Granted Patent B2

US 12,659,190 · App. 18/827,479 · Granted Jun 16, 2026

Inventors: Marciano Carter Preciado (Salt Lake City, UT); Sterling Thomas Sleight (Murray, UT); Jeremy Fillingim (Salt Lake City, UT)

Assignee: PassiveLogic, Inc.

H04L15/24H04L9/3234H04L12/12

Abstract

Claims (38)

1 . A quiescent electronic device configured for optical wake activation, comprising:

a photodetection circuit configured to generate an electrical response to incident light;

a signal conditioning path coupled to the photodetection circuit, the signal conditioning path configured to suppress steady-state illumination and to emit a discrete electrical transition in response to a rapid change in light intensity;

a power control circuit responsive to the discrete electrical transition to couple an energy source to a processor; and

a timing circuit configured to measure temporal spacing between successive discrete electrical transitions,

wherein a plurality of temporally spaced transitions received prior to processor boot are accumulated to satisfy a wake qualification criterion, and

wherein transitions received after satisfaction of the wake qualification criterion are temporally decoded as information symbols.

2 . The device of claim 1 , wherein decoding of the information symbols is performed without measuring a duration of a light pulse or a duration of a voltage level exceeding a threshold.

3 . The device of claim 1 , wherein symbol identity is determined solely from elapsed time between successive discrete electrical transitions.

4 . The device of claim 1 , wherein decoding excludes interpretation of duty cycle, pulse width, or absolute pulse duration.

5 . The device of claim 1 , wherein each discrete electrical transition corresponds to a detected change in light intensity exceeding a rate-of-change threshold, independent of pulse length.

6 . The device of claim 1 , wherein accumulation of the plurality of temporally spaced transitions forming the wake qualification criterion occurs prior to conversion of the electrical response into a digital signal.

7 . The device of claim 6 , wherein the wake qualification criterion is satisfied using analog-domain transitions that directly control the power control circuit.

8 . The device of claim 1 , wherein the information symbols are derived exclusively from time intervals measured between successive discrete electrical transitions.

9 . The device of claim 8 , wherein the information symbols correspond to a modified Morse encoding in which symbol identity is determined by a multiple of a base temporal unit.

10 . The device of claim 9 , wherein the modified Morse encoding defines:

a first interval corresponding to a dot symbol,

a second interval corresponding to a dash symbol,

a third interval corresponding to an end-of-letter delimiter, and

a fourth interval corresponding to an end-of-word delimiter,

each interval being mutually distinguishable.

11 . The device of claim 10 , wherein neither a pulse on-time nor a pulse off-time is used to distinguish between dot and dash symbols.

12 . A method for externally activating and communicating with a quiescent electronic device, comprising:

detecting incident light transitions using a photodetection circuit;

filtering the detected incident light transitions to suppress signals lacking a minimum rate of change;

using at least one filtered transition to enable power delivery to a processor;

measuring time intervals between successive filtered transitions;

accumulating a plurality of transitions occurring prior to processor readiness;

qualifying wake activation when the accumulated plurality of transitions satisfy a predefined criterion; and

after qualifying wake activation, decoding subsequent time intervals as encoded information.

13 . The method of claim 12 , further comprising clearing the accumulated plurality of transitions when a measured time interval exceeds a predefined reset interval.

14 . The method of claim 12 , wherein decoding comprises mapping measured time intervals to a modified Morse symbol set.

15 . The method of claim 14 , wherein the modified Morse symbol set includes distinct temporal representations for dot, dash, end-of-letter, and end-of-word.

16 . The method of claim 12 , further comprising storing a final decoded symbol as an authentication token.

17 . The method of claim 16 , further comprising transmitting the authentication token in response to an out-of-band authentication request.

18 . The method of claim 12 , wherein decoding excludes measuring a duration of a light pulse or a duration of a voltage above a threshold.

19 . The method of claim 12 , wherein wake qualification is performed using analog electrical transitions prior to any digital signal generation.

20 . The method of claim 12 , wherein decoding the encoded information comprises determining symbol identity without measuring a duration of a light-on interval, a light-off interval, a voltage high interval, or a voltage low interval.

Assignments (2)

Continuity (2)

References Cited (256)