Abstract:
A system and method for offline content delivery through an active screen display is provided. Data for display and content to be displayed at a later time are encoded as a display signal for delivery. An active screen display is associated with a computer and coupled to a processor over a physical display interface connection. The display signal is received and decoded to distinguish the data for display from the content to be displayed at a later time. The content to be displayed at a later time is displayed via the active screen display when the computer is one of turned off and inactive.

Description:
FIELD 
       [0001]    The present invention relates in general to personal computer displays and, in particular, to a system and method for offline content delivery through an active screen display. 
       BACKGROUND 
       [0002]    Personal computer and their attached monitors or displays, as well as laptop computers, have become common household appliances, with many homes having more than one personal computer system. The displays generally remain idle when the personal computer is not in use. Nevertheless, many personal computers are often located in central places in a home and the displays could potentially be used to independently display content, for example, pictures, calendar, or advertisements, that does not require the active computational resources of the personal computer. 
         [0003]    Conventional software applications exist to utilize the display for such purposes. Generally, these applications require the personal computer to be turned on to display the content, even though the personal computer is not being used in a manner that involves active human user interaction via the user interface. While running, though, the personal computer consumes energy, is subject to wear and tear, and remains vulnerable to malicious software. 
         [0004]    Personal computer displays are increasingly becoming available with onboard storage, external media readers, and internal logic to unilaterally display content, whether visual, audio, or both. For instance, active digital picture frames are widely available and include a receptacle to accommodate external storage media storing, for instance, digital pictures or music, even when not connected to an active “on” personal computer. However, loading the content from external media requires manual operation by the user and physical custody of the external media, such as a memory card, with the inconvenience of operating and increased costs associated with replicating user interface controls. Moreover, the content to be transferred to the active display oftentimes originates at the personal computer itself, and even though the two devices, the personal computer and the active display, may already be physically connected, a convenient and automated way to transfer the content into the active display&#39;s onboard is lacking. 
         [0005]    One possible approach is to connect the processing unit of a personal computer to an active display using a special purpose cable or via wireless interconnect to transfer content from the personal computer into the active display&#39;s onboard memory. However, matching and compatible computers and active displays are required, in addition to specialized hardware for communication and labor for installation. 
         [0006]    Therefore, there exists the need for a mechanism to transfer content from a personal computer or other external source to an active display for later viewing, particularly when the personal computer is turned off or inactive. 
       SUMMARY 
       [0007]    In one embodiment, an existing connection between the processing unit of a personal computer and an active display is utilized with the active display being provided with additional functionality. Specifically, a computer-implemented system and method for offline delivery of content through an active screen display. A processor includes an encoding application to assemble and encode digitally-stored content into encoded content, and to interleave the encoded content with a signal conveying a live screen representation. The live screen representation includes output of a user interface for applications executing on the processor. An active screen display is coupled to the processor over a physical display interface connection. The active screen display includes a runtime application to identify the encoded content within the signal on the active screen display and to decode the encoded content into decoded content. The active screen display further includes an offline application to unilaterally display the decoded content on the active screen display without use of the processor and in an absence of the live screen presentation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a functional block diagram showing a system for sending additional information to a personal computer display in accordance with one embodiment. 
           [0009]      FIG. 2  is a functional block diagram showing, by way of example, an environment within which the system of  FIG. 1  operates. 
           [0010]      FIG. 3  is a flow diagram showing, by way of example, information encoded within a display signal. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    Typically, a personal computer connects to a display monitor using an analog data transmission cable, such as an RGB (“red, green, blue”) cable, although other data transmission formats exists, such as described in http://computer.howstuffworks.com/monitor3.htm, the disclosure of which is incorporated by reference.  FIG. 1  is a functional block diagram showing a system  10  for sending additional information to a personal computer display  11  in accordance with one embodiment. A connection  13  between the processing unit  12  of the personal computer system  10  carries the information required to render images  14  prepared by the computer hardware to the display  11 . 
         [0012]    Conventionally, the connection  13  lacks the ability to deliver significant amounts of data during normal operation. An application program, either residing on the personal computer locally, or externally delivered from an external source, such as removable media or over the Internet, encodes content to be displayed at a later time as an image on the display  11 .  FIG. 2  is a functional block diagram showing, by way of example, an environment  20  within which the system  10  of  FIG. 1  operates. The personal computer  22  can be remotely interconnected to a Web server  25 , either through wired or wireless connection, via an internetwork, such as the Internet. The personal computer  22  executes the application program  24  and can additional execution a Web browser  23 , with which to access Web content. The application program  24  provides logic for simultaneously delivering content from the processing unit of a personal computer to an active display. The content is sent as part of the images  14  being displayed under normal interactive use, but is encoded in a way that enables the active display to recognize the content as content to be displayed at a later, particularly when the personal computer is turned off or inactive. 
         [0013]    The encoding scheme triggers another application program, which resides in the active display, to decode and positively identify the information as content to be displayed at a later time.  FIG. 3  is a flow diagram showing, by way of example, information  30  encoded within a display signal. In a further embodiment, the information may include additional instructions, for example, timing, ordering, placement, and other directions pertaining to display of the content. 
         [0014]    A suitable encoding scheme encodes arbitrary data sent from a processor  31  to a display  32  in a way that creates a pattern that follows certain rules. The active display  11  (shown in  FIG. 1 ) checks the incoming stream of data. When the application program on the active display  11  recognizes a section that follows the rules, the data is saved for later use. The encoding scheme is chosen to minimize the chances that arbitrary data sent to the active display  11  will be erroneous decoded and misidentified as content to be displayed at a later time. 
         [0015]    One suitable encoding scheme partitions the additional data sent to the active display  11  into fixed length blocks  33 - 34 , and applies a Cyclic Redundancy Check (CRC) to each block, such as described in http://en.wikipedia.org/wiki/Cyclic redundancy check, the disclosure of which is incorporated by reference. As the active display  11  receives the data from the personal computer, a CRC is computed on an ongoing basis. Whenever the CRC correctly validates a block  33 - 34 , the active display  11  stores the data in the block for later use. 
         [0016]    Another suitable encoding scheme uses a Message Digest, for example MD5, such as described in http://en.wikipedia.org/wiki/Md5, the disclosure of which is incorporated by reference. In a manner similar to that used with a CRC, the application program  24  on the personal computer  22  (both shown in  FIG. 2 ) creates an identifier for each data block  33 - 34  and sends the identifier together with the data. At the receiving end, the active display  11  independently calculates the MD5 hash code and compares the result to the one identifier with the data. If the identifier and hash code match, the data in the block is stored for later use. Still other suitable encoding schemes are possible. 
         [0017]    Attempting to decode each possible sequence of bits in the incoming data stream can be computationally expensive. In a further embodiment, to lower computational expense, the personal computer prepends a preamble (not shown) to mark or delimit the beginning of each block  33 - 34 . The active display  11  scans the incoming data for the preamble and only starts decoding the data for potential additional data when a preamble is encountered. Other markings or delimiters are possible, and can be provided prior to, within, or after the additional data. 
         [0018]    The data to be actively displayed is often transmitted from the processing unit  12  of the personal computer  10  to the active display  11  using an analog connection  13 . Such connections, though, can be prone to distortions and transmission errors, which can degrade the quality of the image displayed. 
         [0019]    Moreover, these errors can potentially corrupt the additional data being transferred. In a still further embodiment, to reduce or overcome such errors, the data blocks can be further supplemented with error correction information, for example, by using the Reed Solomon Code, such as described in http://en.wikipedia.org/wiki/Reed-Solomon_code, the disclosure of which is incorporated by reference. Other error correction schemes are possible. 
         [0020]    The additional data to be delivered to the active display  11  can originate, for instance, on the personal computer itself, from removable media, or via a remote Internet site. A section on the screen can be set aside to signal on-going transfer of the additional data. The section can be, for example, a rectangular window or an icon in the system task bar, preferably with a human readable caption, explaining its purpose. Inside the section, the user will see seemingly meaningless shapes and colors; however, the active display  11  receiving the information will recognize the additional data thus displayed as content to be saved for later use by employing the above described techniques. 
         [0021]    In further embodiment, when the active display  11  recognizes an area on the screen as being used to transfer the additional data, an alternate image can be displayed in that area, perhaps using other previously saved data, or the area could be left blank, as to not distract the user with seemingly meaningless image. 
         [0022]    In yet another embodiment, the additional data may be interleaved with other meaningful images, such that the additional data would not marginally degrade the quality of the main image being actively displayed. A stronger version of the above-mentioned encodings and error correction mechanisms could then be employed to recover the additional data from the main image. 
         [0023]    The transfer of data from, for example, a particular Web site served by a Web server  25  to the active display  11  will usually be initiated by the user of the personal computer  22  while the computer is turned on. At times, the active display  11  may need to prompt the user to access the Web site to facilitate the transfer of the additional data. The active display  11  may resize the image sent by the personal computer to not cover the entire screen. The active display  11  may also generate a message or reminder instructing the user on how to access the Web site. Once the information has been transferred, the active display  11  resumes normal operation. 
         [0024]    While the invention has been particularly shown and described as referenced to the embodiments thereof, those skilled in the art will understand that the foregoing and other changes in form and detail may be made therein without departing from the spirit and scope of the invention.