PATENT DOCUMENT

Publication Number: US-8915596-B2
Application Number: US-201314066296-A
Country: US
Kind Code: B2

Title: Method and apparatus for concealing sensors and other components of electronic devices

Abstract:
A concealing structure to at least partially conceal a sensor, light emitter or other component by at least partially preventing reflection of external light by an underlying structure. In some examples, this function is performed by a two-component masking assembly, the masking assembly including a linear polarizer to cause linear polarization of light which passes from the exterior of the device to an underlying component, and a wave plate to shift the axis of any reflected polarized light. In many cases, a high density optical fluid will further be included within the masking assembly to minimize reflections from the other components of the assembly.

Claims:
What is claimed is: 
     
       1. A housing for a computing device, the housing comprising:
 a border area; 
 an optical component mounted in the border area; and 
 a laminate component mounted on the border area, wherein the laminate component at least partially covers the optical component, wherein the laminate component comprises:
 a linear polarizer; and 
 a wave plate positioned between the linear polarizer and the optical component, wherein the wave plate causes at least partial circular polarization of linearly polarized light. 
 
 
     
     
       2. The housing of  claim 1 , wherein the wave plate is positioned substantially parallel to the linear polarizer. 
     
     
       3. The housing of  claim 1 , wherein the linear polarizer is configured to cause linear polarization of light prior to the light passing to the optical component. 
     
     
       4. The housing of  claim 1 , further comprising a frame, wherein the frame defines an aperture in alignment with the optical component. 
     
     
       5. The housing of  claim 4 , wherein an outer surface of the frame has a black appearance. 
     
     
       6. The housing of  claim 4 , wherein the frame forms at least part of the laminate component. 
     
     
       7. The housing of  claim 4 , wherein the frame is a layer of ink. 
     
     
       8. The housing of  claim 1 , wherein the laminate component further comprises a clear cover plate, wherein the clear cover plate defines an outer surface of the laminate component. 
     
     
       9. The housing of  claim 1 , further comprising a blind recess, wherein the optical component is mounted in the blind recess and further wherein the laminate component extends at least partially across an opening associated with the blind recess. 
     
     
       10. The housing of  claim 1 , wherein the optical component is one or more of an optical sensor, an indicator light, and an illuminator. 
     
     
       11. A device comprising:
 at least one optical component located in a recess of a housing; and 
 an laminar mask at least partially covering the recess of the housing, the laminar mask comprising: 
 a linear polarizer; 
 a wave plate positioned between the linear polarizer and the at least one optical component; 
 a translucent cover plate; and 
 a layer of high optical density fluid between the cover plate and the linear polarizer. 
 
     
     
       12. The device of  claim 11 , wherein the high optical density fluid has a refractive index greater than that of air. 
     
     
       13. The device of  claim 11 , wherein the high optical density fluid is an index matching fluid having a refractive index between a refractive index of the cover plate and a refractive index of the linear polarizer. 
     
     
       14. The device of  claim 11 , further comprising a frame component defining an aperture, wherein the frame component comprises an outer surface having a dark appearance around the aperture. 
     
     
       15. The device of  claim 14 , wherein the frame component comprises a layer of dark ink between the translucent cover plate and the layer of high optical density fluid. 
     
     
       16. A method comprising:
 mounting a laminate component on a selected region of an electronic device, the laminate component comprising: 
 a linear polarizer; 
 a wave plate mounted substantially parallel to the linear polarizer and positioned between the linear polarizer and at least one optical component; and 
 a layer of high optical density fluid between the cover plate and the linear polarizer. 
 
     
     
       17. The method of  claim 16 , further comprising mounting a frame component on the electronic device such that an aperture defined by the frame component aligns with the optical component, wherein the frame component comprises an outer surface having a dark appearance for a portion of the outer surface that surrounds the aperture. 
     
     
       18. The method of  claim 17 , wherein the frame component forms part of the laminate component. 
     
     
       19. The method of  claim 16 , wherein the laminate component further comprises a cover plate that defines an outer surface of the laminate component. 
     
     
       20. The method of  claim 16 , wherein the at least one optical component comprises one or more of an optical sensor, an indicator light, and an illuminator.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of and claims priority to U.S. patent application Ser. No. 13/071,330, entitled “Method and Apparatus for Concealing Sensors and Other Components of Electronic Devices,” filed on Mar. 24, 2011, now U.S. Pat. No. 8,567,955, which is incorporated by reference in its entirety as if fully disclosed herein. 
    
    
     BACKGROUND 
     The present invention relates generally to methods and apparatus for concealing sensors and other components of electronic devices, and particularly to concealing the presence of sensors and other components that require placement in a location of an electronic device that allows transmission of light in the visible and near-visible spectrums. A few examples of such components include cameras, infrared sensors, ambient light sensors, indicator lights, etc. 
     Many forms of electronic devices include components (such as sensors and light emitters) requiring the transmission or receiving of light. In many such devices, these components may be mounted adjacent a display. In many cases, a better design could be achieved if the location of these components could be at least partially concealed from view. However, such concealment may be problematic, since the passage of light through any intervening structure or surface is necessary for proper functioning of the optical devices. An example of an existing concealing structure for some types of devices includes a region of micro-perforations formed in a surface. Conventional micro-perforation configurations, however, allow for relatively limited transmission of the available light therethrough, and therefore may not be suitable for all concealment applications; and in some cases may be relatively complex and expensive to produce. 
     SUMMARY OF THE INVENTION 
     The present invention provides a concealing structure to at least partially conceal a sensor, light emitter or other component by at least partially preventing reflection of external light by the underlying structure. In some examples, this function is performed by a two-component masking assembly, the masking assembly including a linear polarizer to cause linear polarization of light which passes through it to an underlying component, and a wave plate to shift the axis of any reflected polarized light. In some such systems, the wave plate will be mounted substantially parallel to the linear polarizer such that it is located between the linear polarizer and optical component, to cause at least partial circular polarization of linearly polarized light which passes through the wave plate to the optical component. In some examples, the masking member may be a laminate structure including the two components. In many examples, the component may be mounted in a border area of a device, adjacent a display screen. 
     The masking member, or mask, may further comprise a translucent cover plate that is spaced from the linear polarizer, and a layer of high optical density fluid held captive between the cover plate and the linear polarizer. The high optical density fluid has a refractive index greater than that of air. Instead, or in addition, the masking member may include an opaque frame member that defines an aperture aligned with a component in the form of optical sensor, to allow the passage of light through the aperture on to the optical sensor. An outer surface of the frame member may have, at least in a region surrounding the aperture, a dark or black appearance. 
     The mask allows the passage of light on to optical sensors beneath the mask, and it allows the passage of light from optical indicators or other illuminators mounted behind it, but it impedes the passage of light from the outside of the device which has passed through the mask and would otherwise be reflected back outwards. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  depicts a front view of a computer monitor according to an example embodiment of a device having masked optical components. 
         FIG. 2  depicts a partial sectional side view, to an enlarged scale, of the computer monitor of  FIG. 1 , showing optical components covered by a laminate mask. 
         FIG. 3  depicts a further example embodiment of a device in the form of a computer monitor having masked optical components. 
         FIG. 4  depicts yet a further example embodiment of a device provided with masked optical component, the exemplary device being in the form of a laptop computer. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description refers to the accompanying drawings that depict various details of examples selected to show how the present invention may be practiced. The discussion addresses various examples of the inventive subject matter at least partially in reference to these drawings, and describes the depicted embodiments in sufficient detail to enable those skilled in the art to practice the invention. Many other embodiments may be utilized for practicing the inventive subject matter other than the illustrative examples discussed herein, and many structural and operational changes in addition to the alternatives specifically discussed herein may be made without departing from the scope of the inventive subject matter. The invention has been described in the context of “electronic devices,” which is used to identify any of a wide variety of electrically powered devices, including without limitation: communication devices such as cell phones or land line phones; music and multimedia players; gaming devices; televisions; set top boxes, such as for televisions and other display systems; controllers, such as remote controls for operating other devices and gaming controllers; Personal Digital Assistants (PDAs); and computing devices of all forms (desktops, laptops, servers, tablets, palmtops, workstations, etc.) as well as associated components such as monitors (either separate or as part of an all-in-one systems), external drives, etc.; and many other types of devices in a variety of fields. As will be apparent from the discussion herein, the techniques and structures described herein are applicable to virtually any application where functional or aesthetic benefits can be obtained by obscuring or concealing the presence of components, and especially of light emitting or receiving components, beneath an outer surface. 
     In this description, references to “one embodiment” or “an embodiment,” or to “one example” or “an example” in this description are not intended necessarily to refer to the same embodiment or example; however, neither are such embodiments mutually exclusive, unless so stated or as will be readily apparent to those of ordinary skill in the art having the benefit of this disclosure. Thus, the present invention can include a variety of combinations and/or integrations of the embodiments and examples described herein, as well as further embodiments and examples as defined within the scope of all claims based on this disclosure, as well as all legal equivalents of such claims. 
     Referring now to  FIG. 1 , therein is depicted an electronic device in the example form of a computer monitor  100  as one example of many possible configurations that may be used to implement the present invention. The monitor  100  comprises a display area or screen  102  surrounded by a border area or periphery  104 . The periphery  104  is defined by a body  106  of the monitor  100 , the body  106  may be formed, for example, of a plastic, metal or glass material. 
     The body  106  the monitor  100  defines a cavity or recess  108  in the periphery  104  to house one or more components such as optical sensors or indicators. For ease and clarity of reference herein, the term “optical component” will be used to identify any component which emits visible light or near-visible light, and/or which receives visible or near-visible light. While the present techniques will often be used primarily with such optical components, due to the need for light transmission for these components, it should be clearly understood that components other than optical components may also be concealed through use of the structures and methods described herein. To avoid doubt, the mechanism that receives or transmits the light can be a structure other than the device that originally emits or uses the light. For example, an light source (such as an LED) could be located at a remote location, but communicate the light through an optical fiber (or light pipe) to the emitting end of the fiber at a desired location for the light, and thus in that example, the optical fiber (or similarly functioning device) is an “optical component” within the scope of the above definition. The terms “optical” and “light” as used herein pertain to electromagnetic radiation both in the visible spectrum and in the infrared spectrum. Thus an “optical sensor” as used herein refers to an optical component that receives light in the visible or near-visible spectrum. 
     In this example, the monitor has a generally rectangular profile, when viewed face-on, with the recess  108  being located more or less centrally, and in an operatively horizontal upper crossbar or band of the periphery  104 . The monitor  100  includes a number of optical components mounted in the recess  108 . In this example, an optical sensor in the form of an ambient light sensor (ALS)  112  and an optical indicator provided by an indicator light  114  in the form of a light emitting diode (LED) are positioned in the recess  108  (see also  FIG. 2 ). The ALS  112  serves to sense ambient light conditions, and may be communicatively coupled to display software or electronics of the screen  102 , to automatically adjust a display on the screen  102  responsive to changes in ambient light. In other embodiments, a camera aperture and/or lens may be housed in the recess  108  together with the ALS  112  for capturing video or still images of a user facing the monitor  100 . Such a camera may automatically adjust properties such as aperture size and/or shutter speed (or other parameters) responsive to feedback from the ALS  112 . 
     The indicator light  114  may be used indicate a particular state or condition of the monitor  100  or associated devices. Thus, for example, the indicator light  114  may automatically be switched on to emit visible light in response to an event or stimulus, or as an indicator of a state of the device: e.g. activation of an associated camera, occurrence of a particular keyboard condition, to indicate an e-mail inbox status, to indicate a battery charge state, etc. The indicator light may include an arrangement of colored LEDs configured to produce a color-differentiated emission depending on the status of an associated device condition. 
     The periphery  104  is covered by a laminate assembly (“laminate”)  116  which extends continuously around the periphery  104  and extends over a mouth of the recess  108  that faces operatively outwards from the body  106 , thus serving as a mask for the optical components in the recess  108 . The recess  108  is a blind recess, by which is meant that the mouth of the recess  108  is the only entrance for incident light to the recess  108 . An outer surface of the periphery  104  is thus provided by the laminate  116 . Laminar components of the laminate  116 , according to an example embodiment, can best be seen in  FIG. 2 , which shows the laminate  116 , recess  108 , and part of the body  106  in cross-section. For clarity of description, the recess  108  is shown to be somewhat larger than may be the case in practice. In particular, for clarity of illustration,  FIG. 2  shows a sizable gap in the recess  108  between the laminate  116  and the optical components mounted in the recess  108 , while, in practice, excess space in the recess  108  will often preferably be limited. Additionally, as will be apparent to those skilled in the art, the surfaces defining recess  108 , and other non-optical surfaces within the recess (as opposed, for example, to lenses and the like) will be matte black so as to minimize internal light reflections within recess  108 . The ALS  112  and the indicator light  114  are likewise illustrated as having flat peripheral outlines in section, but it will be appreciated that at least some of these optical components may have a spheroidal shape. In some embodiments, the optical components, particularly optical indicators such as the indicator light  114 , may include a section of light pipe provided between the indicator and the laminate  116 , to promote uniform light dispersion. 
     The laminate  116  includes an operatively outer translucent or transparent cover plate. In the present example, the cover plate is a glass cover  204  of clear glass and has no significant optical effect on light passing through it. In a region of the laminate corresponding to the location of recess  108  containing the described optical components, the laminate  116  further includes a composite circular polarizer assembly  210  located between the body  106  and the glass cover  204 . The composite circular polarizer assembly comprises a linear polarizer  212  connected face-to-face with a wave plate  216 . The linear polarizer  212  is located on an operatively outer side of the wave plate  216 , with the wave plate  216  bearing against the body  106  of the monitor  100  along the periphery  104 . Light that, in operation, passes from the outside through the laminate  116  and to the recess  108  thus first traverses the linear polarizer  212  and thereafter passes through the wave plate  216 , while the light emitted from the indicator light  114  passes first through the wave plate  216  and then through the linear polarizer  212 . The linear polarizer  212  serves to polarize electromagnetic radiation in the visual and infrared spectrum such that an electric field vector or magnetic field vector of the radiation is generally confined to a given line along the direction of propagation. The linear polarizer  212  thus has a specific optical axis. 
     The wave plate  216  is an optical device that alters the polarization state of electromagnetic wave, typically a light wave, travelling through it by shifting the phase between two perpendicular polarization components of the light wave. The wave plate  216  may be a birefringent crystal with carefully chosen orientation thickness. In the present example, the wave plate  216  is a quarter wave plate that creates a quarter-wavelength phase shift and thus changes linearly polarized light to circularly polarized light, and vice versa. The use of a quarter-wave plate is not the only foreseeable embodiment, as other degrees of phase shifts may be adequate for given applications (such as, for example, a ⅛ wave plate, creating a ⅛-wavelength shift). Additionally, in some embodiments, the laminate  116  may further include a band pass filter to limit light passing therethrough to a particular band of wavelengths in which the wave plate produces optimal performance. 
     The laminate  116  further includes a frame member in the form of a layer of black ink  220  located between the glass cover  204  and the linear polarizer  212 , the layer of ink  220  lying face-to-face with an operatively inner face of the glass cover  204 . The layer of ink  220  defines an opening or aperture  224  aligned with the recess  108 , to permit the passage of light through the laminate  116  into and out of the recess  108 . It will be appreciated that the layer of ink  220  is opaque, obstructing the passage of light through it, and is colored black, to provide a black finish to the periphery  104  of the monitor  100 . In some devices, such as, for example, when the features described herein are applied to a mobile telephone, the glass cover  204  may extend over the entirety of the screen  102  and the periphery  104 , so that operatively outer surfaces of the screen  102  and periphery  104  are flat and co-planar, while the layer of black ink  220  may be provided only along the periphery  104 , to give the periphery  104  a glossy black finish. In embodiments where a matte black finish is required, an operatively outer surface of the glass cover  204  may be roughened or somewhat frosted. 
     In this example system, the glass cover  204  and the layer of black ink  220  are spaced from the linear polarizer  212  by a layer of high optical density fluid, in this embodiment an index matching fluid  228 . The term “high optical density fluid” is used to identify a fluid which has a refractive index greater than that of air, so that the difference between the refractive indices of the index matching fluid  228  and the glass cover  204  is smaller than the difference between the refractive indices of the glass cover  204  and air. The high optical density fluid may thus, for example, have a refractive index within the range of 1.2-1.7, often being within the range of 1.3-1.6. The term “index matching fluid” is used to identify a fluid which is selected to have a refractive index between that of the glass cover  204  and the linear polarizer  212 . A desired refractive index for the index matching fluid may, in one embodiment, be calculated by taking the square root of the product of the reflective indices of the glass cover  204  and the linear polarizer  212 . The index matching fluid  228  may be a liquid of high viscosity, such as, for example, a resin. In the present example, the index matching fluid  228  is a gel or epoxy with a refractive index of about 1.45, the glass cover having a refractive index of about 1.5 and the linear polarizing having a refractive index of about 1.4. In some examples, the index matching fluid may also have a tint to further assist in matching the appearance of the neighboring region having black ink  220 . 
     The layer of index matching fluid  228  is held captive between the linear polarizer  212  and the layer of ink  220  and the glass cover  204 . The index matching fluid  228  completely fills a volume defined by the linear polarizer  212 , the layer of ink  220 , and the glass cover  204 , so that no air pockets are formed in the layer of index matching fluid  228 . 
     The linear polarizer  212  and the wave plate  216  may each be about 0.1 mm thick in many practical embodiments, while the glass cover  204  may be about 0.5 mm thick. The layer of index matching fluid  228  may have a thickness of about 0.05-0.2 mm. The composite laminate  116  may thus have a thickness of about 0.8-1.2 mm, and preferably within the range of 0.6 to 1.0 mm. 
     In operation, unpolarized ambient light, indicated in  FIG. 2  by unbroken arrowed lines  234 , passes through the laminate  116  to reach the ALS  112 , but after reflecting off components of the recess  108 , the reflected light is blocked by the laminate  116 , as described in more detail below. In contrast, light emitted by the indicator light  114  passes through the laminate  116  and aperture  224 . Unpolarized ambient light that does not pass through the aperture  224 , as indicated by arrows  230 , is absorbed by the layer of black ink  220  with minimal reflection from the outer surface of the layer of black ink  220 , to give the laminate  116  a dark or black appearance. Unpolarized light that passes through the aperture  224  (indicated by arrow  234 ), however, passes through the glass cover  204  and the layer of index matching fluid  228  without significant optical alteration, and is linearly polarized by the linear polarizer  212 . In  FIG. 2 , linearly polarized light is indicated by dotted lines  236 . For ease of illustration, polarization effects of a particular layer are indicated by a change in the status of the associated arrowed line at an entrance plane to the particular layer. Thus, for example, an exemplary beam of light  234  is shown as being linearly polarized at a plane defining the interface between the layer of index matching fluid  228  and the linear polarizer  212 . Light  236  which is thus polarized by the linear polarizer  212  has a plane of polarization corresponding to the optical axis of the linear polarizer  212 . 
     The linearly polarized light  236  is thereafter changed to circularly polarized light  238  by the wave plate  216 . Circularly polarized light is indicated in  FIG. 2  by chain dotted lines at  238 . The circularly polarized light  238  thus reaches the ALS  112 , permitting the ALS  112  to sense ambient light qualities. It will be appreciated that circular polarization of the ambient light  234 , as described above, does not significantly affect the effectiveness of the ALS  112 . Although at least the linear polarizer  212  may absorb a portion of the ambient light  234 , the laminate  116  may in some embodiments have a transmittance factor of about 50%. 
     When the circularly polarized light  238  is reflected off components in the recess  108 , it will re-enter the wave plate  216 . The reflected circularly polarized light  238  is converted by the wave plate  216  to linearly polarized light  240 , but the plane of polarization of the newly linearly polarized light  240  is orthogonal (i.e. normal or perpendicular) to the optical plane of the linear polarizer  212 . As a result, the linearly polarized light  240  is absorbed or obstructed by the linear polarizer  212 . The laminate  116  thus allows passage of light from the indicator light  114  through it, but blocks the passage of light  238  which is reflected from the components of the recess  108 . Because the laminate  116  effectively acts as a light trap, so that no light, or only a minimal amount of light, is reflected from the recess  108 , the aperture  224  will appear black to a user when the indicator light  114  is off. “Minimal reflected light” in terms of the identified systems indicates that at least 99% of external light reflecting off of surfaces within recess  108  is blocked or absorbed; while many systems should be configurable to provide 99.9% or even greater blocking or absorption. The particular pigment of the layer of ink  220  may be selected to limit visual distinction between the layer of ink  220  and the aperture  224 , when the light  114  is dark. Because at least a region of the frame member provided by the layer of ink  220  surrounding the aperture  224  is black, the aperture  224  has a similar appearance to the surrounding layer of black ink  220 , and is therefore hidden or masked. 
     When the indicator light  114  is switched on, it may emit unpolarized light  244  that passes through the wave plate  216  without a change in its polarization state. The light  244  is, however, polarized by the linear polarizer  212 , to provide linearly polarized light  248 . Such linearly polarized light  248  passes through the aperture  224  and is easily visible to a user. 
     Provision of the linear polarizer  212  and wave plate  216  combination, together with an aperture in a black background provided by the layer of ink  220 , permits optical sensors and/or indicators, such as the ALS  112  and the indicator light  114  to be hidden. Not only are the particular components mounted in the recess not visible, but the presence of any sensors or indicators in the black background of the periphery  104  is not easily detectable by a casual viewer. The arrangement also allows the passage of more light through it than is the case with known methods of obscuring optical sensors and/or indicators. For example, a micro-perforation configuration, which, in many configurations, allows the passage of less than 10% of incident light (the transmission being a function of the perforation size and spacing, and with transmission being in generally adverse relation to the invisibility of the perforations). In contrast, the laminate  116  may in some embodiments allow about 50% of incoming light therethrough. The greater translucency of the laminate  116 , as compared to, for example, micro-perforation configurations, provides not only improved performance of optical sensors, such as the ALS  112 , but it also allows more light from an optical indicator, such as the indicator light  114 , to pass through it. A visual indicator may therefore consume less power in order to provide comparable light intensity to a user. Production of the laminate  116  is furthermore relatively cost effective, in comparison to, for example, micro-perforation configurations. The layered linear polarizer  212  and wave plate  216  may, for example, be made in a roll-to-roll process and may be laminated onto glass. 
     The provision of obscured visual sensors and indicators in a black setting or background, such as that provided by the arrangement described with reference to  FIGS. 1-2 , may be employed in a variety of applications. Thus, for example,  FIG. 3  illustrates another example embodiment of a monitor  300  having a screen  304  surrounded by a border area or periphery  302  that is covered by a laminate  116  similar to that of  FIG. 2 . Like reference numerals indicate like parts in the respective drawings. Similar to the monitor  100  of  FIGS. 1-2 , the monitor  300  defines a recess  310  in an upper crossbar, with an ALS  112  mounted in the recess. A lens  318  for a video capturing device or video camera is additionally situated in the recess  310 . To minimize degradation of images captured by the camera lens  318 , the layers of the laminate  316  are optically flat. The layer of ink  220  of the laminate  116  defines a more or less rectangular recess  308  that is in alignment or in register with the ALS  112 . 
     The monitor  300  additionally includes an elongated peripheral recess or channel  312  which extends along the periphery  302 . A series of optical components is mounted in the recess  310 . In this example the optical components include a series of light emitters in the form of LEDs  320 . The LEDs  320  may serve to illuminate a face of a user seated in front of the monitor  300 , thus to ensure proper lighting of the user&#39;s face, such as for photos or for videoconferencing. While, in some embodiments, the LEDs  320  may be white LEDs, the LEDs  320  may, in other embodiments, provide a red, green and blue (RGB) lighting arrangement, to permit variation in color characteristics of illuminating light provided by the LEDs  320 . The LEDs  320  may thus, for example, be in communication with the ALS  112  by a control arrangement, to automatically adjust the color of illuminating light provided by the LEDs  320  dependent on the characteristics of ambient light, as sensed by the ALS  112 . Alternatively, the color characteristics of illuminating light may be varied based on image analysis performed on images captured by the lens  318 . 
     The monitor  300  further provides obscured indicia in the form of a pair of scroll arrows  316  located on a sidebar of the periphery  302 . The arrows  316  are constructed in a manner similar to the arrangement described in  FIGS. 1-2 , comprising a pair of indicator lights housed in respective recesses which are aligned with associated apertures in the layer of black ink  220 . The apertures of the arrows  316  are, however, shaped to provide respective indicia or icons, in this example being the respective arrows. Thus, in use, when a display on the screen  304  is being scrolled up or down, the corresponding arrow  316  will become visible due to automatic powering of its indicator light, but will otherwise be practically invisible to a user. 
     Yet a further example embodiment is illustrated in  FIG. 4 , in which reference numeral  400  generally indicates a laptop computer. In this example, the concealing structure is used on an external surface, completely independent of the laptop display. The computer  400  is of typical clamshell construction, comprising a base (not shown) and a lid  406  which are hingedly connected together for operation between an open condition in which a display screen on the inside of the lid  406  is visible, and a closed condition shown in  FIG. 4 . The computer  400  includes an auxiliary hidden display  410  on the outside surface of the lid  406  adjacent a rear edge of the computer  400 . The display  410  comprises an array of colored LEDs mounted in a recess  418  in the lid  406 , although, in other embodiments, an LCD or other type of display may be used. A laminate  116  similar to that described with reference to  FIGS. 1-2  extends over the back surface of the lid  406 , providing an operatively outer surface for the lid  406 . In this embodiment, the laminate  116  extends continuously over the entire back of the lid  406 , to provide a continuous flat surface for the lid  406 . A frame member provided by a layer of black ink  220  in the laminate  116  defines a rectangular aperture  422  aligned with the display  410 , to allow the passage of light through the laminate  116  when the display  410  is activated and emits light. A further optical component in the form of a passive infrared (PIR) proximity sensor  426  is mounted in the recess  418 . The proximity sensor  426  is somewhat larger than, for example, the ALS  112  described with reference to  FIG. 2 . The proximity sensor  426  may have a diameter of 5-8 mm, while an ALS  112  may have a diameter of 2-4 mm. 
     The display  410  may be connected to the proximity sensor  426  to automatically activate the display  410  in response to sensing of the presence of an object such as a human hand. The presence of the recess  418  and its optical components are visually obscured when the display  410  is inactive, due to the trapping of light by operation of the linear polarizer  212  and the wave plate  216  forming part of the laminate  116 , as described above. The aperture  422  will therefore emit no or little light and appear black, thus being indistinguishable from the black appearance of the lid  406  provided by the layer of black ink  220 , so that the lid  406  of the computer  400  has an unbroken black appearance. However, when a user brings a hand close to lid  406 , its presence is sensed by the proximity sensor  426  and the auxiliary display  410  is automatically activated. The display  410  may be arranged to display information a user may wish to access without opening and switching on the computer  400 , such as, for example, information regarding a user&#39;s e-mail account, when the display  410  is implemented to indicate, for example, a number of unread e-mail messages. 
     Further applications of an optical mask arrangement as described above, may include an indicator mounted in a key of a keyboard, so that an upper surface of the key has an apparently unbroken black finish, but displays a backlit letter, indication, or icon when the indicator light is switched on. In a further use, an array or ensemble of proximity sensors, such as infrared proximity sensors, may be mounted at spaced positions on a periphery of a monitor or computer screen in order to, for example, detect human gestures. The proximity sensors may be masked by a laminate  116 , so as to obscure the sensors and provide a clean black surface to be screened periphery. 
     The described masked optical indicators and sensors have been described in the context of devices such as desktop computers, laptop computers, mobile telephones, touchscreen tablets, and the like. However, as noted earlier herein, the methods and apparatus are equally applicable to a much broader arrange of electronic devices beyond the consumer electronics and computer fields. For example, the above-described methods and structures may also be used in automotive applications (for example to provide masked indicators on a vehicle dashboard), on medical devices (for example, as indicators of various types), and in a broad range of other device types and applications as will be apparent to persons having the benefit of the present disclosure. 
     The above-describe methodologies may also be employed using partial polarization. A linear polarizer forming part of the laminate may thus, for example, pass some light having a polarization different from the optical axis of the linear polarizer. This may be the case when a thinner layer of polarizer is used. Instead, or in addition, a thinner wave plate may be used (as in the previously mentioned possible use of a ⅛th wave plate instead of a quarter wave plate). An advantage of such partial polarization is greater transmission of light, with concomitant improved performance of indicators, sensors, illuminators, cameras, and the like. Although partial polarization may cause the hidden features to be somewhat more easily detectable, complete efficacy of the polarizer system may not be required to adequately hide some components. For example, smaller optical components may be effectively hidden from normal viewing, even if not all reflected light is blocked from transmission to the exterior of the electronic device. 
     Many additional modifications and variations may be made in the techniques and structures described and illustrated herein without departing from the spirit and the scope of the present invention. Accordingly, the present invention should be clearly understood to be limited only by the scope of the claims and equivalents thereof.

Metadata:
Filing Date: 20131029
Publication Date: 20141223
Grant Date: 20141223
Priority Date: 20110324
Inventors: AMM DAVID THOMAS
DUDLEY JAMES J.
MAHOWALD PETER HENRY
Assignee: APPLE INC
CPC Classifications: [{"code": "G02B5/3083", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1647", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1605", "inventive": true, "first": true, "tree": "[]"}, {"code": "G02B5/3083", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1647", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1605", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1605", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1647", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02B5/3083", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1647", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1605", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 46026897