Light-to-Frequency Converter for Flicker Detection
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Solution Overview
Problem
Existing methods for light-to-frequency conversion in solid-state lighting systems are not accurate enough to effectively detect and mitigate flicker caused by AC power supplies, which can lead to human discomfort and health issues.
Innovation Solution
A method involving a photodiode that generates a photocurrent from a light source, which is then converted into a digital comparator output signal using an analog-to-digital converter, allowing for the determination of frequency patterns in the intensity of electromagnetic radiation, including flicker frequencies, through the use of clock signals and charge packages, enabling precise detection and reduction of flicker.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If direct connection to AC power supply is used, then power supply simplicity is improved, but flicker accuracy deteriorates
Solution Approach 1:
The patent introduces a specialized light-to-frequency converter arrangement as an intermediary device between the light source and the detection system. This converter includes a photodiode that converts light intensity variations into frequency signals, allowing accurate flicker detection without complicating the power supply connection. The intermediary translates the optical flicker phenomenon into an electrical frequency measurement that can be precisely analyzed.
Solution Approach 2:
The patent replaces direct electrical measurement methods with optical-to-frequency conversion. Instead of measuring flicker through electrical means that would require complex power supply modifications, the system uses a photodiode to convert optical intensity variations directly into frequency signals, substituting mechanical/electrical measurement approaches with optical conversion.
2Ease of operation
If pulse width modulation dimming is applied, then light intensity control is improved, but health harmful factors worsen
Solution Approach 1:
The patent implements a feedback mechanism where the light-to-frequency converter continuously monitors the flicker frequency of the light source. The system measures the frequency of light intensity variations and uses this information to detect problematic PWM dimming frequencies. This feedback enables the system to identify when health-harmful flicker is present and can trigger appropriate responses such as alerts or automatic adjustments.
Solution Approach 2:
The patent performs preliminary detection of flicker frequencies before they can cause health issues. By continuously monitoring the light source characteristics using the photodiode-based converter, the system can identify problematic PWM frequencies in advance and take preventive measures, such as notifying users or adjusting lighting conditions before health effects manifest.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method provides accurate determination of flicker frequencies, allowing for effective reduction or cancellation of flicker, thereby reducing human discomfort and health risks associated with modulated light intensities.
Implementation Method 1
The photodiode can be arranged to detect electromagnetic radiation emitted by the light source... generating a photocurrent by means of the photodiode. The photocurrent can be a measure of the intensity of the electromagnetic radiation detected by the photodiode.
Data Source
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AI summary
A method for light-to-frequency conversion comprises the steps of illuminating a photodiode (21) by a light source, generating a photocurrent (IP) by means of the photodiode (21), converting the photocurrent (IP) into a digital comparator output signal (LOUT) depending on a first clock signal (CL1), generating a first count (C1) comprising an integer number of counts, where the generation of the first count (C1) depends on the first clock signal (CL1), generating a second count (C2) which relates to the time interval between at least two counts of the first count (C1), and determining the frequency (f) of a repeating pattern in the intensity of electromagnetic radiation emitted by the light source and detected by the photodiode (21) from the first count (C1) and the second count (C2). Furthermore, a light-to-frequency converter arrangement (20) is provided.