Abstract:
A computer display system which displays an image and a magnified portion of the image. The magnified portion of the image is selected un,der control of a pointing device connected to the computer. A method is described for changing the characteristics of the magnified portion. A configuration utility which creates the magnified portion of the display includes a menu of display properties for the magnified portion. The properties are selected from the display menu, and each refresh of the area within the magnified portion of the image is refreshed with the selected properties. In a text/browser application, the background color, text color, text style and size may be selected differently than the remaining portion of the image displayed on the computer display.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is related to U.S. patent application Ser. No. 09/046,830. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates generally to computer display systems which have a sliding window for selecting a portion of an image to be magnified. Specifically, a window representing a magnified cursor is generated which is positionable in response to motion of a pointing device. One such system is described more particularly in the aforesaid related patent application. The magnifiable cursor described in the foregoing patent application provides the ability to read small detail on a computer-driven display. The cursor in its normal operation may be used to invoke a magnifiable cursor from a display tool bar on the computer-driven display. Once invoked, the cursor becomes a sliding window which is movable across the display screen. When positioned at a location of interest on the display screen, the slidable window permits viewing of the area under a pseudomagnification, i.e., the detail within the slidable window is expanded to a larger size by using multiple pixels within the slidable window to display the image detail within the slidable window. The ability to change the display scale of certain detail selected by a user should not be application-specific, but rather should be applicable to any browser/editor application independent of the operating system of the computer display system. 
     When positioning a magnifiable cursor over the display screen, it is disadvantageous to refresh the screen within the sliding window during the positioning process. Accordingly, as set forth in the aforesaid patent application, the sliding window is greyed in during positioning of the sliding window, by comparing the velocity of movement of the cursor with respect to a nominal threshold value. As the cursor is positioned to a selected location, the velocity decreases below the threshold value and refresh of the screen, particularly in the area of the slidable window, may be effected. 
     While magnifying a particular portion of a display image is desirable from a number of standpoints, it is also desirable to have properties within a sliding window displayed differently than the remaining portion of the display image. For instance, it may be advantageous to the user to display the portion of the image within the sliding window with different properties, i.e., different colors, text size, or even a different text font than outside of the sliding window. Accordingly, to make full use of the capabilities of the magnifiable cursor, the present invention is directed to controlling these properties of the display image within the sliding window. 
     SUMMARY OF THE INVENTION 
     It is an object of this invention to provide a method to change the properties of image detail displayed within a magnifiable cursor. 
     This and other objects of the invention are provided for by a set of instructions which can be read from a computer readable medium by a computer display system. The computer display system is equipped with a magnifiable cursor which generates a sliding window positionable by a pointing device operated by the user. When the sliding window is located at the user&#39;s discretion on a particular detail to be displayed, the detail is magnified by displaying it over a greater number of pixels than detail which is outside of the sliding window. The sliding window has its own set of properties which may be different from those properties of the displayed image outside of the sliding window boundary. Background color, font style and size, of detail within the sliding window are independently controlled from the properties used to display the remaining portion of the image outside of the sliding window. 
     In accordance with a preferred embodiment of the invention, the selection of the properties for detail displayed within the sliding window may be selected from pull-down menus which are available when the magnifiable cursor is invoked. The pull-down menus can provide selections for background color, text color, font type, or text size as properties to be used to display image detail appearing within the sliding window. 
     In accordance with one embodiment of the invention, the configuration menu may be selected by the user by clicking a mouse button, which is detected as a signal for invoking the configuration menu. Properties for the magnified portion of the image display may then be selected from the displayed pull-down menu. 
    
    
     DESCRIPTION OF THE FIGURES 
     FIG. 1 is an illustration of a magnifiable cursor used in a computer display system; 
     FIG. 2 is an enlarged view of the display screen having a slidable window; 
     FIG. 3 illustrates the pull-down menu for selecting the sliding window properties; 
     FIG. 4A illustrates the process executed by the computer display system of FIG. 1 when using the magnifiable cursor; 
     FIG. 4B illustrates the process used to refresh a moving window; and 
     FIG. 4C illustrates how the moving window is efficiently refreshed for each new position. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to FIG. 1, a computer display system is shown for displaying text in either an editor application or browser application loaded into a personal computer  11 . Personal computer  11  is controlled by the user through the keyboard  12  and pointing device (mouse)  13 . The display  14  produces a display which has across the top thereof a tool bar  16 . Those familiar with the Windows Graphical User Interface will recognize various functions which may be invoked during operation of the editor or browser application for changing text using the tool bar  16 . 
     The tool bar  16  includes an icon  17  which the user may use to invoke a configuration routine for the magnifiable cursor  19 . The bulk of the display  15  contains text produced by the editor/browser application. In the embodiment shown, portions of the text may be enlarged using the magnifiable cursor  19 . Magnifiable cursor  19  is a sliding window which operates in accordance with the position information transmitted from the mouse  13 . The sliding window, shown as a circular boundary  19 , results in the displayed material within the boundary of sliding window  19  being expanded in size. The foregoing feature of a magnifiable cursor is described more fully in the above related patent application, hereby incorporated by reference. In accordance with the description of the magnifiable cursor  19  of the related application, various sections of the display screen may be enlarged by the cursor routine executed in the processor  11 . As set forth in the previous application, the cursor  19  when moved from one portion of the screen to another, is effectively greyed in so that the screen is not refreshed during movement. Once the cursor (sliding window) is moved to a position of interest, the configuration routine instructions detect the cursor velocity to be below a threshold level, and detail displayed within the boundary of the sliding window  19  is then refreshed. 
     FIG. 2 represents an enlarged view of that portion of the display screen  15  which includes the sliding window  19  enclosing the text TO. The enclosed portion of the display screen  15  includes the background color  23 , a font style representing characters  22 , as well as a font size and color. In accordance with the present invention, it is possible to set the properties of the display detail within the sliding window boundary  19  to be different from the properties of the display detail outside of the boundary of sliding window  19 . In accordance with the preferred embodiment of the invention, the method for changing the properties of the sliding window cursor is implemented as part of the configuration utility for the magnified cursor. 
     Referring now to FIG. 4A, the process executed by the computer display system is shown as a flowchart. The program load occurs in step  101  during bootup of the personal computer  11  of FIG. 1. A pointing device driver is loaded in step  102  which permits the user to enter commands via the mouse. Once the computer is booted up, it assumes normal computer operations in step  103  under control of the stored instruction set. 
     If the operator elects to select the magnified cursor, the respective configuration utility is invoked in step  104  by positioning the cursor over icon  17  and depressing a mouse button. If the user has invoked the configuration utility, a set of pull-down menus are available to the user from step  105 . 
     The respective pull-down menus which are selected in step  105  are shown in FIG.  3 . These menus refer to the various attributes and properties associated with image detail which is displayed within the sliding window  19  generated from the magnifiable cursor routine. The display settings illustrated in FIG. 3 include the image area size for the sliding window represented by the magnified cursor, the shape, whether a square, circle, rectangle, etc., magnification factor, i.e., degree to which pixel data within the sliding window is to be expanded, a refresh rate threshold for the information within the sliding window, and a command to invoke the magnifiable cursor. 
     An additional selection  200  from the initial pull-down menu is selected to set the magnifiable cursor  19  properties. This will include properties within the boundaries of the sliding window such as background color, color of text displayed within the window, text size and font style. Each of the individual cursor properties are selected with additional submenus  201 ,  202 ,  203  and  204 . As illustrated in FIG. 3, in the case where a text or browser application is being run by the computer  11 , a font selection, among the generally used fonts in these applications, such as Classic Roman, etc. may be selected by highlighting the choice with the cursor in submenu  201  and making the selection using the mouse button. Further, the colors for the text can be selected among the primary color, red, green or blue, or any other combination which the system designer may specify, as true for the background color within the boundary of the magnifiable cursor from submenu  203 . Text size is similarly selected from a plurality of different sizes in submenu  202 . 
     Following invocation of the configuration utility from operating the mouse button, and selecting and updating the settings in steps  105  and  106 , step  107  determines whether the user has requested to invoke the magnifiable cursor by detecting a subsequent click on the icon  17  using the cursor. 
     If the magnifiable cursor has been invoked, the cursor under control of the pointing device is altered into a sliding window. This results in an expanded cursor size having properties set in step  105  and  106 . 
     Returning to the process of FIG. 4A, step  110  is entered when the sliding window has moved to a position which is determined to be of interest. As set forth in the foregoing related patent application, the refreshed the display detail in this area is effected when the velocity of movement of the sliding window is below a threshold value, indicating that a user has positioned the window in an area of interest on the display screen. 
     FIG. 4B illustrates how, in accordance with the above related application, the user is able to refresh the area within the sliding window of the magnifiable cursor with a minimum of processing time. Step  301  illustrates the step of bisecting an area within the sliding window  19  with a diagonal B. The cursor movement is determined, in step  302 , based on the detected cursor motion factor, and the new area represented by the repositioning of the cursor is added as C to the sliding window in step  302 . The properties within the new area C are changed in accordance with those established for the sliding window in step  303 . Those properties for image details which are common to the new position of cursor  19  and the old position of cursor  19 , represented by  19 B, need not be refreshed. 
     The old boundary area represented by D in FIG. 4C is removed from the sliding window in step  304 , as it is outside the new boundary  19 A, and old boundary area D is refreshed consistent with display detail outside of boundary  19 A. 
     In the foregoing technique, excessive computer time is unnecessary for refreshing common areas which remain after a sliding window representing the magnified cursor has changed position, and only refreshing new areas added to the boundaries of the repositioned cursor is needed. 
     Thus, there has been described with respect to one embodiment of the invention a process for changing the parameters within a sliding window such as a magnified cursor. This process may be incorporated as a set of instructions to be executed with the magnifiable cursor instructions loaded into the computer  11 . The instructions may be entered by way of a conventional floppy disk, so they are stored within the hard drive of computer  11  and available at any time the magnifiable cursor is invoked by the user. 
     The foregoing description of the invention illustrates and describes the present invention. Additionally, the disclosure shows and describes only the preferred embodiments of the invention, but as aforementioned, it is to be understood that the invention is capable of use in various other combinations, modifications, and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein, commensurate with the above teachings, and/or the skill or knowledge of the relevant art. The embodiments described hereinabove are further intended to explain best modes known of practicing the invention and to enable others skilled in the art to utilize the invention in such, or other, embodiments and with the various modifications required by the particular applications or uses of the invention. Accordingly, the description is not intended to limit the invention to the form disclosed herein. Also, it is intended that the appended claims be construed to include alternative embodiments.