The invention relates generally to the field of computers, and more specifically, to an ink manager for acquiring and organizing pen-based ink information for use by pen-aware and other applications. An ink manager running at a computer system receives ink information entered at a pen-based input/display device and accumulates the ink information into ink strokes. The ink manager communicates with a handwriting recognition engine and includes an ink phrase termination engine that is configured to detect the occurrence of one or more ink phrase termination events by examining the ink information.

Upon the occurrence of an ink phrase termination event, the ink manager notifies the handwriting recognition engine and organizes the preceding ink strokes into an ink phrase data structure. The ink manager may also pass the ink phrase to an application executing on the computer system that is associated with the ink information, and it, in response, may return a reference pointer and a recognition context to the ink manager. The reference pointer and recognition context are then appended to the ink phrase data structure. Utilizing the recognition context identified by the application, the handwriting recognition engine generates one or more hypotheses for the ink phrase, and provides them to the ink manager. The ink manager forwards the hypotheses together with die reference pointer to the application and may also append them to the ink phrase data structure.

Here's Apple's summary of the invention: "The present invention, in large part, relates to the observation that client applications and handwriting recognition software in pen-based computer systems can make far more accurate ink-related decisions based on entire ink phrases, rather than individual ink strokes. Accordingly, the invention is directed to an ink manager that is designed to organize ink strokes into ink phrases and to provide these ink phrases to client applications. In the illustrative embodiment, the ink manager interfaces between a pen-based input device, one or more applications (pen-aware or not) and one or more handwriting recognition engines executing on the computer system. The ink manager acquires ink information, such as ink strokes, entered at the pen-based input device, and organizes that information into ink phrases. The ink manager includes an ink phrase termination engine (which may be partially executed in a pen driver component) that is configured to apply one or more ink phrase termination tests to the ink information. If the termination engine detects the occurrence of an ink phrase termination event, the ink manager performs the following steps in order: 1) finishes organizing the strokes into an ink phrase data structure, 2) optionally notifies the current client application program of the termination event by providing it with the ink phrase, thereby allowing the application to determine a suitable affiliation between the ink phrase and a specific input field, specify a reference context (e.g., a pointer) and request a particular recognition context, if desired, 3) notifies the appropriate handwriting recognition engine, so as to allow it to complete its work and provide the recognition results corresponding to the current ink phrase, and 4) sends the now labeled (i.e., recognized) ink phrase to the application, together with any reference context previously identified by the application (in step 2). To the extent the application returns a reference context and/or a recognition context, they may be appended to the ink phrase data structure.

"Significantly, by passing the as yet un-recognized ink phrase to the application immediately upon phrase termination (step 2 above), the ink manager allows the application to make specific input field and context determinations on a more suitable unit of data than previous systems--a phrase, rather than a stroke. Consequently, the system can associate the user's ink data with the input fields intended by the user more consistently, even if one or more ink strokes (including the first ink stroke) is wholly or partially outside of the input field. The system can also recognize the ink data more accurately due to the use of the most appropriate recognition context, again as determined by the application based on the ink phrase.

"In the preferred embodiment, the ink phrase termination engine applies three ink phrase termination tests to the ink information generated at the pen-based device, and also allows the recognition engine to impose its own phrase termination test. First, the ink phrase termination engine initiates a time-out mechanism upon receiving each ink sample. If the time-out expires before the next ink sample is received, an ink phrase termination event occurs. The value of this time-out is preferably adjustable by the end user. Second, the ink phrase termination engine monitors proximity information acquired by the pen-based input device, and issues an ink phrase termination event when the pen is lifted out-of-proximity from the surface of the input device. That is, the input device includes sensors that detect whether the pen, even though not yet in contact with the surface of the device, is nonetheless near the surface or not (i.e., in or out-of-proximity).

"Optionally, the application associated with the current pen session may supply the coordinates of a pen input area to the ink manager and request the ink phrase termination engine to issue an ink phrase termination event whenever the ink samples move outside of this area. Finally, ink phrase termination events can be triggered by the handwriting recognition engine. In particular, the recognition engine preferably applies a word segmentation model to the ink information it is receiving on-the-fly. If the engine determines that a new ink sample represents the start of a new word (e.g., the new ink sample is on a new line or is spaced a significant distance horizontally from the prior ink sample), then the recognition engine may issue an ink phrase termination event.

"While the ink manager may allow alternative methods of data handling, including stroke-based and even point-based ink accumulation by the client application as well as input-area-based phrase termination, the organization of ink information into ink phrases frees pen-aware applications from the low-level ink collection and handling process, improves the correlation of ink information to specific areas on the pen-based input device, and improves the recognition process."

The inventors are Larry S. Yaeger, Richard W. Fabrick and Giulia M. Pagallo. The graphic below is a block diagram of a computer system in accordance with the present invention.

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