Patent Publication Number: US-8115698-B2

Title: Methods and systems for image processing and display

Description:
This patent application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/966,419 entitled “Methods And Systems for Image Processing And Display”, filed Aug. 28, 2007, which is incorporated herein by reference. 
     RELATED APPLICATIONS 
     The present provisional application is related in subject matter to concurrently filed patent application Ser. No. 12/152,009, entitled “Methods And Systems For Projecting Images” by Frank Azor et al. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to image display and image processing and, more particularly, to image display and image processing by an information handling system. 
     BACKGROUND OF THE INVENTION 
     One type of conventional stereoscopic three dimensional imaging systems utilizes a dual panel display system that includes a front transmissive LCD display panel and a rear transmissive LCD display panel disposed in spaced relationship and substantially optically aligned with each other so that an image produced by the rear LCD display panel passes through the front LCD display panel. The principle of this 3D technique is based on polarized light to create images for left and right eye viewing. Left and right eye images are created by dynamically changing the polarity of each pixel. To control the liquid crystal twist, an electric field is applied. Varying the electric field on a per pixel basis results in polarization angles anywhere from 45 degrees to 135 degrees. The user wears passive linearized-polarizer glasses, with the left lens containing a 45 degree axis, and the right lens containing a 135 degree axis. As so viewed together by the viewer, the two images produce a perception of three dimensions to the viewer. One example of such a commercially-available stereoscopic dual panel LCD display system is known as an iZ3D stereoscopic display monitor available from Neurok Optics of San Diego, Calif. 
     Each of the front and rear display panels of the above-described conventional stereoscopic three dimensional imaging system is transmissive to light produced by a back light positioned behind the rear LCD display panel. A diffuser is present between the rear LCD panel and front LCD panel. The rear LCD display panel includes a rear LCD display layer, an input polarizer layer positioned adjacent the rear LCD panel between the back light and the rear LCD display layer to create a plane polarized background light, and an output polarizer layer positioned adjacent the rear LCD display layer between the rear LCD display layer and front LCD panel. The rear LCD display layer selectively rotates light against the plane polarized background to create cross-polarized images using selective electrical charge imparted to liquid crystal materials in rear LCD display layer. Since polarization of the input polarizer layer is orthogonal to polarization of the output polarizer layer, the cross-polarized image of the scene that is produced by the charged liquid crystal material in the rear LCD display layer is visible to the user with or without the polarized glasses. 
     The front transmissive LCD panel of the above-described conventional dual-panel display system includes an output polarizer layer adjacent the front LCD display layer positioned between the front LCD display layer and a viewer of the dual panel display system, with no input polarizer layer provided for the front LCD display panel between the front LCD display layer and the rear LCD display panel. Because no input polarizer layer is present for the front LCD display layer, the corresponding perspective view of the scene that is produced by the selectively charged liquid crystal material in the front LCD display layer that is only visible via polarized glasses. At the pixel level, the liquid crystal material may be polarized from any angle from 45 degrees to 135 degrees. Algorithms of the dual-panel display system are used to orient the left eye image at a 45 degree axis for viewing with the left eye polarized lens that is built with a linearly polarized 45 degree axis, and to orient the right eye image at a 135 degree axis for viewing with the right eye polarized lens that is built with a linearly polarized 135 degree axis. Together, the two simultaneously-displayed images produce a perception of a three dimensional scene to the viewer wearing the pair of polarized eye glasses. 
     Privacy filters for notebook computers and flat panel monitors exist today. These filters are louvered film and are applied to the LCD screen. The louvered film dramatically limits the viewing angle, so that a user has only a few degrees from which to view the content. As a result, the only way to view the contents of the screen is from a position directly in front of it. Thus, the user and people standing behind the user can view the entire content of the screen. 
     Other technology exists for privacy filtering. In one example, a louver affect is selectively provided, with the result that a brighter screen is provided due to less light being absorbed. In another example, a camera is used to track the eye/head movement of a user in a shaking environment (e.g., when commuting on a train, etc.) and to modify the display screen image so that it shakes in synchronization with the shaking body movement of the user due to the train ride in an attempt to prevent a person sitting directly behind the user from viewing the content of the display screen while in the shaking environment. In both cases, the entire screen is viewed privately only under certain conditions, i.e., at certain angles or under shaking conditions. 
     As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems. 
     SUMMARY OF THE INVENTION 
     Disclosed herein are methods and systems for displaying or projecting images (e.g., text, graphic photographic or artistic images, movies, documents, combinations thereof, etc.) from one or more digital files using an information handling system. The disclosed methods and systems may be implemented in one exemplary embodiment to provide the ability for a user (e.g., mobile business user) of an information handling system to view a selected image (e.g., image that is derived from a data file) on a display or projection screen privately, while allowing other images (e.g., images derived from other data files) to appear on the display or projection screen which are publicly viewable. Advantageously, in such an embodiment only the user is allowed to view the private image, as well as the publicly viewable images. Further advantageously, the private image and publicly viewable images may be optionally simultaneously displayed or projected if so desired. The disclosed methods and systems may be implemented to display or project images on any type of suitable display or projection screen to any type/s of users, but in one exemplary embodiment may be employed to display images to a mobile business user on the liquid crystal display screen of a notebook computer (e.g., small business size notebook computers having a size of from about 12″ to about 15.4″). 
     In one exemplary embodiment, the disclosed methods and systems may be implemented using stereoscopic three-dimensional (3D) monitor technology which employs the use of dual LCD panels in a monitor which may be powered, for example, by dual graphical processing units (GPUs) or a common GPU having stereo image data outputs. An optional light diffuser may be positioned between the two display panels. A single front panel linear polarizer may be located in front of the front display panel between the front panel and the viewing location/s of one or more human viewers, or in an alternative embodiment the single linear polarizer may be located in back of the front display panel between the front display panel and the rear display panel. When operating in two-dimensional (2D) mode, the rear display GPU (or rear display output of a stereo GPU) may be selected and controlled to send image data to the rear LCD panel which displays an image that includes content (e.g., content designated as “publicly viewable”) that is visible without further polarization to all viewers (e.g., visible to the naked eye without polarized glasses or other polarizing medium). The front display GPU (or front display output of a stereo GPU) may be selected and controlled to send image data to the front LCD panel which displays an image that includes content (e.g., content designated as “privately viewable”) that is only visible by human viewers with additional appropriate polarization medium that is correctly matched to the polarizer located, depending on the particular embodiment, either in front of the front panel of the monitor or in back of the front panel of the monitor (e.g., by viewers viewing the monitor through a passive polarizer that is cross-polarized relative to the linearly polarized axis selected for use as the single polarizer located either in front or in back of the front display panel). Although the disclosed systems and methods may be so implemented using a stereoscopic three-dimensional (3D) monitor having dual LCD panels, any other configuration of two or more transmissive display layers disposed in relationship to each other such that they are capable of displaying multiple images in the manner as so described elsewhere herein may also be employed. 
     The disclosed systems and methods may be implemented in one embodiment to provide one or more viewers with the ability to privately view (with appropriate intervening polarization such as glasses with appropriately polarized lenses) one or more selected “private” images from digital files on a display monitor system or projection screen. In one exemplary display monitor embodiment, a stereoscopic 3D LCD monitor or screen configuration may be employed such as described above, as may be any other configuration of at least two transmissive LCD display layers disposed in spaced or other suitable relationship. In another exemplary embodiment, multiple (e.g., two) image projection assemblies (integrated or non-integrated) may be configured and positioned relative to each other and to a projection screen in order to allow projection of multiple images onto a projection surface for front or rear projection viewing. In either case, both the private images, as well as other images selected for public display as images visible to the naked eye, may be simultaneously displayed and coexist simultaneously on the same display monitor system or projection screen. In such a case, content of the private images will be visible only to those one or more users viewing the images with appropriate intervening polarization. 
     In one exemplary embodiment, by taking advantage of horizontal viewing angle capability of LCD display panel technology (e.g., allowing viewing angles of up to about 170 degrees), the content of private images may be visible from many viewing locations within a given viewing area in front of the display screen system, e.g., allowing many individuals to stand in a semicircle around the front of the display screen and view the private content of the private image in a manner not possible when using conventional louvered privacy filters. 
     In another exemplary embodiment, a software and/or firmware application may be further provided for execution on an information handling system that uses one or more characteristics of a given digital file to selectably display images either publicly (visible to all viewers) or privately (only visible to viewers with correct intervening polarization medium present). Examples of file characteristics that may be so used include, but are not limited to, file attribute/s assigned to a given file, file type (e.g., text file, graphic image file, html file, etc.). Using this capability, images from any arbitrary file may be selected to be viewed privately from at least one viewing location using appropriate polarization by having that selected file or files displayed on a front display panel of a dual display panel system or other suitable multiple-display layer configuration as described elsewhere herein. Optionally, images from other files may be viewed publicly at the same time from the same viewing location by having the publically-viewable images simultaneously displayed onto the rear display panel of the dual-display panel system. 
     For example, a software and/or firmware application may be provided for execution on an information handling system (e.g., note book computer) that is capable of assigning a viewability attribute (e.g., publicly viewable, privately viewable) to any digital file that is accessed by the information handling system (e.g., accessed from system storage such as optical or magnetic disk drive or non-volatile memory, accessed or downloaded from Internet or other network, etc.). A software and/or firmware application may be further provided for execution on an information handling system that uses this attribute to selectably display images either publicly (visible to all viewers) or privately (only visible to viewers with correct intervening polarization medium present). When implemented to display images on a dual LCD panel monitor such as described above, a “private” attribute setting may be implemented to ensure that image/s from a particular digital file designated with the “private” attribute is displayed only on the LCD display layer of the front LCD panel via an appropriate GPU output signal from the information handling system to the front panel, whereas the “public” attribute setting may be implemented to ensure that images from a particular digital file designated with the “public” attribute is displayed on the LCD display layer of the rear LCD panel via an appropriate GPU output signal from the information handling system. Similar methodology may be selectable public or private display based on file characteristics other than assigned file attributes (e.g., file type). 
     In one exemplary embodiment, an image display application (e.g., software and/or firmware utility) may be provided for execution by one or more processors of an information handling system. The image display application may be configured to allow a user of the information handling system to customize what the user wants to view privately by allowing the user to select a given digital file/s (e.g., by keyboard, graphical user interface, other suitable input/output device, etc.) that is accessible to the information handling system, and to allow the user to assign a “privacy” attribute to the selected digital file/s. For example, a default image file privacy attribute may be set to be “public viewable” so that all files are displayed on the rear display panel of a dual display panel system absent user designation otherwise. In such an example, a user may be allowed to selectively assign a “view privately” attribute for one or more selected files, e.g., so that these files will only be displayed privately on the front display panel of a dual display panel system. Alternatively, the default image privacy attributed may be “view privately” in which case a user may be allowed to selectively assign a “public viewable” attribute for one or more selected files to allow public display. 
     In yet another example, any other type/s of file characteristics (i.e., other than selected file attribute) may be employed by a software to differentiate between privately viewable and public viewable files. Examples of such file characteristics are generic type of image file (e.g., text image file, photographic image file, etc.) and specific types of files (e.g., Microsoft Word document file, JPEG image file, MPEG video image file, HTML file, etc.), file name assigned by a user, etc. In the latter example, an information handling system may be configured to display images having a particular file characteristic either privately or publicly by default (e.g., all text image files displayed privately and all video image files displayed publicly), based on desired system configuration and/or based on user selection of same via input to an image display application. 
     In another example, an image display application may be configured to give a user the ability to highlight/select a file of interest to view privately, and then to perform a HotKey stroke or keystroke combination (e.g., Cntl+key or Alt+key) to confirm this selection to the information handling system. In a further embodiment, a user may be given the ability to instantly (i.e., in real time) change the privacy attribute of a given image file, e.g. “panic button” function. For example, a user may be enabled to change a public viewable file to a view privately file, e.g., with a stroke of a designated keyboard key or other button. In one exemplary embodiment, a user-programmable Hot Key or a Pre-Programmed Hot Key may be provided for this panic button purpose on a keyboard of an information handling system. 
     In one respect, disclosed herein is a method of displaying images, including: providing at least first and second display layers, the first display layer being disposed in relationship to the second display layer in a position between the second display layer and at least one location for viewing images displayed by the first and second display layers, and the first display layer being transmissive to images displayed by the second display layer; providing an information handling system coupled to each of the first and second display layers, the information handling system including at least one processor configured to process an image file and to selectably display an image from the image file on either of one of the first or second display layers; processing a first image file with the information handling system for display of a first image from the image file; and selectably displaying the first image from the first image file on the second display layer or only on the first display layer based on at least one of a file characteristic of the first image file, a user input, or a combination thereof. In one embodiment, an image displayed on the second display layer may be visible at the at least one viewing location without further polarization after it passes through the first display layer, and an image displayed on the first display layer may include one or more portions of light that are polarized relative to background light displayed on the first display layer such that the image is only visible at the at least one viewing location when it is cross polarized relative to the polarization of the one or more portions of light. 
     In another respect, disclosed herein is a method of displaying images, including: providing at least first and second display layers, the first display layer being disposed in spaced relationship to the second display layer in a position between the second display layer and at least one location for viewing images displayed by the first and second display layers, and the first display layer being transmissive to images displayed by the second display layer; and displaying an image on at least one of the first or second display layers. In one embodiment, an image displayed on the second display layer may be visible at the at least one viewing location without further polarization after it passes through the first display layer and the first polarizing layer, and an image displayed on the first display layer may include one or more portions of light that are polarized relative to background light displayed on the first display layer such that the image is only visible at the at least one viewing location when it is cross polarized relative to the polarization of the one or more portions of light. 
     In another respect, disclosed herein is an information handling system configured for coupling to a display system or a projection system, the information handling system including at least one processor configured to process a first image file, the at least one processor being configured to selectably provide image data from the first image file for either of: display on a second display layer of the display system or for projection by a second projection assembly of the projection system, or only for display on a first display layer of the display system or only for projection by a first projection assembly of the projection system. The information handling system may further include an image display application configured to execute on the at least one processor and to select the first image based on identification of the file characteristic of the image file, the user input, or a combination thereof as either of: a publicly viewable file for display on the second display layer or for projection on the second projection assembly, or a privately viewable file for display only on the first display layer or for projection on the first projection assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a simplified block diagram showing an information handling system coupled to a dual panel display system according to one exemplary embodiment of the disclosed methods and systems. 
         FIG. 1B  is a simplified block diagram showing an information handling system coupled to a dual panel display system according to one exemplary embodiment of the disclosed methods and systems. 
         FIG. 2  shows methodology for displaying images on a dual panel display system according to one exemplary embodiment of the disclosed methods and systems. 
         FIG. 3A  is a simplified block diagram showing an information handling system coupled to a dual image projection system according to one exemplary embodiment of the disclosed methods and systems. 
         FIG. 3B  is a simplified block diagram showing an information handling system coupled to a dual image projection system according to one exemplary embodiment of the disclosed methods and systems. 
         FIG. 4  shows methodology for displaying images using a dual image projection system according to one exemplary embodiment of the disclosed methods and systems. 
     
    
    
     DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
       FIG. 1A  shows an information handling system  100  as it may be coupled to provide image data for display on a dual panel display system  150  according to one exemplary embodiment of the disclosed systems and methods. Information handling system  100  may be a desktop computer, a portable information handling system such as notebook computer, or may be of any other suitable configuration for providing image data to dual display system  150  in a manner as described elsewhere herein. In the illustrated embodiment, information handling system  100  includes a one or more processors  104  that include a central processing unit (CPU). An image display software and/or firmware application  102  that is executing on processor/s  104  may be provided as shown to implement one or more features of image display methodology described further herein. 
     Information handling system  100  also includes internal memory  106  (e.g., magnetic or optical disk drive), and GPU  120  having dual image display capability (e.g., via stereo graphics device drivers and two digital video interfaces, DVI  1  and DVI  2 ), it being understood that two separate single image GPUs may alternatively be employed for this purpose. In one exemplary embodiment, GPU  120  may be a implemented using commercially available stereo graphics device drivers such as are available from NVIDIA Corporation of Santa Clara, Calif. Such stereo graphics device drivers allow a single GPU card to output a left and a right channel data stream out of a GPU  120  using two connectors (i.e. 2 DVI connectors, etc). Such device drivers may be further modified to convert from left and right channels into front and rear channels in order to support a front and rear LCD panel architecture of a dual display monitor such as iZ3D stereoscopic display monitor available from Neurok Optics of San Diego, Calif. 
     In the illustrated embodiment, image display application  102  of processor/s  104  is shown coupled to receive and process digital file information in the form of digital data  118  from memory  106 , digital data  108  from network  110  (e.g., wide area network such as Internet, local area network, etc.), and/or digital data  116  from other source such as an external memory device, it being understood that these are components are exemplary only and that a processor of an information handling system may be configured to receive digital data from any one or more sources capable of supplying digital data. Image display application  102  is also shown coupled to receive user command signals  112  from an input/output device, in this case a keyboard device  114 . Image display application  102  is in turn coupled as shown to provide data to GPU  120 , which provides image data  122  and  124  for display by dual panel display system  150  in a manner as described elsewhere herein. Once again, it will be understood that the particular configuration and combination of components of information handling system  100  are exemplary only, and that any other information handling system configuration may be employed that is suitable for displaying images on a dual panel display system in a manner as described elsewhere herein. 
     Still referring to  FIG. 1A , dual panel display system  150  includes a first or front LCD display panel  154  and a second or rear LCD display panel  152  disposed in spaced relationship and substantially optically aligned with each other so that an image produced by rear LCD display panel  152  passes through front LCD display panel  154 , which is transmissive to light produced by rear LCD display panel  152 . As shown, in one exemplary embodiment, each of LCD display panels  154  and  152  may be transmissive liquid crystal LCD display panels with a back (e.g., white) light  156  positioned behind rear LCD display panel  152 . An optional diffuser  156  may be present between rear LCD panel  152  and front LCD panel  154 , although this is not necessary. Further information on display panels for commercially-available dual LCD panel display system technology may be found described in U.S. Pat. Nos. 6,985,290; 6,717,728; United States Patent Application Publication 2005/0146787; and United States Patent Application Publication 2003/0122828, each of which is incorporated herein by reference. 
     As shown in  FIG. 1A , rear LCD display panel  152  includes a LCD display layer  160 , an input polarizer layer  162  adjacent LCD display layer  160  between back light  156  and LCD display layer  160 , and an output polarizer layer  164  adjacent LCD display layer  160  and between LCD display layer  160  and front LCD panel  154  (with optional diffuser  156  therebetween in this embodiment). Input polarizer layer  162  creates a plane polarized background and LCD display layer  160  selectively rotates light against the plane polarized background to create cross-polarized images (e.g., text, graphics, etc.) using selective electrical charge imparted to liquid crystal materials in LCD display layer  160  based on image data  122  sent to LCD display layer  160  by GPU  120 . Polarization of input polarizer layer  162  is substantially orthogonal to polarization of output polarizer layer  164  such that a cross-polarized image produced by the charged liquid crystal material in LCD display layer  160  is visible to the naked eye with no further polarization after transmittal through output polarizer layer  164 . Thus, because two polarizing layers are present in rear LCD display panel  152 , images from all files sent to this panel by GPU  120  are visible to the naked eye at any viewing location within viewing area  180  of dual panel display system  150 . It will be understood that in one embodiment, components of rear LCD panel display  152  may be configured and operate in the same manner as a display panel of a commercially available dual panel LCD display system, such as described in United States Patent Application Publication 2005/0146787. 
     As further shown in  FIG. 1A , configuration of front LCD panel  154  differs from the configuration of rear LCD panel  152  in that front LCD panel  154  includes only an output polarizer layer  172  adjacent LCD display layer  170  between LCD display layer  170  and a viewing area  180  of dual panel display system  150 , i.e., there is no input polarizer layer provided for LCD display panel  152 . Because no input polarizer layer is present for LCD display layer  170 , any image that is produced by selectively charged liquid crystal material in LCD display layer  170  (based on image data  124  sent to LCD display layer  170  by GPU  120 ) is not visible to the naked eye after transmittal through output polarizer layer  172  without the missing polarization normally provided by an input polarizer for LCD display layer  170 , or without further polarization that is orthogonal (or cross-polarized) relative to the polarization imparted by output polarizer layer  172 . In one exemplary embodiment, components of front LCD panel display  154  may be configured similar to a front display panel of a commercially-available stereoscopic LCD display panel system (e.g., such as described in United States Patent Application Publication 2005/0146787) but with the input polarizer layer missing from the display panel. One example of a suitable commercially-available stereoscopic dual panel LCD display system configured with the input polarizer layer missing from the front display panel is known as an iZ3D stereoscopic display monitor available from Neurok Optics of San Diego, Calif. 
     Still referring to  FIG. 1A , a first human user  140  may be positioned as shown at a first given viewing location within viewing area  180  of dual panel display system  150 , and having a line of sight  144 . A second human user  130  may be positioned as shown at a second given viewing location within viewing area  180  and having a line of sight  134 . In this exemplary embodiment, a light transmissive polarizer medium  132  (e.g., transmissive passive polarizing eyeglasses, transmissive passive light polarizing screen or other suitable optically transmissive polarizing medium) is shown positioned in line of sight  134  between user  130  and dual panel display system  150 . In this embodiment, polarizer medium  132  is selected to be cross-polarized relative to output polarizer layer  172  of front LCD panel  154 , so that images produced by selectively charged liquid crystal material in LCD display layer  170  of front LCD panel  154  are created, but not visible, against background light without cross polarizing medium  132 . Therefore, images produced by front LCD panel  154  are visible to user  130  (i.e., after passing through polarizing medium  132 ), and not visible to user  140  (e.g., private images). However, images produced by rear LCD panel  152  are visible to both users  130  and  140  (e.g., as publicly viewable images). 
     For example,  FIG. 1B , illustrates an alternate embodiment of dual panel display system  150  that includes a first or front transmissive LCD display panel  154  and a second or rear transmissive LCD display panel  152  disposed in spaced relationship and substantially optically aligned with each other in a manner as previously described. However, in this exemplary embodiment, configuration of front LCD panel  154  differs from the configuration of rear LCD panel  152  in that front LCD panel  154  includes only an input polarizer layer  174  adjacent LCD display layer  170  between LCD display layer  170  and optional diffuser  156 , i.e., there is no output polarizer layer provided in this exemplary embodiment for LCD display panel  152 . Optional diffuser  156  may be present in this embodiment, for example, to rotate output light from rear display panel  152  to match input light orientation of input polarizer layer  174  of front LCD panel  154  or may be absent where output light from rear display panel  152  already matches input light orientation of input polarizer layer  174  of front LCD panel  154 . Because no output polarizer layer is present for LCD display layer  170 , any image that is produced by selectively charged liquid crystal material in LCD display layer  170  (based on image data  124  sent to LCD display layer  170  by GPU  120 ) is not visible to the naked eye after without the missing polarization normally provided by an output polarizer for LCD display layer  170 , or without further polarization that is orthogonal (or cross-polarized) relative to the polarization imparted by input polarizer layer  172 . 
     Still referring to  FIG. 1B , a first human user  140  may be positioned as shown at a first given viewing location within viewing area  180  of dual panel display system  150 , and having a line of sight  144 . A second human user  130  may be positioned as shown at a second given viewing location within viewing area  180  and having a line of sight  134 . In this exemplary embodiment, a light transmissive polarizer medium  132  (e.g., transmissive passive polarizing eyeglasses, transmissive passive light polarizing screen or other suitable optically transmissive polarizing medium) is shown positioned in line of sight  134  between user  130  and dual panel display system  150 . In this embodiment, polarizer medium  132  is selected to be cross-polarized relative to input polarizer layer  174  of front LCD panel  154  and LCD display layer  170  naturally rotates light (in its non-energized or non-image producing state) by 90 degrees, so that images produced by selectively charged liquid crystal material in LCD display layer  170  of front LCD panel  154  are created, but not visible, against background light without a cross-polarizing medium  132 . Therefore, images produced by front LCD panel  154  are visible to user  130  (i.e., after passing through cross-polarizing medium  132 ), and not visible to user  140  (e.g., private images). However, images produced by rear LCD panel  152  are visible to both users  130  and  140  (e.g., as publicly viewable images). 
     It will be understood that the embodiments of  FIGS. 1A and 1B  are exemplary only, and that a dual panel display system may be provided in alternative configurations. For example, a dual panel display system may be provided with any alternative configuration of optics suitable for producing plane polarized light for illumination of a rear LCD display panel and a front LCD display panel in the manner described herein. Furthermore, any other configuration of multiple displays may be employed that is suitable for producing publically and privately viewable images in a manner as described elsewhere herein. 
     Although the disclosed systems and methods may be implemented as described above for  FIGS. 1A and 1B  using liquid crystal material in LCD display layer  170  that in its relaxed (non-image producing) state naturally rotates light by 90 degrees with a corresponding cross-polarizing medium  132 , it is also possible to employ liquid crystal material that is capable of rotating light by other values, and/or that is capable of selectively rotating light by any one of multiple angles (e.g., at any angle from about 45 degrees to about 135 degrees). It will be understood that a cross polarizing medium  132  may be accordingly selected in such a case based on the selected amount of this variable rotation so that images produced by front LCD panel  154  are visible to user  130  (i.e., after passing through polarizing medium  132 ), and not visible to user  140  (e.g., private images). Further in yet another alternative embodiment, multiple users  130  may be each provided with a different cross polarizing medium  132  that rotates light by an amount that is tuned to a different selected value of rotation. In such a case, a first private image may be displayed using LCD display layer  170  to rotate light by a first selected rotation amount that is tuned to the polarization characteristics of a first cross polarizing medium  132  used by a first user  130  so that the image is visible to the first user  130  but not to a second user  130  or user  140 , and a second private image may be displayed using LCD display layer  170  to rotate light by a second selected rotation amount that is tuned to the polarization characteristics of a second cross polarizing medium  132  used by a second user  130  so that the image is visible to the second user  130  but not to the first user  130  or user  140 . 
       FIG. 2  shows methodology  200  for displaying images on a dual panel display system using an information handling system according to one exemplary embodiment of the disclosed methods and systems. In this regard, methodology  200  may be implemented as a software and/or firmware application executing on one or more processors of an information handling system, e.g., as application  102  of either  FIG. 1A  or  1 B. Thus, the following description of methodology  200  refers to implementation using dual panel display system  150  and information handling system  100  of  FIG. 1A  or  1 B, however, it will be understood that the methodology of  FIG. 2  may be implemented with other combinations of display and information handling system hardware and/or other components. 
     Methodology  200  starts at step  210  and proceeds to step  212  where system  100  boots-up and image display application  102  initially sends all data content (i.e. Windows Desktop and icons, etc.) by default to rear LCD panel  152 . In this display mode all images are visible to the naked eye without further polarization to any user/s in viewing area  180 . However, it will be understood that it is also possible that image display application  102  may be alternately configured to send all data content to front LCD panel  154  so that all images are only visible by user  130  with benefit of polarizer medium  132 . Those display modes where all images are sent to only one LCD panel may also be referred to as two-dimensional (2D) display modes. 
     Next, image display application  102  determines in step  214  if user  130  has selected front LCD panel  154  for display of image data. User  130  may select front LCD panel  154  for display of image data using any suitable I/O device or methodology (e.g., using a button on the dual panel display system, keyboard  114 , icon setting, or other suitable I/O device). When a user so selects front LCD panel  154  for display of image data, methodology  200  proceeds to either step  222  (i.e., when user selects front LCD panel  154  for display of image data from some files) or to step  224  (i.e., when user selects front LCD panel  154  for display of image data from all files). Image display application  102  responds accordingly, i.e., by displaying some images on front LCD panel  154  in step  226  (while displaying other images on rear LCD panel  152 ), or by displaying all image on front LCD panel  154  in step  228 . In either case, all images displayed on front LCD panel  154  are only visible by user  130  with benefit of polarizer medium  132 , while any images simultaneously displayed on rear LCD panel  152  are visible to both users  130  and  140 . 
     In one exemplary embodiment, image display application  102  may simultaneously send some image data to rear LCD display panel  152  and some image data to front LCD panel  154  to implement a three dimensional (3D) display mode for displaying 3D content from a single common image file (i.e., 3D video game, 3D movie, etc.) from a selected source. In such a case, for example, a device driver of GPU  120 , enabled in stereo mode, distributes the 3D content between the 2 stereo channels  122  and  124  to the two respective LCD panels  152  and  154 . In such a case, user  130  (with benefit of polarizer medium  132 ) is able to see the content from both panels  152  and  154 , thus experiencing the desired 3D effect of the 3D file content. In a further embodiment, image display application  102  may be optionally configured to automatically recognize a 3D image file (i.e., 3D video game, 3D movie, etc.) and to automatically display this type of file in 3D display mode without user instruction or request. 
     Returning to  FIG. 2 , if a user has not selected front LCD panel  154  for display in step  214 , then image application  102  may be configured to select between LCD panel  152  or  154  for display of an image from a given image file based on one or more file characteristics of the image file. Examples of such file characteristics include, but are not limited to, file attribute/s assigned to a given file, file type (e.g., text file, graphic image file, html file, etc.). In one exemplary embodiment, the default viewing setting for an image from any given image file is a “Public Viewable” setting, i.e., the same display setting used in step  212 . Using this setting, the image data from the file is sent to the rear LCD panel display  152  in step  218 , e.g., via the rear data port (stereo driver mode enabled) from the GPU  120 . However, if one or more file characteristics of a given image file indicate a “View Privately” setting selected for the image file, then the image data from the file is sent only to the front display panel  154  in step  220 , e.g., via the front data port from the GPU  120 . 
     It will be understood that methodology  200  of  FIG. 2  is exemplary only and that the steps may be performed in other embodiments in different order, and/or with lesser or additional steps. Further, the steps of methodology  200  may be configured to repeat in iterative manner, e.g., by returning to step  214  each time one of steps  218 ,  220 ,  226  or  228  is reached. In addition, a user may be enabled to modify file characteristics and/or default public/private viewing preferences at any time during operation of methodology  200 . 
     Thus, using the disclosed methods and systems only a user  130  employing an appropriate polarizer medium  132  (e.g., wearing special polarizer glasses) positioned in the user&#39;s line of sight  134  and that is tuned to be cross-polarized to the output polarizer layer  172  of front LCD panel  154  of  FIG. 1A  or that is tuned to be cross-polarized to the input polarizer layer  174  of front LCD panel  154  of  FIG. 1B , is able to view the particular selected “privately viewable” file/content. A given user  140  (having no benefit of a polarizer medium in the user&#39;s line of sight  144 ) will not be able to see the private viewable content that has been sent to the front LCD panel  154 . This allows multiple users  130  to view the selected private content, limited only by the availability of appropriate polarizer medium (e.g., the number of available glasses) for the users and the viewing angle that defines the viewing area  180  of dual panel display system  150 . Other users  140  (without benefit of appropriate polarizer medium) in the viewing area of dual panel display system  150  are enabled to see all other publicly viewable content on the monitor (i.e., Word documents, Web Browsers, pictures, etc.), except for the particular selected private viewable content. 
     In one exemplary embodiment, a user  130  may be allowed to select images from multiple files to view privately on dual panel display system  150 , while also displaying multiple files that other users  140  may publicly view on the same dual panel display system  150 . User  130  may make this selection dynamically and in real time (e.g., via steps  214  and  222  of  FIG. 2 ), or may be allowed to pre-select the identity (e.g., file name and/or file attributes) of specific files and/or file types (e.g., Word document type) for automatic private display (e.g., via steps  216 ,  218  and  220 ). In one example, a user may be allowed to pre-set file attributes of particular individual files for private display (with all other files being publicly viewable by default), or may be enabled to select that images from all files of a specific type (e.g., word documents) be privately displayed. 
       FIG. 3A  illustrates one exemplary embodiment of the disclosed systems and methods in which a dual image projection system  300  may be coupled to receive separate image data  322  and image data  324  from an information handling system  100 , although separate image data may be received from any other suitable type of image data source/s. In this exemplary embodiment, dual image projection system  300  may be configured to in turn project separate image beams  380  and  382  that correspond to image data  322  and  324 , respectively. In this regard, image beams  380  and  382  may be projected onto a projection screen  390  in a manner such that the image corresponding to image beam  380  (and corresponding to image data  322 ) substantially completely overlaps with the image corresponding to image beam  382  (and corresponding to image data  324 ), although it will be understood that image beams  380  and  382  may be projected onto projection screen  390  in other manners, e.g., such that the image corresponding to image beam  380  at least partially overlaps with the image corresponding to image beam  382 . As shown in  FIG. 3A , projection screen  390  may be a front projection screen that is configured for viewing by users  130   a  and  140   a , and/or may be configured as a rear projection screen (e.g., that is transmissive to the projected image) that is configured for viewing by users  130   b  and  140   b  from the rear side  386  of the projection screen  309  as shown. It will be understood that the orientation of the images projected by dual image projection system  300  may be inverted or reversed prior to projection so that the images appear correctly oriented to a user  130   b  from the rear side  386  of the projection screen  390 . 
     Although  FIG. 3A  illustrates both front and rear side projection of images on projection screen  390 , it will be understood that dual image projection system  300  and projection screen  390  may be configured only for front projection of images (e.g., to users  130   a  and  140   a ), or only for rear projection of images (e.g., to users  130   b  and  140   b ). Further, it will be understood that image projection system  300  may be configured for front projection of images onto any suitable front and/or rear projection surface (e.g., office wall surface, pull down projection screen, movie theater screen, etc.), or may be configured for rear projection of images onto any suitable transmissive viewing surface (e.g., rear projection television screen or computer monitor screen, rear projection movie screen or other type of rear projection display screen, etc.). 
     Still referring to the exemplary embodiment of  FIG. 3A , dual image projection system  300  includes a first or left projection assembly  302  that generates and projects first image beam  380  onto projection screen  390 , and a second or right projection assembly  304  that generates and projects second image beam  382  onto projection screen  390 . Although the exemplary embodiment of  FIG. 3A  employs a dual image projection system  300  that includes integrated multiple projection assemblies  302  and  304 , it will be understood that any other system configuration may be employed that is suitable for generating and projecting multiple images onto a projection screen in a manner as described herein. For example, two independent and separate (i.e., non-integrated) projection systems may be employed in place of integrated projection assemblies  302  and  304  of  FIG. 3A . 
     As shown in  FIG. 3A , first projection assembly  302  includes first LCD light modulator  360  that is transmissive to light that is provided by projection light source  356  of first projection assembly  302 . An input polarizer layer  362  is positioned adjacent first light modulator  360  between projection light source  356  and first LCD light modulator  360 , and an output polarizer layer  364  is positioned adjacent first LCD light modulator  360  and between first LCD light modulator  360  and projection lens  326  of first projection system  302 . 
     In the illustrated embodiment of  FIG. 3A , input polarizer layer  362  of first projection assembly  302  creates a plane polarized background and first LCD light modulator  360  selectively rotates light against the plane polarized background to create cross-polarized images (e.g., text, graphics, etc.) using selective electrical charge imparted to liquid crystal materials in first LCD light modulator  360  based on image data  322  that is provided to first projection assembly  302 . Polarization of input polarizer layer  362  is substantially orthogonal to polarization of output polarizer layer  364  such that a cross-polarized image produced by the charged liquid crystal material in first LCD light modulator  360  and projected onto projection screen  390  by first projection system  302  is visible to the naked eye with no further polarization after transmittal through output polarizer layer  364 . Thus, because two polarizing layers are present in first projection assembly  302 , images from all files projected by first projection system  302  are visible to the naked eye at any viewing location within front projection viewing area  394  and/or rear projection viewing area  396  of projection screen  390 . 
     Still referring to  FIG. 3A , second projection assembly  304  includes second LCD light modulator  370  that is transmissive to light that is provided by projection light source  357  of second projection assembly  304 . As shown, second projection assembly  304  includes only an output polarizer layer  372  adjacent second LCD light modulator  370  between second LCD light modulator  370  and projection lens  324 , i.e., there is no input polarizer layer provided for second LCD light modulator  370  of second projection system  304 . Because no input polarizer layer is present for second LCD light modulator  370 , any image that produced by the charged liquid crystal material in second LCD light modulator  370  and projected onto projection screen  390  by second projection system  304  (based on image data  324  provided to second LCD light modulator  370 ) is not visible to the naked eye after transmittal through output polarizer layer  372  without the missing polarization normally provided by an input polarizer for second LCD light modulator  370 , or without further polarization that is orthogonal (or cross-polarized) relative to the polarization imparted by output polarizer layer  372  of second projection system  304 . 
     Still referring to  FIG. 3A , a first human user  140   a  may be positioned as shown at a first given viewing location within front projection viewing area  394  of projection screen  390 , and having a line of sight  144   a . A second human user  130   a  may be positioned as shown at a second given viewing location within front projection viewing area  394  of projection screen  390 , and having a line of sight  134   a . In this exemplary embodiment, a light transmissive polarizer medium  132   a  (e.g., transmissive passive polarizing eyeglasses, transmissive passive light polarizing screen or other suitable optically transmissive polarizing medium) is shown positioned in line of sight  134   a  between user  130   a  and front side  384  of projection screen  390 . 
     In the embodiment of  FIG. 3A , polarizer medium  132   a  is selected to be cross-polarized relative to output polarizer layer  372  of second projection assembly  304 , so that images produced by selectively charged liquid crystal material in second LCD light modulator  370  of second projection assembly  304  are projected onto front side  384  of projection screen  390 , but riot visible, without cross polarizing medium  132   a . Therefore, images projected by second projection assembly  304  are visible to user  130   a  (i.e., after passing through polarizing medium  132   a ), and not visible to user  140   a  (e.g., private images). However, images projected by first projection assembly  302  onto front side  384  of projection screen  309  are visible to both users  130   a  and  140   a  (e.g., as publicly viewable images). 
     In a similar manner, when projection screen  390  of  FIG. 3A  is configured as a rear projection screen, first human user  140   b  may be positioned as shown at a first given viewing location within rear projection viewing area  396  of projection screen  390 , and having a line of sight  144   b . A second human user  130   b  may be positioned as shown at a second given viewing location within rear projection viewing area  396  of projection screen  390 , and having a line of sight  134   b . A light transmissive polarizer medium  132   b  (e.g., transmissive passive polarizing eyeglasses, transmissive passive light polarizing screen or other suitable optically transmissive polarizing medium) may be positioned as shown in line of sight  134   b  between user  130   b  and rear side  386  of projection screen  390 . In such a rear projection embodiment, images projected by second projection assembly  304  on the rear side  386  of projection screen  390  are visible to user  130   b  (i.e., after passing through polarizing medium  132   b ), and not visible to user  140   b  (e.g., private images). However, images projected by first projection assembly  302  on the rear side of projection screen  309  are visible to both users  130   b  and  140   b  (e.g., as publicly viewable images). 
       FIG. 3B  illustrates an alternative embodiment of the disclosed systems and methods in which a dual image projection system  300  may be coupled as previously described for  FIG. 3A  to receive separate image data  322  and image data  324  from an information handling system  100 , and to project separate image beams  380  and  382  that correspond to image data  322  and  324 , respectively and in a manner as described before. In the exemplary embodiment of  FIG. 3B , first projection assembly  302  is configured in the same manner as shown and described in  FIG. 3A . However, second projection assembly  304  includes only an input polarizer layer  374  adjacent second LCD light modulator  370  between second LCD light modulator  370  and projection light source  357 , i.e., there is no output polarizer layer provided for second LCD light modulator  370  of second projection system  304 . Because no output polarizer layer is present for second LCD light modulator  370 , any image that produced by the charged liquid crystal material in second LCD light modulator  370  and projected onto projection screen  390  by second projection system  304  (based on image data  324  provided to second LCD light modulator  370 ) is not visible to the naked eye without the missing polarization normally provided by an output polarizer for second LCD light modulator  370 , or without further polarization that is orthogonal (or cross-polarized) relative to the polarization imparted by input polarizer layer  374  of second projection system  304  of  FIG. 3B . 
     Still referring to  FIG. 3B , a first human user  140   a  may be positioned as shown at a first given viewing location within front projection viewing area  394  of projection screen  390 , and having a line of sight  144   a . A second human user  130   a  may be positioned as shown at a second given viewing location within front projection viewing area  394  of projection screen  390 , and having a line of sight  134   a . In this exemplary embodiment, a light transmissive polarizer medium  132   a  (e.g., transmissive passive polarizing eyeglasses, transmissive passive light polarizing screen or other suitable optically transmissive polarizing medium) is shown positioned in line of sight  134   a  between user  130   a  and front side  384  of projection screen  390 . 
     In the embodiment of  FIG. 3B , polarizer medium  132   a  is selected to be cross-polarized relative to input polarizer layer  374  of second projection assembly  304 , so that images produced by selectively charged liquid crystal material in second LCD light modulator  370  of second projection assembly  304  are projected onto front side  384  of projection screen  390 , but not visible, without cross polarizing medium  132   a . Therefore, images projected by second projection assembly  304  are visible to user  130   a  (i.e., after passing through polarizing medium  132   a ), and not visible to user  140   a  (e.g., private images). However, images projected by first projection assembly  302  onto front side  384  of projection screen  309  are visible to both users  130   a  and  140   a  (e.g., as publicly viewable images). 
     In a similar manner, when projection screen  390  of  FIG. 3B  is configured as a rear projection screen, first human user  140   b  may be positioned as shown at a first given viewing location within rear projection viewing area  396  of projection screen  390 , and having a line of sight  144   b . A second human user  130   b  may be positioned as shown at a second given viewing location within rear projection viewing area  396  of projection screen  390 , and having a line of sight  134   b . A light transmissive polarizer medium  132   b  (e.g., transmissive passive polarizing eyeglasses, transmissive passive light polarizing screen or other suitable optically transmissive polarizing medium) may be positioned as shown in line of sight  134   b  between user  130   b  and rear side  386  of projection screen  390 . In such a rear projection embodiment, images projected by second projection assembly  304  on the rear side  386  of projection screen  390  are visible to user  130   b  (i.e., after passing through polarizing medium  132   b ), and not visible to user  140   b  (e.g., private images). However, images projected by first projection assembly  302  on the rear side of projection screen  309  are visible to both users  130   b  and  140   b  (e.g., as publicly viewable images). 
     In this embodiment, polarizer medium  132  ( 132   a  and/or  132   b ) is selected to be cross-polarized relative to input polarizer layer  374  of second projection assembly  304  and second LCD light modulator  370  naturally rotates light (in its non-energized or non-image producing state) by 90 degrees, so that images produced by selectively charged liquid crystal material in second LCD light modulator  370  of second projection assembly  304  are created, but not visible, against background light without a cross-polarizing medium  132 . Therefore, images produced by second projection assembly  304  are visible to user  130  ( 130   a  and/or  130   b ) (i.e., after passing through cross-polarizing medium  132 ), and not visible to user  140  ( 140   a  or  140   b ) (e.g., private images). However, images produced by first projection assembly  302  are visible to both users  130  and  140  (e.g., as publicly viewable images). 
     Although the disclosed systems and methods may be implemented as described above for  FIGS. 3A and 3B  using liquid crystal material in second LCD light modulator  370  that in its relaxed (non-image producing) state naturally rotates light by 90 degrees, it is also possible to employ liquid crystal material that is capable of rotating light by other values, and/or that is capable of selectively rotating light by any one of multiple angles (e.g., at any angle from about 45 degrees to about 135 degrees). It will be understood that a cross polarizing medium  132  may be accordingly selected in such a case based on the selected amount of this variable rotation so that images produced by f second projection assembly  304  are visible to a user  130  (i.e., after passing through polarizing medium  132 ), and not visible to a user  140  (e.g., private images). Further in yet another alternative embodiment, multiple users  130  may be each provided with a different cross polarizing medium  132  that rotates light by an amount that is tuned to a different selected value of rotation. In such a case, a first private image may be produced using second LCD light modulator  370  to rotate light by a first selected rotation amount that is tuned to the polarization characteristics of a first cross polarizing medium  132  used by a first user  130  so that the image is visible to the first user  130  but not to a second user  130  or user  140 , and a second private image may be produced using second LCD light modulator  370  to rotate light by a second selected rotation amount that is tuned to the polarization characteristics of a second cross polarizing medium  132  used by a second user  130  so that the image is visible to the second user  130  but not to the first user  130  or user  140 . 
     It will be understood that the embodiments of  FIGS. 3A and 3B  are exemplary only, and that a multiple image projection system may be provided in alternative configurations. For example, a first projection assembly and/or a second projection assembly may be provided with any alternative configuration of optics suitable for producing plane polarized light for projection through a LCD light modulator in the manner described herein. Moreover, it will be understood that a multiple image projection system may include three or more projection assemblies, with each projection assembly being configured to project images in overlapping manner onto a projection screen. Although first and second projection assemblies  302  and  304  of  FIGS. 3A and 3B  are illustrated disposed in adjacent side-by-side position relative to each other, it will be understood that multiple projection assemblies may be alternately disposed in any other relative positions that are suitable for projection of multiple images on a common projection surface in a manner as described elsewhere herein. 
       FIG. 4  shows methodology  400  that may be used by an information handling system  100  to project images onto projection screen  390  from a dual image projection system according to one exemplary embodiment of the disclosed methods and systems. In this regard, methodology  400  may be implemented as a software and/or firmware application executing on one or more processors of an information handling system, e.g., as application  102  of  FIG. 4 . Thus, the following description of methodology  400  refers to implementation using dual image projection system  300  and information handling system  100  of  FIG. 4 , however, it will be understood that the methodology of  FIG. 4  may be implemented with other combinations of projection system and information handling system hardware and/or other components. 
     Methodology  400  starts at step  410  and proceeds to step  412  where system  100  boots-up and image display application  102  initially sends all data content (i.e. Windows Desktop and icons, etc.) by default to first projection assembly  302 . In this display mode all images projected by dual image projection system  300  onto projection screen  390  are visible to the naked eye without further polarization to any user/s in front projection viewing area  394  and/or rear projection viewing area  396 . However, it will be understood that it is also possible that image display application  102  may be alternately configured to send all data content to second projection assembly  304  so that all images projected by dual image projection system  300  are only visible by users  130   a  and/or  130   b  with benefit of respective polarizer medium  132   a  and/or  132   b.    
     Next, image display application  102  determines in step  414  if second projection assembly  304  has been selected for projection of image data onto projection screen  390 . For example, a user  130   a  and/or  130   b  may select second projection assembly  304  for projection of image data using any suitable I/O device or methodology (e.g., using a button on the dual image projection system, keyboard  114   a  and/or  114   b , icon setting, or other suitable I/O device). When a user so selects second projection assembly  304  for projection of image data, methodology  400  proceeds to either step  422  (i.e., when user selects second projection assembly  304  for projection of image data from some files) or to step  424  (i.e., when user selects second projection assembly  304  for projection of image data from all files). Image display application  102  responds accordingly, i.e., by projecting some images on projection screen  390  using second projection assembly  304  in step  426  (while projecting other images on projection screen  390  using first projection assembly  302 ), or by projecting all images on projection screen  390  using second projection assembly  304  in step  428 . In either case, all images projected by second projection assembly  304  on projection screen  390  are only visible by  130   a  and/or  130   b  with benefit of respective polarizer medium  132   a  and/or  132   b , while any images simultaneously projected on projection screen  390  by first projection assembly  302  are visible to all users, e.g., users  130   a ,  130   b ,  140   a , and  140   b.    
     In one exemplary embodiment, image display application  102  may simultaneously send some image data to first projection assembly  302  and some image data to second projection assembly  304  to implement a three dimensional (3D) display mode for projecting 3D content on projection screen  390  from a single common image file (i.e., 3D video game, 3D movie, etc.) from a selected source. In such a case, for example, a device driver of GPU  120 , enabled in stereo mode, distributes the 3D content between the 2 stereo channels  322  and  324  to the two respective projection assemblies  356  and  357 . In such a case, user  130   a  and/or  130   b  (with benefit of polarizer medium  132   a  and/or  132   b ) is able to see the content projected from both projection assemblies  356  and  357 , thus experiencing the desired 3D effect of the 3D file content. In a further embodiment, image display application  102  may be optionally configured to automatically recognize a 3D image file (i.e., 3D video game, 3D movie, etc.) and to automatically project this type of file in 3D display mode without user instruction or request. 
     Returning to  FIG. 4 , if a user has not selected second projection assembly  304  for projection in step  414 , then image application  102  may be configured to select between projection assembly  356  or  357  for projection of an image from a given image file on to projection screen  390  based on one or more file characteristics of the image file. Examples of such file characteristics include, but are not limited to, file attribute/s assigned to a given file, file type (e.g., text file, graphic image file, html file, etc.). In one exemplary embodiment, the default viewing setting for an image from any given image file is a “Public Viewable” setting, i.e., the same display setting used in step  412 . Using this setting, the image data from the file is sent to the first projection assembly  356  in step  418 , e.g., via the front data port (stereo driver mode enabled) from the GPU  120 . However, if one or more file characteristics of a given image file indicate a “View Privately” setting selected for the image file, then the image data from the file is sent only to the second projection assembly  357  in step  420 , e.g., via the rear data port from the GPU  120 . 
     It will be understood that methodology  400  of  FIG. 4  is exemplary only and that the steps may be performed in other embodiments in different order, and/or with lesser or additional steps. Further, the steps of methodology  400  may be configured to repeat in iterative manner, e.g., by returning to step  414  each time one of steps  418 ,  420 ,  426  or  428  is reached. In addition, a user may be enabled to modify file characteristics and/or default public/private viewing preferences at any time during operation of methodology  400 . 
     Thus, using the disclosed methods and systems only a user  130   a  and/or  130   b  employing an appropriate polarizer medium  132   a  and/or  132   b  (e.g., wearing the special polarizer glasses) positioned in the user&#39;s line of sight  134   a  and/or  134   b  and that is tuned, as the case may be, either to the output polarizer layer  372  ( FIG. 3A ) or input polarizer layer  374  ( FIG. 3B ) of second projection assembly  304 , is able to view the particular selected “privately viewable” file/content. A given user  140   a  and/or  140   b  (having no benefit of a polarizer medium in the user&#39;s line of sight  144   a  and/or  144   b ) will not be able to see the private viewable content that has been sent to the second projection assembly  304 . This allows multiple users  130   a  and/or  130   b  to view the selected private content, limited only by the availability of appropriate polarizer medium (e.g., the number of available glasses) for the users and the viewing angle that defines the viewing area  394  and/or  396  of dual image projection system  300 . Other users  140   a  and/or  140   b  (without benefit of appropriate polarizer medium) in the viewing area of dual image projection system  300  are enabled to see all other publicly viewable content on the projection screen  390  (i.e., Word documents, Web Browsers, pictures, etc.), except for the particular selected private viewable content. 
     In one exemplary embodiment, a user  130   a  and/or  130   b  may be allowed to select images from multiple files to view privately via projection onto projection screen  390  by dual image projection system  300 , while also displaying multiple files that other users  140   a  and/or  140   b  may publicly view on the same projection screen  390 . User  130   a  and/or  130  may make this selection dynamically and in real time (e.g., via steps  414  and  422  of  FIG. 4 ), or may be allowed to pre-select the identity (e.g., file name and/or file attributes) of specific files and/or file types (e.g., Word document type) for automatic private projection display (e.g., via steps  416 ,  418  and  420 ). In one example, a user may be allowed to pre-set file attributes of particular individual files for private projection display (with all other files being publicly viewable by default), or may be enabled to select that images from all files of a specific type (e.g., word documents) be privately displayed. 
     For purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, entertainment, or other purposes. For example, an information handling system may be a personal computer, a PDA, a consumer electronic device, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include memory, one or more processing resources such as a central processing unit (CPU) or hardware or software control logic. Additional components of the information handling system may include one or more storage devices, one or more communications ports for communicating with external devices as well as various input and output (UO) devices, such as a keyboard, a mouse, and a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components. 
     While the invention may be adaptable to various modifications and alternative forms, specific embodiments have been shown by way of example and described herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. Moreover, the different aspects of the disclosed methods and systems may be utilized in various combinations and/or independently. Thus the invention is not limited to only those combinations shown herein, but rather may include other combinations.