Apparatus and method for handling special windows in a display

• US 7,844,902 B2
• Filed: 08/12/2008
• Issued: 11/30/2010
• Est. Priority Date: 09/24/1998
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Cappels, Richard D. Sr., Andrews, Johanna M., Krah, Christoph Horst
• Primary Examiner(s): Lo; Weilun
• Assistant Examiner(s): TRAN, MYLINH T
• Application Number:
  US12/190,502
• Publication Number:
  US 20090037819A1
• Time in Patent Office: 840 Days
• Field of Search: 715/719, 715/720, 715/721, 715/722, 715/726, 382/100, 382/232
• US Class Current: 715/719
• CPC Class Codes: G09G 1/16 the pattern of rectangular co-ordinates extending over the whole area of the screen, i.e. television type raster
• CPC Class Codes: G09G 1/167 Details of the interface to the display terminal specific for a CRT details suitable for both CRT and flat panel G09G5/006, specific for a flat panel G09G3/2096
• CPC Class Codes: G09G 2320/02 Improving the quality of display appearance
• CPC Class Codes: G09G 2320/0686 with two or more screen areas displaying information with different brightness or colours
• CPC Class Codes: G09G 2370/04 Exchange of auxiliary data, i.e. other than image data, between monitor and graphics controller
• CPC Class Codes: G09G 5/10 Intensity circuits
• CPC Class Codes: G09G 5/14 Display of multiple viewports

Abstract

An apparatus and method for handling special windows in a display comprises a window manager in an operating system that is called by application programs to create special windows. The window manager embeds static key signals including encoded special window information, such as the coordinates of a window area to be specially processed, into a video RAM. An existing video interface scans the video RAM and transmits display information, including the key signals, to the display. The present invention further comprises a window decoder in the display, that detects the key signals, extracts the encoded special window information, and controls display circuitry performing the desired special processing. The key signal encoding scheme does not create visually discernible display aberrations that could distract the user or interfere with normal window management.

Claims

1. An apparatus for handling special windows in a display, comprising:

a window manager adapted to embed special window information in a video signal, wherein the special window information comprises a sequence of bits adapted to indicate to a window decoder that a target area of the display is to be specially processed, and wherein the sequence of bits is adapted to indicate color data for one or more pixels of a second display when read by an external device; and

the window decoder in electrical communication with the window manager and adapted to extract said special window information from said video signal and responsively generate a display control signal, wherein the control signal is adapted to designate special processing for pixels to be presented upon the display.

2. The apparatus of claim 1, further comprising

a video interface to transmit data including said special window information to said display.

3. The apparatus of claim 2, wherein the video interface is adapted to transmit to the display a first color signal serving as a video clock signal for said special window information, a second color signal including said special window information, and a third color signal.

4. The apparatus of claim 3, wherein the special window information comprises key signals adapted to indicate offsets for a target area of a special window.

5. The apparatus of claim 4, wherein scroll bars in said special windows function as controls for special processing.

6. The apparatus of claim 4, wherein said key signals include hidden watermarks.

7. The apparatus of claim 4, wherein said key signals include visibly apparent symbols.

8. The apparatus of claim 4, further comprising:

key signal verification circuits identifying said special windows and responsively enabling an attribute;

a vertical counter monitoring a number of vertically scanned lines of said pixels occurring after a vertical synchronization signal;

a horizontal counter monitoring a number of horizontally scanned pixels after a horizontal synchronization signal;

registers storing said target area position in terms of said vertically scanned lines and said horizontally scanned pixels when said attribute is enabled;

a comparator monitoring a position of said pixels in terms of said vertically scanned lines and said horizontally scanned pixels, comparing said position of said pixels to said target area position, and responsively generating said display control signal to enable special processing.

9. The apparatus of claim 8, further comprising:

an internal logic clock signal denoting an intended duration for said special processing of said pixels in said target area; and

a frequency control unit synchronizing said internal logic clock signal to said video clock signal to regulate a horizontal width of said pixels in said target area with a duration of said display control signal, thereby calibrating said special processing with a scan of said display.

10. The apparatus of claim 9, wherein said key signal verification circuits enable said attribute when a duration of said key signals in terms of internal logic clock signal periods is consistent with a key signal format.

11. The apparatus of claim 8, wherein said attribute is disabled by an absence of said key signals.

12. The apparatus of claim 8, wherein said key signal verification circuits enable said attribute when said key signals exist during one scan of said display and persist for a number of scans of said display.

13. A method for handling special windows in a display, the method for use in a display device, said method comprising the steps of:

embedding special window information in a video signal, wherein the special window information is adapted to indicate to a window decoder disposed within the display device that a target area of the display is to be specially processed, and wherein the special window information is adapted to indicate color data for one or more pixels of a second display when read by a second display device;

extracting said special window information from said video signal using the window decoder; and

generating a display control signal in response to said window information to enable different processing of said special windows in said display.

14. The method of claim 13, further comprising the steps of:

specially processing a target area in said special windows in response to said display control signal; and

transmitting data including said special window information to said display using a video interface.

15. The method of claim 14, further comprising the steps of:

depicting pixels in said display;

transmitting a first color signal serving as a video clock signal for said special window information;

transmitting a second color signal including said special window information; and

transmitting a third color signal.

16. The method of claim 15, further comprising the step of:

transmitting key signals including a pattern of bits of said special window information to encode a target area position, and corresponding to a pattern of said pixels depicted in said display.

17. The method of claim 16, wherein scroll bars in said special windows function as controls for special processing.

18. The method of claim 16, wherein said key signals include hidden watermarks.

19. The method of claim 16, wherein said key signals include visibly apparent symbols.

20. The method of claim 16, further comprising the steps of:

identifying said special windows and responsively enabling an attribute using key signal verification circuits;

monitoring a number of vertically scanned lines of said pixels occurring after a vertical synchronization signal using a vertical counter;

monitoring a number of horizontally scanned pixels after a horizontal synchronization signal using a horizontal counter;

using registers to store said target area position in terms of said vertically scanned lines and said horizontally scanned pixels when said attribute is enabled;

using a comparator to monitor a position of said pixels in terms of said vertically scanned lines and said horizontally scanned pixels, to compare said position of said pixels to said target area position, and to responsively generate said display control signal to enable special processing.

21. The method of claim 20, wherein said key signal verification circuits enable said attribute when a duration of said key signals in terms of internal logic clock signal periods is consistent with a key signal format.

22. The method of claim 20, wherein said attribute is disabled by an absence of said key signals.

23. The method of claim 20, wherein said key signal verification circuits enable said attribute when said key signals exist during one scan of said display and persist for a number of scans of said display.

24. The method of claim 16, further comprising the steps of:

denoting an intended duration for said special processing of said pixels in said target area using an internal logic clock signal; and

using a frequency control unit to synchronize said internal logic clock signal to said video clock signal and regulate a horizontal width of said pixels in said target area with a duration of said display control signal, thereby calibrating said special processing with a scan of said display.