US 5,051,736 A · Optical stylus and passive digitizing tablet data input system

Abstract

A stylus and table X-Y data input system for a video display system. The pen includes an optical styling having a suitable pickup mechanism and the tablet is passive in nature and provides direct digitized data readout. Absolute positional information is encoded in binary form in the tablet in such a fashion that the pen position upon the tablet is automatically determinable by illuminating a particular area of the tablet and reading off the digitized X-Y coordinate data stored therein. The pen and supporting hardware/software are rotationally insensitive so that the pen may be held in any desired position comfortable to a user. The system provides greatly improved resolution, sampling rate accuracy and general robustness particularly for such applications as text recognition as well as a wide variety of other graphical input uses.

Claims15

Dependent claims

A stylus locator and data input system for use in conjunction with an electronic computer system comprising in combination:

an optical stylus including an illumination source and a pick up means for detecting absolute binary location data from a passive digitizing tablet when said stylus is passed over the surface thereof,
a passive locator tablet for use with said optical stylus member having permanently recorded thereon and distributed throughout the surface thereof a plurality of discrete sets of tablet address cells (TACs) each TAC comprising a digitally encoded X-Y coordinate pair which defines the absolute location of the TAC on the surface of said tablet,
means on said tablet for unambiguously demarking the boundaries of individual TACs, the density of the TACs being at least 250,000 per square inch and;
means for periodically sampling TAC data picked up by said stylus as the stylus is passed over the surface of the tablet, and
data generating means for producing a complete TAC data pair (X-Y coordinates) from each sampled unit of TAC data, said sampling rate being at least 125 per second.

2 more elements

A stylus locator and data input system for use in conjunction with an electronic computer system comprising in combination:

an optical stylus including an illumination source and optical pick up means for detecting absolute binary location data from a passive digitizing tablet when said stylus is passed over the surface thereof,
a passive locator tablet for use with said optical stylus member having permanently recorded thereon and distributed throughout the surface thereof a high density of discreet sets of tablet address cells (TACs) each TAC comprising a digitally encoded X-Y coordinate pair which defines the absolute location of the TAC on the surface of said tablet,
means on said tablet for unambiguously demarking the boundaries of individual TACs,
means for periodically sampling TAC data picked up by said stylus as the stylus is passed over the surface of the tablet, and
data generating means for producing a complete TAC data pair (X-Y coordinates) from each sampled unit of TAC data,
said data generating means including means for utilizing said TAC boundary demarking means to produce a said complete TAC data pair at the approximate center of the stylus during any sampling period whereby data from any adjacent TACs is ignored and further including
a video memory and means for storing a multi-pixel video image of each unit of TAC data sampled by said stylus, the granularity of said memory and stylus optical system being such that a code dot image stored therein is several pixels wide in both dimensions.

4 more elements

Dependencies are inferred from the claim text.

Optical stylus and passive digitizing tablet data input system

Life of this patent

Optical stylus and passive digitizing tablet data input system

Life of this patent

Abstract

Claims15