Solid-state lighting with imperceptible visual stimuli

Patent metadata

Field	Value
Publication number	US-12550237-B2
Application number	US-202418761773-A
Country	US
Kind code	B2
Filing date	Jul 2, 2024
Priority date	Sep 20, 2023
Publication date	Feb 10, 2026
Grant date	Feb 10, 2026

Abstract

A light-emitting diode (LED) luminaire comprising two sets of LEDs, a phase-amplitude circuit, and an LED driving circuit is used to replace a conventional luminaire with a possible severe temporal light artifact. The phase-amplitude circuit is configured to produce two sets of modulating signals with a predetermined phase retardation between the two. The LED driving circuit is configured to produce two sets of LED driving current in response to the two sets of modulating signals and to drive the two sets of LEDs, resulting in imperceptible visual stimuli at temporal modulation frequencies as a result of possible frequency pre-mix. On the other hand, the imperceptible visual stimuli in another embodiment may cause human brain to perceive modulated lighting stimuli and to demodulate thereof into a benign stimulus in the brain without an apparent flicker, thereby endogenously entraining a gamma oscillation, and drastically reducing eyestrain and visual discomfort.

First claim

What is claimed is:

1 . A light-emitting diode (LED) luminaire, comprising:
a first set of LED arrays and a second set of LED arrays, each with a forward voltage; at least one power supply unit configured to couple to alternate-current (AC) mains and convert a line voltage from the AC mains into a primary direct-current (DC) voltage greater than the forward voltage; and a phase-amplitude circuit comprising a control device and an LED driving circuit, the control device configured to produce a first set of modulating signal and a second set of modulating signal respectively at a first predetermined temporal modulation frequency and a second predetermined temporal modulation frequency, wherein:
the LED driving circuit comprises at least two modulation circuits configured to produce a first set of driving current and a second set of driving current, respectively, in response to the first set of modulating signal and the second set of modulating signal, to respectively drive the first set of LED arrays and the second set of LED arrays;
both the first predetermined temporal modulation frequency and the second predetermined temporal modulation frequency are higher than a critical flicker frequency (CFF), resulting in no perceptible flicker; and
the first predetermined temporal modulation frequency and the second predetermined temporal modulation frequency are pre-mixed in the LED driving circuit such that either the first set of driving current or the second set of driving current comprises both the first predetermined temporal modulation frequency and the second predetermined temporal modulation frequency.

2 . The light-emitting diode (LED) luminaire of claim 1 , wherein the at least two modulation circuits comprise at least two electronic switches comprising at least two bipolar junction transistors (BJTs) each configured to be biased by a signal far greater than a typical base-emitter voltages (V BE ) of 0.7 volts, thereby acting as a nonlinear device, and wherein, when the BJTs operate, switching at the first predetermined temporal modulation frequency and the second predetermined temporal modulation frequency cause an electrical and magnetic coupling between the first set of driving current and the second set of driving current, thereby generating a beat frequency between the first predetermined temporal modulation frequency and the second predetermined temporal modulation frequency and exogenously entraining gamma oscillations in a human brain.

3 . The light-emitting diode (LED) luminaire of claim 1 , wherein the primary DC voltage is configured to apply on both the first set of LED arrays and the second set of LED arrays with respect to a ground reference.

4 . The light-emitting diode (LED) luminaire of claim 3 , wherein each of the at least two electronic switches comprises a first terminal and a second terminal, the first terminal configured to respectively connect to a negative terminal of the first set of LED arrays and the second set of LED arrays, and the second terminal configured to respectively connect to the ground reference.

5 . The light-emitting diode (LED) luminaire of claim 1 , wherein each of the first set of modulating signal and the second set of modulating signal comprises square waves comprising a series of pulses with a duty cycle of at least 40% and a predetermined period, wherein the two sets of driving current comprise two modulating signals both associated with the predetermined period, and wherein respective light emissions from the first set of LED arrays and the second set of LED arrays in response to the two sets of driving current comprise the predetermined period.

6 . The light-emitting diode (LED) luminaire of claim 5 , wherein, when either the first set of LED driving current or the second set of LED driving current is not present, the other set of LED driving current is configured to automatically raise a duty cycle to at least 75% to avoid noticeable blinking in overall light emissions from the first set of LED arrays and the second set of LED arrays, thereby reducing perceptible flicker.

7 . The light-emitting diode (LED) luminaire of claim 1 , wherein a greatest common divisor of the first predetermined temporal modulation frequency and the second predetermined temporal modulation frequency is a nominal 40 Hz, thereby being embedded in the first predetermined temporal modulation frequency and the second predetermined temporal modulation frequency and no flicker perceptible.

8 . The light-emitting diode (LED) luminaire of claim 1 , wherein the first predetermined temporal modulation frequency is a nominal 80 Hz.

9 . The light-emitting diode (LED) luminaire of claim 8 , wherein the second predetermined temporal modulation frequency is a nominal 120 Hz.

10 . The light-emitting diode (LED) luminaire of claim 1 , wherein the control device comprises a microcontroller.

11 . A light-emitting diode (LED) luminaire, comprising:
a first set of LED arrays and a second set of LED arrays, each with a forward voltage; at least one power supply unit configured to couple to alternate-current (AC) mains and convert a line voltage from the AC mains into a primary direct-current (DC) voltage greater than the forward voltage; and a phase-amplitude circuit comprising a control device, a phase retardation circuit, and an LED driving circuit, the control device configured to produce a first set of modulating signal and a second set of modulating signal respectively at a first predetermined temporal modulation frequency and a second predetermined temporal modulation frequency, wherein:
the LED driving circuit comprises at least two modulation circuits configured to produce a first set of driving current and a second set of driving current, respectively, in response to the first set of modulating signal and the second set of modulating signal, to respectively drive the first set of LED arrays and the second set of LED arrays;
the at least two modulation circuits comprise at least two electronic switches and at least two filter assemblies respectively configured to respond according to the first set of modulating signal and the second set of modulating signal and to suppress interference noises induced by switching the at least two electronic switches, thereby rejecting a frequency pre-mix; and
the phase retardation circuit is configured to retard an operation of the second set of modulating signal in a predetermined phase interval, relative to the first set of modulating signal.

12 . The light-emitting diode (LED) luminaire of claim 11 , wherein the primary DC voltage is configured to apply on both the first set of LED arrays and the second set of LED arrays with respect to a ground reference.

13 . The light-emitting diode (LED) luminaire of claim 12 , wherein each of the at least two electronic switches comprises a first terminal and a second terminal, the first terminal configured to respectively connect to a negative terminal of the first set of LED arrays and the second set of LED arrays, and the second terminal configured to respectively connect to the ground reference.

14 . The light-emitting diode (LED) luminaire of claim 11 , wherein each of the first set of modulating signal and the second set of modulating signal comprises square waves comprising a series of pulses with a duty cycle of at least 40% and a predetermined period, wherein both the first set of driving current and the second set of driving current comprise the first set of modulating signal and the second set of modulating signal both associated with the predetermined period, and wherein respective light emissions from the fi

Assignees

• Aleddra Inc

Inventors

• Hsia Chungho

Classifications

• H05B45/31

  Phase-control circuits · CPC title

• H05B45/305 Primary

  Frequency-control circuits · CPC title

• H05B45/39

  Circuits containing inverter bridges · CPC title

• H05B45/3725

  Switched mode power supply [SMPS] · CPC title

• H05B45/20

  Controlling the colour of the light · CPC title