Patent ID: 6184863
Filing Date: 2001-02-06
Classification: G06F

Abstract:
A direct pointing apparatus, comprising:a light emitting module adapted to operate as a pointer aimed at a location on a computer display while being worn by a user of the computer;a light sensing arrangement having a plurality of light receivers positioned around the outer periphery of the display; andinterface circuitry which couples said light receivers to a host computer for processing converted signals, said converted signals being indicative of the value of signals outputted by said light receivers, respectively,wherein said light emitting module includes a directed light emitter used for indicating a target position on the display through pointing the light emitter at that position,wherein the location on the display at which said light emitter is pointing is computed from the intensities of light being sensed by the light receivers, the computing of said location being substantially independent of the distance of said light emitter from said light sensing arrangement, andwherein said interface circuitry filters ambient light and converts analog signals, indicative of signals outputted by said light receivers, into digital signals processed by the computer, through running a host program by the computer, to determine X and Y coordinates of said target position, the X and Y coordinates, respectively, being a function of the values of the light intensities at the light receivers and are determined in accordance with the following relationships, operated on by the computer under the control of said host program:X=(1+K.sub.X)P.sub.X.multidot.(I.sub.R /(I.sub.L +I.sub.R))-(K.sub.X /2)P.sub.X ; and (i)Y=(1+K.sub.Y)P.sub.Y.multidot.(I.sub.B /(I.sub.B +I.sub.U))-(K.sub.Y /2)P.sub.Y (ii)where P.sub.X (P.sub.Y)=the horizontal (vertical) resolution in pixels of the display,1+K.sub.X (1+K.sub.Y) is a constant multiplier that takes into account the additional pixel distance effected by the placement of the light receivers outside the pixel display area,I.sub.R (I.sub.L)=the sum of light intensities received by the light receivers located along the right vertical (left vertical) of the display,I.sub.U (I.sub.B)=the sum of light intensities received by the light receivers located along the upper horizontal (lower horizontal) of the display,the light intensity of each sensor having a normalized weight of from 0 to 1, and(K.sub.X /2)P.sub.X ((K.sub.Y /2)P.sub.Y)=half the additional pixel distance along the X (Y) direction.