Browse Prior Art Database

Electronic Calculator Based on Character Recognition of Input from Stylus Acceleration Dynamics

IP.com Disclosure Number: IPCOM000087230D
Original Publication Date: 1976-Dec-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 3 page(s) / 37K

Publishing Venue

IBM

Related People

Morrissey, JH: AUTHOR

Abstract

Referring to the figure, an electronic calculator system is shown in basic block diagram form which is based on input information being entered into the system by a user-held writing stylus or pen. The pen is equipped with a number of accelerometers whose output is supplied to a character recognition logic block for recognizing input characters and operations. The output from the recognition logic block is then fed into the electronic calculator in more or less conventional form.

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Electronic Calculator Based on Character Recognition of Input from Stylus Acceleration Dynamics

Referring to the figure, an electronic calculator system is shown in basic block diagram form which is based on input information being entered into the system by a user-held writing stylus or pen. The pen is equipped with a number of accelerometers whose output is supplied to a character recognition logic block for recognizing input characters and operations. The output from the recognition logic block is then fed into the electronic calculator in more or less conventional form.

An accelerometer-equipped writing stylus and character recognition system suitable for use with this system is described in U. S. Patent 3,983,535. This patent is directed to signature verification. However, it would be obvious to those skilled in the art to greatly relax the recognition constraints for purposes of rudimentary character recognition.

This system comprises a writing surface such as a piece of paper. However, this surface has no functional relationship to the remainder of the system other than providing a surface on which the stylus is moved. The stylus would conventionally be equipped with at least two accelerometers, i. e., X and Y axis, the outputs of which are connected to the recognition logic block. When the output of the recognition logic block is fed into the electronic calculator the just recognized character is displayed in a conventional manner to verify data entry and finally at the appropriate time the required calculation is performed and the answer displayed. A more detailed description of the operation follows subsequently.

A user writes digits and symbols (for punctuation and math operators) on the writing surface (e.g., a plain pad, income tax form, retail sales slip, etc.). The writing motions (including pen lifts) generate electrical signals (from accelerometer(s) embedded in the stylus) which are carried via wires to the recognition logic block. These analog signals are sampled, A/D converted to an equivalent set of digitized values which are then smoothed, filtered, and aggregated into vectors containing time (since pen down), duration, force and direction of accelerations. These vectors are then matched against a set of similar featu...