Recursive digital filter using fixed point arithmetic

Claim 2

A remote pointing system for controlling a cursor location on a display device comprising: a pointing device for controlling said cursor location on said display device by transmitting a plurality of signals, each of said signals being aimed off a pointing axis of the pointing device in different directions; a receiver for receiving said signals from said pointing device: a digital processor for processing said signals as data representing a of aim on said display device by said pointing device, said digital processor controlling said cursor location on the display device, said digital processor comprising a recursive filter including means for using fixed point arithmetic, said recursive filter including means for saving a remainder after each division and for adding said remainder to a dividend in a subsequent division operation.

Claim 3

A remote pointing system as in claim 1, wherein said plurality of signals includes at least three signals.

Claim 4

A remote pointing system as in claim 1, wherein said pointing device includes a plurality of infrared light emitting diodes for generating said plurality of signals.

Claim 5

A remote pointing system as in claim 1, wherein said pointing device includes a plurality of signal generating means, each of said signal generating means including a circuit for sequentially pulsing said signals with pulse trains for causing said signal generating means to individually and sequentially emit modulated signals.

Claim 6

A remote pointing system as in claim 1, wherein said receiver comprises an infrared detector and amplifier tuned to a predetermined pulse frequency.

Claim 7

A remote pointing system as in claim 1, wherein said receiver includes a demodulator for converting said signals to analog base-band pulses.

Claim 8

A remote pointing system as in claim 6, wherein said receiver includes an analog-to-digital converter for digitizing said analog base-band pulses.

Claim 9

A remote pointing system as in claim 1, further comprising a cursor controller responsive to said digital processor for controlling said cursor location on said display device.

Claim 10

A remote pointing system for controlling a cursor location on a display device comprising: a pointing device for remotely controlling the cursor on the display device, said pointing device comprising: at least three infrared light emitting diodes (IRLEDs), each of said IRLEDs aimed off a main or pointing axis of the pointing device in different directions; and a circuit connected to each of said IRLEDs responsive to a user input for sequentially pulsing said IRLEDs with pulse trains so as to cause the IRLEDs to individually and sequentially emit modulated infrared light signals; a receiver and controller located proximate to said display device, said receiver and controller comprising: an infrared detector and amplifier tuned to a predetermined pulse frequency; a demodulator to convert received signals to analog base-band pulses; an analog-to-digital convertor to digitize the analog base-band pulses; a digital processor to process the digitized analog base-band pulses as data representing a point of aim on the display device by the pointing device, said digital processor controlling the position of a cursor on the display device; and a cursor controller responsive to said digital processor for controlling a cursor position on the display device, wherein said digital processor includes a recursive filter using fixed point arithmetic for performing division, said recursive filter saving the remainder after each division operation and adding said remainder to the dividend in the following division operation.

Claim 11

A remote pointing system for controlling a cursor location on a display device comprising: a pointing device for remotely controlling the cursor on the display device, said pointing device comprising: at least three infrared light emitting diodes (IRLEDs), each of said IRLEDs aimed off a main or pointing axis of the pointing device in different directions; and a circuit connected to each of said IRLEDs responsive to a user input for sequentially pulsing said IRLEDs with pulse trains so as to cause the IRLEDs to individually and sequentially emit modulated infrared light signals; a receiver and controller located proximate to said display device, said receiver and controller comprising: an infrared detector and amplifier tuned to a predetermined pulse frequency; a demodulator to convert received signals to analog base-band pulses; an analog-to-digital convertor to digitize the analog base-band pulses; a digital processor to process the digitized analog base-band pulses as data representing a point of aim on the display device by the pointing device, said digital processor controlling the position of a cursor on the display device; and a cursor controller responsive to said digital processor for controlling a cursor position on the display device, wherein said digital processor includes a recursive filter using fixed point arithmetic for performing division, said recursive filter saving the remainder after each division operation and adding said remainder to the dividend in the following division operation.

Claim 14

A method as in claim 10, wherein said transmitting step includes a step of transmitting at least three signals in different directions.

Claim 15

A method as in claim 10, wherein said transmitting step includes a step of transmitting infrared light signals.

Claim 16

A method as in claim 10, wherein said transmitting step includes a step of sequentially pulsing said signals with pulse trains so as to cause said signals to individually and sequentially emit modulated signals.

Claim 17

A method as in claim 10, wherein said receiving step includes a step of amplifying said signals to a predetermined pulse frequency.

Claim 18

A method as in claim 10, wherein said receiving step includes a step of converting said signals to analog base-band pulses.

Claim 19

A method as in claim 15, wherein said receiving step includes a step of digitizing said analog base-band pulses.

Claim 20

A method as in claim 10, further comprising a step of controlling said cursor location based on said processing step.