Abstract:
A display protection system for use in a portable electronic device includes first and second lenses overlaying the device display. The first lens includes an aperture over a lens sensor mounted in the device, whereas the second lens includes an opaque region in that same area. In this way, the lens sensor may detect the presence or absence of the secondary lens and adjust touch sensor behavior accordingly.

Description:
TECHNICAL FIELD 
     The present disclosure is related generally to mobile device construction, and, more particularly, to a system and method for improving touch screen usability in a portable communication device. 
     BACKGROUND 
     One of the most prevalent and devastating failure modes for portable communications devices (e.g., “smartphones” or high function cellular phones) is cracking of the main lens of the device when the device is dropped or struck. The main lens is typically fabricated from glass, and the cracked glass causes both cosmetic and safety problems. Moreover, for designs wherein the device touchscreen is part of the glass lens assembly, a cracked lens may result in an unusable device. 
     While a cracked lens may be replaceable in some cases, lens replacement is one of the most expensive repairs available for portable communication devices. This is because the lens is almost always laminated to the display module with an optically clear glue. Indeed, aftermarket industries for cases and lens covers are thriving primarily because they help users avoid cracking their main lenses. While a lens cover does offer some degree of protection, such covers are primarily manufactured of a plastic material and frequently obscure the clarity of the display. Lens covers may also cause functional issues with device proximity or light sensors, and may affect the quality of pictures taken with the device&#39;s front facing imager. 
     Glass lens covers can improve image clarity relative to plastic covers, but must be made considerably thicker than plastic covers for manufacturability. This thickness can lead to reduced touchscreen sensitivity due to the increased distance between the user&#39;s finger and the touch sensor. Glass lens liners also scratch easily since they reside on top of the device&#39;s lens. 
     While the present disclosure is directed to a system that can eliminate certain shortcomings discussed in this Background section, it should be appreciated that such a benefit is neither a limitation on the scope of the disclosed principles nor of the attached claims, except to the extent expressly noted in the claims. Additionally, the discussion of technology in this Background section is reflective of the inventors&#39; own observations, considerations, and thoughts, and is in no way intended to accurately catalog or comprehensively summarize the art in the public domain. 
     As such, the inventors expressly disclaim this section as admitted or assumed prior art with respect to the discussed details. Moreover, the identification herein of a desirable course of action reflects the inventors&#39; own observations and ideas, and should not be assumed to indicate an art-recognized desirability. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       While the appended claims set forth the features of the present techniques with particularity, these techniques, together with their objects and advantages, may be best understood from the following detailed description taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a simplified schematic of an example device with respect to which embodiments of the presently disclosed principles may be implemented; 
         FIG. 2  is a perspective view of a portable communications device in keeping with an embodiment of the disclosed principles; 
         FIG. 3  is a partial front view of the device with only the primary lens present in keeping with an embodiment of the disclosed principles; 
         FIG. 4  illustrates the device in partial front view with the secondary lens applied to the front of the primary lens in accordance with an embodiment of the disclosed principles; 
         FIG. 5  is a cross-sectional end view of a device in accordance with an embodiment of the disclosed principles; 
         FIG. 6  is a schematic cross-sectional end view of a device showing a user&#39;s touch both with and without the secondary lens in accordance with an embodiment of the disclosed principles; and 
         FIG. 7  is a flow chart showing a process for constructing a device in accordance with an embodiment of the disclosed principles. 
     
    
    
     DETAILED DESCRIPTION 
     Before presenting a full discussion of the disclosed principles, an overview of certain embodiments is given to aid the reader in understanding the later discussion. As noted above, the lenses of portable communication devices are fragile, and as such, there have been attempts to protect such lenses from damage. While plastic lens protectors are usable, a clearer view of the device display is provided by a glass lens protector. However, glass lens protectors also have drawbacks, including decreased touch sensitivity. 
     In an embodiment of the disclosed principles, two separate glass lenses are implemented in a portable communication device. The first glass lens is laminated to the display of the device while the second glass lens is laminated to the first lens. To prevent the second glass lens from being scratched or cracking, it is also surrounded and protected by the device&#39;s housing. 
     If the second lens does crack or chip, it can be removed by the user and discarded; the device remains fully functional with the first lens alone in an embodiment. A new secondary lens may later be assembled to the device if desired. Therefore, a user will expect the device to be functional with either the first lens alone or with both lenses combined. However, touchscreen sensitivity and edge performance/grip suppression may differ depending upon whether both lens covers are present or only the first lens cover is present. 
     Thus, in an embodiment, the touchscreen sensitivity and edge performance/grip suppression of the device are modified based on the presence or absence of the second lens. The presence of the second lens may be detected by proximity sensor, light sensor, capacitive sensor, or other means in various embodiments. In an embodiment wherein an optical sensor such as infrared proximity sensor or ambient light sensor is used, the first lens includes an optical transmission area in the same region that the second lens includes solid artwork to block light. In this way, the sensor is blocked when the second lens is assembled to the device, and the device thus detects the presence or absence of the second lens. 
     In response to the detected presence or absence of the second lens, the device is configured in an embodiment to alter parameters related touch performance appropriately. In this way, whether both lens covers are present or only a single lens cover is present, the device touch screen responds in a suitable manner, maintaining a positive user experience. 
     With this overview in mind, and turning now to a more detailed discussion in conjunction with the attached figures, the structures and techniques of the present disclosure are shown being implemented in a suitable portable device environment. The following device description is based on embodiments and examples within which the disclosed principles may be implemented and should not be taken as limiting the claims with regard to alternative embodiments that are not explicitly described herein. Thus, for example, while  FIG. 1  illustrates an example mobile device within which embodiments of the disclosed principles may be implemented, it will be appreciated that other device types may be used, including but not limited to personal computers, tablet computers and other devices. 
     The schematic diagram of  FIG. 1  shows an exemplary component group  110  forming an environment within which aspects of the present disclosure may be implemented. In particular, the component group  110  includes exemplary components that may be used in a device wherein the described shielding technique is implemented. It will be appreciated that additional or alternative components may be used in a given implementation depending upon user preference, component availability, price point, and other considerations. 
     In the illustrated embodiment, the components  110  include a display screen  120  (e.g., a touch screen) which will be the focus of much of the later discussion. The component group  110  may also include applications (e.g., programs)  130 , a processor  140 , a memory  150 , one or more input components  160  such as speech and text input facilities, and one or more output components  170  such as text and audible output facilities, e.g., one or more speakers. 
     The processor  140  may be any of a microprocessor, microcomputer, application-specific integrated circuit, and the like. For example, the processor  140  can be implemented by one or more microprocessors or controllers from any desired family or manufacturer. Similarly, the memory  150  may reside on the same integrated circuit as the processor  140 . Additionally or alternatively, the memory  150  may be accessed via a network, e.g., via cloud-based storage. The memory  150  may include a random access memory (i.e., Synchronous Dynamic Random Access Memory (SDRAM), Dynamic Random Access Memory (DRAM), RAMBUS Dynamic Random Access Memory (RDRM) or any other type of random access memory device). Additionally or alternatively, the memory  150  may include a read only memory (i.e., a hard drive, flash memory or any other desired type of memory device). 
     The information that is stored by the memory  150  can include program code associated with one or more operating systems or applications as well as informational data, e.g., program parameters, process data, etc. The operating system and applications are typically implemented via executable instructions stored in a non-transitory computer readable medium (e.g., memory  150 ) to control basic functions of the electronic device. Such functions may include, for example, interaction among various internal components and storage and retrieval of applications and data to and from the memory  150 . 
     Further with respect to the applications  130 , these typically utilize the operating system to provide more specific functionality, such as file system service and handling of protected and unprotected data stored in the memory  150 . Although many applications may provide standard or required functionality of the user device  110 , in other cases applications provide optional or specialized functionality, and may be supplied by third party vendors or the device manufacturer. 
     With respect to informational data, e.g., program parameters and process data, this non-executable information can be referenced, manipulated, or written by the operating system or an application. Such informational data can include, for example, data that are preprogrammed into the device during manufacture, data that are created by the device or added by the user, or any of a variety of types of information that are uploaded to, downloaded from, or otherwise accessed at servers or other devices with which the device is in communication during its ongoing operation. 
     The component group  110  may include software and hardware networking components  180  to allow communications to and from the device. Such networking components  180  will typically provide wireless networking functionality, although wired networking may additionally or alternatively be supported. A battery  190  may be included for providing power to the device and its components  110 . All or some of the internal components  110  communicate with one another by way of one or more shared or dedicated internal communication links  195 , such as an internal bus. 
     Turning to  FIG. 2 , this figure presents a perspective view of a portable communications device  200  in keeping with an embodiment of the disclosed principles. The portable communications device  200  includes a main body  201 , which further includes a housing  203 . In the illustrated embodiment, a display  205  of the portable communications device  200  is located on a top surface of the portable communications device  200  and is surrounded by a rim of the housing as well as other circuitry and elements such as a camera, flash, optical sensor and so on. 
     As discussed in overview above, a substantially transparent primary lens  207  is laid over and affixed to the display  205  to protect the display  205 . The primary lens  207  may include a largely opaque or non-transparent border  209 . In addition to the primary lens  207 , a secondary lens  211  is applied to the primary lens  207  of the device  200 . In the illustrated embodiment, the secondary lens  211  is laid over and affixed to the primary lens  207 . As with the primary lens  207 , the secondary lens  211  also includes an opaque or non-transparent border  213 . 
     As will be shown in greater detail in  FIGS. 3 and 4 , the opaque or non-transparent borders  209 ,  213  (also referred to as “decoration”) of the primary lens  207  and secondary lens  211  are not identical. Rather, these regions include features enabling the device  200  to detect the presence or absence of the secondary lens  211 . 
     Turning to  FIG. 3 , this figure shows a partial front view of the device  200  with only the primary lens  207  present. An optical sensor on the device  200  front is exposed via a sensor port  301  in the primary lens  207 . In other words, even with the primary lens  207  affixed to the device  200 , the optical sensor of the device  200  is still able to sense objects in front of the primary lens  207 . 
     Turning to  FIG. 4 , this figure illustrates the device  200 , again in partial front view, with the secondary lens  211  applied to the front of the primary lens  207 . While the border  209  of the primary lens  207  contained the optical sensor port  301  to expose the device&#39;s optical sensor, the same region  401  of the secondary lens  211  border  213  is opaque. In this way, the device optical sensor can sense the presence of the secondary lens  211  through the optical sensor port  301  in the border  209  of the primary lens  207 . In addition, the border  209  of the primary lens  207  and the border  213  of the secondary lens  211  may both include holes  403  to allow a device camera, flash, or other component to have a line of sight out of the device  200 . 
     As noted above, the primary lens  207  and secondary lens  211  are layered over the device display  205  in sequence when assembled. This aspect may be more clearly seen in the cross-sectional end view of  FIG. 5 . In the illustrated view, the device housing  201  can be seen in cross-section, including the housing rim  501  previously mentioned. The device display  205  rests within and may be affixed to a lower ledge  503  within the housing rim  501 . To this end, a suitable adhesive may be applied to one or both of the inside of the housing ledge  503  and the device display  205  to structurally secure these components to one another. 
     In addition to being affixed to the housing  201 , the device display  205  may be mechanically supported by or affixed to other surfaces or elements within the device  200 , e.g., standoffs, brackets and so on. Moreover, once assembled, the device display  205  is further connected electrically to a driver and other components within the device  200  for display and sensing. 
     Continuing with  FIG. 5 , the primary lens  207  is affixed to the top surface of the device display  205 . The securing of the primary lens  207  to the device display  205  may be via an adhesive between the display  205  and the primary lens  207 , an adhesive between one or more edges of the primary lens  207  and the surface of the housing ledge  503 , or electrostatic or other non-adhesive attractive means. Finally, the secondary lens  211  is applied over the primary lens  207  by the same or other means as used to apply the primary lens  207  to the device display  205 . 
     During assembly of the various lenses  207 ,  211  onto the display  205  within the housing  201 , each layer should be accurately indexed to the others so that, for example, the display areas of each layer coincide and the optical sensor port  301  of the first lens  207  aligns with the optical sensor of the device  200 . In an embodiment, the adhesion between the primary lens  207  and the secondary lens  211  is sufficiently weak that removal of the secondary lens  211  from the primary lens  207  will not damage the primary lens  207 . 
     Given that the secondary lens  211  may be removed, e.g., upon breakage thereof, and the primary lens  207  used as the touch surface by the user, optimization of the touch sensing behavior of the device  200  is provided in an embodiment. To clarify the reason for this optimization more clearly,  FIG. 6  provides a schematic cross-sectional end view of the device  200 , showing a user&#39;s touch both with and without the secondary lens  211 . 
     In the first case  601 , the user&#39;s finger  603  spans both the housing rim  501  and the secondary lens  211 . In this case, there is no obstacle to sensing the user&#39;s finger across the entire surface of the secondary lens  211  and hence the entire surface of the display  205 . However, in the second case  605  shown, the secondary lens  211  has been removed. In this case, the user&#39;s finger cannot touch a portion of the primary lens  207  near the joint between the primary lens  207  and the secondary lens  211 . 
     An exemplary process  700  for optimizing the display sensing characteristics in various situations is shown in the flow chart of  FIG. 7 . At stage  701  of the process  700 , the device display  205  is activated, e.g., by the user touching or turning on the device  200 . The device  200  then employs its optical sensor aligned with the optical sensor port  301  of the primary lens  207  at stage  703  to determine whether the secondary lens  211  is in place over the primary lens  207 . 
     At decision stage  705 , the device  200 , e.g., a controller of the device  200 , sends the process  700  to stage  707  if the secondary lens is determined to be present, and otherwise sends the process  700  to stage  709 . The device processor calibrates the display  205  for a first sensitivity and first edge performance at stage  707  (i.e., if the secondary lens  211  is determined to be present) and calibrates the display  205  for a second sensitivity and second edge performance at stage  709  (i.e., if the secondary lens  211  is determined not to be present). In either case, once the display  205  is deactivated at stage  711 , through inactivity or user selection, the process  700  terminates until the display is again activated. 
     In this way, the display  205  of the device is protected by two lenses, while allowing for essentially the same user experience if and when the second lens is removed. More generally, it will be appreciated that a system and method for device display optimization have been disclosed herein. However, in view of the many possible embodiments to which the principles of the present disclosure may be applied, it should be recognized that the embodiments described herein with respect to the drawing figures are meant to be illustrative only and should not be taken as limiting the scope of the claims. Therefore, the techniques as described herein contemplate all such embodiments as may come within the scope of the following claims and equivalents thereof.