The patent involves a method and device for accessing a broad data field having a fine resolution. The user selects a scale which can be varied. The scale controls a range within the data field. By moving the range to encompass different portions of the data field, the user can scan that portion of the data field. The present invention allows the user to simultaneously select the scale while moving the range over different portions of the data field. Thus, the user can "zoom in" and "zoom out" of different portions of the data field.In one embodiment of the present invention, a particular piece of data within the broad data field can be accessed. First, the scale is selectively varied, thereby controlling a range within the data field. Then, the range is moved to encompass portions of the data field in which the piece of data resides. Next, the scale is successively decreased while, simultaneously, points successively closer to the location are kept with the range. The scale is decreased (i.e., increasing the range's resolution) and the range is moved in this manner until the piece of data is actually accessed.

Here's Apple's background on the invention: "Many types of data have a broad range and a fine resolution. For example, a videodisk is composed of a continuum of frames. The video disk can store up to a series of tens of thousands of frames. Thus, it has approximately five orders of magnitude. Likewise, electronic music composition requires controlling frequencies over the entire audible scale ranging from 15 to 20,000 hertz. Thus, three orders of magnitude are required to cover this range. Similarly, a five second digital audio clip may require five orders of magnitude to access each bit sample. These types of data are often linear in the sense that there are starting and ending points and many linked 'frames' of data between the starting and ending points.

"In order to access a videodisk, one needs frame accurate control over the entire medium. In other words, a user must be able to readily pick out one particular desired frame nestled among tens of thousands of frames. It becomes readily apparent that tasks such as adjusting key frames in an video film or manipulating audio samples, can be quite time consuming and frustrating. What is needed is a method or apparatus which lets the user find and access one particular desired piece of data which is located among a broad range of data.

"In the past, this was accomplished by using scroll bars. However, scroll bars typically can handle only two orders of magnitude. Consequently, a scroll bar would need to be approximately twenty yards long in order to grant access to each frame of a video disk. This is impracticable.

"Another method used in the prior art was to implement VCR-type controls. This allows the user control over the entire range of data. However, these types of controls lack selectivity. For example, it would be difficult for a user to stop precisely on one particular desired frame of a VCR tape. The user would probably either overshoot or undershoot the desired frame and would probably go back and forth searching for that particular frame. What is needed is a method that gives the user control over a broad range, while giving the user random access to any particular piece of data within that range, especially at fine resolutions.

"Yet another method used in the prior art to solve this problem is to provide one control for magnification of the data and another control for scanning at the selected magnification. One product utilizing this technique is SoundEdit.TM. by Farallon Computing, Inc. However, this implementation has a drawback in that it requires two separate controls. A further disadvantage is that these two controls cannot be operated simultaneously. A user has to change the magnification control independently from the navigation control. Such a system results in wasted time and effort. Thus, what is needed is a method for providing the user with easy and fluid interaction over varying magnification scales while simultaneously providing the user with the capability of scanning at that magnification scale.

And here's Apple's summary of the invention: "In view of the problems associated with providing a user with control over a broad range of data, particularly linear data, one objective of the present invention is to provide the user with access to data down to very fine resolutions in a simple, natural, and cost effective method by utilizing a cursor positioning device such as a mouse, a trackball, touch tablet, joystick or other input device having the capability of providing control for movement in 2 dimensions (2 degrees of freedom) of a cursor.

"Another objective is to increase the speed, accuracy, and selectivity of accessing data over a broad range by providing the user with easy and fluid interaction over varying magnification scales, while simultaneously providing the user with the capability of scanning the data at that magnification scale.

"A method and device for accessing a broad data field having a fine resolution is described. The user selects a scale which can be varied by the user. The scale controls the magnification at which the user accesses and/or examines the data, and it may be considered that a selected magnification provides a particular range of the data (from one point to another point in the data). By moving the range to encompass different portions of the data field, the user can scan that portion of the data field. The present invention allows the user to simultaneously select the scale while moving the range over different portions of the data field. Thus, the user can "zoom in" and "zoom out" of different portions of the data field.

"In one embodiment of the present invention, a particular piece of data within the broad data field can be accessed. First, the scale is selectively varied, thereby controlling a range within the data field. Then, the range is moved to encompass portions of the data field in which the piece of data resides. Next, the scale is successively decreased while, simultaneously, points successively closer to the location are kept with the range. The scale is decreased which increases the magnification (i.e., increasing the range's resolution). The range is moved in this manner until the piece of data is actually accessed.

This is accomplished by using an input device having two degrees of freedom (e.g., a mouse, trackball, touch tablet, joystick, etc.). These two degrees of freedom can be provided by movement along two different axes. For example, movement can be along the x and y-axes in a Cartesian coordinate system. Movement along one axis controls the selection of the scale, while movement along the other axis controls the particular range at that scale. In one preferred embodiment, these axes can be remapped to control the position of a cursor on a display screen, instead of the scale and range. In other words, the same input device can either control the position of a cursor or control the scale and range, simply by remapping the axes of the input device."

The inventor is Daniel Scott Venolia. The graphic below shows an example of the reduction of a full sized textual document for one embodiment of the present invention.