metal or other material such as metal  49  on the upper surface of lower glass layer  96  and an opening in masking layer  90  such as opening  92 . An advantage of using metal (including metal alloys) for the alignment structures (e.g., metal structure  49 ) is that metal is generally reflective to visible light. This helps ensure that alignment markers  48  (e.g., metal  49 ) will be visible during the alignment process. Another advantage of using metal for the alignment structures is that metal is generally opaque and light from backlight structures  106  therefore cannot escape through metal structure  49  (e.g., light cannot escape through alignment structure  48 ). Metal  49  may sometimes be referred to herein as an alignment structure, a metal structure, alignment metal, and a metal alignment structure. 
     An opening in masking layer  90  such as opening  92  may be provided to allow metal  49  to be illuminated by light  68  and to allow alignment mark  48  to be visually inspected (e.g., using camera equipment  70 ). During alignment operations with alignment and assembly tool  58  of  FIG. 3 , cover glass  44  is aligned with display module  52  by ensuring that edge  112  of masking layer  50  is parallel with edge  114  of active layer  42  of display module  52 . Lateral and rotational alignment operations may be performed. As shown in  FIG. 4 , alignment marks  48  may be provided at opposing corners at one of the ends of display module  52 , so as to define an axis such as axis  116  that runs parallel with edge  114  of active area  42 . 
     It can be difficult to view edge  114  directly with tool  58 , but metal  49  will be visible through opening  92  in masking layer  90 . Because the alignment marks are fabricated on display module  52  so that axis  116  is aligned with edge  114 , it is possible to align edge  112  of opening  54  with edge  114  of active area  42  (i.e., to make these two edges parallel to each other) by aligning alignment marks  48  to edge  112  of masking layer  50 . There may be a slight separation D (e.g., 0-5 mm) between edge  114  and edge  112  of opening  54  and edge  114  active area  42 , but when alignment is obtained, all four edges of the opening formed in masking layer  50  will be parallel to the four corresponding edges of active area  42 . The opening in mask layer  50  will also generally be centered over active area  42 . 
     There may be any suitable number of openings  92  in layer  90  in a given display module  52 . For example, there may be two openings  92  at opposing corners of display module  52  or there may be more than two openings. If the size of openings  92  is too large, light from backlight structures  106  might leak into view by a user of device  10  through the transparent layers of display module  52  and cover glass structures  44 . Openings such as opening  92  may therefore be configured to consume a relatively small fraction of the inactive area in the end of device  10  (i.e., less than 30% or less than 10% of inactive portion  20  of  FIG. 1 ). Metal  49  and openings  92  (e.g., alignment marks  48 ) may have any suitable shapes and sizes. In the example of  FIG. 6 , metal  49  and hole  92  are triangular (e.g., mark  48  is triangular). In the example of  FIG. 7 , metal  49  and hole  92  have a cross shape (e.g., mark  48  has a cross shape). As other examples, metal  49  and openings  92  (e.g., alignment marks  48 ) may be formed in a circular shape, a rectangular shape, a square shape, a star shape, a random shape, a crescent shape, a polygonal shape, and a shape from a combination of these and other shapes. If desired, the shapes of metal  49  and openings  92  may be based on the shape of display  16 . For example, metal  49  and openings  92  may be formed in a crescent shape when display  16  is circular or has curved edges. 
     Illustrative steps involved in aligning cover glass structures  44  and display module  52  using equipment of the type shown in  FIG. 3  are shown in  FIG. 8 . 
     At step  118 , the position of the cover glass structures relative to alignment marks  48  is determined by visual inspection. The orientation of edge  112  of masking layer  50  on the underside of cover glass layer  98  ( FIG. 5 ) may be compared to the orientation of the axis defined by alignment marks  48  (i.e., axis  116  of  FIG. 4 , which is parallel to edge  114  of active display area  42  on display module  52 ). This allows the angular orientation and linear displacement of cover glass opening  54  relative to active area  42  to be determined. 
     At step  120 , appropriate adjustments are made to the relative positions of cover glass  44  and display module  52  to align cover glass opening  54  and active area  42 . These adjustments may include lateral position adjustments and adjustments in angle A that alter the relative position between cover glass  44  (and opening  54 ) and display module  52  (and area  42 ). Position adjustments may be made using positioning equipment  62  and  64  (manually or using commands provided by control unit  60 ). 
     Once alignment is complete, positioning equipment  62  and  64  may be used to attach cover glass  44  to display module  52  (step  122 ). A layer of pressure sensitive adhesive such as adhesive  84  of  FIG. 5  may be used to attach cover glass  44  and display module  52 . Once display module  52  and cover glass  44  have been assembled in this way, the resulting module may be assembled into device  10  (e.g., flex cable  74  of  FIG. 4  may be connected to a logic board and the module made up of cover glass  44  and display module  52  may be mounted in the interior of housing  12 ). 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.

Metadata:
Filing Date: 20090911
Publication Date: 20131015
Grant Date: 20131015
Priority Date: 20090911
Inventors: GETTEMY SHAWN R.
WURZEL JOSHUA G.
Assignee: APPLE INC
CPC Classifications: [{"code": "G02F1/133354", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/1333", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133354", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/1333", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02F1/133331", "inventive": false, "first": false, "tree": "[]"}, {"code": "G02F1/133331", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 43730212